Brown & Sharpe #2 grinder restoration

[Greg Q]

A few months ago me compadre Miguel and I agreed to buy a basket case Brown & Sharpe #2 surface grinder that was on ebay. With shipping to my lair it cost juat shy of $500 and worth about 1/500th of that.

The finish was completely gone:cracked paint where there was paint, rust where there was none. Grit, oil, dried coolant, bird droppings, expired pie remnants, and general workshop snot adorrned the workings. On arrival I was tempted to write "DOA" on the pathology report and retire to the library with a snifter of brandy to soothe my ruffled feathers. Alas, my more Calvanistic angels propelled me to engage in restoration of this basket case. So then...

[Greg Q]

The first thing we did was go to Costco and buy a ten pack of shop towels, then 4 litres of turps and some degreaser. This thing was an extravaganza of cracked paint, decades old caked-on grease and the grit of a thousand miles of yeoman grinding service at the hands of a couple of generations of tradesmen.

Upon delivery, courtesy of Machtool and his high mojo trailer, Mike and I started our survey: at first glance it appeared that the longitudinal travel was as expected for its age, and accurate relative to the spindle. (This ain't typical, by the way, of machine tools. Grinders though are a bit like panel saws in that they slide the workpiece to the tool and as such only need to be predictable at one location longitudinally)

The lateral travel was stiff, and the indicators showed at least 0.0005" of variation*

*sorry for the imperial measurements, but y'all have calculators, no?

Next: we get jiggy with it.

[Greg Q]

No offence intended for those readers who are more devout than I.

The first step in a machine tool reconditioning process is donning the wet suit and firing up the compressor. Load the Kero gun with a litre of turps and go crazy. Repeat until morning tea or until your supply of solvents is exhausted. Its that bad: Years of dried coolant. Grit, grease, dead mice, and many old lottery and drycleaning chits will all need to be shovelled out of the deeper recesses of the unit. Take heart fellow restorer-there's only so many litres/gallons of crap that these things can hide. Dig it all out.

[Greg Q]

The Brown and Sharpe, and I am sure the Reid #2 grinders had the options of 1: an internally housed motor driving a flat belt around two idlers and a counter-weighted arm which compensated for the z travel of the grinding head, or 2: a simpler grinder spindle cartridge driven by a rear mounted motor.

In both schemes the vertical ways held the grinder spindle assy fixed in all axes but the vertical: this allowed a predictable performance at the grinding wheel while allowing the spindle freedom in the vertical axis to accommodate different workpiece dimensions. The vertical travel was constrained by an acme screw driven, through a pair of 45 degree bevel gears and a horizontally mounted handwheel. The handwheel on our grinder is calibrated in 0.0005" increments, on the perimeter of the cast iron handwheel.

The grinders of this era came in a model with belt-driven longitudinal and lateral feeds, and a more basic model with manual feeds. The Brown and Sharpe #2 grinder was delivered in both guises.

[Greg Q]

Before survey begins in earnest, cleaning and repainting works for me. I cannot abide trying to wrest some precision from a machine element while fighting grit and grime. I am more than happy to clean and paint, repair, then touch-up my recent paint than try to do all of that while swimming in a sea of dirt. Costco sells blue shop towels in a 12 roll pack for about $24. I cannot imagine a better value in the shop. All of my mates use them in the kitchen too in place of the consumer grade toilet-paper-towels.

For me, a kero gun loaded with mineral spirits or turps is an important first step in de-gunking a project machine. Super Cheap Auto* sells an alkaline degreaser which also works, but you have to rinse it off with plenty of water that you can safely dispatch down the drain. I use plenty of shop towels and turps to get to the essence of a machine. A steam cleaner and air compressor would also get use in my shop on some of the more petrified pieces.

Paint for generic machine tools is " machinery grey" from White Knight in both bulk and spray packs. It has a nice blue-grey colour that is not as drab as the European grey ( Maus grey, RAL 7005 colour code as found on the Euro machines in the pre-green era (resada green, RAL 6011)
GQ

*for North American readers: Pep Boys, Canadian Tire, Sears, Bob's Autorotica, etc will all carry something similar.

[China]

Looks similar to my robot surface grinder, which from all my research aparently does not exist, looking forward to see your progress

[.RC.]

Paint for generic machine tools is " machinery grey" from White Knight in both bulk and spray packs. It has a nice blue-grey colour that is not as drab as the European grey ( Maus grey, RAL 7005 colour code as found on the Euro machines in the pre-green era (resada green, RAL 6011)
GQ

*for North American readers: Pep Boys, Canadian Tire, Sears, Bob's Autorotica, etc will all carry something similar.


That is just a bit dull..... Be daring...... GO hot pink..... :D

[RayG]

Hi GQ,

Congratulations on the new restoration project :2tsup:

+1 on the blue costco towells,

This will be an interesting thread, I'm looking forward to following the progress of the machine survey and I guess bearings, scraping, electrical

Was there much in the way of accessories with it?

Regards
Ray

[Greg Q]

Hi GQ,

Congratulations on the new restoration project :2tsup:


Was there much in the way of accessories with it?

Regards
Ray

Yes indeed! There was a wrench. Oh yeah, it has an Eclipse magnetic chuck, but that's it. Some time ago I was buying some stuff on ebay and the seller casually mentioned he had a grinder vise and wheel dresser which I bought.

[Greg Q]

So, the Dulux part of the process taken care of, the next stage was undertaken: the motor and drive mechanism. This machine was originally built with open ball bearings in all of the idler pulleys and the motor. Grease fittings were either plugged or missing, and water , grime and time had ruined all of them.

The 11 foot long flat belt made a great random linisher when loaded with grit, so all of the pulleys were oddly worn-some tapered, some hourglass.

We removed the drive components and removed the perished bearings by using heat and a ten ton (ha) shop press. Idler pulleys were trued up on Mike's Rivett 608 lathe...his beautiful machine looked like hell under all that cast iron dust afterward.

We also removed the electric motor rotor to turn the shaft which was very badly scored from years of slipped set-screws. Of course the sheave had a 1" bore, the motor had a 25mm shaft. Genius.

Photos of motor internals and one of the idler assemblies

[Anorak Bob]

Sorry GQ,

I should have done this earlier. From my catalogue collection.

BT

[Greg Q]

As always, many photos taken during disassembly are a great help. Even better is to actually look at them :-. I had to do one idler twice...my penalty for relying on memory.

I happened to be walking past Kowloon bearing company so I grabbed the bearings for the pulleys and motor. The motor, being old school British, has imperial sized bearings. I was able to get sealed bearings so I plugged the old lubrication holes. In a non production environment I expect them to last for practically ever.

Idler bearings, and this is a WW forums exclusive tidbit, are 6204. 2RS for rubber seals. If you don't get to Hong Kong much, try VXB bearings on eBay for reasonable quality inexpensive bearings, or a local supplier if you can score a trade discount. I have learned that the price for bearings here depends on how much they reckon you need shearing.

The motor bearings are probably unique to this dinosaur so I won't bother looking up what I bought.

Illustrations: 1. the motor with cleaned up shaft, new bearings and wiring. 2. The left hand idler assy and support arm during re-assembly.

[Greg Q]

Excellent, thanks Bob. I am trying in vain to copy PDF pages from my manual on Goodreader on the iPad. It is the only copy I have, and its 21 M. I need to find somewhere to host it.

Greg

[Anorak Bob]

The vice as illustrated in the 1925 catalogue.

And +2 on the Costco paper towels. Gregory very kindly brought me a roll on one of his stop overs. I have rationed myself to one sheet per shed visit. Sadly the roll is closing in on its core. Don't suppose Costco do mail order.:roll:

BT

[Stustoys]

Great work so far Greg, you might end up with a silk purse yet :D

Stuart
Costco is coming to Ringwood :hpydans2:

[Abratool]

Greg
Viewed your photos this morning, & immediately thought about keepng the "Patina" on old machines as discussed with BT Bob many times on this Forum.
However, accepted, that your Brown & Sharpe Surface Grinder is way beyond hanging on to any Patina.
I have heard these Brown & Sharpe Grinders in operation (Shows my age) & they have a very pleasant musical sound as the mechanical trippers on the table are in operation.
It will be wonderful to follow the restoration process as the machine develops.
All the best.
Bruce

[Greg Q]

Greg
Viewed your photos this morning, & immediately thought about keepng the "Patina" on old machines as discussed with BT Bob many times on this Forum.
However, accepted, that your Brown & Sharpe Surface Grinder is way beyond hanging on to any Patina.
I have heard these Brown & Sharpe Grinders in operation (Shows my age) & they have a very pleasant musical sound as the mechanical trippers on the table are in operation.
It will be wonderful to follow the restoration process as the machine develops.
All the best.
Bruce

Thanks Bruce. I have never purchased a machine with an acceptable paint job ever. The Deckel was almost as bad as the grinder, and the lathe was just...goofy. My wood bandsaw was about the same. I got a diamond grinder on gumtree that had been painted with a mop so that too will need a minor tart-up. Funny thing is I hate painting with a passion.

Greg

[Bryan]

So, the Dulux part of the process taken care of,

Greg, did you forget to post pics? :)

[Greg Q]

Some progress about week three...

I am sorry about the sideways images...I am posting by ipad and the forum software insists on rotating it.

The contrasting colour is silver hammertone from a spray can...HiChem brand, which seems to last longer than most brands, and dries rapidly.

The sharp eyed will note the castors under the grinder...they are just for shop convenience during the overhaul stage. I find the pallet jack is too cumbersome for any fancy moves in a crowded garage.

[RayG]

Hi GQ,

It will work better if you set it up this way. up.. :)


237621

That grinder is certainly looking the good :2tsup: nice work..

I just got back from Carrum Downs ( via Stuart's marvellous shed).. Now to clean up that laser...

Regards
Ray

[Greg Q]

Hi GQ,


I just got back from Carrum Downs ( via Stuart's marvellous shed).. Now to clean up that laser...

Regards
Ray

That laser is going to be sweet as, bro. I couldn't get over how thoroughly that ancient foam was trying to return to its crude oil origins.

Here's another few shots of the grinder: the motor compartment with the motor on new rubber pads. I use engine block enamel in white for insides of castings just to completely anal about it. Plus I'll be using those lower compartments for tool storage in future.

The other shot is of the untouched last few pieces of the casting yet to be cleaned and painted, and a look into what Brown and Sharpe calls the oil tank...the area that catches all the drips and dust. Of course that's where the feed mechanisms live, so there's some repair work ahead of us there too.

[RayG]

That laser is going to be sweet as, bro. I couldn't get over how thoroughly that ancient foam was trying to return to its crude oil origins.

The Laser Brea tar pits... gently dabbing metho and lots of paper towells seems to be working, I feel like an artwork conservator.. Good news is it powers up, and the laser appears to be working.. documentation is the usual high end standard for HP gear, full service manual circuit diagrams, and fault finding charts, test and calibration records... I was a bit dubious when I saw all the black crap, but underneath... it's a gem! Don't reply here I'll start a new thread..



Here's another few shots of the grinder: the motor compartment with the motor on new rubber pads. I use engine block enamel in white for insides of castings just to completely anal about it. Plus I'll be using those lower compartments for tool storage in future.


Wow, what a difference to the original condition.. I think cleaning up and re-wiring are an essential part of a machine rebuild such as this, I've found the older wiring insulation sometimes just crumbles into dust and you are left with lethal bare copper.. Are you going VFD?

Regards
Ray

[Greg Q]

The Laser Brea tar pits... gently dabbing metho and lots of paper towells seems to be working, I feel like an artwork conservator.. Good news is it powers up, and the laser appears to be working.. documentation is the usual high end standard for HP gear, full service manual circuit diagrams, and fault finding charts, test and calibration records... I was a bit dubious when I saw all the black crap, but underneath... it's a gem! Don't reply here I'll start a new thread..



Wow, what a difference to the original condition.. I think cleaning up and re-wiring are an essential part of a machine rebuild such as this, I've found the older wiring insulation sometimes just crumbles into dust and you are left with lethal bare copper.. Are you going VFD?

Regards
Ray


Yes, I bought a Danfoss VLT last week. Stupidly I didn't chase the other two they had a bit harder.:doh:

[Greg Q]

Some notes: Anorak Bob mentioned the little laser exchange that Ray G and I had. It pertained to a laser survey system that Ray bought at auction. I was with Stustoys at the inspection and was astonished that all the foam nests for the coonents made circa 1972 had reverted to crude oil, hence my comments to Ray.

Today I cleaned and painted the three reamining components: the top of the machine's main casting, the saddle, and the work table. I also cleaned, degreased and painted the " oil tank" which houses the longitudinal and lateral feed screws. I am very glad to see the end of cleaning and painting.

Pictured here is the basic machine casting with cap bolted in place. I had to counterbore for a 1/4-20 capscrew which I had in stock to replace a long gone machine screw. There are quite a few missing fasteners on this machine. Mike has already made four cheesehead screws from 5/16 UNF bolts. I reckon we need to do about five more to populate all the vacant threaded bores on this thing.

Also pictured is the counterweight arm pulley which Phil Machtool kindly turned for me one evening after an an already long day in the salt mines. It had been abraded in some random shape which was no match for the big Nardini and a carbide tool (the piece would not fit on Mike's Rivett). The pulley as found was a two-ratio sheave in cast iron with a bronze bore liner. Both it and the shaft it rode in on were scored a treat. I asked Phil to counterbore both sides of the pulley to accept aome 2RS bearings that I had on the shelf because I wanted a back end of the machine that did not need regular oiling/watering/assuring that its ass did not look too big in that dress.:D

*the shaft, and the bronze bore liner in the pulley were rooted by the action of grinding dust and a plugged oil port. Hence the attraction of low maintenance sealed bearings at commodity prices.

The pulley was trued and bored, and its mating shaft is being turned down as I write over at Mike's place. I expect that the spindle drive components of the machine should all be mounted by close of business tomorrow, which leaves only the he-man stuff of survey and correction of the ways. Oh yeah, and hard chroming and re-grinding of the spindle. This grinder is proving my theory that a worn-out machine is too expensive even if it is free.

[RayG]

Hi GQ,

What are you doing for the drive belt? I'm interested in the details of how you are going to do the cylindrical grinding on the spindle, I'm going to have to do something similar on the mill one of these days.

Regards
Ray

[Greg Q]

Hi Ray...

I am going to re-use the belt that was in place. One I de-gunked all of the coolant + oil + grit it revealed itself to be in good nick with no hard spots. Green backed composite.

Tday I am wondering why I bother as there are two nice grinders on Gray's right now for under $400, ending tomorrow.

Yestrday I was musing that a bloke could CNC this thing without a world of trouble if he was so inclined.

Senor Garwood bought a 650mm ballscrew from China, custom machined features on each end for $109 couriered to his door. I was impressed.

Greg

[.RC.]

Excellent work Greg, while I disapprove of the colour scheme the painting quality looks good...

Are you scraping the ways at all? Or getting the long ways ground and scrape the short ways to suit?

You are right about the work to rebuild something from scratch... To do it properly is a lot of work..

[Greg Q]

Wait til you get a load of the large pink polka-dot stickers that will be the crowning touch, RC:wink:

The ways on this thing are a mixed bag: the lateral ways (cross feed, if you will) will need about 6 thou taper scraped out. It is going to be a chore and a half. The longitudinal ways which of course see most of the wear are totally rooted. The vee and flat ways are so worn in fact that they are no longer making contact...rather, the flat tops of the vee way are now lapping themselves into the table, and the flat ways have worn right down to the parent casting!

Oddly. Queerly even, the quick survey I did showed no discernible variation in height over the travel. The random number generator came up "zero" this time.

The repair scheme right now is either to bond some phosphor bronze to the table and scrape it in, or use turcite. Phil reckons that a hobby machine of this light weight would do well with Turcite. There are no way wipers, but they could be retro-fitted. A vacuum and/or coolant would go a long way to preventing 90% of the wear that you'd otherwise expect, as you know.

Right now I am contemplating making a spotting tool per MTR for the vertical ways...I could get that made in the morning and get to levelling the machine for a serious geometrical survey.

Since we have gone this far there's no point in not going the whole hog. There's only time to be spent on it at this stage. Well, that the chroming & grinding of the spindle. And the electrics, but I probably have most of that in stock already care of ebay rainy day purchases.

Greg

[Greg Q]

Mike G from Adelaide sent me four 3/8" button oilers which he sourced from a US supplier whose name cannot be mentioned. These will replace the three missing/broken ones from the table. The Brown & Sharpe folks thought that it would be OK to have a slightly uphill run from the rear oilers to the oil wells which supply the rollers that spread the goodness between the ways. Of course, being perished, the rear wells were dry, and the rear way is comprehensively, completely stuffed.

Today was a shop day...making storage cabinets for my surface plate stand and a new base for my bandsaw. I had the reverse Midas touch this morning, so I'm not sure if I made any progress or not. Lots of firewood, and lots of mess.

Mike G, my local mate, returned one of the three idler pulleys that I had asked him to revisit on the lathe. Turns out it had been sleeved in the past, a little egg shaped, and 0.06mm undersized. I was wondering why the bearings weren't happy once the assy had cooled. All good now:2tsup:

Greg

[Greg Q]

The only progress made this week was today. Several years ago I was given this cat iron sliding table from an old Felder woodworking machine. It was a bad design as it had fairly small ball bearings running on cast ways. They brinelled easily, ruining the part.

For my purposes it should be good. I needed a tool 175mm wide and 680mm long. As luck would have it this allowed me to remove the two thick sides and save them for other tools. (Straightedges, gib strips).

I used three 1.2 mm abrasive wheels to do this job. The tool is 8mm thick and is a manageable weight. Now I have to clean it up, relieve the centre section and scrape it flat. It should be stable enough for what I hope will be a single day's use.

[Anorak Bob]

Much swearing accompany the task GQ? :o

Still, probably nicer than cutting 0.47mm corrugated iron where the grinder wants to run away.

[Greg Q]

Actually Bob it went very easily. That 5" Protool grinder is fantastic, and the Makita stainless steel cutting discs were plenty aggressive. After I took the photos I cut it to length, removing about 40% of the length. My required dimension allowed me to keep a rib at both ends.

I am saving the swearing for the scraping.:wink:

GQ

[jhovel]

I've been using the Smith and Arrow cut-off disks (both 1mm and 0.8mm) smith and arrow items - Get great deals on Inox Cutting Wheels Disks, Flap Discs 100mm items on eBay Stores! (http://stores.ebay.com.au/smith-and-arrow)
and found them the best I've ever come across. I use them for pretty well all metals. Great for steel and cast iron and they even work reasonably well with aluminium.
Cerful with the 0.8mm ones. Only cut work held in a vice or clampred properly and hold the grinder VERY steady. And keep your head out of the plane where shattered blade bits could fly :cool:. I guess full face protection is really in order. But they cut very quickly because they remove so little material. I've used them successfully - and carefully - to cut HSS lathe tools to shape before grinding.
At the price well worth a try.

[Greg Q]

I've been using the Smith and Arrow cut-off disks (both 1mm and 0.8mm) smith and arrow items - Get great deals on Inox Cutting Wheels Disks, Flap Discs 100mm items on eBay Stores! (http://stores.ebay.com.au/smith-and-arrow)
and found them the best I've ever come across. I use them for pretty well all metals. Great for steel and cast iron and they even work reasonably well with aluminium.
Cerful with the 0.8mm ones. Only cut work held in a vice or clampred properly and hold the grinder VERY steady. And keep your head out of the plane where shattered blade bits could fly :cool:. I guess full face protection is really in order. But they cut very quickly because they remove so little material. I've used them successfully - and carefully - to cut HSS lathe tools to shape before grinding.
At the price well worth a try.

Thanks Joe! They look good. Have you ever used their fibre discs on an angle grinder? They might be useful. I bought and wore out a wire brush for the angle grinder on this project. Very rapid paint removal, but you do get the odd unwanted piercings from fugitive wires.

Greg

[Ueee]

Thanks Joe! They look good. Have you ever used their fibre discs on an angle grinder? They might be useful. I bought and wore out a wire brush for the angle grinder on this project. Very rapid paint removal, but you do get the odd unwanted piercings from fugitive wires.

Greg

I went through 4 wire brushes on the shaper.....After the first five minutes i put my leather apron on, and by the end it looked like an echidna!

For most work i use 1.5mm wheels, they are a bit more forgiving but still cut way faster than the old thick wheels.
The grinder looks good Greg, nothing like breathing new life into an old machine.

[Greg Q]

This morning I glanced into the guts of the grinder to find a garden snail happily ensconced therein. A snail, for cryin' out loud. I guess I need to step up the pace a bit:-

Greg

[Techo1]

Looks similar to my robot surface grinder, which from all my research aparently does not exist, looking forward to see your progress

China, did you end up getting any information on your Robot, I have one that also needs some attention.

[Techo1]

Any further progress on the grinder Greg?
As this machine is very similar to a ROBOT, I have been watching this thread and gathering ideas for the various repairs required on my machine.

Regards, Lex.

[rodm]

Maybe Greg is still trying to catch up to that snail :)

[jhovel]

Well, the snail actually died there..... :no:

and with it went Greg's enthusiasm I fear.

As indicater in another thread, Greg offered it to forumites to continue the good fight - and I put my hand up quickest (just lucky).
Long story short, it now lives in my shed and has restarted metamorphosing back into a surface grinder.
I went over the spindle with the fine tooth comb that are my measuring tools and found little to correct. I removed a couple of faint proud rings on the plain bearing and nose cone of the spindle and polished the entire surface. It fitted perfectly back into the bronze mate in the housing. Greg had provided new rear AC bearings which I fitted and now the spindle turns (by hand) beautifully. I'm still undecided wether to stick with the complex, counterweighted 6-pulley flat belt drive, or attempt a mod to fit a direct drive via Lovejoy coupling. I have a suitable flange-mount 3-phase motor and it looks quite feasible...
As I go on with this project, I'll take photos and continue here.

Thanks again Greg - and Mike - for the opportunity to participate in your restoration!

[RayG]

Nice one Joe, :2tsup: I look forward to seeing the pictures.

Regards
Ray

[mmgarwood]

Yes, Joe, please keep us informed and post photos.
I would like to come see when it is up and running.

-Mike

[jhovel]

Well, I pursued the option of a direct drive spindle and found some photos and diagrams of the direct drive option offered by B&S later on in the No2 model life. As it happened, I already had a suitable 1hp 2880rpm 3-phase motor and a suitably sized Lovejoy coupling. Looking at how these could be fitted, I found a heavy cast iron pulley which could be repurposed into a motor mount. I was able to machine that on my half-finished 'new' lathe successfully.
Last Saturday, during a visit to Phil in Thomastown, he surface ground the spindle back plate (which is scraped where it mounts on the spinfle housing and slides in the vertical column, but cast finish on the back. He also made sure that my motor mount was really parallel.
During the week I bored one half of the flexible coupling to match the motor shaft. I also made a keyway shaper tool for the Douglas and cut the keyway.
The only way to fit the other half of the coupling was to replace a spacer and the preload and retaining nut at the back of the grinder spindle. To do this, something stronger than the aluminium Lovejoy coupling half I had. I decided to make a new one out of some decent tool steel I had, incorporating a tightly reamed spigot and internal thread. I roughed out the shape of the coupling and then trued it mounted on the (removed) grinder spindle in my friend Peter's (prk) Sheraton lathe. We then machined the 'drive dogs' for the coupling on his Van Norman universal mill. Lovely old machine to work on!
Finally, I drilled and tapped all the mounting holes, made the 'custom offset' right angle motor mounting lugs/studs in the 4-jaw and trial assembled the lot. Looks like a goer! So far, everything remains reversible - in case it doesn't work out.
I'll repair the spindle drip oiler next weekend (after I'm back from Perth and WA visiting Anorak Bob and co) and wire it up to try the spindle drive..... then onto the slideways....

[.RC.]

Very nice work there Joe....

[Ueee]

Very nice Joe.

I have only used lovejoys that were made of oil impregnated steel, oilite? I've never seen an ally one. Does the grinder have coolant? I reckon its worth it just to keep the dust down....

Cheers,
Ew

[Greg Q]

Great work Joe...

I am so gratified to see that the machine washed up on friendly shores :)

Greg on the Gold Coast.

[.RC.]

Greg on the Gold Coast.

sigh, border security is just so weak these days.... :D

[Greg Q]

I swam across the Tweed in the dead of night. Plus I was wearing a hat made of banana leaves, which seems to be the border patrol's secret sign :D

Gregorio

[j.ashburn]

:2tsup:
Very nice work there Joe....
:2tsup:plus plus Joe i i get mine half as good will be happy.

[.RC.]

I swam across the Tweed in the dead of night. Plus I was wearing a hat made of banana leaves, which seems to be the border patrol's secret sign :D

Gregorio


I was trying to hatch a secret plan with Phil, to smuggle my OD/ID grinder into your furniture truck removing any useless stuff like beds or sideboards etc to make room, and get border security to remove it for me at the border when they arrested the notorious El Gregor... alas it never came off.. :D

[jhovel]

Just a little update - mainly for Greg and Mike - but also for anyone else interested.
I decided to mount my large old-school Telemecanique Altivar VFD on the back of the grinder (where all the pulleys and belt used to be). I've had this VFD on my mill for the past 20 years (and have now replaced it with a Huanyang 3kW one). It is a 1.5kW model with a frequency range of 5 to 70Hz. No control panel and no parameters....
Anyway, I found a suitable enclosure and tried it out.
The grinder has made it's first sparks! :U Now I was getting cocky and wound the wheel down to the magnetic chuck: just touching mind, and pushed the table across. Looks like the table slide and the chuck are still flat! Yippee!
The front bearing heated up quite quickly though :(
A little more research gave me a better handle on the ancient oil viscosity recommendation on the grinder: 100 secs Saybolt at 100 deg F can be actually converted to ISO 22 or SAE 20. So it seems to me that the thin oil sample kindly provided by RC may be running away too quickly. My next try will be with the ISO 10 Greg gave me. That should tell me if thicker oil reduces the heat gain. If so, I'll then go for some 20....
Next I took the motor off to check the drive and found it a little tight axially. That is easily adjusted.
I next surveyed the vertical slides. Greg, the front one is as straight as a die and the rear one has a few 10ths bow (worn hollow in the centre section). That matches the finding on the grinder at Phil's. Since Phil ground the rear spindle box cover, I now have a fitted master to scrape the sideways to. Anyway I spent about an hour today scraping and got it pretty straight and flat, maybe another hour to get bearing should do it.
I've also managed to win a German eBay Siemens 1/3rd Hp VFD (and my sister is visiting from Germany in a couple of weeks :wink: ) for the little 3phase gear motor I have planned to use to drive the table back and forth. A bit more design to go into the engagement mechanism yet, maybe a couple fo gears to cut....
Slowly making progress.....

Cheers,
Joe

[mmgarwood]

Joe,

This is all too good!
All I had hoped for was an old grinder to do a handful of small projects and here it has become a thing of wonder!
Very nice to know it is in such caring hands.
More photos please when you can and as it progresses.

Michael

[Greg Q]

Joe, that is excellent work. Its interesting that the front vertical ways were flat...Without doing a survey I had expected the fugitive grit to have done its worst in wearing that slideway.

installed a vfd on his grinder purely for the slow starting/shutdown. He reckoned that the slow starting prevented the grinding wheel from being jarred out of perfect co-axial mounting and thus negating the need for re-dressing every time.

I don't recall if I mentioned it but Phil Steamwhisperer put me on to a firm in Greensborough that repairs that drip oiler for the spindle. It just needs the glass and a couple of seals.

Greg

[jhovel]

@GregQ:
I have a suspicion that the rear spindle slide plate was somehow bowed and allowed the rear slideway to wear more than the front in the centre of travel. Anyway, the wear in the front slideways was visible (worn off scrape marks) but not measurable by me. So I rescraped the entire front, going a little heavier where the previous scraping was still visible and just to break up the surface to hold oil in the centre. Blueing showed not much difference before and after.
I already rebuilt the oiler - I used it in the trial run with RC's thin oil.....

A little more progress on the rear as well: spent a couple more hours scraping and blueing the rear slideways and the back of the spindle block (which sets the slide clearance). All good now! Moves nicely and tightly.
Very difficult to photograph....
A couple of pics of the painted and fitted enclosure for the VFD, the insides of the VFD and it's cover fitted,
I also found a nice period cast iron fuse box that I adapted for the VFD controls - complete with period speed potentiometer knob - modern E-stop button :U (just sitting on top there for the photo, not mounted where it belongs yet....)

I've also figured out how to mount the coolant system on the right hand side of the base. that way the entire machine is self contained.
More pics to come as the work unfolds....

289516289517289518289521289522289520289519

[.RC.]

My thin oil Joe, It that the velocite 3 stuff? I think I sent Greg a litre of it... It is the stuff like Diesel.... ISO 2 grade

It was a grade Brown and Sharpe did I believe recommend, but only in the plain bearing model....

Roller bearings should probably be something slightly heavier at a guess.... ISO10 maybe?

[jhovel]

Hi Richard. Yes it's the stuff like diesel. I used it in the (front) plain bearing only. The rears are high precision A.C. bearings. The whole spindle is specified for the same oil, just very different intervals - rear bearings just once a week....

I wired up and mounted the VFD 'control panel' just then and I think it looks just right....


Cheers,
Joe

[Ueee]

Hi Joe,
Great work! I love seeing all that scraping, it just screams precision.

As for the coolant tank, i'm not sure why but grinders always seem to have big tanks. Mine is 100l, i think the smallest H&F machine with coolant is 50. There is no real way of filtering the coolant before it gets to the tank, so you will need a few baffles. The other thing to do is put a removable tin under the inlet, that way you can lift it out periodically with (hopefully) most of the sludge that seems to build up real quick in there......

Cheers,
Ew

[Techo1]

So how does it grind Joe?:2tsup:

[jhovel]

So how does it grind Joe?:2tsup:

It doesn't yet.... give me a bit more time to go over all the rest!
Greg warned me about the state of the table ways. I haven't even put a straightedge on them yet....
I will get to them shortly though :C

[jhovel]

Hi Joe,
Great work! I love seeing all that scraping, it just screams precision.


Thanks, Ewan. It's as good as my skills allow - precision is of course a relative term :U


As for the coolant tank, i'm not sure why but grinders always seem to have big tanks. Mine is 100l, i think the smallest H&F machine with coolant is 50. There is no real way of filtering the coolant before it gets to the tank, so you will need a few baffles. The other thing to do is put a removable tin under the inlet, that way you can lift it out periodically with (hopefully) most of the sludge that seems to build up real quick in there......

Oh. My coolant system holds about 20 or 30 litres at a guess. It has 3 baffled chambers in it, with the pump sitting in the last and biggest one. I intend fitting a removable 'gutter' under the table drain. Thanks to your suggestion, I'll make that deeper than originally intended. I'll also be fitting a few magnets in the first tank chamber and a magetic 'filter' on the pump outlet. As it happens, Josh (Brobdingnagian) and I had a chat about this today and he made a suggestions using an electromagnet and a backwash valve.
I guess if my tank is too small I'll find out quickly. Or should I not even bother with that tank?

[Ueee]

I'm not sure if there is any hard rules on tanks and grinders, but my thinking is-
There needs to be enough coolant in the section that the pump is in as the pump may pull 5l or more out of there before any is returned. I find it best to really flood the area when grinding, the flow rate would be more than double what i would use on the mill, so there is a lot of coolant on the table and in the drains.
99% of the grinding dust ends up in the coolant. You don't want to be cleaning the tank out every week!
You loose a lot of coolant as well, the speed of the wheel turns some of it to mist and it ends up floating off or getting spayed over the machine (this is were splash guards are really important).

On the note of splash guards, if you can make them perspex i think that would be much better for visibility than steel like mine are. The Blohm is pretty high and i find seeing can be an issue with the guards on stacked 2 high.

Cheers,
Ew

[Machtool]

As for the coolant tank, i'm not sure why but grinders always seem to have big tanks. Mine is 100l, i think the smallest H&F machine with coolant is 50. Thermal damping /Heat Sink. Its an easy way of adding thermal mass, and the bigger the tank the more stable the temp is. Which is a good thing at grinder tolerances.

When I'm out and about working, in the auto industry, things like pin and main crank shaft grinders, and cam lobe grinders will have refrigerated chillers and or heaters, to keep the coolant stable.

Regards Phil

[jhovel]

Thanks Phil, that makes a lot of sense. I'll review my options then (in light of my likelyhood of running 3 shifts a day grinding precision flat parts for CERN as soon as my 70 year old machine is restored :U).
I think I might actually just "suck it and see" for now. :roll:

[jhovel]

Alright, an update.'Nursing' my injured finger, I managed to scrape all the ways on the B&S grinder today. In fact they were as dead straight as I could measure. So I left the shape alone. They all had a small (1.5mm wide roughly) ridge on the outside of all V-ways, corresponding with the outside edge of their mating parts. In other words, that was the edge of their wear. Obviously, Greg was worried about them sliding on just that ridge. So I decided to remove them. They were very thin as it turned out, maybe a thou or less and it took only a few minutes each to get rid of them with the Aldix - I'm starting to love that machine! :)Running a stone along the ways, I could see a few shiny spots still and took them out with the hand scraper. The stone then touched the entire width of the ways - done!Greg also had grave concerns about the depth of the entire wear on the table. It had worn so deeply into the V-way of the table that the edges of the saddle way was toughing and starting to gouge into the underside of the table. I actually think that this machine was very heavily used industrially but maintained very well. So what we were seeing is actually a combination of wear AND rescraping. There were still traces of flaking at one end of the V-way.... Greg had investigated using Turcite or broze strips to regain some height, but that looked too expensive to me. Given that the male V-way on the table underside has worn and been scraped narrower and the female counterpart of the saddle wider, the was no point in my view keeping the tops of the female parts (which were contacting the table underside outside the ways), since they would never be in contact again anyway. So my solution was to grind off about 1mm off the tops (outside of the V) of the saddle V-way, That now gives it 1mm clearance - which I won't wear through in my lifetime of hobby use...Messing with the speeds of the Aldix and different tip radii a bit, I found that I could an 'imitation of flaking' to break the slip-stick of these ways. No photos today - sorry, but they are coming soon. Anyway, it all went together quite well - lots of detail cleaning and lubrication. And quite a few puzzles as to how it went back together (remember I didn't take it apart... most of the smaller parts came in a big plastic tub). I think there are a few things missing as well, but I have a manual and can probably make them or get them (e.g. a lead screw thrust bearing, some spacers, a couple of dust covers, that sort of thing).I then ground the top of the table and the wheel touched it everywhere exactly the same gentle touch. I then took off a few tenths of thous to make it all 'shiny and new' :)I'll get back to it tonight and finish making some temporary chuck clamps (no mill at the moment) and give the chuck a lick. Oh, and take some photos.

[jhovel]

OK, I'm done for today....
Finished the clamps for the chuck and took some photos of the ways (which I wanted to check anyway) and then ground the chuck.
Now I'm happy. :U
317624
These are the scars to the right of the slideway that stymied Greg. There is another much like it at the other end.
317622 317623
The ways levelled and 'flaked'.
317621
Bed ground
317625
Chuck mounted
317627
Chuck ground - first attempt. There are some brown lines in line with what appear to be pins or rivets. They must be a different material... or operator error.... :roll:

[Techo1]

Nice work Joe, these small grinders are perfect for the home shop.

Regards, Lex.

[Michael G]

Looks good Joe, although your chuck looks like it should be a little bit bigger. What size is it?

Michael

[jhovel]

Looks good Joe, although your chuck looks like it should be a little bit bigger. What size is it?

Michael

The grinder has a capacity of 6"x18" and the chuck is 6"x14"

[RayG]

317627
Chuck ground - first attempt. There are some brown lines in line with what appear to be pins or rivets. They must be a different material... or operator error.... :roll:

Looks good Joe, :2tsup: The next step might be to grind some test blocks, put some small blocks on the chuck, corners and middle, and see how they compare for thickness after grinding both sides.

Ray

[jhovel]

Well, I made the first 'improvement' modification to the B&S surface grinder....
I noticed my toolmaker friend's SG had a dial gauge fitted (by him) on the front which he set to '0' every time he touched the wheel on a new surface, then read off that how far he advanced the spindle, rather than the hand wheel graduation. When I asked why, he said that this was a safer direct indication relative to the work piece and overcame having to consider and remember any backlash.
I considered where and how I could fit something similar to my B&S, since it has rather a lot of backlash on the vertical screw and the handwheel graduations are very difficult to read in any case.
This is my implementation. Works like a charm. I had the Mitutoyo 0.01mm gauge with nice and widely spaced divisions already. It has 10mm travel, plenty for surface grinding I think.
318516
The first job using it was a z-shaped lathe saddle rail for azzrock (Aaron) which needed exactly 0.305mm reduction in height and made parallel in the process.
So I ground a reference surface flat, turned it over and set the 'clock' to zero. I then ground the worn step flat - that took 0.060mm and then ground the mounting surface down by 0.365mm to achieve the new height between step and mounting face. Reading the half divisions is easy on this gauge. I have a high level of confidence now that it will fit correctly. I like direct measurements!

Th next planned modification is to fit a toothed belt DC motor drive to the vertical axis. The hand wheel moves the spindle 0.050" per turn and is not easy to turn for me (up where it is). So I contemplated my options, including fitting a stepper motor drive with some sort of direct position input for each pass - and I might yet go there one day.
However for now, I will fit a 24V DC 6A motor I have, operated with just two momentary push buttons - up and down. I'll see how the speed works out and may or may not fit a variable speed control. The pulleys I have with this motor are 17 and 88 teeth, and the motor is rated for 2500rpm no-load. Given the torque needed to move the heavy grinding head and tight slides, I'm guessing it will max out at 1500rpm. That would bring it down to 290rpm or 4.8 turns per second on the hand wheel. I've counted that I turn it at about 2.5 turns per second winding it fast by hand. So the motor should turn it about twice as fast as me. We'll see how it works out. I fitted the large pulley to the hand wheel boss itself tonight and added a needle roller thrust bearing to the spindle on the bevel gear end.
I'll develop the motor mount over the next few days and then take some photos.

[Ueee]

.050" per turn? You Lucky bugger, mine is only .040". I had to wind it up to fit a 400mm high job in last week. It was a lot of winding, both my arms were like jelly by the time i got there!

There is one issue with directly ready the dial and presuming that the workpiece has been reduced the same, and that is wheel wear. It probably wasn't a problem with a small part like Aarons, but it can easily amount to .005mm or more when grinding larger areas or a lot off. If you can set up a dial off the wheel guard/spindle housing then you can zero it on a test piece, gauge block or shaper gauge set to the required height. Then you can check you're part and see just how much needs to come off. Far easier than removing the part and measuring it.

Cheers,
Ew

[Stustoys]

Hi Joe,

My jig grinder as a setup just like that.
Might be interesting to see if things move at all once you've set the height.



.050" per turn? You Lucky bugger, mine is only .040". I had to wind it up to fit a 400mm high job in last week. It was a lot of winding, both my arms were like jelly by the time i got there!
Stop your complaining, try 18" at 0.005" a turn. Granted it will only be done once as I realised I did in fact need to wire up the motor. :D
I used to use a J&S with 0.040" down feed. I was some what disappointed the day I found out there was a power option that it didnt have lol

Stuart

[.RC.]

For something like the downfeed, can you run a stepper motor to drive the feed, without needing a computer to control it running something like mach3?

[pippin88]

A stepper motor requires a specific driver that converts a pulse stream (what the computer generates) into the electrical phases. You can use a micro controller instead of a computer, but all of this would be more work than a simple DC motor with forward and reverse switch. Unless you need precise "move x distance" then I wouldn't bother with a stepper for this.

[jhovel]

R.C. Yes that was my thinking exactly. I've been clonsidering using the driver and processor like my digital rotary table/divider and modify the firmware to suit. That way it could all remain stand-alone (no PC or Mach). But as Pippin says, the DC Motor may be just fine.
I think I figured out the DC motor mount now and will go ahead with that - in between rebuilding the Cash mill....

[.RC.]

It you want downfeed, it has to be precise.... A 0.001" cut for a small surface grinder is a deep depth of cut..

[jhovel]

Hi Ewan,
i understand your concerns and considerations and appreciate them.
A more sophisticated grinder like RayG's gives very precise indications of the cuts made, but they too are 'only' vertical movements, as far as I know. Are there methods by which the wheel wear can be measured or predicted?

R.C.,
I just calculated that a stepper motor with the reductions in the drive I have would take 88 half steps per 0.001 spindle movement. Using 4 or 8 or 16th steps selected in the driver, it would be relatively easy to have exact moves of 0.0001 or less I believe.

I'm in a conversation with Steve Ward (of Worldofward.com and the initiator of the digital rotary divider project) about adapting the firmware and hardware of that controller for this purpose. It may come to something down the track and will be easy to exchange the DC motor for a stepper then.
My thinking about the formware is that the controller could have multiple speeds for jogging (up and down positioning moves iby push bottons), option for setting total planned grinding depth, dividing that into the number of passes at a specific depth, spark-out pass count, advance by limit switch(es) - at the end of each in/out pass (Y-axis) and an external relay connection to switch off the table drive(s).
THat would allow me to roughly position the spindle, then move it manually to touch the work piece, then set the contorller to zero, key i the total planned depth and the depth of passes, spark-out passes, set the table going (once motorised), press 'Go' and take my hands off.....
Sounds like a modern surface grinder to me.... We might yet see how this works on a 1930s model B&S :)

[Ueee]

Well the 58' Blohm could have come with all that. No transistors mind, mine has one valve and spaces for another 2 for the rapid and downfeed. It and i think Rays machine use a "microtip" downfeed unit, Rays with a linear actuator to drive it. https://www.youtube.com/watch?v=w55vLyjN-uI

As for coping with wheel wear, big cuts will wear the wheel faster, i tend to stick to .001" unless i have a lot to remove. If i do take a lot off i generally have to dress again before finishing.
For the .015" (i'm going to work in imp as that is what the blohm is) you took of Aarons part, i would take .014" off first, then measure to find how much i have left to go. It may be .0011 or .0015 depending on the size of the part. Then feed from there. The other option, as i said is to clock a gauge block or sample and then the job to see just how much is left. If you can avoid taking the job off the table you remove the risk of putting it back down on a bit of grit.

Ew

[RayG]

The automatic downfeed on mine is a tiny hydraulic cylinder that drives a ratchet, similar to the buttons on Ewans, there is a second hydraulic cylinder that engages it and a knob that allows you to select the number of clicks of downfeed.

At the end of each cross feed the crossfeed reverses and triggers the downfeed cylinder. When in slotting mode I have a microchip pic controller that picks up a proximity switch and drives the downfeed. the prox is in the center of the travel, and the micro measures the time between pulses and calculates when the end of travel occurs and times the downfeed accordingly, I added a pot to select the number of passes between downfeeds.

For what Joe is thinking, I think a stepper motor controller would do nicely.. or a solenoid and ratchet would work as well..

Ray

[jhovel]

Well, I managed to fit a 24V 100W DC motor and drive to the vertical feed. Looked OK.
When I connected it temporarily for a trial, it was able to slowly crank the spindle down - drawing about 7-8A (design motor current 6A max) and the voltage dropping quite a bit, but no go winding it up at all. :C
So I tried a BIG power supply, since the motor would never be running continuously, that made the poor motor draw over 10A and it got hot quickly (not surprisingly) it was JUST able to wind the spindle up slowly....
Back to the drawing board....
I'm actually wondering it the slides are too tight since I scraped them. Might have to revisit that too....

Here is the general arrangement in its 'raw' state:

318679 318678

Should there be much force involved winding the spindle down?
I'm guessing there should be some to stop the spindle riding up (within the backlash of the screw & nut) when cutting uneven surfaces to start with - or an accidental heavy feed. I just don't have any sense of how much force it should take.... Winding up would obviously be that force plus the force required to lift the weight of the spindle block and motor.
Any opinions?

[Pete F]

As for coping with wheel wear, big cuts will wear the wheel faster, i tend to stick to .001" unless i have a lot to remove. If i do take a lot off i generally have to dress again before finishing.
For the .015" (i'm going to work in imp as that is what the blohm is) you took of Aarons part, i would take .014" off first, then measure to find how much i have left to go. It may be .0011 or .0015 depending on the size of the part. Then feed from there. The other option, as i said is to clock a gauge block or sample and then the job to see just how much is left. If you can avoid taking the job off the table you remove the risk of putting it back down on a bit of grit.

Ew

That will depend on how you use your grinder, 0.001 doesn't strike me as a heavy cut, and you may try to reduce your stepover and increase the downfeed. My grinder is a toy compared to the ones you guys use, yet I normally grind with a 0.10 mm (4 thou) downfeed but a small stepover. I tend to favour feeding in one direction too, with the work feeding from front to back. What happens then is the wheel wears with a ramp on the leading edge, but the rest of the wheel holds its size well and sparks out the work as it steps across. For the finishing passes I step the reverse way and use the relatively fresh edge on the other side that I keep in reserve. No point in using that when just hogging off material.

Unless it's critical grinding I'm doing, I'll rarely bother dressing the wheel before use. The soft-start/stop gently brings the wheel up to speed and slows it afterwards, so runout isn't an issue. Although it's still grinding perfectly to size, eventually that ramp creeps far enough across the wheel that it's not efficient to keep persisting. But the main reason to dress the wheel is because the abrasive particles dull and the wheel just doesn't cut as well. It's very easy to tell the difference, mainly in the finish, but it just doesn't cut as aggressively. It would be a big factor in a commercial shop, but doesn't bother me as much, and I'd rather have longer wheel life.

It's possibly a slower way to grind, but I've found it works well and saves constantly dressing wheels, and I'd suggest giving it a try to compare with how you're grinding now.

[.RC.]

I thought with step over it should be around 2/3rd wheel width per pass...

[Ueee]

Interesting, I normally run with a .100-.150" step over, it's a bit random sometimes.

If I need to take a lot of the machine will easily eat .004" per pass, normally I drop the step over to .050" and slow the feed down a bit. Depends on the wheel type and bond too of course.

Ew

[snapatap]

I thought with step over it should be around 2/3rd wheel width per pass...

Yeah thats what I've been taught to, and 1-2 thou deep for rough passes and half a thou or less for finish. On the grinder at work we can get 3thou deep but its a pretty rigid grinder. We dont dress the wheel very often on the grinder a work and we dont have any problems. Pete do you have problems with heat buildup with your method? or do you have coolant?

[Pete F]

I thought with step over it should be around 2/3rd wheel width per pass...

Yes that's the "traditional" way to grind; small downfeed and large step over. I was screwing around trying different things and independently discovered (well re-discovered, I'm definitely not trying to claim any credit, I was just ignorant of other possibilities), doing it the way I suggested above. It works very well, at least in my opinion. My grinder doesn't have a very large wheel or more the point motor, so I can't push things too much, but I believe some guys with "proper" grinders like yours are downfeeding much deeper than I can.

It's dinner time and the wife has cooked lamb (yay!), but I'll try to dig up some references.

Oh sorry I forgot the question. No particular problems with heat, I don't use coolant so that's always a constant battle for me however. Indeed I feel there's less heat put in the work this way. It could be different for you guys who could hog deeper cuts however. My motor will bog down if I get greedy.

[Pete F]

Grrr, I typed and posted a message with links but the server was overloaded and dumped it :((

Ok I'll try again, briefly, as I'm in the middle of machining gudgeon pins ... 1.5 mm gudgeon pins. My life has reached a new low :)

Anyway, what I said are here are a couple of links to what I was referring to. That Chaski article is credited as behind this method, although I find that difficult to believe. As I mentioned above, I found this method myself just by bumbling around, and I'm no Einstein, so I can't believe others didn't already discover this before the age of the internet. I only found these references when I saw Richard referring to 0.001" as a "deep" depth of cut, I was surprised as I thought everyone did it the way I do it these days, and I searched to try to see what others were using. I was using 4 times that depth on a grinder a quarter the size! Credit however really goes to Phil (Machtool) for getting me to traverse the table faster and prevent the work burning.

Here's a couple of links that discuss it better than I can.
Surface grinding- Deeper cuts for better finishes ? (http://www.practicalmachinist.com/vb/greatest-hits-links/surface-grinding-deeper-cuts-better-finishes-110659/)
Grinding help (http://www.practicalmachinist.com/vb/general-archive/grinding-help-79190/)

[Michael G]

Pete, as a reference point, what's your grinder and it's specs?

Michael

[Pete F]

It's a small Hercus surface grinder, not too many of them about. Specs I have no idea about, but it's reasonably accurate, good enough for what I need anyway and I never have problems with that side of things. It came out of a University so I don't think had seen much use.

The issues with it however relate to the fact it's a completely manual machine, and that gets VERY tedious after a while. It's not very powerful, no doubt appropriate for its size however. But other than being manual my main gripe is it doesn't have coolant, and I need to be very conscious of heat at all times. Oh, it's only a 6 x 12" machine, so I run out of room at times, in Z as well occasionally, typically when I'm trying to bodge it to be used as something other than a surface grinder! :wink: I wouldn't call it an ideal machine by any stretch of the imagination, but the reason I have it is because it's a small footprint so i can actually have a grinder! My workshop is weeny and I need to shoehorn lots of machines in, if it wasn't small I couldn't have one, and I use my grinder a LOT! I wouldn't want to be without one.

[Michael G]

Thanks. It sounds of a similar size and power to mine, so I'll have to try it. Small compared to something like Ewans can sometimes mean a 2 hp job with a 14x6" table. As I'm 3/4hp with a 10x5" it may well be worth a try once I am powered up.

On Edit: the links are interesting too and worth reading. Thanks.

Michael

[Techo1]

Should there be much force involved winding the spindle down?
I'm guessing there should be some to stop the spindle riding up (within the backlash of the screw & nut) when cutting uneven surfaces to start with - or an accidental heavy feed. I just don't have any sense of how much force it should take.... Winding up would obviously be that force plus the force required to lift the weight of the spindle block and motor.
Any opinions?


Joe, I measured the torque required to wind my grinding head up and down and found that very little effort was needed, about 15in/lb going up and slightly less on the way down, around 13 - 14in/lb.
I used a dial type torque wrench directly on the hand wheel shaft nut.

Regards, Lex.

[snapatap]

Well I've learned something. The links were a very interesting read, thanks Pete. I might give it a go if i ever get my grinder working properly.

[jhovel]

Thank you very nuch Lex, that helped me tremendously!
In the intervening time, this has been bugging me enough to go and do some checks:
I undid the vertical jack screw (which moves the spindle block up and down) and found that for all intents and purposes the head was 'locked' tight. I could not budge it. So I took the drive motor off and the rear plate which hold everyting tight and in position (see my earlier photos of the spindle motor conversion). I then clamped the spindle block with some large clamps to ensure the original location in the box slide ways, and put a straight edge across the ways. THe rear plate had in fact no play at all, maybe was even sprung a bit - on the tight side! If that makes any sense.
So I cut some 2 thou shims and put it all back togethe. WIthout the jack screw I still can't move the spindle up or down with reasonable force, so it certainly is still tight.
Once the spindle motor was back on, I reconnected the electric jack drive again and 'voila'! It worked! THe mittle motor draws around 5A going down and a bit over 6A on the way up. I discovered a tighter spot near the very top, where it draws nearly 7A just before the spindle hits the top limit. I can live with that. The spindle is now MUCH easier to wind by hand too! I'm guessing its still a bit more than yours, Lex, but no longer a chore.
So tomorrow I'll clean up the motor moutn and paint it and wire up a DPDT momentary switch I found I had with the right current rating, all my puch button switches had too low a rating. This switch will easily fit in the column dust cover and will be quite unobtrusive - and keep all the 24V wiring short.
I'll take more photos when its all finished.

I read all the discussion about grinding methods with great interest too! My spindle motor is 1Hp and will at a pinch grind a couple of thou if the table is moved laterally slowly. I was amazed at how much power surface grinding actually takes, I must admit. My wheels are only 1/2" wide and I'm no longer surprised and the large motors on wider wheeled grinders. I'll try the 'creep feed' deeper grinding method one day, see what that does to the wheel and the finish.

I think the next project will be cooling though, dry grinding makes an amazing mess!

[jhovel]

Well, it was 'cutting and splitting firewood' day at the Hovels' hovel today :C .... but I managed to sneak off into the shed for a couple of hours :U
I made a bit of progress on building the spark guards and towards the splash guards for coolant use.

319009

I also figured out how to fit the coolant tank and pump on the side of the base removably (for easier cleaning out). Will make a start on cleaning up and painting the coolant setup as I go, and make the mounting frame for it.
I think I have decided to use another 24V DC motor for the in-out feed (Y-axis) as I can see an obvious way of mounting that and I have the bits to do so. After the vertical motor installation and tests, I think these motors are up to the task of driving the saddle.
I've also reassembled the 3-phase gear motor (after digging out and connecting the star point a little while ago) and tested it on the designated VFD. It is a 2-pole motor and perfectly happy to run at 175Hz! Just for a test mind you. This motor will be driving the table left and right under limit switch control. I expect it not to run above 50 or 60Hz ever. I'll have to find or make two gears to fit that in and have the handwheel selectively isolated from the the drive. I'll dig around my 'useful box' and see if I got something that fits, if not I'll make them on the shaper....

[Ueee]

I really like he clear guard Joe, much easier than a solid one to work with.

I have spent a fare bit of time today finishing my sine plate. I have tried grinding with 2/3 step over and 1-2 thou feed. It has worked well, the only thing is it seems to show up poor dressing more than the smaller step over. What I don't know is how fast my table travel should be. Having 8 (from memory) hp means there is not really any signs of "slow down this is too much"

Ew

[simonl]

Looking good Joe!

I like the clear perspex guard too, not that I have any experience with SG, but I like it none the less!
I've been keeping my eye out for SG too. After seeing yours I got SG envy!

Wood cutting day eh? That must be quite relaxing, especially when using that machine you have, the trees must really cringe when you fire that up! :D

Simon

[Greg Q]

Joe, I wanted to thank you publicly for ringing the other day and getting me back on the forum. I am very impressed with your restoration of this machine. It is also gratifying, as a foster parent of this machine, to see that it found a very good home.

Best,

Greg

[jhovel]

Well Greg, with a great project like that thanks to your generousity, how could I not include you in the loop somehow. Phoning you was the obvious option - and I'm glad you had a look at the progress - and the forum in general.
Welcome back!

[jhovel]

Well, it's been a while - of distractions, contemplation and other 'interim projects' - but progress is being made:
I've completed the guards for the table, drilled & tapped the table for a drain, cleaned and repainted the coolant system (with a white bottom to more easily see sediment when cleaning), fitted a single phase motor to the coolant pump, made up a nozzle and plumbing and found and fitted a filter in the delivery line.
334299 334300 334301 334302 334303

Still to make and fit is a 'mudguard' do the wheel to stop coolant getting sprayed up on the 'uphill' end of the wheel. Didn't even think of that until I tried it out :doh:
In the meantime I have ordered and received a container of Ecocool 610 clear grinder coolant. So I'm all set!

The table has a low area around the t-slotted 'boss' which obviously collects coolant but can't drain. Fitting a secondary drain at that end is too complicaed. So I've started filling that table end with epoxy filler (in thin layers because fo the hot weather). I'll fill it to the bottom of the T-slots with a slight slope towards them. That will allow the right side to drain along the T-slots to the left and dry out. The coolant is meant to prevent surface rust after it's dried off. RayG has found that to be reasonably effective.

Remaining tasks are the motorisation of the table in both axes, but the design is well under way. A DC motor and drive system is selected for the y-axis along wiht limit switches and controls. A 3-phase gear motor, VFD, suitable drive gear and switch (visible in the last picture) have all been collected.
I'll update the thread when any progress is made on those.

[simonl]

Watching with much interest Joe. I've read a bit about the clear coolant use on sg so I may have to look at that too.

Cheers,

Simon