What have you invented?

[neksmerj]

Could be something simple like sticking a laser pointer up into the chuck of your mill to indicate the centre of a hole.......or some electric sox.......or a bottle of Scotch that never runs out. The "Chairman of the Board" would love that one.

Anything you have done, and kept quiet about it. Maybe an electric clothes line that rotates when there's no wind. Got the idea?

$10000000000 to the winner, 'cept I'm not paying, he is.

Ken

[pjt]

I'd say I re-purpose gadgets moreso than invent new stuff, typical of something I do is my laser line on the bandsaw, nothing really invented, just re-purposed, I took the laser bit out of a laser level and mounted it on my bandsaw to give me a looooong (2.5m +) line on the infeed sled, the other thing was way too short, now I can line up the edge of a slab and know where it will be cut.....


Pete

166449 166451 166450

[BobL]

Like pete I fiddle and diddle with a lot of stuff.

Of the hundreds of gizmos I've made and use, I reckon my third chainsaw mill (the BIL Mill) is my best effort. In principle it's a basic alaskan mill but it has a lot of not very visible extras on it that make it much easier to use than any other alaskan mill I have tried.

With apologies to those who have seen this before.
http://www.woodworkforums.com/attachments/f132/127648d1264247757-how-do-you-clean-sump-oil-millingbobstyle.jpg

The top-of-the-wazza-gizmo is this remote motorcycle throttle and kill switch. It also incorporates a locking knob so I can let it run solo.
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=95838&stc=1&d=1233996868

I spend a lot of time planning many of these gizmos and usually build up much higher expectations about how they will work that what they turn out like in practice. The BIL Mill is a rare exception in that it works far better that I ever thought it would and is a real pleasure to use - or not use as shown above.

[Anorak Bob]

That looks like a well deserved bottle of ! Hard ,hot, noisy, dirty work!
Your saws are impressive.

[BobL]

That looks like a well deserved bottle of ! Hard ,hot, noisy, dirty work!
Your saws are impressive.

Cheers AB.
My day job is dealing with people, endless paperwork with an occasional stint in a quiet ultra-clean 22.0 +/- 0.1ºC laboratory. CS milling is kind of like my antidote to all this.

What I would really like to have is ~1% of your machining skills - that way some of my other ideas might actually work better than they do.

[RayG]

Hi All,

Here are a few recent projects, I don't know if you'd call them inventions. These are some I've done with my eldest son Matthew.

The most recent was audience participation device for a theater company in Adelaide

It uses a battery powered hand held controller pic microprocessor, with an accelerometer and zigbee wireless network, and rgb leds.

Oribotics by Matthew Gardiner | Art | ZigZag (http://oribotics.net/art/ZigZag)

The main project last year was the Ars Electronica Festival in Austria.

Networked robotic origami flowers... what else...

http://oribotics.net/files/2/275_oribotic-futurelab-2.jpg

Some of the mechanicals were machined on the HM52, but most of the parts were 3d printed.

Here is a video of Matthew describing the project.

Oribotics [the future unfolds] on Vimeo (http://vimeo.com/16429167)

Working with artists is always good fun, they seem to come up with the weirdest ideas, and then I get to design and build the electronics.

Makes a nice change from industrial control.

Regards
Ray

[Anorak Bob]

Bob L,

Looking at your blog makes me realize I'm just fumbling around!

Beautiful work.

Bob T

[Anorak Bob]

Ray,

The artist as the inventor of joy.

Bob.

[Andy Mac]

Some nice innovative work there!
I potter around making all sorts of things, but my favourite useful item is the two grinder stand I showed some time back. Each time I use it fills me with satisfaction, space efficient and sturdy!

Cheers,

[Jekyll and Hyde]

Some nice innovative work there!
I potter around making all sorts of things, but my favourite useful item is the two grinder stand I showed some time back. Each time I use it fills me with satisfaction, space efficient and sturdy!

Cheers,

Interesting - I've been contemplating doing something like that with my grinder, since I want to add another to the collection. Nice implementation!

I'm also thinking of making a table for general marking out and rough fabrication, but with a top made in two halves which can be swiveled into the vertical position next to the legs, allowing grinders or similar to be elevated up in the centre...

[Dave J]

I could do with something like that as well. Late last year I wanted another grinder or two so I could have them set up with different wheels. After looking around at new prices for Chinese grinders, I was shocked at how much they had gone up and also the quality had gone down.
I went to the markets and came across 4 near new 6 inch grinders for $15 - $20 each, the wheels where either not used or barely used. Each time my wife saw me come back she said not another one. lol
I think people buy them or get them as presents thinking they are handy and they just site in the garage.
So now I have 5x6 inch, 1x8 inch and a dental lathe (which is a smaller type polisher)and they take up a heap of space on the bench.

Maybe a big wheel with 4- 5 grinders on it made into a bench?

Dave

[eskimo]

I could do with something like that as well. Late last year I wanted another grinder or two so I could have them set up with different wheels. After looking around at new prices for Chinese grinders, I was shocked at how much they had gone up and also the quality had gone down.
I went to the markets and came across 4 near new 6 inch grinders for $15 - $20 each, the wheels where either not used or barely used. Each time my wife saw me come back she said not another one. lol
I think people buy them or get them as presents thinking they are handy and they just site in the garage.
So now I have 5x6 inch, 1x8 inch and a dental lathe (which is a smaller type polisher)and they take up a heap of space on the bench.

Maybe a big wheel with 4- 5 grinders on it made into a bench?

Dave


did i read right...5 off 6inch grinders....you into collecting grinders?:)

[Dave J]

Yep I got carried away that day, but because I never looked for them before I didn't realise how many where around the markets, not no more.lol
I think it cost me around $90-$100 for all of them and they all work perfect. I would have only got 1 1/2 at the shops price.

Dave

[jatt]

Dave J you sound like a man who likes to grind!!

[Dave J]

Dave J you sound like a man who likes to grind!!

Or a man that doesn't like changing grinding/buffing wheels.
You maybe right though, I have around 10, 4 to 9 inch angle grinders and 4 die grinders all with different disc's so I don't have to change them as well.

Dave

[BobL]

Gents,

I want to register a informal invention.
After allocating space for woodworking machines (BS, TS with Router table, Small Lathe, Planer/thicknesser combo and a yet-to-be-acquired Linisher) in my new shed I reckon I can just squeeze in a ;
- Small Welding bay
- Drill press
- Metal cutting table saw
- MW Lathe

I also have a corner in my workshop that I want to use for grinding/polishing and buffing. Problem is it's a small corner and I have 3 grinders (2 with 8" wheels and 1 with 10" wheels)

I am thinking of a triple grinder carousel setup like this.
http://www.woodworkforums.com/attachment.php?attachmentid=166508&stc=1&d=1302174444

I actually have another grinder and would like to set up as well but a quad carousel is too cluttered in the space I have.

I have a 1m long, 100 mm diam 5 mm wall thickness piece of pipe and possibly even a 4wd wheel bearing I could use.

Comments and thoughts?

[Anorak Bob]

Nice Bob L.

A neat simple idea for that addresses the ever present problem of limited space.

How would you lock it in the required position? Maybe a locking mechanism could be conceived that avoids the requirement of a bearing and the associated machining of it's housing.

Bob T

[BobL]

Nice Bob L.

A neat simple idea for that addresses the ever present problem of limited space.

How would you lock it in the required position? Maybe a locking mechanism could be conceived that avoids the requirement of a bearing and the associated machining of it's housing.

Bob T

Yeah I don't really need a ball bearing. It's not like it needs to spin or it will just tangle the power cords. maybe just a bronze washer and a grease nipple is all I need? It just needs to be able to rotate 120º one way and then the other.

What about turning up a steel collar that sits into the top of the pipe post and a short shaft that passes though a bronze washer and the collar and has a steel disc welded on top of that . A 1/2" bolt passing through the pipe and collar and into appropriate recesses on the shaft should hold it in place.

http://www.woodworkforums.com/attachment.php?attachmentid=166512&stc=1&d=1302177722

A pair of stops on the disc and the collar should stop it spinning more than 360º and tangling the cords?

[Anorak Bob]

I imagine that after a while your locking bolt will mutilate the shaft even if you mill flats into the shaft. Something along the lines of a cotter type clamp might work. What ever you use to lock the arms has to resist the forces of heavy grinding. You don't look like Willo the Wisp, Bob.

BT

[BobL]

I imagine that after a while your locking bolt will mutilate the shaft even if you mill flats into the shaft. Something along the lines of a cotter type clamp might work. What ever you use to lock the arms has to resist the forces of heavy grinding. You don't look like Willo the Wisp, Bob.

BT

Most of the grinding I do is for wood work blade shaping so it's usually ziiittt, Zittttt, ZiiTTTTT, Zit (dip). But knowing how much vibration grinders put out I agree with you about mutilating the shaft.

By cotter type clamp do you mean the following. Start by making the shaft bigger and adding a slit in the top part of the collar and adding some tabs etc like this?

http://www.woodworkforums.com/attachment.php?attachmentid=166524&stc=1&d=1302180455

[Anorak Bob]

Bob,

I will take a photo of the bronze cotters in my dividing head, tomorrow morning for you.

Bob.

[eskimo]

Gents,


I reckon I can just squeeze in a ;
- Small Welding bay
- Drill press
- Metal cutting table saw
- MW Lathe



your gunna need a mill...even if you now think you wont......so make room

[Anorak Bob]

Bob.

A few photos of the cotters used to clamp the Hercus dividing head spindle. Your suggested method would be easier to build. Both methods achieve the same result.

Bob

[BobL]

your gunna need a mill...even if you now think you wont......so make room

Oh please don't say that!!!! :(

I do have reasonable access to a Bridgeport at work so I'm putting this off as long as I can. :D

[BobL]

Bob.

A few photos of the cotters used to clamp the Hercus dividing head spindle. Your suggested method would be easier to build. Both methods achieve the same result.

Bob

Wow - I like it - that is a very elegant solution to clamping - and that is definitely going on my next chainsaw mill whether it needs it or not.

[RayG]

Hi Bob, (Anorak Bob that is... )

Thanks for posting those pictures, I think I can use that as the clamping mechanism for clamping the collar for the z-axis drive on the mill cnc conversion.

Regards
Ray

[Anorak Bob]

Bob and Ray,

If you do utilize the cotter type clamp and are in a position to do so, machine the cotters and bore simultaneously. I had to make the cotters independant of the dividing head casting using a boring head in the mill, a bit of awkward mucking around.

BT

[Dave J]

Hi Bob, (Anorak Bob that is... )

Thanks for posting those pictures, I think I can use that as the clamping mechanism for clamping the collar for the z-axis drive on the mill cnc conversion.

Regards
Ray

Ray,
You have the same set up in your quill.

Dave

[franco]

Apologies for the long post, but it is difficult to describe the function of the machine without going into some detail about the end result. This is not really an invention, but a slightly more modern redesign of Thomas Blanchard's early 1820s gunstock lathe.


About ten years ago I realised I was going to need between eight and twelve rebuilt wood spoked wheels for my 1920s cars if I ever get around to finishing restoring all three of them, because the original spokes were too far gone for safe re-use. After pricing having the wheels rebuilt professionally, I thought no way - they can't be worth over $300 each. (I now know I was wrong)! I thought it would just be a matter of turning up a set of spokes on the wood lathe and assembling the wheels - wrong again.


Closer inspection showed the spokes were tapered and more or less oval in section, with the shape varying along the length of the shank. The shanks are curved or offset away from the vehicle, but the dowel on the outer spoke end must be parallel to the face of the spoke butt which is sandwiched between the two halves of the hub, though it is not on the centre line of the spoke blank. The butt ends of the spokes in a 12 spoke wheel have a taper of 30 degrees so they will fit together in the hub, and have an additional cross compound taper of 10 degrees so they can be assembled with the wide and narrow sides of the tapers alternating, then put in a press to lock them into place. Since the spoke are curved away from the vehicle this means that there are two types of spokes in each wheel, those curved away from the wide face of the butt, and those curved away from the narrow face.


To produce these some form of copy lathe was obviously needed. About this time Model Engineer ran a historical article on the early Blanchard lathes in the Science Museum in Britain, where the author deduced the feeds and speeds used by counting the teeth on the various gears. Using this information I built this spoke lathe, using mainly what was available from the scrap box. The two headstock spindles and the leadscrew turn at 17 RPM and the feed is about 45 mm/min, fairly close to the M E figures. The cutter is a modified laminate trimmer with round nosed router bit, and the pattern is a modified original spoke if a good enough one is available - otherwise a new pattern must be made. The same pattern can be used for both spoke types by varying the relation between the pattern and the workpiece. A second operation and a second pattern with a round section offset from the centreline by the amount of offset of the spoke from the hub is needed to get the dowel on the spoke end located in the centre of the outer end of the spoke.


The hardest part about re-creating this piece of mid 1800s technology having never seen one in the flesh was probably working out in advance what controls were needed to make it work. Now, thirty something wheels later, I don't think I ever want to see another wooden spoke again!


The photos show :
1. Front view of the lathe with the saddle positioned about the middle of the ways, which are down towards the bottom of the lathe. The two copy frames are pivoted on the saddle and connected by an adjustable pivoted link on top.
2. Assembled wheel mounted on metalworking lathe faceplate. The spokes have been faced and are about to be bored for the hub.
3. A complete wheel.


Frank.

[Dave J]

Frank, beautiful work.:2tsup::2tsup::2tsup:
I would love to see some close up photo's of the machine, if it's not to much trouble.

Dave

[Stustoys]

Hey BT, you dont have one of those!

Great work Frank. Hows the rest of the cars going? Or shouldn't I ask.

Stuart

[franco]

Great work Frank. Hows the rest of the cars going? Or shouldn't I ask.

Stuart

Err... yes... restorations....one just needs a couple of jobs done to get it back on the road. I need to get it out of the shed to work on it, but it seems to have been raining here almost continuously since the start of the 2010 wet season in late 2009. I used the few short periods of fine weather to finish off the wheels - assembling and machining new wheels in periods of high humidity is not a good idea, because the spokes tend to shrink and loosen when the humidity drops. I want to be fairly sure of a reasonable spell of dry weather before tackling the repairs on this one.

The second one has had most of the mechanical work done, but the body needs complete re-wooding and a bit of panel work....I hate body work.... at present it seems to have entered a state of suspended animation....I keep on getting sidetracked with things I'd rather do, like building copy lathes... The third one is untouched except for the body being dismantled, and needs a complete restoration except for the four re-built wheels - if someone local wants to buy it I will probably sell it, since at the present rate of progress I doubt it will ever get finished.

Frank.

[franco]

Frank, beautiful work.:2tsup::2tsup::2tsup:
I would love to see some close up photo's of the machine, if it's not to much trouble.

Dave

Hi Dave,

Here you go:

!. The top deck showing the pattern spindle on the left and workpiece spindle on the right. The pattern follower wheel mounted on the back copy frame and the router mounted on a self-levelling table attached to the front copy frame can be seen towards the back of the beds. The method of timing the workpiece to the pattern using a square is also shown.

2. Shows the adjustable top link between the copy frames, and another view of the pattern follower wheel and router mount. As a matter if interest, note the nice decorative band of vibration markings on the follower wheel which I get when facing with my Chinese 13x40 lathe at 250 RPM!

3. Shows a view of the carriage from the headstock end. From right to left the frame lock lever, partly obscured behind this the half nut lever, the bottom end of the front copy frame, the bottom end of the self-levelling router mounting rod, the shiny vertical piece next to it is the mounting plate for the half nuts, the leadscrew, bellcrank and spring for the copy frames to hold them in contact with the work, and the bottom pivot for the back copy frame.

4. A partly obscured view of the half nut actuating plate

5. The main transmission dog clutch.

Frank

[pjt]

That is a good bit of gear Frank, 10 out of 10:U, and a good looking wheel:2tsup:


Pete

[Blu_Rock]

I did not so much invent these chuck key holders, but more found a use for a bunch of old hard drive magnets I had lying around.

[Dave J]

Frank,
Thanks for the extra pictures, you have done a really great job on that. It would be worth a few bucks to the right person when you are finished with it.

Dave

[Black Bear]

My mate has come up with a novel way to aerate his lawn. It may be already invented, but this is the first time I have seen one.

The device consists of a pair of stilts with the foot of each stilt a block of wood at about 250 X 100 X 100mm with old bolts screwed into smaller drilled holes, and with the top cut off and sharpened to a sharp point.

Mate said that he had a couple of tumbles in the early days as the points of the bolts stuck into tree roots, but he has now perfected his plan of attack. The introduction of the tinnie was a necessity, says mate, as after enough tinnies the falls don't hurt.

These stilts strap onto the lower part of his legs, like plasterer's stilts, and, with cold tinnine in hand he stomps around his lawn 'drilling' air holes for the collection of fertilizer and for aeration.

Brilliant!! Thought I.

BB

[BobL]

My mate has come up with a novel way to aerate his lawn. It may be already invented, but this is the first time I have seen one.

The device consists of a pair of stilts with the foot of each stilt a block of wood at about 250 X 100 X 100mm with old bolts screwed into smaller drilled holes, and with the top cut off and sharpened to a sharp point.

I've seen a picture of this in a pre-WWI book on DYI and gardening

[HavinaGo]

I did not so much invent these chuck key holders, but more found a use for a bunch of old hard drive magnets I had lying around.

:2tsup: simple and effective - they are strong little magnets!

Do the parts so held become magnetic and thus attract steel swarf?

[Black Bear]

I've seen a picture of this in a pre-WWI book on DYI and gardening

Well there you go! There is nothing new under the sun, as someone once said.

Was the necessity of the tinnies stressed in that gardening book?

[Blu_Rock]

Do the parts so held become magnetic and thus attract steel swarf?

No, I can't say that I've noticed any significant magnetism.

[Stustoys]

No, I can't say that I've noticed any significant magnetism.
But why would you notice? You have some where to keep the keys other than laying around in the swarf ;)

[BobL]

Well there you go! There is nothing new under the sun, as someone once said.

Was the necessity of the tinnies stressed in that gardening book?

It was invented before beer ever came in tinnies. :D

[citybook]

Hi All,
this is more a "has anybody invented" question.

I got my first lathe about 1970, so you might think I should have done more about this by now. Sort of just complain and do nothing to fix it.

My gripe is work holding, especially on a mill table. There are several good clamping kits and similar, but most work by putting downward pressure on the top of the job.

Well, that usually seems to be the face I want to cut - and I don't want clamps in the way.

So has anyone come up with a fixture that clamps the sides of a job - maybe like a 4 jaw independant vyce - particularly suitable to use on a rotary table.

Cheers,
Bob.

[pipeclay]

You can get individual jaws that work as you say.
The height of the jaws may be a problem and packers may be needed to give adequate clearance for full face machining.
The are other types of smaller clamps that work on a Cam action,not 100% sure of how much holding force they would provide if heavy cutting conditions are used.

[Stustoys]

Hi Bob,
How thick is the work piece you are trying to hold?
One of the many jobs I am working on at the minute is some low profiles clamps for a mill table.

Stuart

[Bryan]

Some ideas here: Mitee-Bite Products Co. (http://www.miteebite.com/)

[Dave J]

There are things called mite bites (spelling?) and there are a few homemade designs like this around, if thats the type of thing your after.
Powerful but Simple Wedge Clamps (http://madmodder.net/index.php?topic=4743.0)

Dave

[citybook]

Yes Pipeclay, I think the individual jaw approach is handy - I need to modify the idea a bit to suit my rotary table, which only has 3 radial T slots.

Stuart, the thickness varies - often the sort of thing I do begins with a steel plate - maybe 1/4" to 1" thick depending on the bright idea I am having at the time - so I want to skim the plate to make a reference surface for the rest of the project.

Some time back I wanted to re-surface the bottom face of a hydraulic valve block - no place to put clamping blocks - took me 2 days to set it up and 10 minutes to cut it.

In that case there was plenty of vertical room as the block was about 75mm thick, but often I don't have this luxury.

So I would be interested to know more about your low profile clamps.

Yes Brian, the Mitee Bite stuff is cute - I don't actually have any - do you ? I find that hi tech stuff hard to resist, but I seem to get mixed results with it.

Dave, those wedged clamping blocks are something I can relate to - I will have a crack at making some up tomorrow. Like the Klank fellow said, the idea might be 20 years old but you don't see it about.

Thank-you all for your replies and ideas - they are all interesting.

Cheers,
Bob.

[pipeclay]

Can you for some of this work use a 4 jaw chuck.

[citybook]

Yes, chucks are currently my main way of holding work on my rotary table - and for a some things this is Ok. But for rectangular jobs and odd shaped stuff it is not so good.

I am thinking of making a rectangular table out of mild steel and fitting that to the rotary table - and organising this one with individual jaws, looking a bit like a 4 jaw chuck when the jaws are on diagonals - and more like a vyce when the jaws are on opposing parallels.

And Dave's wedge jaws could be ideal for this.

Cheers,
Bob.

[Stustoys]

Hi Bob,

Here are some pictures of the ones I am making up. As they are the minimum would be about 10mm. I started making them as the other designs I had seen up until the used a grub screw against the bottom of the Tee slot. They should also allow gripping and angles should that ever be an issue. They aren't finished in that picture(and aren't finished in the shed either). The face against the work and the back edge need to be machine so they are vertical as it it sitting in the picture so that it pushes against the work as it is tightened.
Of course having said all that, I cant guarantee that they will work lol

If I get a chance I'll have a go at finishing at least one tonight.

Stuart

p.s. The bolts are 1/2 UNC

[RayG]

- often the sort of thing I do begins with a steel plate - maybe 1/4" to 1" thick depending on the bright idea I am having at the time - so I want to skim the plate to make a reference surface for the rest of the project.


Hi Bob,

What about a mag chuck, or a vacuum table?

Regards
Ray

[Jekyll and Hyde]

Yes Pipeclay, I think the individual jaw approach is handy - I need to modify the idea a bit to suit my rotary table, which only has 3 radial T slots.

Stuart, the thickness varies - often the sort of thing I do begins with a steel plate - maybe 1/4" to 1" thick depending on the bright idea I am having at the time - so I want to skim the plate to make a reference surface for the rest of the project.

Some time back I wanted to re-surface the bottom face of a hydraulic valve block - no place to put clamping blocks - took me 2 days to set it up and 10 minutes to cut it.

In that case there was plenty of vertical room as the block was about 75mm thick, but often I don't have this luxury.

So I would be interested to know more about your low profile clamps.

Yes Brian, the Mitee Bite stuff is cute - I don't actually have any - do you ? I find that hi tech stuff hard to resist, but I seem to get mixed results with it.

Dave, those wedged clamping blocks are something I can relate to - I will have a crack at making some up tomorrow. Like the Klank fellow said, the idea might be 20 years old but you don't see it about.

Thank-you all for your replies and ideas - they are all interesting.

Cheers,
Bob.

If you have a look on CDCO's website, he sells low profile clamps, set of 6 for $27 US. I was going to make some, but saw those when I was getting some stuff from him anyway, so added them on :-. Not worth making them at that price! Of course, if you have different size t-slots to a Bridgeport/clone, doesn't help much, although maybe he does different sizes.

Haven't had a need for them since buying them of course :rolleyes:, so no idea how well they hold.

[RayG]

Hi Stuart,

I like the flat clamp idea, I wonder if it would be better to reverse the step, what I mean is to make the fixed stop with a step that stops the angled wedge from lifting up at the back.

I could draw a picture, but I hope you get what I'm thinking.

Regards
Ray

[Stustoys]

Hi Ray,
Think I'm going to need a drawing. Whats going to make the angled wedge lift up at the back?

Stuart

[RayG]

Hi Stuart,

This is what I mean...

http://www.backsaw.net/pics/Misc/stusclamp2.jpg

As you tighten the clamp it's going to want to ride up at the back, putting a step would
stop that...

EDIT: I guess the bolt would stop it anyway, so it probably won't make any difference?

Regards
Ray

[Stustoys]

My guess is the bolt will be pushing down on both ends. The reason I put the step in was so the corner wasn't against the table and to bridge the tee slot. I better get my finger out and finish one tomorrow and see.

Stuart

[Stustoys]

Well I machined the faces off this morning. It seems to work fine. Tightened with one finger and thumb on the short end of the allen key I cant move the blocks by hand. If you turn the allen key around you can tighten it further and I believe the Tee nuts start slipping. The clamping range is something less than 0.4mm. One thing that did surprise me is that when the clamp is undone its not locked against the work.

Stuart

p.s. I've just put a DTI on each of the fixed clamps. Paper or not paper they are still moved. I'd say the clamp is gripping tight enough.

[citybook]

Hi Stuart,
I have been out playing also and have some ideas.

The clamp should be gripping on the table, not depending on the T nut in the slot for grip - so if the nut is slipping in the T slot maybe a longer clamp design that spans 2 slots is needed (for the anchor block, at any rate - the clamping block can be shorter).

On the wedge clamp that Dave found, I realise that there is a slight tendancy to lift the work - ie. the wedging section rotates slightly as the bevelled end sinks toward the table - and the other end tends to lift the work.

So now I think I favour your design - as your block against the work rotates it is turning downwards, which is much better than upwards..

Both clamp designs have a weakness in that they have a thin line of contact with the work piece - ie. the clamp is at a slight angle to the table, so therefore it is not square to the work - therefore reducing the gripping area in contact.

I don't think a small clamping range is a problem - after all, the clamp is positioned against the work before the first block is tightened down.

Cheers,
Bob.

[Stustoys]

Hi Bob,

I think I've confused you. When I said the Tee nuts were slipping I mean the fixed clamp(the black part in the pictures) is slipping. In fact the tee nut may not be moving at all as we are talking about a very small movement, about 0.006" before the clamp bottoms, I'll check. I'd like to be able to measure the force involved as when tightening the bolt the needle of a 0.0001" dti goes around at about the same speed as the allen key so roughly 2mm of vertical movement of the clamp would equal about 0.2mm movement of the fixed clamp.

Stuart

[RayG]

Hi Stuart,

I can understand why that clamp moves... after all something has to, you wouldn't expect the material to deform by that amount. that just proves how much clamping force there is. I'd say it's a success! :2tsup:

On another note, I bought a vacuum table on ebay last week, one of these eBay Australia: Buy new & used fashion, electronics & home d (http://www.ebay.com.au/itm/270778293024?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649) it's for clamping flat non-magnetic stuff on the surface grinder. I'll let you know how it goes, but I hoping 15 pounds per square inch should clamp nicely.

I'll need to set up a coolant trap before the vacuum pump..

Regards
Ray

[Stustoys]

Hi Ray,
Yeap something has to move. I trying to think of a way to do a rough crush comparison. Something like two pieces of alum MIG wire squeezed between metal plates by the clamp and then repeating the wire squeeze in one of my milling vices to see just how hard you need to wind to crush them about the same. Shame I have no alum MIG wire. Would copper wire do? I guess I can try it and see easy enough.

The table looks cool. Never seen one used on a grinder
You have a real vac pump?
If you get anything like a vacuum is a coolant trap going to work?
I wonder what volume you need to pull if you only have part the table covered? or is the idea to cover as many holes as you can with scrap?
Can you fix it to your magnetic table?
14.7psi ;)

Stuart

[citybook]

Hi Stuart,
I think there is a problem with trying to anchor the clamp with one T bolt.

How about something like this ?

Cheers,
Bob

[Stustoys]

Hi Bob,
I had thought about two tee nuts but that limits you to clamping square to the Tee slot. I could add extra plates but I'm not sure they are necessary, as Ray said, its going to move somewhere. It seems that both fixed clamps are moving.

I cut some 3/4" lengths of 0.70mm copper wire and squeezed two between the step blocks you can see on the right in the pictures and the fixed clamp you cant see. The wire came out at 0.50mm. I then put two the same length in my hydroloc vice and did it up pretty tight. They came out the same or just a little bigger. So I seem to have plenty of clamping force and I can double or triple up. But a vice isn't going to "slide".

I guess it comes back to what work you want to do with them. I'd think mostly they would be used to facing cuts.

Stuart

[RayG]

Hi Ray,


The table looks cool. Never seen one used on a grinder
You have a real vac pump?
If you get anything like a vacuum is a coolant trap going to work?
I wonder what volume you need to pull if you only have part the table covered? or is the idea to cover as many holes as you can with scrap?
Can you fix it to your magnetic table?
14.7psi ;)

Stuart

Hi Stuart,

Been away for the day, yes I have a "real" vacuum pump, it's a multistage RobinAir, the place that sells the vacuum tables also sells a coolant trap, but I've got a vacuum chamber that is used for degassing plastics and all I need to do is run a hose from that to the table, when it's sealed and running, there won't be any coolant getting into the vacuum side anyway, but the little bit that will get in accidentally needs to be stopped from getting into the pump.

I'm going to bolt it on a steel plate and that goes on the mag chuck.

I had a nice find on ebay, a 12"x8" compound magnetic sine table, it's a Robbins, who are now owned by Suburban, got it for a $450 inc shipping, you wouldn't want to know the new price! :)

eBay Australia: Buy new & used fashion, electronics & home d (http://www.ebay.com.au/itm/250876058665?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

Note to self, stay off ebay...:rolleyes:

Regards
Ray

[Anorak Bob]

That's a real nice bit of gear Ray. You have to love Yank names, Omer!

It will be interesting to see how long you have to wait for it to arrive. I'm into week 5 for a Dumore part. Bryan has been waiting longer for something he purchased from the States.

Bob.

[RayG]

Hi BT,

Thanks, Omer is a great name.. I've had over 4 weeks wait for stuff recently, so I'll be expecting it in 4-6 weeks... maybe.

When I looked at it I suspected it might not be magnetic, although the description and the manual they picture say it is, the pictures don't look like it. First there is no sign of laminations, second there's no handle, and third it doesn't look deep enough. I won't be dissapointed it it turns out that it's not a mag chuck, I really want the compound sine setup.

Regards
Ray

[Stustoys]

Hi Ray,
How does a coolant trap work in a vacuum?wont the water just evaporate? hmm but the oil wouldnt right?(sorry thinking aloud lol)
I was surprised to read that it will work with a shop vac.

That table sure is pretty. There was a non magnetic one over here not long ago that went for almost that much and I'm not sure it wasn't "home" built
Did you get some gauge blocks to go with it?

Stuart

p.s. I think you're right about it not being magnetic. Thirdly tapped holes
"USAF" hey

[RayG]

Hi Ray,
How does a coolant trap work in a vacuum?wont the water just evaporate? hmm but the oil wouldnt right?(sorry thinking aloud lol)
I was surprised to read that it will work with a shop vac.

That table sure is pretty. There was a non magnetic one over here not long ago that went for almost that much and I'm not sure it wasn't "home" built
Did you get some gauge blocks to go with it?

Stuart

p.s. I think you're right about it not being magnetic. Thirdly tapped holes
"USAF" hey

Hi Stuart,

Here's the liguid seperator that they sell to go with that table, they have a pretty fair range of vacuum clamping stuff. Liquid Separators (http://clampusystems.com/Liquid%20Separators.html)

I don't have gauge blocks, it's on the list, but all the ones I liked are too expensive.. (familiar story)

Just going back to the clamps you are making, the amount of clamping force you are getting must be huge. I wonder if you could limit the force by making the angled part from some softer material like copper or aluminium.

Regards
Ray

PS I liked the USAF too!

[Stustoys]

I don't have gauge blocks, it's on the list, but all the ones I liked are too expensive.. (familiar story)

They are on my list to, but I dont really have a good excuse to buy them. Now you do.

Yes its seems I over did it with the 1/2 UNC on the clamp, I only used that because thats the size of my clamp set. I have some 50x40mm Alum bar I could try making a clamp out of that. I have a couple of other ideas I'll try. I could just make a short allen key lol

Stuart

[jhovel]

Here is a collection of photos I've found over the years for "future projects" and to recognise if I saw one at a garage sale or market:
(The single piece one is called a 'toe clamp' and can be supported against a the head of a short bolt in a T-nut to execrt more force.)

[RayG]

Hi Joe,

Thanks for those pictures, I like the toe clamp, I think that shape would work nicely with Stuarts idea.
http://www.woodworkforums.com/attachments/f65/180068d1314276419t-what-have-you-invented-v_accessories-toeclamp.jpg
The step on the bottom would automatically limit the force....

Simple to make as well.

Regards
Ray

[jhovel]

I guess the last image most closely approximates your idea Stuart?

[citybook]

From my point of view we are missing the point here a bit.

The toe clamp (left pic) works by pressing down on the top of the work, and it's fixing is in tension - works well.

A problem with this is that you can't machine the area where the clamp is pressing on the work - ie. the top surface. You have to muck about moving the clamp to somewhere you have already machined and then make another pass to clean up where the clamp was before - and hope the work didn't move when you undid the clamp.

This one on the right is a pinch clamp - it works by pressing on the side of the work, and the fixing is in shear.

One reason for using it is that it does not obstruct the top surface of the job.

And this is what the question was about.

The clamps both Stuart and Dave came up with are pinch type clamps.

Characteristics of this sort of clamp is they develop a lot of force over a short range - they don't have very good contact with the work - and the fixing is in shear.

The last bit - ie. shear load on the fixing - is the reason most of the pics above that are pinch clamps have two T bolts.

Personally, I don't want a clamp that is "going to move somewhere" - an airborne workpiece can be a very character building experience.

Cheers,
Bob.

[citybook]

Alright, the pictures didn't come out where I tried to put them - I am sure you will know which is which.

Ok RayG, how did you get your last pic in the middle of your text ?

Cheers,
Bob.

[RayG]

Hi Bob,

There's an image box in the editor, it's that square icon that has a mountain wierd yellow sky.. hang on... http://cdn.woodworkforums.com/images/editor/insertimage.gif that's the one..

Before you click on that, you need the url for the image you want to insert. If you right click an image and choose view image info, you can cut and paste the url.

Click the image button and paste the url.

If the pictures are on your own computer, you'll need to upload them to somewhere, that's accessible by others.

That's it.

Regards
Ray

[citybook]

Hi Ray,
thanks for that - I am gradually learning my way around this thing.

I haven't got around to acknowledging your comments on magnetic and vacuum work holding - these are things I don't have any experience of - so I look forward to your gripping tales of suction.

I have used mag drills, and my main recollection of these exercises is the profanity associated with trying to do something that sounds deceptively simple.

Thanks for the tip on the image box,
cheers,
Bob.

[jhovel]

Maybe I misunderstood the function of the toe clamp?
I thought you would position it against the side of the workpiece - as Stuart did with his clamps. I may have misled Ray in the process as well.
Now that you expressed your view, Bob, I realise I may have been wrong. Do you suppose they are made to fit OVER the edge of just one size material?
I guess you could put packers under the little foot end....

[citybook]

Hi Jhovel,
I am not in the business of right and wrong.

The clamp you spoke of would be a handy thing in it's place - and if you look at shops selling to the F&T brigade, most of the clamps they offer are the compression type.

For me at any rate, I would say I spend more time at my mill setting up jobs than actually milling. And often I finish up making the fixture, which consumes even more time.

So this is why I asked the crew here what they thought about clamping a job by the sides.

Although I don't post much, I read a lot of what goes on here simply because people here have a lot of interersting ideas - and see, there was more than 3 pages of discussion on clamps.

All the best,
Bob.

[Stustoys]

The toe clamp (left pic) works by pressing down on the top of the work, and it's fixing is in tension - works well.

Tension?


The last bit - ie. shear load on the fixing - is the reason most of the pics above that are pinch clamps have two T bolts..
I can only see one picture that has two T bolts, the one you added making two.


Personally, I don't want a clamp that is "going to move somewhere"
Every clamp moves somewhere or something breaks. Adding another Tee nut may not stop them slipping(if in fact they are slipping) It will just require more force.
Most clamps are compression in one plane and in shear in the other two.

Its a question of how much clamp force is enough. This of course depends on what you are wanting to do. The clamp in the pictures exerts in excess of 120kgs of horizontal force(I would say far in excess but that's as high as my scales go). Force in the same ball park as my mill vice. I'm yet to think of a way to check its vertical force. Unless the work piece was very small there will be two of them. I can't image trying to take roughing cuts with the work piece held by these clamps alone.

Stuart

[citybook]

Hi Stuart,
yes, the toe clamp fixing is in tension - what's wrong with that ?

Yes, there aren't as many clamps there with two T bolts as I thought.

It's very rare that my clamps move - I want my job to stay put while I machine it - the job is in contact with the clamp - so if the clamp moves the job moves - not good.

Yes, it does depend what one wants to do - I want clamps that don't obstruct facing the top face of the job.

And yes, I have used pinch clamps to hold jobs for both roughing and finishing.

Cheers,
Bob.

[Stustoys]

Hi Bob,

yes, the toe clamp fixing is in tension
What part of a toe clamp is in tension apart from the bolt?

Stuart

[citybook]

Hi Stuart,
no part of a simple clamp is in tension other than the bolt. The bolt is the fixing. Take the bolt away and the clamp isn't fixed anymore.

When the tension in the fixing balances the compression in the work plus the packing then nothing will move.

My previous point is that when we choose to use something like a pinch clamp then there is a big issue with shear force - that shear has to be translated into compression of the work - otherwise something will slip.

This then comes back to the T bolt - really good in tension - pretty ordinary in shear - not usually used in compression.

As far as I am concerned, get this right before turning the machine on and the clamps (or job) won't move.

Cheers,
Bob.

[Stustoys]

Hi Bob,
:doh:I'd thought you were talking about the contact point between the clamp and the work. I'll have to go back and read your posts again.

Stuart

[RayG]

Hi Bob, Stuart,

I've been trying to work out how to clamp a 6mm thick bronze sheet about 400mm x 600mm, and ultimately came up with vacuum as the best solution, the clamping force for vacuum is going to be vertical, and the horizontal holding force is dependant on the friction between the table and the plate. At 15 psi ( ok 14.7) that works out to ~2500 kg vertical, and the cooefficient of friction for bronze on steel (oily surface, for worst case) is 0.16, so the horizontal holding force is ~400kg. I can't see how you would get that sort of holding force on a flat sheet any other way.

Back to moving clamps, I think there was some confusion over the clamps moving. In the following setup. What happens as the clamp is tightened? Either the clamp deforms or the work deforms (if the force is great enough) or, the fixed clamp moves.

The fact that the fixed clamp moved, is probably a good indication that the clamping force is sufficient to push the t-slot clamp. I can't see any difference between this clamping arrangement and a milling vise, provided the surface areas are equivalent.

EDIT: By that I mean you could easily take the same idea and make the clamps (say) 100mm wide, covering multiple t-slots with say two t-nuts on each fixed point.

http://www.woodworkforums.com/attachments/f65/179995d1314231220-what-have-you-invented-stuclamp1.jpg

In fact this setup would be better than a milling vise, if you could get clamps on multiple sides. (like the 4 sides of a square part)

Interesting question, work holding is almost always the trickiest part of a lot of jobs.

Regards
Ray

[citybook]

Hi Ray,
of course I am curious about why you are setting up a thin(ish) sheet of bronze for machining ?

Yes, I agree with you that setting up jobs can be tricky - could it be that home machinists set themselves (!) up with tricky jobs ?

Got a pic of this vacuum rig of yours ?

Cheers,
Bob.

[RayG]

Hi Ray,
of course I am curious about why you are setting up a thin(ish) sheet of bronze for machining ?

Yes, I agree with you that setting up jobs can be tricky - could it be that home machinists set themselves (!) up with tricky jobs ?

Got a pic of this vacuum rig of yours ?

Cheers,
Bob.

Hi Bob,

The bronze sheet, is a simple enough job, it's some scrap bronze that I'm finishing for a friend who makes in-fill planes, the source material is some unused bronze cast plaques. I just need to skim the top and bottom flat. But, holding it flat has proven to be a tricky problem. The vacuum table hasn't arrived yet, I'll post some pictures when it does, but there are some videos of how they are set up on their website, that will give you the general idea. Vacuum Tables (http://clampusystems.com/Vac%20Tables.html)

Regards
Ray

[BobL]

Back in April Last year I proposed this idea
http://www.woodworkforums.com/attachment.php?attachmentid=166508&stc=1&d=1302174444

Well after a lot of cussin, and metal dust here it is and it works a treat.
http://www.woodworkforums.com/attachment.php?attachmentid=207606&stc=1&d=1336307227

The steel was all bought at scrap prices. The pedestal base uses a 20 mm x 350 mm diam steel floor plate and a gusset reinforced 100 x 5 mm SHS column.
I have set it up temporarily on some timber cross pieces so that it wont tip over while I am building it and while I work out where I will eventually put it. Eventually the timber will be removed and it will be anchored to the concrete floor using concrete anchor bolts.

The turntable base uses a 16 mm thick x 315 mm diam steel plate and works just like a giant lazy susan bearing using 25 mm diam roller balls.
http://www.woodworkforums.com/attachment.php?attachmentid=207608&stc=1&d=1336307227
In the middle there is another bearing and a shaft goes through the central bearing to stop the top plate sliding around.

The turntable toplate is 12 mm thick steel plate turned to be the same diameter as the turntable base.
http://www.woodworkforums.com/attachment.php?attachmentid=207613&stc=1&d=1336307227
The top plate is bolted centrally to the shaft that passes through the central bearing which is in turn bolted to the plate underneath. Unlike a lazy susan the top plate does not go round and round but only rotates 240º one way or the other.

Those bits of angle hanging out from the sides of the base plate support a 5 mm thick steel band that wraps around the edges of both the top and bottom plates and acts like a brake. It effectively locks the movable turntable top plate to the fixed bottom plate together, using that massive swivel locking handle - this works really well.
http://www.woodworkforums.com/attachment.php?attachmentid=207609&stc=1&d=1336307227
A round galvanized steel plate then covers the top plate and the locking band to prevent grinding dust from falling down inside the turntable.

The 75 x 50 x 3 mm RHS arms that support the grinders are then bolted to the top plate using 10 mm tensile bolts. 25 mm diam x 3 mm thick tubular spreaders are welded vertically inside the arms to prevent the tightening bolts from crushing the RHS.
http://www.woodworkforums.com/attachment.php?attachmentid=207607&stc=1&d=1336307227
The large slots cut in the RHS are so that the grinders (which all have an 8 mm thick steel base plate bolted to them and a 200 mm long 5/8" all thread rod welded to the underneath of the middle of the baseplate) can be positioned more or less anywhere along the length of the arms, as will be shown later.

The grinders are locked into position using these chunky handles.
http://www.woodworkforums.com/attachment.php?attachmentid=207611&stc=1&d=1336307227
The round locking nuts (A and B) have been turned from 38 mm diam steel rod. The handles attached to the locking nuts are turned from 12 mm rod.
I made several locking nuts like type A before I realized that the relatively shallow angle of the handle whilst easy to rotate made it difficult to push the grinder on its base plate out of the way up against the turntable. I have since made two locking nuts like B which work a lot better. Handle C is the turntable locking handle. This swivel type handle, even though it is relatively short, works really well.

Here is what it looks like from underneath.
http://www.woodworkforums.com/attachment.php?attachmentid=207614&stc=1&d=1336307227
http://www.woodworkforums.com/attachment.php?attachmentid=207615&stc=1&d=1336307227
The 4 bolts that hold the turntable base to the pedestal are long enough so that double nuts can be employed to raise and level the turntable after the pedestal has been bolted to the floor. I will use these once I bolt it down.

As well as moving the grinders in out out from the turntable, the grinders can also be rotated on their baseplate like this.
http://www.woodworkforums.com/attachment.php?attachmentid=207612&stc=1&d=1336307227
This provides for much better access than even is possible with a single grinder up against a wall - this feature is especially useful for things like the buff. This works really well.

Finally a view from above.
http://www.woodworkforums.com/attachment.php?attachmentid=207610&stc=1&d=1336307227
Once I get that old bench frame behind the pedestal out of the way I will be able to push the whole thing back some 350 mm so it will take up relatively little space up against a wall.

Still to sort out are a coolant tray/tank and the power cables . One has to remember to make sure a cable is not draped in the wrong place or the rotation of the turntable might guillotine it.

I will use it like this for the time being and iron out any bugs and then I will take it apart and pretty it up a bit. Meanwhile I have been using it all weekend and I love it already. The thing is so heavy that even though it is not yet bolted to the floor it is moderately smooth and already much better than any of my previous arrangements.

Making this has been a real learning exercise for me. I have not welded 20 mm steel plate before and making metal things fit on a slightly larger scale than I usually do has not been as forgiving as I thought it would be.

[jhovel]

sorry mate, but only your first photo is visible... something gone astray. You should be able to edit the message and add the missing photos.
Joe

[Graziano]

Cool!, so what I thought was a novel idea has already been done before. There was a guy on Practical machinist with a fixed version of what you've built, but made I think after your proposal. What I'm building was based off his version with added rotation.

[BobL]

sorry mate, but only your first photo is visible... something gone astray. You should be able to edit the message and add the missing photos.
Joe

That's funny because it was working for me but I went in and reloaded them again and hopefully that will work.

Cheers
Bob

[jhovel]

Working fine now, except the second photo.... maybe too big a file?
Anyway, very nice design and very nicely implemented!
Looks very useful.
Cheers,
Joe

[BobL]

Working fine now, except the second photo.... maybe too big a file?
Anyway, very nice design and very nicely implemented!
Looks very useful.
Cheers,
Joe

Thanks Joe.
I worked it out - I already loaded 10 pics - anyway here is that 11th pic.
Nothing special about it that cannot be seen in the other pics.
http://www.woodworkforums.com/attachment.php?attachmentid=207622&stc=1&d=1336308525

I guess I should also acknowledge WA forum member Franklin for supplying the central bearing.
Cost was $40 for the steel, ~$20 worth of fastenings and $29 for the roller bearings.

[NCArcher]

All working fine for me.
Nice work Bob. :2tsup: I'm assuming a dangly powerpoint over the middle of the Trigrind-rotator 3000

[BobL]

. . . .I'm assuming a dangly powerpoint over the middle of the Trigrind-rotator 3000

Yep - Franklin has suggest that as well and it seems to be the way to go.

I like the name you have proposed but was thinking T3, Trigrind, Turntable, Thing-eh-me-bob. ?:D

[NCArcher]

Or even the T³ :U

[issatree]

Hi Joe,
I can see the 19 Photos.

[Dave J]

Hi Bob,
Really well thought out and a great job,:2tsup::2tsup: That is going to make life a lot easier having them all in one spot.
I am trying to work out something for all mine, and might use some of your ideas.

Dave

[Johncs]

Yep - Franklin has suggest that as well and it seems to be the way to go.

I like the name you have proposed but was thinking T3, Trigrind, Turntable, Thing-eh-me-bob. ?:D


Triple Grind sounds like a coffee, so TripleGrind Rotator.

Append Mark I, Mark II etc when and if needed.