Fix the Lathe i got

[Calm]

Hi, i was thinking last week about purchasing the lathe on Ebay worth over $6,000. In the end i spent too much on a thicknesser and motorbike so had to put my "wants" on hold.

Today i thought why replace it and not fix it up a bit.

What dont i like about the lathe i got. It has a good solid bed and is soundly bolted to the floor. The rest is ok and i need a shorter one - DJ can help me out there when i give him the dimensions. It can do a 380mm bowl over the bed or the head will rotate to the side for larger bowls.

The tailstock is sloppy on the bed but hasn't stopped me doing what i want - i could always build it up to take the slop out - just reduce the clearances would do that.

What dont i like - the slowest speed is 500 rpm and DJ tells me there is not enough tourque to use a Bowl Saver.

66603

$785 from Jim and i think that will give me slower speed and more torque as well.

What do the Experts think of that. The current motor has a 9/16" shaft (i think). The new motor has a 16 mm so i could bore out the pulley for that and still have the 10 speed positions that come with the original motor as well as the variable speed. Saves me heaps and gets me closer to the lathe i want. Some more photos to help the advice. I turned the motor to the side to take some of them.[
66605

66606

66607

66608

[artme]

I'd take Jim's advice on that motor.
As for the pulley, donnt just drill it out. You are likely to get off centre and bugger things up.
It may be less expensive tobuy a new pulley with correct size hole.

[DJ’s Timber]

I'd be incline to get rid of the reeves pulley system all together and put in a stepped pulley setup. The current pulley setup up is the reason for the lost of torque not the motor. But with Jim's motor and and stepped pulley it will do all you need.

[hughie]

One aspect to consider is that your using a MC900 or 1100 so the motor shaft is a special. That is its extra long, around 100mm so your new motor may not fit the reeves system that you already have.

That leaves you with the suggestion of stepped pulleys, with that you may have to cut into the cast housing a so as to get you stepped pulley on and be able to changes the belt.

If going to do some mods also look at securing the headstock a bit better to prevent it moving with large out of balance blanks. Once you have running better this will be the next hassle you will have.

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=31145

hmmm cant find my pics to show the mods to the case for my stepped pulley arrangment

[Big Shed]

David, that seems a lot of money to spend on what is a basic lathe (I know I have one).

By the time you will have done the mods required I can't see you having much change out of a $1000, and you will have over capitalised your lathe. You'd never get anywhere near your money back.

Bit like spending $100k on renovating a house that cost you $200k and will never fetch more than $250k.

[killerbeast]

David, that seems a lot of money to spend on what is a basic lathe (I know I have one).

By the time you will have done the mods required I can't see you having much change out of a $1000, and you will have over capitalised your lathe. You'd never get anywhere near your money back.

Bit like spending $100k on renovating a house that cost you $200k and will never fetch more than $250k.

I think the mod looks great, but kind of agree mostly because i have already been thinking about doing mods on my own, and did the calc (sorry i think in dk) lathe 2200. mods cost min-3-4000dk + god knows how many hours. . . total end cost 6200dk... and still with the limitations of a cheap lathe.....

Cost of large lathe deliverd on my dorsteep : jet 1642 around 14500,- or the danish build promat. 17.000...

I love to read about all the mods you guys make thou :-) i wish i had the time to make them myself.......

[Calm]

One aspect to consider is that your using a MC900 or 1100 so the motor shaft is a special. That is its extra long, around 100mm so your new motor may not fit the reeves system that you already have.

That leaves you with the suggestion of stepped pulleys, with that you may have to cut into the cast housing a so as to get you stepped pulley on and be able to changes the belt.

If going to do some mods also look at securing the headstock a bit better to prevent it moving with large out of balance blanks. Once you have running better this will be the next hassle you will have.

Thanks for your opinions, first I realise that i am spending $1000 on a $400 lathe but to replace it would be $4000 to $6500 or as we saw on Upay the other day $3500 for a secondhand one. So i can afford to do this and that will fix the only things i dont like about the one i have.

Hughie i will take on board your "bolt down" idea but hopefully if i slow it down the out of balance should not be as bad.

The new motor revs from 500 to 1700 RPM so to get 130 to 2975 i need ratios of 3.84:1 up to 1:1.75 motor to lathe. I can go up to a 115mm pulley on the lathe and still have 12mm to get the belt off, a motor pulley of 30 mm will give me a slow speed of 130RPM. A lathe pulley of 40 mm to a motor pulley of 70mm will give me 1.75:1 or 2975rpm on the lathe. To get down to 100 rpm i need a 23mm on the motor and probably cant get one that small.

Mounting the motor will be by a home made bracket that bolts on to the existing 3 bolt holes with provision for tension adjustment.

Hopefully there wont need to be any work on the existing housing, a mate (engineer) with a metal lathe and mig will come in very handy for the conversion. A trip to Bearing service will sound out the options for pulleys, unless we turn them ourselves.

WHat are the thoughts on this so far.

[Jim Carroll]

Another option on belts and pulleys is to get the flat poly vee belt and pulleys.
This way you can get smaller pulleys, more room for pulleys, more positive drive than a vee belt.

[Big Shed]

That's a good suggestion Jim. My tablesaw uses this poly V belt and pulleys, supposed to give better power transmission and they are certainly quieter.

[robyn2839]

Another option on belts and pulleys is to get the flat poly vee belt and pulleys.
This way you can get smaller pulleys, more room for pulleys, more positive drive than a vee belt.

hi jim is a flat v pulley like they have on the nova 3000?.bob..

[Frank&Earnest]

I concur with the previous comments about cost/benefit. If you really want to play around with mods and are confident about what you are doing, IMHO you would be better off searching around for a second hand motor and speed control. If you are totally satisfied with the results, wonderful, otherwise you have gained valuable experience and wasted only a couple of hundred dollars.

[robyn2839]

[quote=Frank&Earnest;678298]I concur with the previous comments about cost/benefit. If you really want to play around with mods and are confident about what you are doing, IMHO you would be better off searching around for a second hand motor and speed control. If you are totally satisfied with the results, wonderful, otherwise you have gained valuable experience and wasted only a couple of hundred dollars.[/quote

if you find a second hand motor and speed controller ring me i have been searching for one (they are non existent i think. but at the end of the day i think i agree with frank and others in thinking you should maybe replace it rather throwing money at it, with the price you would spend on motor plus what you could sell yours for your half way there, bob

[Jim Carroll]

Yes bob that is the style prefered.
The belt and pulley are wide so you get a larger drive surface and a lot less loss of power compared to the V pulley style.
You dont need a lot of tension on these belts either, just the weight of the motor is enough. Not like the old V bels where you had to lever the motor to get more tension.

[TTIT]

Might as well throw in my 2 bobs worth :shrug:. For what you're going to spend on these mods David, you could have yourself a brand new, Aussie made, good quality lathe by grabbing a Leady. I know doing all the mods yourself is half the fun, but at the end of the day, it's still going to be an MC with all it's associated grief. It might be different if you were able to pick up a lot of the bits and pieces on the cheap (ie: for nix!) but if it's going to cost about $1000, the Leady isn't that much more.

[Calm]

Thanks again for the opinions, I take them all on board. Vern i had a quick look at the Leady lathe and its speed was 400 to 3000 in 5 steps. I think i would really like to get slower than 400 if i can. Jim I think i know the belts you are talking about and i agree that is definetly the way to go.

I went around to my engineer mates place last night and he made a very good point that hadnt dawned on me. Try the bowlsaver first and see if it works before you change the lathe. I intend to buy one anyway, i dont like the idea of throwing good wood out the door as chips if i can get something out of it.

Jim email is on the way for a bowlsaver this week and i will try that first. As he said the Bowlsaver was the instigator of this project so i should try it first on the lathe as is.

Next one for the electricians out there he mentioned buying a reco 3 phase motor about $100 wiring it 240 volt single phase and using it with some computer type gismo that gives variable speed. (they use these at his work and there might be a "cheap" one around) Apparently it can go from about 300 or 400 up to 200% of its speed so a 2 stepo pulley would do the job. Havent got my head around this yet and will definitely followup.

Keep the ideas coming it is good to get a lot of opinions before i make any changes. Ern might feel sorry for me and offer to swap the "STUBBY" :rolleyes::rolleyes::U

[rsser]

Ahem :rolleyes:. Happy to swap advice ...

Bear in mind bowlsavers have to be set at the right height so may well not be interchangeable btwn lathes.

Eg. with the Woodcut you have to specify the post height to suit your lathe, and with the McNaughton the post and gate take up a bit of height so won't fit eg. the VM175 (leastways last time I looked).

[robyn2839]

why not something like this ? big motor 8 speed, slowest 270, 16'' swing, rotate head 28'' bowl, under a grand.and a good lathe, also upgradeable to the variable speed at a later date bolt on bolt off . bob

[artme]

Jim's pulley and belt suggestion is the way to go. You apparently get better transfer of power thi way, apart from other benefits already mentioned.

[Big Shed]

David, how is this project progressing?

Or have you given up on the idea of upgrading your existing lathe with the variable speed motor?

[Calm]

David, how is this project progressing?

Or have you given up on the idea of upgrading your existing lathe with the variable speed motor?

We decided to try and work with what i have first to see if it will work before i change motors etc.

The Bowl Saver turned up (thanks Jim) and i tried it on a peice or Cypress 400 mm across. 1st problem was the post supplied was only going into the Tool post banjo about 10mm max so i had to be carefull. (anyone ordering one needs to give height from top of tool post holder (banjo) to centre in tailstock as well as diameter of tool post) As my lathe tool post is 25mm the longest one supplied is 110mm so i am getting a new one made 20mm longer (freeby from a mate)

I took a 5" bowl out of the centre of the cypress and it worked ok but the belt did slip a bit. I pulled the cover off the belts and found the spring loaded pulley on the motor just open up under load and let the belt come loose, hence no drive. My engineer mate is making a collar that will go on between the pulley and the spring with a grubscrew in it and i will tighten that up to overcome that problem.

Hopefully early next week the lathe will be going again so i can have a go at taking out a larger bowl with the bowlsaver.

It will be at Ern's if he can get it going for the turnfest. I will probably take it down a couple of weeks before hand so he can "play" and set it up.

Thanks for the interest and i will get some photos next time its going to add to the update.

[Big Shed]

Thanks Dave:2tsup:

[Skew ChiDAMN!!]

FWIW, I'll go against the flow here... I reckon "go for it." I've toyed around with the idea several times myself.

Sure, the motor and var speed is an exxy bit of kit but if you carefully and properly adapt any new pulley to fit the existing shaft - not the other way around - and put the existing pulley setup and motor in storage, then you can always "revert" the lathe to stock condition and move the new motor/pulleys to another lathe.

So, really, all you have to lose is your - and your mate's - time.

It's easy to say "spend more and buy a better lathe instead" but where's the fun in that? Or the educational moments when you discover "well, that doesn't work" and why? :U

[Calm]

In the last post i stated that the Bowlsaver caused belt slip therefore i couldn't use it.

Well a $2 part has changed the lathe from no torque (caused by belt slip) to as much as the bowlsaver required.

Before when the pressure came on the pulley on the motor just opened up a bit more on the spring and the belt came loose. Originally i was going to fit a collar on the pulley with a grub screw to lock the pulley in place but at 3.30 am when i couldnt sleep i came up with the solution.

As the first photo shows on the slowest speed the belt is almost at the bottom and the pulley is opened as wide as it ever should be. The spring is not fully compressed and there was enough movement to allow the pulley to open a bit more and loosen the belt. ( the spring on the motor pulley is the only thing that keeps the belt tight. What we did was machine a spacer that goes inside the spring and at the slowest speed it prevents the pulley opening any more. Being an old Gokart racer we found a spacer off the front wheel was 16.5mm inside diameter, fitted inside the spring and had to machine it from 20mm long to 17mm. The keyway goes full length so i ground the last 17mm down level with the shaft to allow the spacer to sit there.

At a higher speed it just sits there but when you go to the slowest speed the spacer prevents the pulley opening further keeping the belt tight and it has totally eliminated any slip at all.

The only thing i havent done is acheived a slower speed but i wont worry about that for now. We also made a longer post for the bowlsaver.

The bowl saver worked really well on the cypress 400mm diameter and took no time to remove the second bowl. The first one i did with the belt slipping.

Next problem is how do i hold the "cutouts" to finish them. I can only think of a longworth or donut chuck and make a tenon on the bottom to fit the sn2 chuck.

If you cant understand this i will pull the thing to bits and take photos so others can do the same thing if they want to.

[Groggy]

I like simple and cheap fixes :2tsup:

[rsser]

Jim, how'd you reckon we'd go fitting David's unit - 25mm post - to the Stubby for demo purposes - the Stubby banjo post hole is 1". It has scope for two fixing bolts at 90 degrees to each other.

Would they be enough to hold the post do you think, to reduce slop to acceptable proportions?

I've not tried anything like this but would imagine the key thing would be to keep the cutting tip at the centre line so keeping droop to the min. would be important.

Added: btw, the Stubby swing with bed in place is 250mm.

[rsser]

David,

Re your last qtn ... how would this work? ...

1. Reverse the cored out piece and as best you can centre it back into the blank. Bring up the tailstock and cut a tenon. The resulting rough bowl will still need its foot cleaned up.

or

2. With the first cored out piece out of the way, cut a groove in the inside of the remaining mounted blank to expand your chuck into. When all coring is finished, mount each blank with the chuck expanded into the groove and do your stuff with the foot and shape the outside; when reversed it can then be held either in clamp or expansion mode depending on how you did the foot treatment.

Make sense?

[Calm]

Next problem is how do i hold the "cutouts" to finish them. I can only think of a longworth or donut chuck and make a tenon on the bottom to fit the sn2 chuck.

Ern,

probably should start a new tread for the BOwlsaver but i might save that for you to do after you have a go with it.

I like your idea to hold the cutouts but i am going ou to the shed and run one over the jointer and use a hot glue gun and block to finish it. I wont be using 3000 rpm like FC (cos my lathe only does 2000:D:D). No i think gently gently will do.:D

Added:- the jointer idea didn't work so i used the longworth chuck and hot glue gun to turn the bowl, then used the longworth again to finish the bottom off. Good result - sorry no pictures

[hughie]

how'd you reckon we'd go fitting David's unit - 25mm post - to the Stubby for demo purposes - the Stubby banjo post hole is 1". It has scope for two fixing bolts at 90 degrees to each other.
Would they be enough to hold the post do you think, to reduce slop to acceptable proportions?


Ern the two screws at 90' should hold ok. The variance between the two is not great, .4mm. I guess how far the post sinks in to the Stubby banjo would be the deciding issue.



I've not tried anything like this but would imagine the key thing would be to keep the cutting tip at the centre line so keeping droop to the min. would be important.


The droop could be catered for in the initial set up, slightly under centre ie .5mm to maybe 1.0mm would not be a major problem especially if its feed rate is fairly sedate .As long as the work is secure so as to prevent it climbing up the tool.

David, I think your right re the bowl saver thread

[rsser]

Thanks Hughie.

David, what's your centre height? And post length?

[Calm]

Thanks Hughie.

David, what's your centre height? And post length?

Ern

the post supplied is 110 mm and on my lathe the distance from top of the tool post banjo to centre is 140mm and the post goes into the tool post about 10 mm

Your tool post to centre height is 95 mm so 140-95 = 45 plus the 10 mm it goes into my holder means you should have is 55 mm into the holder. I will bring the new one as well which is 20 mm longer so one of them will definitely do the job.

If the short one is too long it can be shortened as it is no good for my lathe.

[rsser]

David,

The Stubby centre height is 255mm, the banjo top is 160mm above the ways, and the post would need to go in at least 40mm.

[Calm]

I am reviving the thread where i discussed the options of improving the lathe i already had. Thsi is the work done whle i was in Queensland.

The first photos are the process of making the plate to carry the motor and the pulleys a freind turned up for me.

The motor is a 3 phase as required for VSD 1440 rpm 50hz

The last few are of the belt adjuster that we designed to change the belts without anything to undo.

The pulleys are 40mm -125 mm, and 95mm - 75mm The centres distance was calculated at 200mm meaning the polyvee belt is the same length for both low and high speeds. (660mm) # 260J8

The VSD is set variable from 25hz to 100hz.

[hughie]

Next one for the electricians out there he mentioned buying a reco 3 phase motor about $100 wiring it 240 volt single phase and using it with some computer type gismo that gives variable speed. (they use these at his work and there might be a "cheap" one around) Apparently it can go from about 300 or 400 up to 200% of its speed so a 2 stepo pulley would do the job. Havent got my head around this yet and will definitely followup.



Calm, This is the way I went on my MC1100. It was not expensive in the end and well worth it. :2tsup:

[Calm]

The final photos are the control box mounted at the tailstock end and the finished lathe.

The control box is mounted there so the E stop can be hit without having to go past the rotating work. i elected not to fit a seperate/portable E stop box as when the button is released the lathe would then start again whereas this way uses the original button supplied with the lathe.

There is still a tidy up to do with the cable from the box to the motor (clip to lathe bed), which is sheilded cable to help reduce any interference with neighbours tele's.

COST well this is hard to calculate but cash - Motor $149, aluminum for pulleys $155, Plastic box for VSD $55, belt not sure but about $55 for 2 (1 spare) and postage to Queensland, the rest was "aquired"/donated or whatever phrase you wish to use.

Cheers

[DJ’s Timber]

Looks like a very good mod Dave, you must be happy with that.

So that should mean you'll no longer covet my lathe :U

[Calm]

Looks like a very good mod Dave, you must be happy with that.

So that should mean you'll no longer covet my lathe :U

Thanks DJ:2tsup: it was a very interesting job - still a couple of things to change to improve.

One question for the Gurus - What speeds/Hz's can the VSD be set too?

A stop gap measure until a VL300 comes on the market - dont sleep toooooooo soundly yet DJ:D:D:D

Then again to catch Cliff i need to start collecting some more lathes.:D:2tsup:

[DJ’s Timber]

Going by the latest shots, it looks like you're back home, is this correct?

[weisyboy]

looks good:2tsup:

should have plenty of talk now.:U

[Calm]

Going by the latest shots, it looks like you're back home, is this correct?

Yep got home Monday night about 8.30, been too busy to put the photos up - only painted the lathe today so it's still wet.


looks good:2tsup:

should have plenty of talk now.:U

I did a bowl about 12 inches diameter in Queensland with the lathe G clamped to a bench and was peeling off curlies the full width of the wing on a 1/2 inch bowl gouge - It was green Silky oak but still a good test to cut more than 1./2 deep in one cut. It only pulls 2 or 3 amps max and i threw the reset once (on high speed) and then it only drew 4.7 amps. The motor is a 1500 3 phase

Appears to be a very sucessful job.

Thanks & cheers

[Grumpy John]

David, I sent you a PM with my pulley setup.

[Calm]

David, I sent you a PM with my pulley setup.

Yep i got it, just need time to calculate what yours is doing - whast is the speed range in low and high please.

I have had to sdo a fair bit of "farm" work and appointments over the last few days and hopefully tomorrow will finish that and let me get some "real" stuff done.

Trying to organise time to get to Melb Saturday so hopefully will see you there.

Cheers

[Ed Reiss]

I am reviving the thread where i discussed the options of improving the lathe i already had. Thsi is the work done whle i was in Queensland.

The first photos are the process of making the plate to carry the motor and the pulleys a freind turned up for me.

The motor is a 3 phase as required for VSD 1440 rpm 50hz

The last few are of the belt adjuster that we designed to change the belts without anything to undo.

The pulleys are 40mm -125 mm, and 95mm - 75mm The centres distance was calculated at 200mm meaning the polyvee belt is the same length for both low and high speeds. (660mm) # 260J8

The VSD is set variable from 25hz to 100hz.

Nicely done David...it closely resembles the motor pulley/spindle pulley set-up in the Nova 1500. Of course the VSD gives you the speed adjustment advantage over changing the belt on step pulleys.

[Grumpy John]

..........
whast is the speed range in low and high please.
..........
Cheers

Sorry Dave, I forgot to include rev range. Low range 50 - 1262, High range 128 - 3252. I think I said the RPM of the motor was 1420, the spec plate was hard to read, it could have been 1440. :;

[TTIT]

Bloody ripper David - top looking mods :2tsup:. We'll see how long it is before you set up the remote :;

[Calm]

I am proposing to make a couple of alterations to the work done. As you can see in the photo/chart the high ratio is too high and i think i will get changes made to have the high range pulleys the other way around. (lower top speed and bigger overlap in speeds) - this will need the drive pulley recut smaller and the driven pulley machined down and a sleeve fitted over one side and then the pulley recut, there should be enough aluminum left from the original pulleys for this job.

The other change is the belt adjuster i am going to change the mount from the top of the headstock to the side it is on leaving the top of the headstock clear - this wont be any harder than drilling 2 holes and turning the bracket around.

Does anyone have any experience as to what ranges the VSD/3 phase motor can run at. As you notice in the chart mine is from 25 to 100 hz and the figures GJ gave me show 5 too 145 Hz

Thanks in advance

Cheers

[artme]

You din't waste any time after leaving Bris. Dave! I'm glad everything has come up trumps for you.

Can see people buying p MC900s and making better lathes! :U:U:U

[Paul39]

Here is a forum about VFDs I found most informative.

"http://www.practicalmachinist.com/vb/forumdisplay.php?f=11"

One caution I have read is that running the motor slowly with the VFD may make it overheat. A fan blowing on the outside of a sealed motor or a duct blowing air through an open motor is advised.

[Calm]

Here is a forum about VFDs I found most informative.

"http://www.practicalmachinist.com/vb/forumdisplay.php?f=11"

One caution I have read is that running the motor slowly with the VFD may make it overheat. A fan blowing on the outside of a sealed motor or a duct blowing air through an open motor is advised.

Thanks for that, i have now changed it to range from 15 to 120 Hz, I know that 15 is too slow but it will never turn at that speed for any length of time.

Cheers