lathe problems

[BrokenBiker]

right, granted it has taken me a while since collecting the RandA lathe from cyberprog, but I am now in a position to get it going properly, however ive run into problems.

I have had it running using the old belts, but they are now too far gone to be repaired. I bought new belts when I got the lathe but have only just put them on. its 3 ply flat belt, the same dimensions as the original leather, joined with alligator lacing strips.

now to the problem. if there is any slack at all the motor slips on its belt and the belt starts to burn, the belts have to be seriously tight and if I tension the belts enough that they will spin the chuck, no matter what pulley configuration I use, or back gear, the whole machine vibrates like a cement mixer, and then as soon as I try and put a cut on the chuck stalls and the belts slip again. even on a 2 thou cut on brass.

I am getting really frustrated with this, the machine is mounted on a very heavy wooden table, its more of a job to move the table than it is to move the shed, yet this lathe shakes and rattles it to the point where it moves across the floor.

I have checked all bearings and bushes and everything is like new apart from the grease, which was removed and then replaced with very good quality chain and gear wax.

with the old belts it was ok, I never tried doing any serious turning with it but it did cut and was stable and quiet.

any ideas in what is going wrong here, id like to get it sorted as it looks to be a good little lathe providing I can stop it trying to pull itself off the bench

 

[MattF]

Belt type and photo's of setup? Flat belts should never be really tight as such. The grip comes from the surface more than the tension, as with V belts.

 

[BrokenBiker]

cant upload photos, my phone wont let me. the belt isn't leather, its a 3 ply rubbery type belt. if the belts aren't as tight as they can be the motor will just slip straight away

at the moment the motor is behind the lathe, mounted to the table, the motor feeds a shaft with 3 pulleys on it which in turn feed the lathe with opposing pulleys on it. does it matter that due to the rotation direction of the motor the belt is effectively being pushed away from the motor as opposed to being pulled towards it?

 

[Paul99]

I'll be watching this thread with interest as I've had a very similar experience with my old lathe. Spent hours messing / adjusting bearings which has improved things a little and it is at least usable with light cuts but it's still no where near right. I'm sure for someone who knows what they are doing it would be an easy fix and would make a cracking lathe once sorted but I've got to the point that should a more modern small lathe come up at the right price I'd simply upgrade and sell the old one on as is.

 

[BrokenBiker]

well I have checked all the bearings and bushes, spindle bearing are like brand new, no play in them and turn freely, spindle is straight, there are some bronze bushes that have no visible wear on them and are a good fit for the shaft they are on, the motor spins silently and no vibration when it isn't connected to a belt, even with load put in the shaft (my boot), but when it is connected up all hell breaks loose

 

[slim_boy_fat]

If it worked well with the old belt [leather?] but is vibrating with the new one, that suggests that it's got to be related to the belt change. Where did you source the new belt? Is it the balata type? I'm currently running my RandA with a balata one which I had to cut in half [depth-wise] to get it flexible enough to move over the pulley curves well. I think my surgery wasn't accurate enough as it tends to wander on the pulleys, probably because it's not completely regular in section , but I have plenty of belt left to have another go. I'll probably end up getting one of the thin flat Betalon belts from http://store.lathes.co.uk/belts/betalon-multiply. That apart, it runs smoothly enough. My pal has the cross-slide at his place atm as there was play in some threads and he's making new ones to fit.

I did manage to turn some brass and steel before we removed the bits though.

 

[brightspark]

u can get belt dressing for it but only use certain types suitable for leather not just the general purpose stuff for rubber belts . heres one http://www.averyknight.co.uk/itemlist.php/clashist/-1,279,284/findclas/284/findchil/1 its a bit of a minefield if u use the wrong stuff and wont do the belt any favour so do some research on it ist

 

[Fintray]

Try something like this perhaps:
SB1-500B Belt Dress. ign Spray 500ML
SOL-732-0060K
500ml aerosol.
Solent Belt Dressing rapidly restores grip to flexible belts. Use on fabric / rubber driving belts. Belts operating in exterior conditions. Always stop belt before application. Stops belt slippage. Solent Belt Dressing film increases adhesion between belt and pulley, reducing slipping, glazing, overheating and drying out of belts.

Always test on scrap rubber or plastic belts to ensure suitability before general application. Ensure adequate ventilation during application. Shake can well before application. Effective in damp conditions.
UN1950

Pale white colour
Solvent
Not soluble
43 degrees Celsius applies to product before aerosol packing -50 ̊C to 80 ̊C

SB1-500B BELT DRESSING SP.RAY 500ML

TECHNICAL BULLETIN

Information contained in this publication or as otherwise supplied to users is believed to be accurate and is given in good faith, but it is for the Users to satisfy themselves of the suitability of the product for their own particular purpose.
We give no warranty as to the fitness of the product for any particular purpose and any implied warranty or condition (statutory or otherwise) is excluded.

Manufacturer Identification

Telephone
Fax
E-Mail (competent person)

Emergency telephone number

Solent, Osbourne Works, Wigston, Leicester, ENGLAND, LE18 2FS

0116 288 8000 0116 288 8222

Action Can Ltd.,
Dixon Close,
Old Boston Trading Estate, Haydock, St. Helens, Merseyside. Wa11 9SF. 01942 713667
01942 716235 info@actioncan.com

01942 713667 (Mon – Fri: 9am to 5pm)

 

[Paul99]

Have you put a dial gauge on the spindle and seen if there is movement in the spindle bearings when yanking up and down on it with a bar? my bearings look to be in decent condition too but they needed major adjustment - I failed to get them spot on after hours of messing but certainly improved it which reduced chatter a little.

As for drive issues I think a lot of mine comes down to the bodged up counter shaft that it came with and the way I set it up. It's too weedy and bends / flexes under pressure too easily which has the effect of loosening the other drive belt to the motor. I really need to spend more time working on it but with several other more important projects on the go its going to have to keep for a while.

 

[BrokenBiker]

If it worked well with the old belt [leather?] but is vibrating with the new one, that suggests that it's got to be related to the belt change. Where did you source the new belt? Is it the balata type? I'm currently running my RandA with a balata one which I had to cut in half [depth-wise] to get it flexible enough to move over the pulley curves well. I think my surgery wasn't accurate enough as it tends to wander on the pulleys, probably because it's not completely regular in section , but I have plenty of belt left to have another go. I'll probably end up getting one of the thin flat Betalon belts from http://store.lathes.co.uk/belts/betalon-multiply. That apart, it runs smoothly enough. My pal has the cross-slide at his place atm as there was play in some threads and he's making new ones to fit.

I did manage to turn some brass and steel before we removed the bits though.

yes its a balata belt, but its plenty flexible enough. do you have a pic of your lathe?

Have you put a dial gauge on the spindle and seen if there is movement in the spindle bearings when yanking up and down on it with a bar? my bearings look to be in decent condition too but they needed major adjustment - I failed to get them spot on after hours of messing but certainly improved it which reduced chatter a little.

As for drive issues I think a lot of mine comes down to the bodged up counter shaft that it came with and the way I set it up. It's too weedy and bends / flexes under pressure too easily which has the effect of loosening the other drive belt to the motor. I really need to spend more time working on it but with several other more important projects on the go its going to have to keep for a while.

have had a dti on the spindle, each of the pulleys, the chuck, the face plate, the backing plates, there is less than 3 microns variation at worst. I can live with 3 microns as my cheap little chester had 0.01 and that worked fine, however that was gear driven and not belt driven.

 

[Wendelspanswick]

Do you have a Toolstation near you as they sell Belt Dressing in an aerosol can. I used to use it on the flat belt on my tractor driven saw bench before I converted it to PTO drive and it worked a treat.

 

[BrokenBiker]

i can get belt dressing in work, but i don't think that will help. I have just removed everything except the motor and 1 belt, got it going with a normal amount of tension and it still rattled and vibrated.

 

[slim_boy_fat]

yes its a balata belt, but its plenty flexible enough. do you have a pic of your lathe?.......

Here she is, as said compound slide is off for the moment, but this is when I brought her home first

 

[BrokenBiker]

that is the lathe i have but the next model down, i don't have compound slide and a slightly different pulley system. Same overall lathe though

 

[MattF]

Get your hands on an old timing belt or leather belt, slightly longer than needed, and cut and glue as a temporary test. I'd bank on it being the Balata belt. It's bloody nasty stuff, IMHO. I have a length of the stuff outside and it's not a shade on leather. The direction of rotation should have the belt pulling away from the top of the lathes pulley towards the drive pulley, if you're using a short run. You're trying to maintain some tension. Feeding it to the lathes pulley would be rucking it. If you had a long run it would be different, as belt sag would act as a damper and add grip, but with a short run you definitely want to be pulling. Other way is to fit a tensioner which will push down on the belt slightly, so that you're not introducing too much straight sidewards load onto the headstock.

Best option would be to have the countershaft underneath the bench on a pivot assembly, so that the weight of the motor alone is applying tension, and all force is downwards. I'd definitely ditch that Balata belt and try some proper stuff first though. Too much tension will lead to oval bearings down the line.


p.s: I think the above is correct, but may have confused myself somewhat. The whole flat belt thing can be counter-intuitive on occasion, so quite easy to go astray.

 

[graffian]

I used to drip Sodastream concentrate, a few drips, onto the pulley when it was in use and the belt would stick to the pulley like sh1t to a blanket. I used sodasteam concentrate as I bought a car with loads of bottles of it in the boot. So to give dressing a try, before you buy, give some sugary stuff a try.

 

[BrokenBiker]

well i got it running late last night, however it was simply the motor powering the spindle.

i have decided to replace the pivoting bushes on the counter shaft mounts with bearings to remove any play there as i think that was causing a lot of the issues.

so that is the job for later when i get home from work and see if it makes any difference

 

[MattF]

i have decided to replace the pivoting bushes on the counter shaft mounts with bearings to remove any play there as i think that was causing a lot of the issues.

Before you do owt with it, post a photo. Some things are meant to pivot somewhat. If they are original and manufacturer made, they're unlikely to be your problem.

 

[BrokenBiker]

cant upload photos, my phone wont let me and my laptop is dead. I rigged it up in the bearings clamped to some wood and it made it much better and running it without the counter shaft it runs better. As soon as i put the counter shaft back with its original mounts is terrible again

 

[MattF]

Are there any photo's in that thread of Cyberprog's, (it was he whom you got it from?)? If they're the old Babbitt type bearing hangers, don't risk knackering them by trying to jury rig them. Those things are hard enough to get hold of these days as is. It's easy enough to build an alternative countershaft unit.