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Poolewood Superlathe Belt Problem

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djansi

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Hello, I`m new to this forum and reasonably new to wood turning.
Also I`m no engineer, but believe I can understand basic mechanical problems, but just now I`m baffled !
Apologies for the long description, but it might avoid lots of questions if I go a bit into detail.

A couple of years ago I bought an old Poolewood 28-40 Superlathe, the mechanical variable speed version. From photos I`ve seen on the forum I believe mine has been altered or is not the standard set-up.
The ones I`ve seen have one wide belt which drives the shaft directly from the motor. However, as you can hopefully see in the photo, mine has three belts, one of which has been replaced with a "link" one.
I have used the lathe a lot over the last two years, and over the last month it got continually louder. I had heard of others having this problem before, but the only comments I read were that that seemingly happens with age.

Today while sanding the outside of a bowl the noise suddenly disappeared, and it went really quiet (nearly like a modern lathe :D ). At first I thought some problem had solved itself, but not so. Shortly after, a different noise appeared, but only when I put pressure on the sandpaper / bowl.
So I stopped the lathe and had a look inside. It appeared that all three belts didn`t feel tight at all.

The speed of the lathe should only be changed when the lathe is running, and I don`t think I accidentally ignored this. But even if, I can`t see how all belts would be slack.

There are four shafts over which the belts run. Let`s call the furthest away one A, the next, motor driven one B, the next one with the two pulley wheels C and the final head stock shaft D.
Shaft A and D are absolutely fixed and can`t be adjusted or moved.
Shaft B is attached directly to the motor, and can be adjusted by moving the motor back or forwards. The three bolts holding the motor were/are absolutely tight, and I`m 100% confident that the motor hasn`t moved. Also the motor is fixed in the position of nearly full stretch to the belt, but the belt is extremely slack.
Shaft C is the only movable one, which changes position when the speed wheel is turned.

So I could understand if the two belts running over shaft C were slack if I had made some mistake with the speed wheel , but the belt between shaft A and B is by far the slackest ! It`s a toothed belt, and I can easily move it about between the different "tooth marks" on the wheel. It doesn`t look damaged at all, just as if it was too long, which it obviously can`t be, as the lathe has worked perfectly until now.

As I said, I`m baffled, but there`s probably (hopefully !) an easy explanation and solution for this...
Especially as I need to finish three commissions before the end of the week !

If anyone could help with advice that would be much appreciated !!!

Many thanks,

Ansgar
 

CHJ

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Not had experience of that version of the drive but it sounds like the mechanism of the two sliding cone pulleys is out of kilter allowing them to stay apart and not closing.

Is there a loading spring involved ?
Has the either of the outer coned pulleys slipped (moved along its spindle) ? depends on the design and where the loading spring is, can't see enough detail in that small image.
 

Spence

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The inside of your lathe headstock looks much different to this one (https://www.ukworkshop.co.uk/forums/28-40-lathe-head-stock-rebuild-bearings-belt-etc-t24306.html) posted by another member, he states the same model as yourself. Perhaps a previous owner has modified it heavily as you think. It may make it difficult to source replacement parts if one of those pulleys has a fault and you may have to attempt a repair rather than replacing a part.

I have some experience with fixing reeves drive lathes like yours. I'd really like to see some footage of this lathe running with the cover off. I think the belt is slipping, this could be due to the pulley not coming together properly. This can be caused by wear or debris.
 

Phil Pascoe

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CHJ":38fzasyp said:
Not had experience of that version of the drive but it sounds like the mechanism of the two sliding cone pulleys is out of kilter allowing them to stay apart and not closing.
It looks to me as if the pulley on the spindle is fixed? If it is there'd be no purpose in the pair moving. :?
 

CHJ

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phil.p":1osqikja said:
CHJ":1osqikja said:
Not had experience of that version of the drive but it sounds like the mechanism of the two sliding cone pulleys is out of kilter allowing them to stay apart and not closing.
It looks to me as if the pulley on the spindle is fixed? If it is there'd be no purpose in the pair moving. :?
It looks to me that in that version of the lathe it has a normal speed motor instead of the six pole slow speed version and that the there is a swivelling counter shaft fitted containing two of the 'Reeves' stile coned pulleys.

I suspect both, or one, of the coned pairs is not closing for some reason when (if?) the pulley centres are adjusted.
 

djansi

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Hi again, thank you for all your replies !
Looks like this one is quite different from the "standard" version. I do suspect someone changed the original one-belt set-up to this one, for whatever reason.
Last night I literally couldn`t sleep as it really bothered me that I didn`t understand how the belt between shaft A and B could be loose, so I went back into the workshop after midnight, and had another look.
Eureka ! Looking from a certain angle I noticed that shaft A did look as if it was not in line inside and outside of the head stock. I noticed two little grub screws, and when I checked them one was completely loose, the other not very tight either. First I thought there was a bearing inside which had broken, but the whole shaft is actually eccentric (spelling ?), and via the square shaft end, which you can see to the right of the orange belt, one can adjust the tension of the belt.
So now the lathe works fine again, but is still extremely noisy.
I`m not familiar with technical "lathe" terms, but I will try to answer some questions. There is no loading spring and the two coned pulleys in the middle run free on the shaft, they are not attached to it.
I don`t know what a reeves drive lathe is I`m afraid ?
Apologies, as you have probably guessed already, English is not my first language :)
Again, thank you everybody for your suggestions, I hope the lathe will last a little bit longer.
Maybe she was just jealous as I had just bought another lathe ( an Axminster AW1416VS) about two hours before this one started playing up !
I don`t know if it`s ok to ask this on this forum, if not please delete. But if anybody has any spare parts or accessories for this lathe for sale please get in touch. Also any accessories with a 1 1/2 x 6 tpi thread I would be interested in.
Many thanks, Ansgar
 

CHJ

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Glad you have managed to fix the basic problem Ansgar

If the lathe is sounding noisier than previously I suggest you try and investigate which part of the drive is causing it and see if you can cure it, it may be that whatever is causing the noise is why the grub screws worked loose in the first place.

djansi":3sda5ip5 said:
…... I do suspect someone changed the original one-belt set-up to this one, for whatever reason.
There are several incarnations of the Poolwood lathe which changed the drive mechanism.

Also the thread standard of the spindle could be 1-1/2" X 6 TPI Whitworth (55 deg) or 1/2" X 6 TPI UNC (60deg) . You need to check before you obtain any other chucks etc.

The two versions of the lathe that I had were different thread forms.

djansi":3sda5ip5 said:

I don`t know what a reeves drive lathe is I`m afraid ?
A basic Reeves drive consists of a spring loaded split Vee pulley on the motor and a mechanically adjusted (width) pulley on the output shaft, as show here:


As you vary the width of the gap on the output pulley, the motor pulley either closes or opens against the spring pressure to accommodate the belt and remove any slack, this of course changes the relative gearing between the two pulleys.

On your lathe I suspect that by adjusting the position of the counter shaft you are moving one belt to the top of one pulley whilst moving the other to the bottom of the adjacent pulley, thus changing the gearing.
 

djansi

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Thank you for the info CHJ.

I was told that others had this noise problem with similar lathes, and apparently it`s the pulleys` wear and tear where they sit on the shaft. The metal (aluminium ?) the pulleys are made of seems to be softer than the shaft, so they will have a small amount of slack after a certain amount or running hours. But I`ll have a look at the weekend if I can locate where the noise comes from exactly.

I must have been lucky so far with the thread size, as I have bought a scroll chuck with insert, a collet chuck and a faceplate, and they all fit my lathe. They were all just advertised as 1 1/2 x 6 tpi, and I didn`t know there are two types of these !

Thanks again, Ansgar
 

CHJ

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djansi":ma25ehty said:
I must have been lucky so far with the thread size, as I have bought a scroll chuck with insert, a collet chuck and a faceplate, and they all fit my lathe. They were all just advertised as 1 1/2 x 6 tpi, and I didn`t know there are two types of these !
Sounds like you have a later UNC version.

Dependant upon how generous the clearance is on the component thread it is not unusual for a UNC socket accessory to 'fit' onto a whitworth thread.

I had a Poolwood Whitworth Chuck that would not fit on my UNC Poolwood but when I recut the thread to give clearance for the UNC it still fitted the Whitworth lathe. Not Ideal but workable.
 

Spence

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djansi":1f4b3cvb said:
Thank you for the info CHJ.

I was told that others had this noise problem with similar lathes, and apparently it`s the pulleys` wear and tear where they sit on the shaft. The metal (aluminium ?) the pulleys are made of seems to be softer than the shaft, so they will have a small amount of slack after a certain amount or running hours. But I`ll have a look at the weekend if I can locate where the noise comes from exactly.

I must have been lucky so far with the thread size, as I have bought a scroll chuck with insert, a collet chuck and a faceplate, and they all fit my lathe. They were all just advertised as 1 1/2 x 6 tpi, and I didn`t know there are two types of these !

Thanks again, Ansgar
Reeve's drive lathes are pretty loud generally, the noise tends to vary a great deal depending the speed you choose to run at. My old AWVSL1000 would be very loud at lower speeds and fairly quiet at high speeds. Unfortunately the lathe had such a poor stand that high speeds were out of the question unless I were just doing spindle turning.

They do generate a lot of wear on the belts and the pulley. I believe the pulleys were aluminium in mine, very brittle too! Luckily the spindle and the keyway were of stronger material
 

Trevanion

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phil.p":290t93gj said:
Is there an easy way of telling a Whitworth thread from a UNC?
Whitworth has a 55 degree form whilst UNC is 60 degrees. A couple of pitch gauges would be excellent, but in a pinch you can sometimes use a metric bolt that closely matches the suspect UNC thread to check if it is indeed 60 degrees as metric thread is also 60.
 

Phil Pascoe

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Surprisingly enough, I haven't an 1 1/2" bolt. :D I suspect my spindle's Whitworth, but I need to be sure. I'll try to think of a way to check it.
 

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phil.p":1xyd5psr said:
Surprisingly enough, I haven't an 1 1/2" bolt. :D I suspect my spindle's Whitworth, but I need to be sure. I'll try to think of a way to check it.
Not 'Fail-safe' but in general, if the crest of the external thread is 'rounded' it will be Whitworth - if 'flat', Unified or Metric.

As said before the best way is to used a cheap thread-gauge. That will also tell you the pitch (which may be relevant).
 

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