Lathe belts

[Darren]

On of the biggest probs with my S&B lathe is belts.
Too slack and little power/slipping
Tight enough to help the slipping but not eliminate it and they break after a while, not too long a while either.

So I was thinking, how about one of those flat type car engine belts. You can get them with ribs running lengthways as opposed to crossways like teeth.

It would mean taking the spindle out to fit it, but shouldn't be that hard to do.

That is all assuming I can find one the right length of course.

What do you think, should help the grip tremendously, and it should take the punishment really well. Can anyone foresee any other problems?

This is the sort of thing....

http://images.google.co.uk/imgres?imgurl=http://farm4.static.flickr.com/3044/3099612000_f367a7fa00.jpg&imgrefurl=http://www.practicalmachinist.com/vb/showthread.php%3Ft%3D169584&usg=__vTVJ9qCv2XNybIR8X79Fbla_8wU=&h=375&w=500&sz=131&hl=en&start=94&sig2=auRkMtpTu0NDB_7Frd4kmQ&um=1&tbnid=hQW2Eetqf46m8M:&tbnh=98&tbnw=130&ei=2deuSf6uGYqS0AXvs-2jDg&prev=/images%3Fq%3Dlathe%2Bcountershaft%26start%3D84%26ndsp%3D21%26um%3D1%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DN

[bogstandard]

Darren,

Mention it to me tomorrow, and I might have an easy solution for you.

John

[Darren]

HI John,

I have just this min taken the belt off the lathe and popped it in the car, was going to visit Halfords on the way to yours to see what they might have. It's a 50 mile round trip for me just to go there (yes I'm that far out in the sticks, hills, mountains chaps..... lovely, mostly  )

Not wishing to push you, do I hang fire or pop in there anyway?

I have tried gluing and crock clips but it just don't hold. The glue holds ok but the belt breaks next to it. The crock clips just fall apart after a while and rip out. Trie leather belts, leather/nylon, and some funny stuff I'll show you tomorrow.

It's the join that gives the problems, hence thinking car belts. Surely they must be strong enough. I think the real prob it that this is a high speed lathe, up to 3000rpm

[bogstandard]

Darren,

Call into Halfords on the way.

John

[Baldrocker]

Darren
Used a flat car belt on an old kit lathe I am possesed by.
Idea worked fine but found that turning the belt inside out
helped grip considerably
BR

[Darren]

After discussing my belt problems with John and Stew last weekend whilst visiting Johns place, it became clear that something was very wrong with my S&B lathe.

When doing anything a little tough, like cutting a 10mm thread with a die, my lathe belt would slip making the job impossible to do. John previously indicated that my lathe should manage a 10mm thread with ease. But it couldn't.
The situation was such that I would tighten the belt to such a point that it would destroy itself. If I didn't it just wouldn't grip. I have tried 3 belts now. One leather, one nylon backed leather and one synthetic type called Belta.
This is the Belta, as you can see it's tearing apart and it's not been on very long.

Lathe belts

So I decided to try a car "Serpentine" belt. The reasoning was that such a belt on a car had a far harder life than my lathe would ever subject it to. The other bonus is that it would not need jointing.

Lathe belts

So, now having purchased a suitable belt from Unipart I set to stripping the headstock in order to fit it. Worth noting is that Unipart can select a suitable belt by the length you specify in mm. This makes life far easier than trying to find which car you need a belt from, such as in Halfords. The belt cost £12 which is a bargain.

Here I have started to strip the headstock, look at the diameter of that front bearing, 4 inches 

Lathe belts

It became clear that the spindle had to come out the front, so off comes this lot.

Lathe belts

Now out comes the front bearing, turns out to be a double race.

Lathe belts

Spindle out, look at the size of it for such a small lathe....

Lathe belts

The rear bearing

Lathe belts

Alas, it now became apparent that a continuous belt could not be fitted to this lathe. Here is why.

Lathe belts

The headstock

Lathe belts

Well, a jointed belt it has to be then. The headstock parts were cleaned, re-lubed and put back together. Thankfully everything was in excellent contdition with no signs of any detectable wear to be found.

One bonus, I found a spindle lock. Long overdue/missed and will come in real handy when removing the chuck....

[Darren]

Well I needed a new belt, so what to do....

I now had the serpentine belt and I didn't really want to go down the leather route again so I took the plunge and cut the belt, drilled some some holes in it.

Lathe belts

Then I threaded it together with some fishing line

Lathe belts

Lathe belts

Interesting point to note, against the pulleys the line slips inside the belt grooves. This will protect the line from abrasive wear. I have tried this type of lacing before with leather belts. But it never lasts long due to rubbing on the pulleys.

Time to do some test cuts. I kept the belt slack. In fact it was slack enough to change pulley speeds without slackening the motor leaver thingy that you would normally used.
Here I am taking a 100 thou cut, yes that's right 1/10th of an inch !! No problem, the belt was slack and it didn't slip.

Lathe belts

And the real test, a 10mm thread, yep, no sweat, it cut this with ease, again no belt slip...

Lathe belts

What a revelation, a slack belt and plenty of grip.

The fishing line by now didn't look too good, it was starting to give. So I re-laced it with Stainless welding wire.

Lathe belts

Lathe belts


This type of belting is a revelation over leather types. It's far smoother, quieter and has bags of grip. I don't need to tension the belt much at all now and hopefully it will last as a result. And so will the headstock bearings...
Not to mention that they are cheap and readily available in many sizes too... can't be bad.

Only one thing to do now, I would like to find a better way of jointing the belt. Maybe an over band and rivets....

Suggestions please.. ..

[dsquire]

HI John,

I have just this min taken the belt off the lathe and popped it in the car, was going to visit Halfords on the way to yours to see what they might have. It's a 50 mile round trip for me just to go there (yes I'm that far out in the sticks, hills, mountains chaps..... lovely, mostly  )

Not wishing to push you, do I hang fire or pop in there anyway?

I have tried gluing and crock clips but it just don't hold. The glue holds ok but the belt breaks next to it. The crock clips just fall apart after a while and rip out. Trie leather belts, leather/nylon, and some funny stuff I'll show you tomorrow.

It's the join that gives the problems, hence thinking car belts. Surely they must be strong enough. I think the real prob it that this is a high speed lathe, up to 3000rpm

Darren



I have had a thought on this and wonder if you have ever used a belt dressing on this lathe or belt. THis would reduce the slipperyness of the belt and make it somewhat sticky. This would mean the belt would not have to be as tight to get a grip to turn the spindle. This in turn would place less stress on the joint.

The belt dressing that I used to use looked like a stick of tar about 1 /2" Dia. x 8" long. You just held the end of it against the belt and the friction caused heat and melted a bit off onto the belt causing it to be a bit sticky.



Cheers   

Don

[Darren]

Hi Don,

John and Stew mentioned this stuff to me at the weekend, I'd never heard of it. Amber they called it. I suppose I should have given it a try. The Belta belt is sort of rubbery, you'd think it would offer tons of grip but it didn't. Rather took me by surprise as that's why I bought it.

I have the serpentine belt now, so I'll see how that goes. I've been doing a bit of googling on these belts today. Seems that yet again I've come up with nothing new 

Over on Practical machinist many over there swear by these belts over leather, seems to be a leather revolt going on 

[dsquire]

Hi Don,

John and Stew mentioned this stuff to me at the weekend, I'd never heard of it. Amber they called it. I suppose I should have given it a try. The Belta belt is sort of rubbery, you'd think it would offer tons of grip but it didn't. Rather took me by surprise as that's why I bought it.

I have the serpentine belt now, so I'll see how that goes. I've been doing a bit of googling on these belts today. Seems that yet again I've come up with nothing new 

Over on Practical machinist many over there swear by these belts over leather, seems to be a leather revolt going on 

Darren

I remember this stuff from when I was a kid with my grandfather back in the late 40's. Grandpa would always put it on the belts running from the tractor to the different equipment on the farm. I have even used it on ocasion on a v belt that wanted to slip to keep from having to put to much pressure on the spindle or shaft to keep from slipping. This would also decrease the load on the bearings.

While typing this I have just thought of another belt. It is a link type belt that can be made in any length. I have seen it advertised for table saws to promote smooth running as the belt does not take a set like a v-belt does which in turn can sometimes take up a vibration. If I can find anytthing on this I will get a link to you.

cheers 

Don

[Darren]

Don, are you thinking of this stuff?

http://www.shopfloortalk.com/forums/showthread.php?t=18326&page=2

Be nice to find more info on it, seems a bit elusive?

[John Hill]

For all your Imperialists, this is the remains of a portable sheep shearing plant as was once popular in the better class of colonies.



In use a leather belt went around each flywheel and up to the overhead shaft you can see with the split pulley de-clutching arrangement.

We had one on our farm which must have handled a million or so sheep in its time and all the while the leather belts were held together with 'copper bifurcated rivets'.  The two ends of the belt were butted together then a short length was riveted on top so it was double thickness at the join with the short bit, of course, being on the outside.

[Darren]

What's a "copper bifurcated rivet" 

[John Hill]

I dont know about Amber but we had quite a bit of farm equipment using flat belts with the bigger ones using something that looked like a composit of woven fabric and rubber.  For those belts we used rosen as the belt dressing, just a few crystals dropped on the belt when it started to slip,  it used to build up on the pulley though.

Rosen, if I am not mistaken is tree sap and if you want to be really extravagant I expect you can still buy it at the music shop for your violin.

Oh, a copper bifurcated rivet is a split rivet, ( hence 'bifurcated" ) when you drive it through the leather the two legs spread apart then you bang them down from the other side.  Leather work shops would have them for sure.

[Darren]

That's it, That's what I need...

"Description: The bifurcated rivet is used as a self-piercing rivet. Materials such as leather, plywood, vulcanised fibre and plastics can all be joined with bifurcated rivets.

When set, the rivet legs can be forced back into the surface material to leave a relatively smooth surface. By riveting fibre board through fabric, the joints produced are very much stronger than stitching."


Now where to find some.....



http://www.findtheneedle.co.uk/products/81719-bifurcated-rivets.asp

[rleete]

We use strap wrenches at work.  Used to tighten large diameter (6-8") clamps.  Basically, they are a woven belt looped through a cast metal handle.  They have to have resin applied so as to not slip.  This resin may be the same as the amber mentioned above.  Available from MSC or McMaster.

[sbwhart]

Hi

It was resin John and I were on about I think the confusion arose when we said it looked like amber. Darren I may be able to lay my hands on some crocadile teeth to join your belt, I'll have a look to see what I can find.

Cheers
 
Stew

[Darren]

Hi Stew,

Are you thinking of these chappies?

http://cgi.ebay.co.uk/FASTNER-FOR-BALATA-BELTING-DRIVE-BELT-no-27-BELT-CLIP_W0QQitemZ130280547004QQcmdZViewItemQQptZUK_Garage_Equipment_Tools_Tool_Boxes_Storage?hash=item130280547004&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A10|39%3A1|240%3A1318

This seller is a hardware shop local to me, it's the same as I used on the belta that I showed ripping apart.
I have some spare. I was reluctant to used them thinking maybe rivets wouldn't be so aggressive to the belt. The clips are quite sharp edged.

But then again I can run the new belt quite slack, so maybe it won't be a problem anymore?

[sbwhart]

Yes thats them  don't know the proper name i just call them crocidile teath for obviouse reasons.

Stew