Flat belt drive system

[bigegg]

i want to get my Holbrook 5P lathe up and running - it has a 3 wheel (4,5,6 inch) flat belt pulley on the headstock

Various insurmountable issues (lack of ceiling height + a built in thread chaser headstock) means that the drive has to be underslung, and if a "simple" mechanism, would involve an 18" pulley + various stepdown gear boxes even from a 1400 rpm motor - even then, I would only have about 120deg of contact per drive wheel

Having glanced at a picture of the timing belt in my ovlov, it occurs to me that I could make a much easier/more efficient system if I could apply tension to the back of a flat belt.
Can this be done with a leather/balata(?) belt? or would I have to source a rubber (jointless) belt of the correct size?

 

[eLuSiVeMiTe]

i want to get my Holbrook 5P lathe up and running - it has a 3 wheel (4,5,6 inch) flat belt pulley on the headstock

Various insurmountable issues (lack of ceiling height + a built in thread chaser headstock) means that the drive has to be underslung, and if a "simple" mechanism, would involve an 18" pulley + various stepdown gear boxes even from a 1400 rpm motor - even then, I would only have about 120deg of contact per drive wheel

Having glanced at a picture of the timing belt in my ovlov, it occurs to me that I could make a much easier/more efficient system if I could apply tension to the back of a flat belt.
Can this be done with a leather/balata(?) belt? or would I have to source a rubber (jointless) belt of the correct size?

My flat belt showed no indication of which side should be in contact with the pulleys.
Can't see why it would be an issue.

Watching with interest

 

[Agroshield]

Look on the Internet Archive for a book or books called 'Treatise on belting'. Inter alia, it will tell you which side of the belt (hair side or skin side) should be in contact with the pulley for best transmission of power.

There was a device called a Lenix drive which did exactly what you want, a weighted or spring-loaded roller on the back of the belt to increase the wrap (i.e. turn up the volume of the P. Diddy LP).

There is a picture of a Lenix drive on the front of 'Belt drives in the small workshop' by Duplex. See:

https://www.ebay.co.uk/itm/Belt-Drives-Small-Workshop-Duplex-Myford-ML7-/362964155209

Try also here:

https://books.google.co.uk/books?id...TAAegQIChAB#v=onepage&q="lenix drive"&f=false

 

[bigegg]

Look on the Internet Archive for a book or books called 'Treatise on belting'. Inter alia, it will tell you which side of the belt (hair side or skin side) should be in contact with the pulley for best transmission of power.

There was a device called a Lenix drive which did exactly what you want, a weighted or spring-loaded roller on the back of the belt to increase the wrap (i.e. turn up the volume of the P. Diddy LP).

There is a picture of a Lenix drive on the front of 'Belt drives in the small workshop' by Duplex. See:

https://www.ebay.co.uk/itm/Belt-Drives-Small-Workshop-Duplex-Myford-ML7-/362964155209

Try also here:

https://books.google.co.uk/books?id=V7wfAQAAMAAJ&pg=RA2-PA66&lpg=RA2-PA66&dq="lenix+drive"&source=bl&ots=2rcSHTa58o&sig=ACfU3U3L43ujJWYtpWcg1I4vnZLJUQOqmw&hl=en&sa=X&ved=2ahUKEwjNwJe_0_DqAhXKRBUIHfb4DHw4ChDoATAAegQIChAB#v=onepage&q="lenix drive"&f=false

thanks very much!

 

[eLuSiVeMiTe]

To add. I wasn't referring to leather in post.

Balata belting has rubber both sides.
https://www.stationaryengineparts.com/3-Ply-belting-4.5mm-thick/

 

[Robotstar5]

If your motor is too fast, get yourself a stationary engine this is one of mine running at about 700rpm and using a Balata belt

 

[Pete.]

I had a length of Balata belting and I didn't find that it gripped well at all. In the end I got rid of it for vee belts.

I use poly-vee belts in place of flat leather, you need a much smaller belt for the same duty. If you can't fit it endless then you can cut and splice them.

 

[bigegg]

I had a length of Balata belting and I didn't find that it gripped well at all. In the end I got rid of it for vee belts.

I use poly-vee belts in place of flat leather, you need a much smaller belt for the same duty. If you can't fit it endless then you can cut and splice them.

I'm stuck with flat pulleys for the final part of the drive (at least until I get the lathe running, and can turn new pulleys!)

or are you suggesting I run a vee belt on a flat pulley?

 

[Pete.]

I'm stuck with flat pulleys for the final part of the drive (at least until I get the lathe running, and can turn new pulleys!)

or are you suggesting I run a vee belt on a flat pulley?

A poly-vee belt, yes. They work very well, and you don't have to run them on the flat back the vee groove side grips very well.

Millions of washing machines can't be wrong

 

[timgunn1962]

A lot of the South Bend lathes used a V-belt drive with the motor having a V-pulley and a "flat" driven pulley. The reduction was pretty substantial IIRC, so the small motor pulley had the "wedging" effect to provide grip and the flat pulley had well over 180 degrees of wrap to help the grip.

It's mentioned on http://www.lathes.co.uk/southbend/page4.html

May be worth looking into?

 

[Agroshield]

Modern flat belt example is Optibelt Optimax HF.

Technical/design manual here, starting at page 129:

https://www.signettrade.co.uk/files/ww/Technical Manual V-Belts.pdf