View Full Version : Poly V-Belts on Machinery?

10-05-2005, 07:11 PM
Has anyone attempted a conversion to poly V-belts on their machines? They seem to be smoother, quieter and stronger than standard v-belts or timing belts. It looks easier to "cut" your own new pulleys too.

Are the V groves standard on poly V's? They look about 30* or there abouts and all the same depth. Only the width and number of groves change. I couldn't find any specs.

How do you measure for them?

John Stevenson
10-05-2005, 08:16 PM
Halfway down this page.


John S.

10-05-2005, 08:36 PM
<font face="Verdana, Arial" size="2">The purists will say the angle is wrong...</font>

LOL That's why I was looking for specs. http://bbs.homeshopmachinist.net//biggrin.gif

Great idea though!

John Stevenson
10-05-2005, 08:40 PM
I have the poly vee design book here but it's 2:30 am as well.
If you get stuck I'll scan the page on the J series tomorrow for you if you want.
Quick specs for the J series are

Bugger it the books not where it should be....
O well tomorrow then, good night gentlemen and Mr Wolf.

Richard the 3rd - formerly known as John S.

[This message has been edited by John Stevenson (edited 10-05-2005).]

10-05-2005, 08:43 PM
Thanks John. While you're at it, could you get me tonight's lottery numbers? It's only 8:30 here. The drawing is at 10:20. http://bbs.homeshopmachinist.net//biggrin.gif

10-05-2005, 08:43 PM
ahso glasshopper say.. slipping belt is bletter than blocken gears http://bbs.homeshopmachinist.net//smile.gif

all the best....mark

John Stevenson
10-05-2005, 08:49 PM
Bugger it couldn't sleep.

Richrad the 3rd - formerly known as John S.

10-05-2005, 08:54 PM
Goodyear has some specs online but I don't have the link handy.

I wanted to convert my lathe to poly-vee but the foot brake system stopped me ... for now at least.

added - this link has some cross sectional drawings for their sheaves:



[This message has been edited by nheng (edited 10-05-2005).]

Steve S
10-05-2005, 09:27 PM
In my work as woodworking machine tech, I have converted the drives of a number of Powermatic 66 tablesaws, and recommend it anytime someone will listen. They run with considerably less vibration.

Parts cost about $100.00 to change over.

I believe that the new 10" tablesaw from Powermatic uses a poly-V drive. They are also standard issue on CTD industrial wood cutting chop saws. My experience is that it is far superior to standard V belts.

Forrest Addy
10-05-2005, 10:12 PM
Poly-V belts are great only so long as the housing in whick they run stays clean and dry or they have at least one reverse bend idler. Otherwise the gooves fill up with crap and they bear against the crests of the pulleys losing drive and possible smoking the belt.

One drop of tramp oil will make your drive a slip sliding mess.

10-05-2005, 10:19 PM
That's understandable Forrest; However, they seem to work quite well under the hood of a car. http://bbs.homeshopmachinist.net//wink.gif

Oil and dirt on any belt system reduces it's effectiveness.

[This message has been edited by CCWKen (edited 10-05-2005).]

10-05-2005, 10:24 PM
Forrest, You brought up a very good point and one that I had forgotten. I spent hours picking sharp steel swarf out of a poly-vee belt on an Emco Super 11 which I was cleaning up (and lacking a replacement). The belt was "fully" covered by the end housing of the headstock.

Just shows how much stuff can slip thru the cracks. Oh yeah ... it was a PITA getting it out of the tiny vees.

10-07-2005, 01:08 AM
........My 1981 vintage 11x36 Logan/Powermatic has a poly-V driving the spindle. Looks to be about 1.5" wide. I'd suspect it's the original as it's labeled Powermatic, but no way to know for sure.


10-07-2005, 03:44 AM
I've replaced leather belts with poly-v belts. They run just fine on the original crowned pulleys. They won't develop their full power transmission capabilities without grooved pulleys, but I don't need them to do so - they just have to work better than leather. And, so far, they have.