poly-vee belt profile

Bob, Get an 11 tpi pipe thread Coventry die head insert and plunge in. Not quite the correct angle, poly vee is 40 and pipe thread is 55 but the pitch is nearly spot on.

The purists [ Hawk - spit - ding ] from the comfort of their armchairs will throw their hands up and decry it's not on but sod it been doing it this way for years. Got some drives that run 8/5 at 9,000 rpm and have been doing so since 1999 and a belt last over a year.

See here:-

If you need the exact specs it's 40 degree angle, 2.34 pitch between grooves,

3.0 for the end grooves and 2.06 depth, 0.20 rad at top of tooth, 0.40 rad at bottom. .

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

pitch is nearly

grooves, 3.0 for the

Thanks John,

Spot on info as ever. You are a star!

I'm pretty certain I have an 11TPI chaser in the drawer which should do nicely.

I'm planning to drop the speed on my Startrite 18-s-1 Bandsaw for metal cutting as well as wood.

Currently a single speed machine giving about 3300 ft/minute -ideal for wood. I have an inverter on the motor but there is not much grunt running below 10Hz. So I plan to add a pair of poly vee pulleys - big one ripped from a washing machine which is in fact flat (or maybe slightly crowned) and make the tiddler from a bit of steel.

Best regards

Bob

I did this but used a 2nd hand tap off eBay in the tool post instead. - instant poly V pulley. I've been using it over a year and it doesn't slip, smoke and hasn't fallen in bits, it just works. I've used this for 150mm cast iron pulley and and a 30mm ally pulley, no probs at all.

Steve