Which Belt Profile

[manofgresley]

Hi all.

I am converting my Milling machine to CNC. I have decided that due to the Milling head being v. heavy to use a drive belt on the Stepper motor @ 3:1 ratio, ie. 20 TPI on the Stepper & 60 TPI on the spindle. My question is this, in view of the myriad of choices, what do the forum members recommend by way of profiles, AT,T,STD,HTD,3mm or 5m pitch.

Were is the best / cheapest place to buy this equipment ?

Your help would be highly appreciated.

Regards

Ray

[Jonathan]

Most people use HTD belts.
Bearingstation (http://www.bearingstation.co.uk/Products/Pulleys/HTD_Pulleys/HTD_Pulley_5mm) are the cheapest place I know of in England, but lately you'd probably get them quicker if you ordered from aliexpress! There's also Belting Online (http://beltingonline.co.uk/), who offer a boring and tapping service for the pulleys, which may be worth the small extra cost if you haven't got the means to do this, i.e. a lathe and milling machine.

[manofgresley]

Hi Jonathan
Any preference on pitch, 3 or 5 mm ?

Ray


Most people use HTD belts.
Bearingstation (http://www.bearingstation.co.uk/Products/Pulleys/HTD_Pulleys/HTD_Pulley_5mm) are the cheapest place I know of in England, but lately you'd probably get them quicker if you ordered from aliexpress! There's also Belting Online (http://beltingonline.co.uk/), who offer a boring and tapping service for the pulleys, which may be worth the small extra cost if you haven't got the means to do this, i.e. a lathe and milling machine.

[Jonathan]

Definately 5mm

[jcb121]

what width of belt is best? and is it better to have a longer pulley on either the motor or the screw? or does this not matter?

[Jonathan]

The width depends on what you're doing, but in general 15mm wide is fine. If it's a long belt then increasing to 25mm is a good idea as it will raise the stiffness.

By longer I think you mean the width of the pulley? If so, you generally just want pulleys which are nominally the same width as the belt. In reality the pulleys are slightly wider, so there is some clearance between the belt and pulley flanges. The main thing is to make sure the pulleys are aligned axially, so the belt isn't rubbing against the flanges.

P.S. There are many threads discussing this on the forum (http://www.google.co.uk/cse?cx=partner-pub-3900933576813855%3Ayj2gzr-ru4w&ie=ISO-8859-1&q=which+belts&sa.x=-1287&sa.y=-146&siteurl=www.mycncuk.com%2Fforums%2Flinear-rotary-motion%2F6622-belt-profile.html%23post49928&ref=&ss=2850j760446j17#gsc.tab=0&gsc.q=which%20belts&gsc.page=1).