Searched now for hours and can't find any amount of info on the use of timing belts to provide primary motion in the place of ballscrews or R&P. Unless I'm missing something belt drive should be the simple way to get precision motion.
R&P has gear mesh issues, dirt buildup, ballscrews need quality supports or live with backlash, with using a rolled screw you have lead error and then to get fast ipm's you have to consider critical speed. So it appears that a 1"
min width belt, Kevlar , with a few simple pulleys in alignment solves a lot of build and accuracy issues. Open for any comments. Specific application:50" square moving table router. Any links to existing threads, please insert.
Thanks

Have you checked the SDP site? http://www.sdp-si.com/ they have tables and charts, also their free catalogues read like engineering manuals.
Al.

There are a few on this forum who use belts, including myself.
I fully recommend this as a cheap alternative to traditional rack and pinion setups.
Sorry there are not many pictures of my setup, but you can have a read here http://www.cnczone.com/forums/showthread.php?t=6143

Al
I've got catalogs from SDI, Thomson, Nook, numerous suppliers, MSC, etc.
Also have many Online manufactures, suppliers, etc that I study their site engineering info. What I can't find on cnczone is info of users of belt drives.
Everybody seems stuck on ballscrews and R&P. Who has made a sucessful
belt drive unit with a table over 3'?? Andy

What I can't find on cnczone is info of users of belt drives.
You could always try here too http://www.cnczone.com/forums/showthread.php?t=5017&highlight=moondog

I always consider this picture to be the best inpiiration for a belt driven machine.
http://www.cnczone.com/gallery/data/500/medium/2793pinion2.jpg

There are some other pictures of driveing setups in my photo gallery.
http://www.cnczone.com/gallery/showgallery.php/cat/500/page/2/ppuser/2793

Ynneb
Thanks for the thread links, moondogs link.
The belt drive he used at the end is what I was proposing to build. I assume you use that setup also. Am I correct it works well? Andy

This is Moondogs web site. You can see what he makes with his belt driven machine.
You be the judge.
http://www.capeboatworks.com.au

Oh and my very unfinished web site. You can also see what I have made with my belt driven machine. www.kitscut.com

Yep, I think a belt drive will be just fine for my unit.

Breco make anti-stretch belts for this application in what length you want with the suitable coupling piece to attach to the carriage.
Al.

After more research, I'm wondering about which type of belt to use.
Is a metric HTD series better or just use a Standard H series belt. Does this make any difference? Most likely design is to use a open belt, however it will be attached to the moving table frame with clamps, one flanged pulley on each end.
Drive one pulley with the servo/stepper. Belt width of min 25mm, maybe wider?

Read the info at SDP-SI, and you'll find that the GT or GT2 belts have the least backlash.