[daedalus]

Hi,

I was wondering if anyone has a good suggestion for a low backlash timing belt? Im building a 15:1 reduction drive which needs to be very low backlash. Its for a robot im building, and similar robots currently made use a cable driven system (see pic), how would timing belt backlash compare to this?

does anyone actually have a measure of backlash on these belts? most of the suppliers i have found list parts as low backlash, but dont give a figure.

Thanks for the help,

Tom

[NC Cams]

We use HTD's on our cnc mill (BPT EZTRAK) and it mills masters at accuracies of 0.0001" with servos geared 2:1. Supposedly there are newer "backlash free ones" but I suspect it would be hard to measure an improvement over what we've go.

Our backlash comp is in the 0.0001-0.0002 range. The prime source of our backlash was the b/l in the ball screw and the lack of rigidity of the ball screw bearings.

Preloading the screws and using true, heavily preloaded ball screw bearings took care of the B/L in the system. The timning belts are the original ones that came with the machine (1996 mfg date).

Providing that you use a "timing grade" toothed belt, so called belt backlash shouldn't be an overpowering issue.

I suspect you'd ultimately see more B/L in your 15:1 gearing than in the belt you choose providing you choose a properly sized cogged and tooth belt/pulley arrangement (with proper centers, tension(ers) and adjustment and pulley wrap).

The devil is in the details and execution, not in the "big stuff"....

[ViperTX]

Contact the manufacturer for information regarding their timing belts and ask them the same question....they should have some "white papers" or "application notes" regarding the selection of belts.