What do you know about timing belts? We have the wrong tooth pitch on the x-axis belt on our 90w generic red/black Ruida laser. We made measurements and found that we need a belt where the distance between peaks is approximately 3mm. The belt we are using has a smaller pitch than that. We thought we had purchased the correct replacement but when we went to install it yesterday, we found it was exactly the same as the existing incorrect belt. I’m confused between designations like 3m, 5m, and MXL, vs gt2, gt3, and 3gt (which seems to be different than gt3?). Basically, I’m lost. I’m adrift at sea. We need to get the correct belt for the job and I have no idea what to search for. How could we measure both the tooth pitch and tooth shape of the pulley and determine which letters and numbers I need to search for to get the right belt? Any help would be appreciated. Thanks!
Caveat: I am not an expert!
Gates is a Name to conjure with in the field, so devoting time reading their doc and studying their catalogs will give you the basic vocabulary and ideas of how belts work:
In particular, you want a “synchronous” belt, with the teeth perpendicular to the belt length, rather than a “v-belt” with the teeth parallel to the belt.
The “GT2” and “GT3” terms identify the belt material / construction / whatever and, contrary to what I first thought some years ago, do not indicate the tooth pitch. With that in mind, you can get a GT3 belt in 3 mm pitch:
https://www.gates.com/content/gates/us/en/search.p.9356-000000-000000.html?fl-pitchmm_string=3
The Design Manual on that page will keep you occupied for hours!
AFAICT, you and I now know more than a typical Amazon / eBay seller. Admittedly, we set a low bar (
), but believing anything in those listings matches external reality is a Bad Idea™. In particular, brand names or trademarks seem fanciful; I have adhesive tape proudly marked 3M that cannot possibly have any DNA in common with the 3M I knew from back in the day.
Thanks, I’ll check it out.