Those are GT2. It doesn’t look like anyone offers “long length” in GT3, it might be special order only. I managed to dig up the part number for it and no site other than Gates lists it: LL2MGT06 So take that number and contact some reps at Gates.
Gates doesn’t offer GT3 long the length. I have a engineering friend that works there. On their website it says they do, but according to him they actually don’t.
Don’t get too caught up in the GT2/GT3 thing… the important part is that it’s Gates. Genuine GT2 is almost as good as genuine GT3 and is going to be a super high performance belt compared to most knock-offs.
So glad this subject was brought up. Getting down to the nitty gritty details is what I am all about. Can we discuss pulleys? I know you can get quality pulleys from sdpsi or BBMAN but they are very expensive. I have had a mixed bag of result with chinese pulleys, some are decent and some are total crap with miles of runout. I have noticed that larger bore pulleys seem to run truer than the standard 5mm bore pulleys. I am also concerned that the Chinese pulleys are not pitched to tolerance. Anyone have a good source on pulleys that have reliable quality and wont break the bank?
Yes. I care a lot about this aspect, as I want to push (or abuse) the envelope a rather a bit.
With larger printers and faster print speeds, the amount of stretch in a belt matters quite a lot. I bought a belt off Amazon. It is made of rubber (maybe) and reinforced with … something. Maybe.
What I really want is a belt reinforced with Kevlar (best stiffness to weight, so far as I can tell), and some engineering grade of rubber.
Any chance of getting a first-tier belt vendor to chime in?
@Kyle1 I’ve seen a lot of variation in quality. I’m not sure it’s quite as important as the belts though. I tend to use SDP/SI but I have a fair number of cheap Amazon pulleys and can’t pin any actual failures on them.
@Preston_Bannister the important thing for belt stiffness is to get a quality belt that is NOT polyester cord.
- Polyester cord is quite stretchy and is great for shock-load applications, but causes ringing in 3d printers. Most cheap China knock-off belts are polyester core.
- Fiberglass and aramid/Kevlar belts are nearly identical performance. Kevlar creeps a bit so you have to re-tension it more, but it’s slightly stiffer, and doesn’t really thermally expand, which can be useful in certain heated chamber designs. In practice >99% of printers do very well with fiberglass and there is no reason to spend more money on Kevlar. It’s fine if you want to use it though.
- Steel core is ok IF you use unusually large pulleys or only use it on low-cycle stages like Z so it doesn’t fatigue.
Neoprene vs polyurethane rubber doesn’t matter for this application. However, the specific elastomer formulation IS quite important to tooth stiffness, and that’s another area cheap manufacturers scrimp and get lower performance.
Net net, genuine Gates GT2/GT3 neoprene/fiberglass belts are pretty dang close to zero-stretch and you should try them out before trying to upgrade to Kevlar, steel, heavier-duty belts, or anything else.
@Ryan_Carlyle Fair enough. Suggested places to buy belts?
Also … poked Gates on Facebook. 