Hi there,
I am building an LR4 and and used the calculator for my target working area of 650mm x 1250mm. So I got a 1505mm long steel tube and cut my Y belts to 1625mm (actually a few mm more). But now I have no chance of stretching them over the entire length of my build. As the 3d printed pieces touch the steel tube, I can’t move them close enough together to make it work. Looks like I am missing about at least 20mm to make it work, maybe double that to make it work comfortably. I already used the minimum amount of belt inside the blocks (its barely coming out on the other side) and I double checked the belt around the stepper, looks all good. Oh and of course I now also removed it and double checked the measurement. Laying it out on my table, it looks like it is long enough to be stretched between the blocks, but not enough to go around the stepper. I guess I will now order new belts.
This seemed weird to me, so I ran out and snapped some photos.
My Y rail is 1820mm. I’d estimate my belts are maybe 2000mm but here’s a picture of how much longer they are than the rail (maybe 40 mm on the left, longer on the right, but could be much shorter.) These are the same belts I used for my LR3 so the table dimensions are the same, so i didn’t use the new calculator.
Is that similar to how yours are? I would estimate that rail length + 120mm + whatever the motor pinion loop is would be sufficient for the belt length.
Edit: if you had your braces (mine are gray) all the way at the end of the tube, I could see why that could be too short, since the endstop belt holders would have to be farther out. I had to slide my braces in slightly, as pictured.
Thank you, mine looks very similar, also pushed in my end clips a few cm. For me, the (30mm) tube does touch the “front” of the end blocks when I line them up with the outside edge of the clips, but again not a big difference to yours.
I just quickly measured, I need about 30mm belt to get to the end of the belt holder in the Y1 max block, and 15mm on the Y1 min side. then add 25mm each for a comfortable loop around the M3 screw. This leaves me with 25mm total to get into the YZ plate, around the pulleys and stepper motor and back out, this is just not enough.
Ah, darn. Can you just cut your Y rail a little shorter? (I didn’t have a specific length for mine, other than being > 48", to cut a half sheet of US sized plywood, so the Y rail length wasn’t critical for my needs.) Sounds like the calc might be off…
I did, and I should receive them tomorrow, but I should have known better than to just trust the calc… For me it’s the downtime with the LR sitting in my living room more than the expense of the belts.
My son cut mine, he disagreed intitally when I said to use the whole 8 metres, divide the excess across the belts and we can trim later. Glad we did though
I’m using a LR3 kit I bought locally, you initially sold a year ago. was never used, but was complete. Absolutely perfect, just needed the upgrade kit that I bought off you.
I always take what the calculator says for X belt, add 20mm or so to it and cut that off. Then take whats left and cut it in half. That has worked real well for me in the past. But the past time I ordered 3 kits and some funny guy sent all 3 kits worth of belt in one long bundle, so now I have to measure out the Y as well
