Delta missing steps(I'm pretty sure it's haunted)

So I've been battling with my homemade delta for a while with layer shifting or missing steps, I've tried everything from changing a motor, changing a belt, changing the controller, running from a pic and running from a screen, nothing, it's rather tall(about 1 metre) it's not my first delta, and I never had problems with my other one, so I'm just curious, I'm using t2.5 belts and pulleys and I was wondering if anyone has had any problems with them, I'm thinking of swapping them out for gt2 belts but I don't know if that's the problem, my belts seem to be wearing but not excessively, I haven't noticed any big problems in the belt I took off, and the pulleys are fine, I can't even get the belts to slip if I try, and yes they pulleys are tight, yes they grub screws are torqued down, no the motors aren't overheating, the stepper drivers aren't overheating, any advice would be awesome

Are you using 24v? That's a good idea if you aren't.

I've got no experience with t2.5 belts, but gt2 seems to be the defacto standard and I've never known them to slip, the pulleys will loose grip before the belts, and 9mm belts (if they'll fit) would seem to be an improvement on 6mm. But I use 6mm and they work fine. Avoid the white steel/PU belts unless you're using 20t pulleys, with 16t pulleys the metal wires fatigue.

Make sure you have flats on your motor shafts, if not grind some in there.

Try to set your motor current at 80% of their rated capacity. 60 deg C is around the point at which its too hot to touch but is actually a very safe temperature for them to operate at. I bought some stickers that change colour at 60-70-80 etc.. so you quickly see if you're overheating a component. High motor temps are usually a problem when they are attached to printed parts. Try turning them down a little until the missed steps comes back for a reduction in motor temperature.

Edited 1 time(s). Last edit at 02/14/2017 08:50AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi, thanks for the reply, I've already tried everything from 1A to 1.7A on my 1.7A rated motors, and they aren't overheating where I've got them set now which is around 1.4A, I'm running smoothieware so I can set it in software, and no I'm not using 24v, I'm using 12v, I didn't even think that would be a factor, I ran 12v on my old machine and I never had a single problem, I might try that as a last resort though, i used the t2.5 belts on my old machine and never had a problem, but it's possible which how much bigger my new one is there is a problem somewhere, I guess I need to peel back some more layers of the proverbial onion

Hmm if you are at the rated current and they aren't heating up at all, then I wonder if that might be the issue. I have some fairly hefty 48mm 1.68A 0.9 deg steppers and they are set at 1.3A and they get up to 45-50 degrees (with TMC 2100 drivers). A4988 / DRV8825's maybe a little cooler but I wonder if there's something there.

I have no idea how to actually measure motor current - clamp ammeter around one motor wire, then double it for total motor current??

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Sorry I guess I was a little vague, they do get warm, between 40-50C but they aren't overheating, granted I'm trusting software but I've never seen anything about smoothie ware giving the wrong current to the motors, I'm almost certain it has something to do with either the belts or the pulleys, the only other thing it could be which I doubt is the slicer, I'm using repetier with the cura engine, but again I've never seen anyone online having problems like that, I can always try craft ware, just to rule it out

It depend how large are your layer shift and if they are random but if its multiple shift and look random it can be that the belt is not tight enough. When I first build my delta the walls of print were not great until I tight my belts a good amount ( also arround 1 meter height). Mine require a scary amount of tightening I was scare to bend my .25 inch motor plate I had to use a big screw driver as lever to tight them enough.

Okay I will try tightening them more, they are quite tight now, not stupidly light, but like I said I couldn't get them to skip teeth when I tried, but thanks for the advice

So I tightened the belts more, a lot more, and I just got through a 15 hour print, I think that was the issue, thank you for the advice

No problem always happy to help