Best posts made by Hobsie

@hurzhurz @T3P3Tony

Thanks for you help guys, we have a winner!

My new tough metal core belt turns out to be not so tough and must have softened (probably from friction/heat) at some point and has actually stretched in the area over the toothed pulley.

I checked the movement as @T3P3Tony suggested and it was elongated near the centre of the bed's Y axis but not towards the edges. After @hurzhurz mentioned his issue with his Anet belts I then went and checked the belt and found this:

You can actually see where the rubber has stretched and increased distance between the belt's teeth!

Thanks again for everyone's help - turned out to not be a duet related issue at all but you guys got me looking in the right place.

That looks like it’s done the trick, thanks!

Left cylinder printed with default bang bang for the heated bed and then with the Pid tuned values for M307 (and voltage compensation) on the right

I was printing a TPU Tyre for an OpenRC build and suddenly it started printing longer in the Y Axis. I let it finish as at the time it looked like a minor layer shift but it actually started printing very consistently larger and slightly offset in the Y axis.

After checking the mechanics over I have it another shot only to find the 2nd wheel was entirely longer in the Y axis with no signs of layer shifting!

I figure if it was just layer shifting or slipping belts then it should actually shift in one direction and/or get smaller, not longer? But this seems to be a very consistent increase of about 2-3% size in the Y Axis alone. So now I’m wondering if it’s a possible software or electronics issue.

I’ll keep looking for mechanical faults as I still think it’s most likely that but has anyone experienced something like this before?

Using a DuetWifi on firmware 1.21

I've added some pictures for reference

@phaedrux Thanks for the link Phaedrux. Just ordered some myself.

Judging from the images you've posted, even if they're "fake Gates" they look pretty good quality.

Also, an fyi for everyone/anyone - i've gone and edited the reprap wiki page on choosing belts to include a wee warning about steel core polyurethane belts and small pulley diameters for others to find.

Link here: https://reprap.org/wiki/Choosing_Belts_and_Pulleys