I made a Lowrider 2 Dual Endstop (one motor per driver) running with SKR1.3, DRV8825 and TFT24. Stepper motors 2 Amp, VREF set to 0.9.
I’m setting up my step per mm and my Y axe is trolling me. I ran two time the same gcode, once starting approximately 200mm from the right side of my table, and one 700mm. I’ve take care to start my gcode with a all current position = origin.
I have also homed correctly my Y axe : both sides start at the exact same distance from the right side of the table and when i move it with screen command, it reaches the left side of the table with the exact same distance from edge as well. That is why I’m lost actually.
So my question is : it is not a step per millimeter problem, is it ? So what is it ?
I have been told that it can be because my table support is not very stable, so table vibrates a bit when the machine moves… I’ll change it but i’m suspicious about this being the reason.
Unless you have a weird pulley or belt you should probably reset your steps/mm as that is a fixed value based on the size and spacing of the teeth and the rotation of your stepper and shouldn’t be changed if you got the specified parts. You did get a reenforced belt right? They don’t stretch.
You probably have a loose grub screw on one or both pulleys be sure to tighten screws on the flat part of the stepper shaft and locktite or superglue the threads they ALL eventually work loose so glue them all.
If your machine is really out of square it’s possible you are binding and losing steps but this is less likely.
If this doesn’t fix it; post a picture with the dimensions penciled onto the piece so we can better help.
I bought this kind of belt, with fiber inside : link
I cant tell if it is stretching or not, or maybe i should tight them more to the support on the table ?
Sounds like poetry (I dont speak english), are you talking about theses ?
understood ! I had to do it for X axe already (painful). But it was really obvious this was the problem, here it is not the same, the pulley actually turns whit the shaft… I’ll check it.
Yeah just a drop, you aren’t really trying to glue it so much as keep it from vibrating out. Superglue is brittle so it should break if you give it a good twist.
There are also commercial products specifically sold as “thread lockers” and they come in different strengths, such as temporary and permanent. In the US, a common choice for this use is the blue (temporary) Locktite brand. (The compound is blue but comes in a red bottle.) This will prevent the screws from vibrating loose but will release with a little extra wrench pressure when you need to maintain the machine. The permanent version (red fluid in a red bottle) require application of significant heat to break the bond.
