Greater distance along the X axis

Hey. Only recently I found that my lowrider2 travels a greater distance along the X axis. This does not apply to the Y axis - only X. At a distance of 1000 mm, the real displacement is 1005 mm. I did not make changes to the move code, I use the prepared firmware from Github - MPCNC_Rambo_T8_16T_LCD.

I can’t say whether it was from the moment of construction, as I previously performed work where the extra 5mm was not noticeable … What could be the reason?

Rambo 1.4a

5mm… Hmmm. Is your timing belt stretching out?

Cnc works very little time. I checked the tension, checked the settings and other axes. This is very strange, I have not come up with anything yet. I made an airbrush and now it’s a problem because the picture is distorted …

What hardware do you have?

Did you buy steel belted belts?

Not to toot my own horn too much but this generates a test pattern that might tell you something:

In particular it will tell you if your apparent length error is uniform or “lumpy” and whether it is influenced by backlash-like effects.

What hardware do you have?

Did you buy steel belted belts?

All parts of the machine are bought on the list on the site. I use a 2GT-6 belt with steel threads. Belts are the same on the X and Y axes.

All parts are the same on the machine, if something is wrong with the parts for X - this would be equivalent for Y. My Y is 2050 mm and it is precisely positioned. Today I will try to replace the belt, as well as make a linear drawing of the marks.

I also connected the E0 engine and the servo for the airbrush module, does this cause problems in the firmware? Everything works fine except for this problem with X.

Steel reinforced belts have a tendency to break and cause some stretch. While I’m not sure that’s 100% the problem, it doesn’t help. The rapid changes in direction on the rollers will cause the steel reinforcement to work harden and break, for this application/belt routing, fiberglass reinforced belt is recommended.


I can’t think of a reason why it would be a problem.

You gotta ditch the steel, very quickly they break internally and you will have teeth further apart than 2mm. These were instantly an issue and continue to be. This is not the application for steel belted belts.

Recommendations for the “support” part I can order, and “number of supports” for a span of 96"?

Thank you in advance…


Probably 2 on the long side.

I replaced the belt - and the problem is solved! Strange: but the same belt is installed on the Y axis and there is no problem with it (maybe because two belts are installed on Y and the force is evenly distributed?). I will replace the belts with a fiberglass version, thank you for your help!

They just haven’t work hardened yet. It’s the bending that breaks the wires.

1 Like