Stuttering X-Axis

[Infrisios]

Hello,

I've got a GEEETech i3 pro c with a lot of problems, the only axis that worked from the beginning was the Y-Axis.
Got the Z-Axis to work reliably with some custom modifications, now the X-Axis and the extruder are the remaining issues. This thread is about the X-Axis.

The problem is that it doesn't move reliably in the positive direction and stutters often, as shown in this video:

https://youtu.be/-3juftd6uNM
(worst stuttering is visible around ~30 seconds in)

The other direction works fine, I can always send it home reliably.

The extruder block can be moved easily by hand and even if the motor stutters, pushing it VERY lightly is usually sufficient to make it move. I do not see any mechanical issue that could create friction strong enough to prevent moving.

Any ideas?

[Gingko]

Maybe you can try these:
1, Tighten the belt of X-axis first, it seems not tight enough.
2, Check the voltage of A4988 of X-axis, adjust it to around 1.1V.

[_kaktus_]

Hi


I am curious how you set the head movement?

You have sent the G0 command with the parameters or you can click on the movement button several times.

If the second option applies, then it is all right.

[Infrisios]

Hi


I am curious how you set the head movement?

You have sent the G0 command with the parameters or you can click on the movement button several times.

If the second option applies, then it is all right.

I used the movement buttons, but that doesn't mean it should stutter within a single movement command.

Maybe you can try these:
1, Tighten the belt of X-axis first, it seems not tight enough.
2, Check the voltage of A4988 of X-axis, adjust it to around 1.1V.

The belt was relatively tight when I started, loosened it a bit to test around which is why it was loose in the video..
I adjusted the voltage and it solved the primary stuttering issue. Also helped the extruders extrude reliably. Thanks a lot for that tip, I didn't know it was possible to set the voltage!

However, another issue arose during my first printing test: The movement in the positive x-direction (away from home) is slower than that in the negative direction. That means that movement along the axis creates an offset towards home until it reached home, so the extruder prints next to the heating bed. Any ideas for that?

I'll try to tighten the belt more and tinker around with the Voltage for now, but the offset is over 25% of the movement, so I doubt it'll help.

[_kaktus_]

Hi


Did you lubricate the linear guides with oil?

Try using Home X and then:

Code: Select all

G0 F5000 X200

for right-hand traffic, The parameter F determines the speed (e.g. 1000-10000)

Code: Select all

G0 F5000 X0

for left-hand traffic


Do various tests and present the results.

[Infrisios]

If I try that it does not at all move in positive direction (just hums a bit) and (if I manually moved it to X200 before) VERY fast in negative direction

[_kaktus_]

This can be a mechanical problem with the head cartridge.

What Vref voltage have you set on the specstick module?