Linear Module defective and FW Feedback

Hi there,

I recieved my kickstarter A250 around 3 weeks ago and have been printing some tests since. I had the same issues as others with bed leveling so i upgraded happily to the FW with a 5x5 autolevel grid. That seemed to make things a little bit better.

I switched to PETG a few days ago and had some issues getting a proper first layer. I did several calibration runs till today the calibration run failed. It made a loud noise on moving in Y direction and didn’t move the bed to the first calibration point. Instead it drove the nozzle right into the printing bed (see first picture).

I then aborted the calibration and went on with test prints. PROBLEM IS: Although you DO NOT save the calibration process (as i used the backwards arrow in the upper left corner of the touch screen) it saves or resets the z-offset. That resulted in a printing head deeply carcing into the print sheet (see second picture)

So I tried to move the Y Axis with the touchscreen and sometimes it made that loud noise again but sometimes not. I dismantled the heating bed and the transport platform to check if it was an issue with bended parts or something.

When i then tried to move in y direction you see that one the right linear module does not move at all (see video) video of movement

I already checked if it was a faulty cable but switching them up didn’t change anything also the next step prooves that something seems to be off with the linear module.

when i try moving them by hand i can feel that with the faulty one i need much more force then with the working one (see video) video of manual movement

I opened up the upper cap (that one with no cable) to check if something was inside the module like other users reported, but everything looked normal.

I’m also contacting support@ with this issue and hopefully can get a replacement asap as I’m in the middle of printing covid masks :frowning_face:

I think the current FW needs to check the calibration process so that the offset doesn’t get saved although the whole process is canceled. At least that could have saved my printing sheet. Now it may be pure coincidence but can it be that something changed with the calibration process and the used speeds? I noticed that after a downgrade and using the calibration the loud noise happened less often.

Sorry for this confusing thread, i hope i can give some details in solving the issue.

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second picture of the carved printing bed is here as i’m only allowed to post one picture and two links in one post :grimacing:

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I am having a similar issue with the X axis linear module. I start the print, leave it alone, come back an hour later to see the print head only moving back and forth in Y and slowly up in Z. I cancel the print, can not move the X axis with the touchscreen controls. I restart the printer, X is able to move again. I start another print, same story again :confused:

Hi @Nikola, I will PM you.

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I wonder if the connector to the X-axis module is having issues? I would try plugging and unplugging the connector a number of times in order to sort of clean the contacts.

There could be something showing up in the log.

Actually, there is a silicone pad (silica pad) on the circuit bard inside the linear module, which is used for heat dissipation.
See images:

The chip will stop working without it due to the heat generated by the current.

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Hey there,

First of all thanks Edwin for the fast support! Finally (package was delayed due to unknown circumstances in Ganzhou) the linear module arrived and is now roking like a charm. I hope the silicone pad is mounted on this one :wink:

So thanks again! my issue i resolved with the new linear module!