homing problems

One step forward, three steps back again.

Just as I was getting reasonably confident with printing it's started playing tricks - the latest games are to stutter badly on the x plane & now it won't home properly; perhaps they two things are related.

The x drive seems weak & will stop and make loud clicking noises then resume to lay the next layers about 2mm too far back. I always babysit the first layers - it does this hesitation after a height of perhaps 2-3mm, when I've left the room. Of course I end with a tangle of plastic to add to my growing collection.

The motor stalls, it isn't a case of the belt slipping or the pulley loose on the shaft. If I test the push of the carriage the force is quite strong then it gives up & the carriage can be pushed back a few cms. I've fitted tensioners but it still does the same if the belt is tight or slack.

The x homing is very strange, it's now just rising as it should, moving 5mm away from the motor then lowering - no movement at all toward the motor. It's completely ignoring the majority of the batch file. I've tried another SD card in case it was that - exactly the same. If I repeat the homing command it just ends 5mm further away. I can still move the carriage in both directions using Pronterface. The y homing is not affected. All motors are set at 1000. The bed levelling won't work as the x & y homing hasn't worked.

There were no big bangs or signs of impending disaster - not even a phut. The wiring is OK, everything seems in the right place.

Could someone help? I'm again defeated & clueless.

Richard

Quote
cua193
The x homing is very strange, it's now just rising as it should, moving 5mm away from the motor then lowering - no movement at all toward the motor. It's completely ignoring the majority of the batch file. I've tried another SD card in case it was that - exactly the same. If I repeat the homing command it just ends 5mm further away. I can still move the carriage in both directions using Pronterface. The y homing is not affected. All motors are set at 1000. The bed levelling won't work as the x & y homing hasn't worked.

Sounds like a problem with your proximity sensor, or the attached wiring, or the M558 or G31 command in your config.g file, or the homing files. Check the Z probe reading in the web interface. With the head 5mm or more above the bed, it should read close to zero except when the sensor is over the homing tab. At that point it should be several hundred.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Could it be a bad linear bearing? does it get stuck when u move with no belt attached?

Edited 1 time(s). Last edit at 11/24/2015 02:27PM by Darathy.

As DC42 says, your X homing issue is due to the wrong reading on your Z probe, or an incorrect threshold vale set up.

Check that your config file has set up the correct X current - I set it to 1000mA. If that's OK, then with the printer switched off, check that all 4 wires to your X motor are properly connected at both ends, and if you can use a meter to ensure that they all have continuity.

Dave