Welcome to the SeeMeCNC Community

I just completed my build of a Rostock Max V3. Everything seemed to go very well. Last night I fired it up and loaded the firmware and Matterhacker control software. I then performed a G29 calibration and it crashed down hard to the X axis. The belts are adjusted properly. I double checked the wiring. It does list I2C error in mattercontol console. I took a video of whats happening. The Z axis is set at 395mm but X and Y aren't showing the measurements. I have tried setting it in matter control settings, but it doesn't seem to make a difference.

https://www.youtube.com/watch?v=WTgfPBLu7IA

Please help,

Thanks
Clint

I can't tell from the video, but do you have the glass bed in place atop the Onyx bed? I got that same behavior with a GekoTek plate, but installing the glass let it calibrate properly.

The other thing I would check, is to home the printer, then use the LCD to move the head to the bed and set the z zero height.
Then home the printer and try recalibration. At least the printer will know the exact height to your end stops.

If all this fails, then others will hopefully chime in.

Hi Alan,

It is fully assembled including the glass plate. Ill try to 'home' the printer tonight. I struggled for 3 hours last night, finally quit cause beer was gone.

It looks like you may have the EEPROM settings for the bed size too large. Check that the max X length and max Y length are 250.
Dale

SOLVED! It turns out i had a bad I2C connection at the hotend. I tinned the wires and reinstalled and now everything is great. Thanks again for the assistance.

Clint

Glad to hear that you got it resolved.

Now clip the tinned portion off, re-strip and re-install.

NEVER, EVER, EVER, tin a wire that's going into a compression terminal. EVER.

Why? Because eventually the pressure will cause the solder to "squeeze" out, and you'll be left with a intermittent connection that will drive you crazy. If you do it on the hot end or heated bed wires, the failure will lead to increased resistance and you'll melt the connector shell on the board.

g.

I had one hell of a time seating the 28 gauge wires in the connector. For now I'll run it like this. Thanks for the advice!

+1 for Geneb's advice.

Try this experiment: Unroll a foot or so of solder, and bend it so that the unrolled solder is stuck up at a 45 degree angle to your desk. Now watch the end of the solder. It will slowly creep downwards until after a minute or so, it will be resting on the desk.
The same thing will happen inside your terminals, especially if there is any heat involved.

Don't tin wire that's going to be crimped or screwed.

If you have trouble getting thin wire to be crimped, then strip two or three times more than the connector needs, and bend the wire back on itself so that you have double (or triple) the amount of copper to grab onto.

Ok. Thanks to you both. I folded end over end and it was sucessful. Thanks again!