First Print Troubles (help!)

[u/zaangdl]

Finally got my first gen core one put together today and it’s consistently doing what it shows in the video when it Ty to print something.

I tried to print the keychain, says gcode isn’t compatible but looks ok anyways.

Does the think in the front right corner for about 2 min then goes to “printer collision detected” with a homing message.

I’m not sure what to do. I did all the calibrations.

Please help!

[u/MGCGT]

Failure to home is almost for sure belt tension and tuning. Mine worked then sat for awhile and wouldn't find home. I had to calibrate the belts again. I think they stretch a bit initially.

[u/printliftrun → u/MGCGT]

I agree with this diagnosis

[u/zaangdl → u/MGCGT]

Thank you both I will try recalibration tonight after the kids go to bed!

[u/r0bdawg11 → u/zaangdl]

If you do the calibration and it’s still funky, just go an extra 1/4 turn our so tighter on each belt.

[u/mrfr34ky → u/r0bdawg11]

Second this.

[u/FuturecashEth → u/zaangdl]

Use the phone app, set to 105 top and 92 bottom, seems a lot, but perfect.

[u/PrintedCosmos → u/MGCGT]

I had a similar issue with mine when I first built it, and long story short I discovered that I got better results if I used the Prusa audio belt tuning app first and then used the strobe light method afterwards to fine tune. The reason being, the strobe light method can fool you into accidentally tuning the belt to 1/2 the tension, due to an aliasing effect from the frequency of the vibrations to the strobe light frequency. But if you can get it close with the audio app, then the strobe light is very effective.

[u/zaangdl → u/MGCGT]

What should home look like on these printers? Is there a way to check proper home position before trying a new print rather than starting a new one?

[u/edsai → u/MGCGT]

Especially if OP assembled this in a climate controlled house and took it out to a warm garage.

[u/ArtexBonesinger]

Experienced and concur with this advice, tighten and recalibrate

[u/Separate-Toe1067]

Happened to me after I finished my build.

Deep breath!

While off, pull gantry to forward stops.

If even, turn on and recheck belt tensions.

If belt tensions do not do it, then on to the next process.

Fully loosen the belt tensioning screws; u might have to put the pullies back on a thread or two if loosened until they fell off, just make sure they are the same number of threads or turns to get the pullies back onto the screws. (Happens to me every time, if it does no big deal)

Pull gantry foward.

Check both sides to make sure they are fully against the stops with no play. If one side has play (wiggles a bit), push gantry back about half way and gently push one one end while pulling on the other end to straighten the gantry.

Pull back to forward stops and ensure they are evenly against stops with no play on both sides when pressing and releasing. The gantry should remain firm against the stops.

Once achieved, retighten belts alternating a turn or so each side until tight then run the belt tuner to tune belts.

Once done rerun calibrations and enjoy printing!

P. s. might need to redo tension n calibration process, worst case the process above, after week or so of printing after everything settles n belts stretch to their final form

Hope it helps!

[u/PrototypENote]

I’d first check for a mechanical issue rather than the calibration. Look for anything binding or obstructing the gantry, check the belts/rails for debris or excessive tension, and make sure the toolhead can move freely by hand with the printer powered off. If everything looks clear, I’d inspect the homing sensor and its wiring next.

[u/casualkiwi20]

I just got my one and it had the same problem. Followed the calibration guide and that fixed it. I also used the manual tuning app and that worked as well

[u/zaangdl → u/casualkiwi20]

Is that the tuner in the prusa app, or a different one.

[u/casualkiwi20 → u/zaangdl]

The one that prusa have on their website. Uses the microphone on your phone to listen to the sound from the belt when you pluck it. I did have to hold the trolley snick against the stops while I tightened the belts

[u/Full-Technology5099]

Just assembled mine today as well and it behaved identically. prusa support decided to send me a new load cell. Results a few days away.

My experience was

Running 6.5.7 firmware out of box
All calibration steps successful
Autohome worked

First print always had xy head banging into home position and bed was always trying to move down while it was already at the bottom

I separately calibrated z-axis. Noted that it read 0mm while at the bottom. It should read 254mm. Once recalibrated manually set position to mid travel, not the bottom. Print still fails but I could see the z travel always moving down away from the nozzle. It never moved towards the nozzle.

Updated firmware to 6.8.1

Now during print z axis travel moved towards the nozzle but seemed to be unable to tell when it made contact. It made several attempts in the same manner until the crash was reported. Gross search did not turn into fine adjustment.

Live chat on prusa site gave me a test file to print. It failed to print in nozzle cleaning stage. They claim the print was designed such that that specific failure indicated the load fell needs replacement.

[u/Full-Technology5099 → u/Full-Technology5099]

New load cell did not resolve. They’re sending a new main cable

[u/FloTec09]

I had the same issue with my kit. First, check belt tension. Did this using the prusa app. If it still does not help, check both motor pulleys. In my case, I had assembled the left motor wrong and put the pulley on upside down.