Recalibration after a 'crash'...?

[AlanZ]

As they say, "no good deed goes unpunished"

A few days ago, I attempted to make a print that pretty much filled the bed from side to side.
Unfortunately, the effector plate crashed into the Y-Z plane lexan panel of my enclosure, and this forced the hot end into the build platform.
That was embarassing, and I should have known better.

However since then, my calibration is way off. I used to be within .02mm when doing the tower calibration routine, and now I'm off by .2mm in some spots.

I checked to see that the towers were still vertical, and perpendicular to the bed, and that all seems fine.

I don't quite understand why a crash like this would throw the calibration so far off. I am assuming that the crash was the cause, but who knows, it could be coincidental.

Is there anything else I should check before biting the bullet and adjusting the end stop screws to try to realign everything?

Thanks?


Thanks,
Alan Z.

[Xenocrates]

Belt tension, carriage adjustment (If you don't have the injection molded ones), joint friction (in case any have seized. Should only apply to really old ones), and endstop firmness (You may not have noticed them coming loose over time. Can't be sure.)

[teoman]

Check that the effector platform connections were not damaged.

Besides that i cannot think of anything.


Btw, i prefer to use the eeprom instead of fiddling with the screws.

[AlanZ]

I can't see any issues with th effector plates. When I saw how badly the calibration was off, I switched to another effector plate that has a digital indicator mounted to it, and that confirmed the error I was seeing.

I don't have any instructions for calibrating via the eeprom values (vs end stop screw technique) is this documented? Is there an advantage of one technique over the other?

[teoman]

Screws are fiddly in my opinion, with the eeprom you mostly use an excell sheet to do the calculations and input to software.

[teoman]

http://forum.seemecnc.com/viewtopic.php ... obe#p44817" onclick="window.open(this.href);return false;

[DeltaCon]

I used to be within .02mm when doing the tower calibration routine, and now I'm off by .2mm in some spots.

Check the firmness of the distanceholders under the bed. Probably one is squeezed a bit. I assume us use the glass to print on, so that is probably pretty even. In my view the endscrews are just there for this kind of correction, so I would not hesitate to adjust them to get things right again.

Oh, check the arm mounts on the cheapskates, did one of them slide a bit or got loose during that "exercise"?

[Eric LB]

In my case post crash calibration was thrown out by the fact that I had not completely seated the three screws that hold the inner and outer carriage halves together around the towers. If those half's can spread apart even minutely, it affects the effective length of the Delta arm on that side of the carriage. That was my problem - not discovered until I had wasted days recalibrating and recalibrating . It's real subtle, but very real effect. I was pullinv my hair out till I found it. Also causes a slight tilt in the effecter plate. Hope this helps. You can compensate with the stop screws but the calibration won't hold after rapid moves or another crash .