Bed calibration out of wack.. Looking for a bit of advice

[travelphotog]

So I am a bit at my wits end here guys. I am having an issue which I have worked to solve for about a week or so and i have come up empty each time. So here is the deal. Since I build my Max V2 it has printed like a champ and never had any major issues overall. I even moved it across the country in a giant tank of a crate standing upright and it arrived perfectly, I just gave it a fast calibration and it start printing like a champ right away after the move. All was perfect in my 3D printing world until... I was asked by one of the guys at the makerspace to bring the printer down to a local community event for some kids to experience 3D printing in person. Of course I jumped at the chance to share 3D printing with some local kids and they LOVED watching the printer make a Spitfire wing over the course of the afternoon. While at the event the printer worker perfectly and the spitfire wing was a great sample print as it uses almost the entire bed size and the delta arms were moving all over the place and the kids loved it.

So here now is the rub.. I brought the printer home (placed it on a few blankets laid down and secured it in with a few towels on the sides and drove the SUV nice and SLOW there and back on smooth roads) and put it back in my office. Not a single issue in transport and I was by the printer's side the entire day and nothing hit or messed with it at the event. But right away I noticed an issue when I did my next print. At 12 and 6 the head seems to "dive" down super close to the bed. at around the 3 and 9 areas it seems to raise up. the further out on the bed the worse this gets.. Ok no matter, a fast calibration should fix this I thought.. Sure enough it was a bit off and I got it all dialed back in with my dial indicator and thought that would be that.. Nope... It is dead calibrated but still has the same issue in the same spots... Rechecked the calibration and it was spot on... Issue still there.. OK... Center still printed ok and I had some small stuff the kid next door wanted printed, so I threw a few prints on the plate and they did well enough in the center area. Next day go to print and bed heater is not working.. Hmm ok... Check that issue out and find the 12V in on the RAMBO cooked off and was melting.. OK... Did a 24V conversion with Meanwell 500W power supply and a Crydom SSR following Nightwatchman's posts.. Just removed the screws to the top plate below the bed and raised it up. Installed everything it worked like a charm the first time i fired it up. OK...

Put everything back together and recalbraite thinking of COURSE now the issue from before will be gone, I just took the printer half apart right? Nope... Not a chance... Still same issue in same spots... OK.... Time to get drastic I guess... Went around and loosened all the upright screws on the top and bottom supports.. Check that everything is reseated and all looked fine.. OK tighten it all back up, re-calibrate and bam.. Same issue, same spots... Grrr Time to consult the experts and find out what silly, right in my face issue I have overlooked to cause this.

I think what is really driving me mad is not just the issue, but this is the last thing holding up our release of the aluminum and carbon fiber mounts... I need the printer working 100% (as it always has) to print the mailing boxes for the mounts so i can ship out the mounts. We are releasing the web link tonight for early orders for folks who gave so much ffedback and such early on and the main site will go up Friday for publis sales.. But I need the mailing boxes to fill orders so I have to get this issue sorted out, not to mention i have other paid 3D prints in the wings waiting.. I can not keep up with plane orders right now as it is!

So here is a shot of a calibration ring I made and use to check the bed.

12 and 6 are thin.. 9 and 3 are raised up too far above the bed....

thin at the 6 position.

not much better at 12 by the Z tower.

9 are is so high that it is not even pushed down at all on the bed, head is 1-2mm above the bed here.

About the same around the 3 area. Raised and not even within 1mm of the bed.

Center looks pretty good over all. I made the Y tower line thicker to keep track of orientation once I remove the pattern.

I am open to any ideas.. I'm sort of at a loss right not short of flashing the Max and start over dead from scratch which I would like to avoid unless someone feels that is my only choice. I know that someone will know the fix here. it just escapes me right now. My thought was I bumped something in transporting the printer to the event.. But after doing the 24V conversation (which I LOVE and recommend to anyone doing lots of prints!) and checking the towers.. I am sort of at a loss. Thanks for all the help in advance guys. Above all it is the community around the Max that helps to make it by far one of the best DIY 3D printers.

[geneb]

You might try building yourself a Poor Man's Z-Probe (alligator clip on one wire, 0.1mm feeler gauge on the other) and give OpenDACT a shot.

Did you rotate your bed glass at all after you recalibrated?

g.

[travelphotog]

I did not move the glass or anything after calibration. I have always used my effector mounted calibration dial and it works great. It is telling me that all 4 points are zeroed out. Yet I started getting this odd pattern on the bed after coming home from the event. I have always calibration with the effector plate mounted dial indicator and used the "old" method it seems.. I would set Z zero to be 1/2" above the bed so the dial reads "0" or 1/2" above the bed. Then i would do to each tower and get all 3 zeroed out. then check middle... Adjust the horizontal radius then recheck each tower until all 4 points read zero. This was done with the bed heated to 65C. I would then remount the hot end, heat it to 125C then set the Z zero with a feeler gauge.

Reading the new guide I see this has changed (or I misread the old way?). So thinking to flash to the newest firmware, mount the dial indicator and re-calibrate with the new method in the guide and see how it goes from there.. At the very least I will have the new firmware on the printer at last. I had not changed over to it yet since until now it has worked like a champ.

I have been using this for calibration.

OK I googled openDACT but came up dry.. I am sorry to admit I am not really sure what it is but I am willing to try anything if it will get my printer back up and going.

[teoman]

I doubt it is related but check you limit switch screws (the ones that hold the switches). I recently discovered that mine were loose.

Check the recent threads.

[geneb]

Here's the thread: http://forum.seemecnc.com/viewtopic.php?f=36&t=8698

Since you've already got a rig to handle a gauge, scroll down to the "Manual calibration" heading in the first post and follow that guide. The calibration process has you entering data from your gauge as the g-code (listed in the post) runs - you enter the data in a program that runs in a browser (local to you).

If you build a z-probe, you can run the automatic version that he's written. Once it becomes a MatterControl plugin (I think mhackney is working on that), people with Z-probe equipped machines will never have to do a manual calibration again.

g.

[travelphotog]

Thank you! I will get on this today!