P3Steel - Great except origin corner issue....

Hi Everyone,

I've got my P3 Steel re-built and running really close to perfect with the exception of the Front-Left corner of any print keeps curling up while printing with PLA for the sake of clarity I will reference test printing a 20x cube. It's clear to see that when the printer draws the Front-Left corner of the test cube(or any print) it does not execute the corner smoothly like it does other corners -there is a little jolt or jerk most easily seen when printing skirt-loops or the first enclosed layer. It's clear from testing various print settings that this corner is not getting pressed into the bed as tightly as the other print corners but its limited to the spot right on this corner. The first layer outlines look perfect and are well squashed into the bed elsewhere.

It almost feels like this jerk produces a "lift" of some sort that pulls the corner up, there is always a little residual bump on the layer right before the printer makes the corner. - spent the morning reveling everything to no avail so I decided to ask the question and take a break.

I can minimize this issue by increasing first layer height to 150% and first layer width to 150%(typically I try to keep these both @ 100%) the corner still warps a little but I've been able to print 10+ hours of successful parts with that hack. But in my mind this shouldn't be necessary because the issue is isolated to just this one corner.

- bed level, Belts, Jerk, Accel all tuned
- Printing Red PLA @ 70 bed, 225 HE
- First layer speed is 10mm/s

Ideas I haven't Tried:
- Increase retraction speed from 30mm/s to 60?
- Try using a different slicer, currently all tests have been done using S3D... don't think this makes sense but?

I'd be thankful for any other pointers or directions to pursue at this point.

Cheers!

Andy

Edited 1 time(s). Last edit at 02/20/2016 02:09PM by atheimer.

Ancient Chinese proverb say "one picture is worth a thousand words"...

Try putting a steel ruler on the bed to see if it is flat.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Here you go, I've leveled, re-leveled, put the printer on a different surface and no change.... This corner simply will not stick. If I put the nozzle in the problem corner area and go to Z0.00 a piece of paper slider perfectly underneath, dragging as it should. It's almost just like the aluminum sucks there and everywhere else its fine.

Anyhow, here the pictures:






The best idea I was able to find was to decrease the XY travel speed, thinking it was pulling to fast to the new perimeter or area but that didn't help.

Edited 1 time(s). Last edit at 02/20/2016 10:57PM by atheimer.

OK, now that is weird. What happens if you put the print in other parts of the bed - is this a problem just with that specific area or does the problem move with the print?

Edited 1 time(s). Last edit at 02/20/2016 11:07PM by JamesK.

I'll give that a try tomorrow, I've spent the better part of the day on this one... thank you very much for your reply!

Are you trying to print directly on the aluminum? Usually you want to put something like a layer of kapton or blue painter's tape on it. If there's any oil on the aluminum at all you'll have a hard time getting anything to stick to it.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I must get around to trying out the kapton tape at some point. The glue stick works well enough that I didn't feel the urge to try the tape, but it does leave a white residue on the prints and it would be good to know the characteristics of kapton in case the glue stick lets me down.

Based on some of the last comments I dug up a piece of glass I had somewhere and put that on the MK3 bed. The glass was off the bed a hair in the corner giving me trouble.. FYI this was not detectable using a steel T-Square as previously suggested.
I clipped that sucker down, re-leveled, and just printed a perfect cube.

You would think a 5mm MK3 ALU heatbed would be perfectly flat but still.... it deforms under tension.... or its crap from the supplier. sigh...

Well, I have a sheet of printbite that I was going to use anyways so I just have to decide if I want to use glass long-term or find a level bed.

Thanks for your input on this one, definitely helped me get in the right direction.

If you want flat aluminum you have to buy flat aluminum- cast tooling plate. It comes milled flat.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]