Intractable bed adhesion issues

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dramsey
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Re: Intractable bed adhesion issues

Post by dramsey » Thu Mar 17, 2016 4:49 pm

Jim, I can't set more than one decimal place in "Z Axis Origin Offset", so I guess that's not actually where I set global offsets in Simplify3D. Nor can I figure out where to do so...

EDIT: Never mind, found it.
Last edited by dramsey on Thu Mar 17, 2016 5:30 pm, edited 1 time in total.

dramsey
Posts: 124
Joined: Tue Feb 16, 2016 6:07 pm

Re: Intractable bed adhesion issues

Post by dramsey » Thu Mar 17, 2016 4:51 pm

Tim wrote:
dramsey wrote:Won't stick to blue tape, either. I'm beginning to think there's something wrong with this role of filament.
Bear in mind that if this is a new roll/color/brand of filament, especially if it is a brand you haven't used before, then you can be having multiple issues combining to make life difficult. Fixing the gap to the bed is certainly the most important thing. But you may have to tweak your bed temperature, your extruder temperature, and/or calibrate the extruder multiplier as well to get back to the automatic print-and-go. You might also have exascerbated the situation by choosing a print with a lot of sharp travel reversals, which are always the most difficult to get to stick on the first layer. Making sure you are printing inner perimeters first, outer perimeters second can help, as the inner perimeter will likely have fewer sharp reversals. The outer perimeter is the one you care about, anyway. If the inner perimeter ends up with some defects, it won't show, and the print will probably recover after a couple of layers.
Same roll of blue Makergear PLA I've been printing with for weeks now. I do think it's multiple issues, although what caused them to appear so suddenly after over 100 successful prints is a mystery.

dramsey
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Re: Intractable bed adhesion issues

Post by dramsey » Thu Mar 17, 2016 6:26 pm

OK, I think I may have found The Original Problem. And Jules' and Jim's suggestion of adjusting the Z Offset was the key.

Like many of you, I obsessively read the forum waiting for my printer to arrive. There's a thread on printing a 2mm calibration cube and using it to set the Z offset for the filament you're using.

I did that when I got the printer. Don't recall the Z offset but it was a small negative number.

Somewhere when I was playing around, I started over with the default process parameters and forgot to update the Z offset, so it was zero.

After a morning of obsessive head-plate distance settings and bed leveling, I printed the calibration print and it was....2.04mm high.

So I set the Z offset to -0.04mm (I'm sure it was just a coincidence that this is the exact value Jules recommended) and I think I might be out of the woods.

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Jules
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Re: Intractable bed adhesion issues

Post by Jules » Thu Mar 17, 2016 6:54 pm

dramsey wrote:After a morning of obsessive head-plate distance settings and bed leveling, I printed the calibration print and it was....2.04mm high.

So I set the Z offset to -0.04mm (I'm sure it was just a coincidence that this is the exact value Jules recommended) and I think I might be out of the woods.
Coincidence my ass.....I'm that good, dude! 8-)

(Okay.....maybe it was a co-inky-dink!) :lol: ;)

Are you guys seriously going to let me get away with that BS? :lol: :lol: :lol:

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PcS
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Re: Intractable bed adhesion issues

Post by PcS » Fri Mar 18, 2016 12:43 am

How much are you paying him ??? ;)

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Jules
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Re: Intractable bed adhesion issues

Post by Jules » Fri Mar 18, 2016 12:47 am

PcS wrote:How much are you paying him ??? ;)
(Shoot, he figured it out.......) :roll: :lol:

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jimc
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Re: Intractable bed adhesion issues

Post by jimc » Fri Mar 18, 2016 4:31 pm

:lol: :lol:

dramsey
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Re: Intractable bed adhesion issues

Post by dramsey » Fri Mar 18, 2016 4:59 pm

Here's the post-mortem on my situation. May it serve as a cautionary tale to other newbies.

My original problem was that after a couple of weeks and over 100 prints with Makergear PLA on bare glass, I started having print adhesion problems. At this point the problem was that the glass wasn't perfectly clean.

However, I didn't understand that, and started doing all kinds of things: adjusting Z-stop height, bed leveling, playing with new params in Simplify3D. At some point in playing with Simplify3D, I managed to start without the calibrated Z offset that I'd been using previously.

All this made things much worse. I sure wish there was a way you could write-protect Simplify3D process defaults, so that changing anything would force you to save under a new name. But anyway...

After many hours I'm back to printing again...on bare glass even (I wipe it down between prints with a microfiber tower and 100% alcohol, which you can buy in cans at Home Depot. Even so, try not to touch the bed surface with your fingers.)

The solution consisted of fixing everything I'd screwed up originally:

1. Adjust head gap in center of bed to 0.15mm using feeler gauge
2. Carefully level bed using 0.15mm feeler gauge
3. Print 2mm calibration cubes at several points on bed. I used top left, top right, center, bottom center.
4. If max difference in cube height is 0.05mm or less, use the largest deviation to set Z-offset in Simplify3D. Goto Step 6.
5. If max difference in cube height is > 0.05mm, Goto step 2.
6. Done!

And at least if I see bed adhesion problems in the future, I'll know that I just need to bust out the glue stick. Of course, my PEI and tape should arrive Real Soon Now, so that should set me up for good. RIght?

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Jules
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Re: Intractable bed adhesion issues

Post by Jules » Fri Mar 18, 2016 5:49 pm

Yep! As long as you keep the gap set correctly. ;)
(You're gonna love the PEI). :D

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ednisley
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Re: Intractable bed adhesion issues

Post by ednisley » Fri Mar 18, 2016 6:45 pm

dramsey wrote:The solution consisted of fixing everything ...
Now, if we could just convince everybody to use those squares as a confirmation test, we'd be set: until you can print simple squares correctly, you can't print anything else correctly, so don't even try.

Asking whether a few thinwall squares have verified the Z Offset and platform alignment (among other things) should be right at the top of our "Have you done this?" debugging tree...

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