Auto_Bed_Leveling: Enhanced G29 command

[Roxy]

That's how I do it, too. A solid spacer at origin, and springs on the other 3. I also have the Safe Z Homing set to go to X10 Y10 instead of the centre of the bed, to always home on the unchanging corner.

Do you get a slight bow or bump in the center of the bed because of this? My guess is if the springs are pulling down at all you will see a bump.

[AbuMaia]

Yes, I do have a slight hump in the middle, but the springs are pushing up on the bed, not pulling the corners down.

Recv: Bed Height Topography:
Recv: --0.05021 --0.00271 +0.00104 --0.05196 --0.15621
Recv: --0.02296 +0.05454 +0.08254 +0.02554 --0.09296
Recv: --0.02321 +0.05554 +0.09354 +0.04929 --0.07521
Recv: --0.02246 +0.05329 +0.08929 +0.06579 --0.02796
Recv: --0.05021 +0.02954 +0.05879 +0.05604 --0.13871

Can I say again how much I love this enhanced code? Yes, it shows me I have a slight hump in my printbed, but it also shows me that it's damn near perfectly level, too.

[DarkAlchemist]

That bump looks like it is due to your probe being there. Mine was really bad so the only thing I could do with it is make the bed NOT level which removed the bump (due to the boro glass being perfectly flat) then the ABL worked flawlessly. I wish I could fix the level and the bump manually but I couldn't after several hundred hours of trying. Now I live with it and ABL happily does its job.

[AbuMaia]

You mean it's showing how much the glass is flexing from the probe coming down to touch it? Awesome

[DarkAlchemist]

You mean it's showing how much the glass is flexing from the probe coming down to touch it? Awesome

In your case YES. I was seeing the same thing until I removed the thermistor then I lifted the entire setup higher so the thermistor was floating in the air (basically) and the bump was gone. The only issue I finally had, that I could not correct on the I3, was that it refused to go level. So, yeah, that bump is probably your thermistor and if you could see the actual stress (I forgot what camera testing setup does this but I saw it once) you would see how it pokes in the middle and goes down like a stake in a tent until it finally rests again. This is how much Z has in resolution to allow us to see this.

Pretty awesome stuff actually, heheheh.

[AbuMaia]

I don't see how it could be the thermistor. It's on the opposite side of the heatbed from the glass. And the heatbed is suspended above the wood platform by one spacer and three springs.

[DarkAlchemist]

Might not be in your case (the heated bed needs a thermistors in the middle if you are using a heated bed) but are you using boro glass? Plain window glass isn't as stiff, nor as flat, as boro glass and it was the best 25 dollars I spent on this printer BECAUSE nothing else worked.

[AbuMaia]

Nope, using glass from Lowes. Don't know where to pick up any borosilicate.

[DarkAlchemist]

Yep, I tried dollar tree glass frames (was 1/16in thick and far too thin to even cut and I had to buy 5 before I said eff it due to that and how it was flexing so easily). I bought one from Lowes that they cut for me (was 1/8 inch thick) and it helped but still no go as it would flex downward by a small amount as soon as I put the clips on. So I bought the Borofloat glass for $24.99 delivered and never looked back. My seller is no longer selling any but here is the alternate one I was going to buy before I found his excellent price - http://www.ebay.com/itm/Borosilicate...item3388c8d3a8

Mail http://www.ebay.com/usr/bluskreen?_t...10.m2749.l2754 (bluskreen who was my seller) as he will respond quickly and is in the USA.

[AbuMaia]

What's with the odd dimensions? 214x200. I might need to get the corners cut off at that size.