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Topic: Print bed seemed slightly concave at the center?

I just got my Solidoodle 3 a few days ago.  After some Leveling and Z calibration, I noticed a slight concavity of the print bed.  Any advice?  I'm still trying to pin point it with leveling print bed and Z calibration and can't say with certainty if it is a concavity or just my mis-calibrations...

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Re: Print bed seemed slightly concave at the center?

I got mine in November. Once I was done (or thought I was) calibrating everything I knew how to, I can across this discovery as well. I called Solidoodle, and they told me to snap an image of the bed with a straight edge laying on it and send it to them, informing me they would send me a new bed.

Printit Mason and Printit Horizon printers
Multiple SD2s- Bulldog XL, E3D v5/v6/Lite6, Volcano, Hobb Goblin, Titan, .9 motor, Lawsy carriages, direct Y drive, fishing line...the list goes on
Filawinder and Filastruder #1870.....worth every penny!

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Re: Print bed seemed slightly concave at the center?

Or you could just get a piece of glass cut 8"x 8" spray both sides with Aqua-net and lay it on on the Bed with the Kapton still in place.  It should stick once the bed heats up.  With no clips holding the glass it lays nice and flat.  As a plus you will have much better adhesion to the bed and it is much easier to level with a flat surface.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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Re: Print bed seemed slightly concave at the center?

A glass bed works wonders, as does a level bed. With a glass bed you might need to print one of these before adding the glass: http://www.thingiverse.com/thing:162400 (at least that was the version that worked on my solidoodle 2). It allows you to move the z-stop screw down far enough to take into account the thickness of the glass.

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Re: Print bed seemed slightly concave at the center?

Claghorn wrote:

A glass bed works wonders, as does a level bed. With a glass bed you might need to print one of these before adding the glass: http://www.thingiverse.com/thing:162400 (at least that was the version that worked on my solidoodle 2). It allows you to move the z-stop screw down far enough to take into account the thickness of the glass.

On the SD3 with the aluminum bed you shouldn't need it.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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Re: Print bed seemed slightly concave at the center?

I put a straight edge on it and the heat bed is indeed concaved at the center.  I could even slide a piece of paper under the center.

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Re: Print bed seemed slightly concave at the center?

With the bed being concave you will not get even heating of the glass because of the air gap in the middle.
If you use regular glass and flex it with clamps to follow the bed. you take a chance of it glass breaking when heated.

It has been my experience that if the bed is warped it will just get worse with use.

Ultimaker S3.

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Re: Print bed seemed slightly concave at the center?

You could wait for SD to help you out or you can stop fighting it and go buy a piece of glass.
It is one of the most recommended upgrades on this forum and you won't care if your bed is warped. big_smile

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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Re: Print bed seemed slightly concave at the center?

I took a pic with a spirit level bar on the heat bed.  The concavity is quite visible.

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Re: Print bed seemed slightly concave at the center?

I believe the print bed is simply cut from Al sheet stock which is not perfectly flat.  I have a similar problem with my bed except it exhibits a convex surface meaning is was likely assembled upside down from the way that yours was.  I am currently using Borosilicate glass on top off the bed.  I found this to be a quick and effective fix. However, if you are handy with a rubber mallet, the bed can be removed and gently pounded flat by laying across another hard flat surface and carefully striking as you check flatness with a straight edge.  I believe this has been suggested here on this forum before.  I tried it this past weekend for another purpose and it worked well.

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Re: Print bed seemed slightly concave at the center?

Any suggestion on where I could get some Borosilicate glass?

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Re: Print bed seemed slightly concave at the center?

Hi user64x, you should be able to get the pyrex glass at about any decent sized supplier of flat glass other than that I believe there are people on ebay selling various sized pieces of it.

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Re: Print bed seemed slightly concave at the center?

user64x wrote:

Any suggestion on where I could get some Borosilicate glass?

I have been using the same piece of cheap glass that I had cut at the local Ace Hardware store for seven months now and never had any problems with it.  I am running a 500 watt AC bed heater so it heats up to 108 really fast.  I thought it would crack but so far it's been fine.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

14

Re: Print bed seemed slightly concave at the center?

I fixed my problem by picking up two 6x6 mirrors last weekend. And let me tell you, 99% of my problems are now instantly gone! You can print a few of something like http://www.thingiverse.com/make:60038 to prepare for it, or just simply use some of those TINY clips (the bigger sized are at a risk of hitting the Y motor and X wires).
The thingiverse clips are only good for a print or two though until they start warping from the heat...but it gets you by until you feel like actually going out to buy some more clips!
i Just run the heat on my bed a touch longer before my first print, then the mirror actually helps retain the heat for the next print.

Printit Mason and Printit Horizon printers
Multiple SD2s- Bulldog XL, E3D v5/v6/Lite6, Volcano, Hobb Goblin, Titan, .9 motor, Lawsy carriages, direct Y drive, fishing line...the list goes on
Filawinder and Filastruder #1870.....worth every penny!