Cura and UMO+ - bed size

[dampmaskin 0]

Hi. I have configured Cura 15.04.5 in Machine settings to have a print bed size of 210 x 210 x 205 mm as advertised on the UMO+ page (https://ultimaker.com/en/products/ultimaker-original).

But when I try to put a model measuring 195.4 x 197.5 x 4.4 mm in Cura, the model shows as grey, and Cura refuses to calculate the print time.

To make the model yellow in Cura, I need to scale the model down to 96%, which means 187.6 x 189.6 x 4.2 mm.

I had the same situation in 15.04.04.

I have tried "Center on build platform", and I've tried rotating the model 90 degrees. What am I doing wrong?

Update:

Size Y = 191.016 mm gives me a yellow model, but y = 191.018 mm gives me gray.

When I rotate the model 90 degrees, the size X behaves in exactly the same way.

Update 2:

I realized that I can trick Cura by setting the build plate to 250 x 250 or something like that. I suppose everything from now on is at my own risk. I still don't understand why the configured limit is one thing, and the real limit seems to be somewhat smaller, but I think I'll make do anyway.

Maybe it has something to do with brim/skirt? Both are disabled, but maybe they play a part regardless.

Edited March 22, 2016 by Guest

[nallath 567]

Brim influences this, same goes for the bed clips.

[dampmaskin 0]

Thanks. It sounds logical.

Now to increase the countersinking in the heat plate, so that the glass plate lays flat on it without resting on the corner screw heads, so that I can utilize all of the build plate without the first layer getting squashed to zero thickness near the corners.

I'm guessing this will give me a more even and maybe higher build plate temperature as well.

Edited March 23, 2016 by Guest

[neotko 1,361]

There's a trick to check the bed but it's quite nasty to do.... using a bit of oil on a microfiber cloth on the back of the glass and checking the contact spots, the problem it's that it's a mess to clean.. so dont do that.

If your Screws don't go 'all in' and make the glass miss contact with the heating bed, check this post and the solution by gr5

https://ultimaker.com/en/community/10335-glass-plate-not-flat

[dampmaskin 0]

No need to check: The gaps between the heat bed and the glass plate are clearly visible. The glass plate is resting on the screws. I actually contacted UM support about this when the UMO+ was new, but they didn't get what I meant, so I figured it was probably not that important, and let it go. But now I need to be able to use those corners, so it's DIY time.

Great idea about simply using a larger drill bit instead of a countersink bit. That means I don't have to go buy anything.

Will try to do it with just removing the glass and the screws, but not the whole heat bed. I should probably carefully vacuum the printer afterwards, to get rid of any metal shavings. Don't want them to find their way into the electronics.

Just have to wait until the current print is finished.

Update: Even a cheap drill bit cuts the aluminium like butter. I used two different sizes, and managed to get the screw heads level, or in some cases below, the heat bed. Of course I overdid it on one hole, the drill bit chewed in, and I ended up with an ugly, jagged ellipse instead of a nice round hole. Still, it worked. My bed is now practically level, and I believe I can use all of it (avoiding the clips, of course). Mission accomplished.

In hindsight, I should have had seven M3 washers ready, because now that the screws sit lower into the heat bed, the nuts bottom out on the screws before everything is snug. The result is that the glass plate clips are slightly loose and wobbly. It hasn't proven to be a problem yet, knock on wood, but I'm still on my first print. If I put some washers between the nuts and the heat bed, the screws will sit tighter and the clips will be more stable and snug again, so sooner or later I will probably do that.

Edited March 23, 2016 by Guest