Switching to Ultrabase bed + custom bed probe: How to modify firmware?
Hi there,
For easy print removal I purchased an Ultrabase bed by Anycubic. I am aware that the Pinda probe will not sense the steel bed through this 4mm thick glass plate. Therefore I purchased a different sensor, which has can detect metals from 5mm, and since the glass sheet is 4mm, I assumed this should work. Indeed, by hooking up the sensor to the board, I figured out that it worked. See pictures: https://imgur.com/yigEnWw
https://imgur.com/wsNXzgu
Now I am wondering, what do I need to change in the firmware to account for these changes. The bed size has changed (as the glass plate is 200x200, instead of 250x220), see image: https://imgur.com/DjgHH6e . This needs to be adjusted in the firmware somehow. And of course the new sensor is a NO (normally open) sensor, instead of the Pinda sensor being NC (normally closed).
I imagine that I will also need to play around with the Z offset of the probe, to get it to take into account the thickness of the glass sheet. Also, I couldn't really find out how I indicate that the effective printable area is just slightly smaller than the original Prusa bed.
Thanks in advance for your help!
Best regards,
Ludo
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
Inbelieve you can alter the bed size and Z height, in Slic3r
put the glass in the front left hand corner. 
As you are sensing past the glass, you shouldn't need to adjust the bed size in firmware, bed levelling should still work on the original bed under the glass (assuming you have steel under the glass there)
, otherwise the bed sensing will be flakey off the copper...
regards joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
Thanks Joan,
Since the bed is smaller, I will need to change the position of the mesh bed levelling points, but I think I figured out how to do this.
What about the fact that the sensor is NO instead of NC? I'm assuming I should invert this in the firmware somewhere.
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
I tried a glass Ultrabase and found it to be less than useful on a Prusa so I bought an Ender-3 to use it.
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Chuck H
3D Printer Review Blog
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@joantabb
Hi , Joan
How should I install my 220x220 ultrabase on my MK3 ? I have the original sensor , original Prusa Heatbed , as well as the new aluminum heatbed that comes with the Ultrabase.
Can I use the glass on my original Prusa Heatbed?
How will I go about the levelling/calibration , and how do I compensate for the 4mm thickness of the glass ?
I am an absolute beginner , I don't want to make assumptions on how to do this.
Thanks in advance 🙂
Jo
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
Hi Jo,
If you just want to temporarily print on the glass bed, I think this website can help you out: https://mattshub.com/2017/04/11/printing-on-glass/
If you're looking at changing to the Ultrabase permanently however, then there's some more work involved. I got it to work, but I had to change to a different bed levelling probe (strong enough to sense the steel through the glass), and thus had to print a modified extruder part to accomodate for this new probe. Besides this, the new probe was a NO sensor, which had to be changed in the firmware. If you want to do this, I can give you a more detailed explanation. See pictures here: https://imgur.com/a/y4fIuq7
Cheers,
Ludo
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
I tried a glass Ultrabase and found it to be less than useful on a Prusa so I bought an Ender-3 to use it.
Charles, you really do try everything. Doesn't that basically turn your expensive Prusa Mk3 into an inexpensive Anycubic i3 Mega? I'd expect ringing on Y to be bad with all that extra weight unless you drop speeds. Part removal less convenient. Is there any gain to doing this?
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@bobstro
you get a shiny bottom... 🙂
I had a glass bed on My Mk1...
I did not like it!
in my experience it was difficult to get the models to stick without using additives like ABS Juice, glue or painters tape...
and the additives tended to build up on the glass where the prints did not stick, making the clean up after a print, a bit messy...
however I believe glass works better than ultem/pei with some of the more exotic filaments and
Glass should be FLAT!
perhaps FLAT should be in capital letters, because some users of the mk1 used to complain that their glass was not flat...
Prusa used Borosilicate Glass, (High temperature glass) some folk used Ikea Mirror tiles...
occasionally a print would stick so well that it would tear a sliver of glass out of the build plate. which was neither good for the build plate, nor the model.
the glass was held down with bulldog clips which often got in the way... (at least the Mk2 and Mk3 printbeds have a non printable margin around the edges front and back which would make this less of a problem)
regards Joan
Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@ludolambers
Hi Ludo
Thank you so much. Additional info on the process + what I should buy will be really helpful as I am looking to use the ultrabase permanently.
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
Allright, but I must warn you that it's not an easy process, and I recommend only doing this if you know what you're doing (it would be great if you have some experience with fiddling with 3D printers). Another thing: I used just the ultrabase glass bed, not the glass+heatbed combination. So in your case it might be a little different, and I'm not sure how I would go about replacing the entire heatbed with the one you have. To be honest, I would suggest to just use the glass plate and leave the heatbed as it is.
The Ultrabase glass has some adhesive tape underneath, I used this to stick it onto Prusa's original PEI coated bed. If you want to hold onto the original Prusa bed, than you can also use a sheet of steel or aluminum (cut to the same dimensions) to stick beneath the glass bed. Without this sheet of metal beneath the glass, the bed levelling probe won't be able to detect it (for some reason Prusa's heatbed alone does not trigger it).
I switched to this bed levelling probe: https://www.aliexpress.com/item/32799682123.html?spm=a2g0s.9042311.0.0.27424c4dl3uqyN
The adapted extruder part to accomodate for this new probe is added in a zipfile (see bottom of the post). Print it, and replace the original part with this one to attach the new probe.
Lastly you will need some slightly adjusted firmware. Since I already did this, you can just download the firmware package (zipfile), and flash it to your board (more info on how to do this you can find here: https://github.com/prusa3d/Prusa-Firmware)
Download the zipfile here: https://we.tl/t-YLzwz201hZ
Good luck!
Ludo
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@ludolambers
Thank you so so much for this !
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
Hey @ludolambers (or anyone who can help),
Can you say what changes you made to the firmware? You had said, "Since the bed is smaller, I will need to change the position of the mesh bed levelling points, but I think I figured out how to do this." I think this is the issue I'm running into on my project https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-user-mods-octoprint-enclosures-nozzles-.../build-prusa-i3-with-spare-parts-after-upgrades/
I have been banging my head on a wall working out different issues I'm come across over the past couple of weeks.
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
As for that prox sensor in the link... wow. I wonder if I should start selling my Z-Axis upper supports, but charge extra if I print them in Submarine Yellow or even a gold tone. After all, they certainly improved my print capabilities by at least a fraction of 1.
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@jadedreddragon
Could you explain exactly what problem you're running into? It's not very clear from your post. In the end all I did was adjust the size of the area that is used for bed probing. However, the XYZ Calibration function did no longer function, as it could not find the trigger points that are in the original Prusa bed. This is not a big issue though, you can print perfectly well without running this kind of calibration.
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@ludolambers
Eh, I figured it out myself, thanks though! The issue I was having was the printer wasn't finding the calibration points where it thought they should have been, or it didn't find them at all. The XYZ calibration would fail due to this. Also it wanted to crash the nozzle into the bed even when just doing mesh bed leveling. I found what to edit in the firmware and everything is working correctly now, except now I need to fix the issue of Thermal Runaway...
RE: Switching to Ultrabase bed + custom bed probe: How to modify firmware?
@ludolambers
Hi, Ludo
I am only getting around to do this now and I cannot find the zip file on my PC for the adapted extruder part to accomodate for the new probe .. Will you please send it again as the link has expired?
Joandri