Removable print bed for Original Prusa i3 M2?  

Re: Removable print bed for Original Prusa i3 M2?

Using a metal bed will completely mess up the auto calibration system on the MK2! The MK2 heat bed has small metal disks (not magnets) at set points embedded in the heat bed which the probe has to be able to find to calibrate the printer. To be honest I've had no problems removing prints from the PEI covered bed so far (PLA, ColorFabb XT)...

Re: Removable print bed for Original Prusa i3 M2?

I agree that the GeckoTek metal sheets would likely not work. But is there another similar approach? After having removable print beds on both my printers, I've found that it really makes the process easier/quicker, and I'd like to keep that advantage.

It looks like several places sell 10x10 sheets of PEI 0.8mm thick, which could be trimmed a bit and clipped onto the i3 MK2's print bed, which could be swapped pretty easily. I'm guessing a sheet of plastic wouldn't affect the probe, and that 0.8mm is within the range of configurability. Though having to avoid the head hitting binder clips is a hassle, it's minor.

I think I'll try it on my current printers to see what happens. It's a cheap experiment, and might be awesome.

Re: Removable print bed for Original Prusa i3 M2?

Actually, event 0.8mm may be too much for the probe. It will depend on how lucky you are and how sensitive your probe is.

Re: Removable print bed for Original Prusa i3 M2?

Check out this article about printing on glass with a Prusa i3 MK2:
http://www.prusamk2.com/printing-on-glass-with-youre-prusa-i3-mk2-ohhh-so-smooth/
Won't get my printer for about a month, so I can't try it ... but it looks like a possible path to accomplish your goal.

Re: Removable print bed for Original Prusa i3 M2?

Thanks!

Re: Removable print bed for Original Prusa i3 M2?

Using a metal bed will completely mess up the auto calibration system on the MK2!
Not at all. They would only get back to calibration process similar to version 3.0.3 - probe fixed coordinates. Full metal heatbed would just trigger anywhere on its surface. 😎 I use one i3-like printer with full metal heatbed and inductive probe with no problems.
It would actually work easier than now.

Re: Removable print bed for Original Prusa i3 M2?

That means that you lose the XY calibration. It's not a minor difference...

Re: Removable print bed for Original Prusa i3 M2?

That means that you lose the XY calibration.
Assemble it precisely and you won't need XY calibration any more. 😉

Re: Removable print bed for Original Prusa i3 M2?

I have an Ultimaker 2+ along with my home built genuine Prusa Mk1 to Mk2 printer kit. My prints are as good and often better with my Prusa I3 Mk2 printer. I use Simplyfy3d across all my printers.

Re: Removable print bed for Original Prusa i3 M2?

My first and still loved homebuilt 3D printer is a Think3dPrint3d Kossell Mini. It still gives me great prints after 3 years this year. It has a removable glass plate as a build bed. I use a similar product to hairspray for initial bed adhesion. Yesterday I printed a Pug for my granddaughter as a test. She is 7 and took in all my explanation of how 3D printing works. And watched it develop . She will be a future ambassador. I hope her school will get a 3D printer in the future.

I recommended a genuine Prusa I3 MK2

She also took home a 3D printed Pug 🙂 I promised to scale up and paint the next Pug. She is into Pugs .

Re: Removable print bed for Original Prusa i3 M2?

I plan on buying a Prusa Original i3 MK2s. It costs a little more, but I like to support the research, with a stream of new capabilities (e.g. variable layer height printing, multi-material Bowden upgrade) and it seems very well supported.

I have ordered sheet PEI which I will try with my current printers. If it works well, then I _think_ that will provide me with removable print beds for the Prusa, at which point it'll do nearly everything I want from a printer.

Re: Removable print bed for Original Prusa i3 M2?

Check out this article about printing on glass with a Prusa i3 MK2:
http://www.prusamk2.com/printing-on-glass-with-youre-prusa-i3-mk2-ohhh-so-smooth/
Won't get my printer for about a month, so I can't try it ... but it looks like a possible path to accomplish your goal.

Interesting link / idea, but I'm allergic to the "you'll need to create free membership to view the remaining content on this page."

That's of course just before the revelation of the start code needed for this glass plate (or whatever extra plate) addition.

So, what is the code?

It must be something that tells the printer to add "X"mm to all z heights in the .gcode file, with "X" being the thickness of the glass.
Could anyone post it here, please?

Re: Removable print bed for Original Prusa i3 M2?

So, what is the code?

It must be something that tells the printer to add "X"mm to all z heights in the .gcode file, with "X" being the thickness of the glass.
Could anyone post it here, please?

Here it is. Never used it so I can't vouch for its usability.

M115 U3.0.9 ; tell the printer latest firmware version available
M300 S1567 P240
M301 P22.18 I1.27 D96.74 ; PID Tuning for your printer, you can delete this line if not used
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G1 Y-3.0 F1000.0 ; go outside printing area
G1 F600 Z+30
G4 P30000 ; pause for 1 minute
M300 S1567 P240 ; Play a Beep
M117 One minute remaining ; One minute remaining warning
G4 P30000 ; pause 1 more minute
G1 Z2.3 ; consider glass thickness Measure your glass thickness first
G92 Z0 ; Set absolute positioning for remaining print
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line

Re: Removable print bed for Original Prusa i3 M2?

From my understanding of gcode:
The script only works if the glass plate is not installed at first. This is critical. You will smash the nozzle on the glass.

This block does the initial calibration and then takes the head outside the printing area, moves it 30mm up, pauses for 1m and then beeps.
Install the glass plate when the head finished moving the 30mm up. After 1m you will hear a beep and receive a message on the LCD. You will have one more minute to finish the process. You can also choose the Pause function on the LCD to have more time.

M115 U3.0.9 ; tell the printer latest firmware version available
M300 S1567 P240
M301 P22.18 I1.27 D96.74 ; PID Tuning for your printer, you can delete this line if not used
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G1 Y-3.0 F1000.0 ; go outside printing area
G1 F600 Z+30
G4 P30000 ; pause for 1 minute
M300 S1567 P240 ; Play a Beep
M117 One minute remaining ; One minute remaining warning
G4 P30000 ; pause 1 more minute

The next instruction moves the Z to 2.3mm. This should be the glass thickness. You need to change this value to your glass thickness. I'm not sure about the .3. Could it be the initial layer height? I'll test this.

G1 Z2.3 ; consider glass thickness Measure your glass thickness first

This will tell the printer that the head is at 0, the current Z position is the new origin. This does not move the head.
G92 Z0 ; Set absolute positioning for remaining print

The initial line
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line

This script looks good and it uses the normal bed leveling routine. I have to try it.

Re: Removable print bed for Original Prusa i3 M2?

I tried printing PETG on a common 2mm glass plate (no borosilicate) on a Prusa I3 MK2 with the damaged PEI sheet removed, and using the adapted gcode.
This works reasonably well with PETG. It sticks to the glass and is easy to remove after the glass plate is cooled down.
The only problem is that the heated bed is warped, which is compensated by the mesh bed levelling. But when using the glass plate, which is pretty flat, the mesh level compensation for the heated bed is used while printing on the glass plate. With a dial indicator micrometer i measured Z-level compensations that were > 300um. When printing on glass, these unnecessary compensations are visible in the first layer when printing a square of 5x5cm.
I'm not using bed level correction for now (all set to 0), so the compensations are caused by the mesh bed levelling.
Because i can not simply "switch off" the mesh bed levelling, i guess the only way to get rid of these compensations is to make sure that the heated bed is less warped, by using washers/shims under the positions where the bed is connected to the Y-axis frame.
Much nicer would be when the mesh bed levelling could be executed with the glass plate on the bed, but that is not possible when using the PINDA probe.

My first thought was to put some adhesive copper tape at one side of the glass plate so the PINDA probe can do the mesh bed levelling on that side of the glass plate. Then turn the glass plate around to start printing.
I will need to do some experimenting to see if this could work.

Any other idea's ?

Re: Removable print bed for Original Prusa i3 M2?

I realize this is an older post, but I recently came across something from BuildTak.
They have made a flexible, magnetic surface for the Prusa I3 mk2. It was referenced by Joel (3D printing nerd) in one of his vlogs.
He will be testing it in the near future. Seems promising, but I'm also wandering about the working of the pinda probe.

(about 45 s in he talks briefly about it and shows it)
(again here at 1m20s)

Re: Removable print bed for Original Prusa i3 M2?

As with a glass bed on top of the mk42 bed, the mesh bed leveling will have to be done before putting the flexplate on top of the mk42.
I think that such a thing could be useful for materials that are sticking too much on the PEI (PETG, PC, flexibles...), but useless for PLA for example.

Re: Removable print bed for Original Prusa i3 M2?

It would SEEM, from this post:

http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/broken-p-i-n-d-a-probe-replacement-t4402.html#p40489

that we could change the PINDA sensor and have it set at a higher Z value, OR this could enable us to print on thicker print surfaces and even the removable flexible ones. I am happy with the PEI sheet currently, but like the idea of something removable.

Note that the user above indicated this PINDA replacement worked fine with no changes, but I wonder if with the extra sensitivity if there is a loss of precision on the mesh bed leveling. Might be hard to measure/tell (which I guess means it doesn't matter?).

If anyone tries the new BuildTak surface for the i3 MK2, please post the results here. We are interested.