Up Mini Adjustable Bed mod for Raftless Printing

Post improvements made for UP, and share ideas.
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Woodlake
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Joined: Sat Aug 22, 2015 6:58 am

Up Mini Adjustable Bed mod for Raftless Printing

Post by Woodlake » Tue Jul 26, 2016 4:12 pm

After reading about using PEI for raftless printing, I wanted to give it try on my Mini.
I just needed to figure out a way to make the bed adjustable for it to work.
Apart from replacing or heavily modifying the stock platform, I don't recall seeing any mods that would allow the Up Mini to do this.

I published the solution I came up with (and the files required) for anyone that might be interested on Thingiverse:

http://www.thingiverse.com/thing:1690155

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The mod is completely reversible as it does not alter the printer itself.
I can now level the bed to within 0.1mm across the entire print area.
I am currently using 0.03" PEI laminated to 3mm borosilicate glass (with 3M 468MP adhesive sheet), but I can still use the original perf boards too with this mod if needed.

So far it seems to be working well...

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Tiertime-Jason
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Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Tiertime-Jason » Wed Jul 27, 2016 2:19 am

This mod could save majority of the scrapped UP mini. Good work!

arhi
Posts: 256
Joined: Sun Mar 08, 2015 10:51 pm

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by arhi » Wed Jul 27, 2016 3:02 am

Woodlake wrote: I am currently using 0.03" PEI laminated to 3mm borosilicate glass
have to ask, why glass under PEI? I do get ppl that want smooth finish go with glass and hair spray but under PEI?! I don't get the idea? It's thick, it expands/contracts with heat "a lot" (even borosilicate), it's not readily available in any glass cutting shop and it's thermal conductivity is terrible? Why not go with 2mm aluminium plate? Cheaper, easier to get, easier to cut, easier to machine, thinner, stronger, better thermal conductivity.. I don't get the glass choice at all.. if you were printing directly on glass, ok, I'd understand it (I dislike it, especially with UP!'s puny underpower heated bed), gets super smooth surface, but if you are going with PEI on top all the imperfections of the ALU plate are not present as its PEI sheet that's now "affecting" the surface finish..

Woodlake
Posts: 30
Joined: Sat Aug 22, 2015 6:58 am

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Woodlake » Wed Jul 27, 2016 3:11 am

Tiertime-Jason wrote:This mod could save majority of the scrapped UP mini. Good work!
Thanks Jason, I hope so! The non level bed was one if its biggest issues (I swapped out he thermistor for an 80deg one - it's other main problem).
I love my mini. For my purposes now that the bed is adjustable, it's close to perfect.
Last edited by Woodlake on Wed Jul 27, 2016 3:59 am, edited 1 time in total.

Woodlake
Posts: 30
Joined: Sat Aug 22, 2015 6:58 am

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Woodlake » Wed Jul 27, 2016 3:35 am

arhi wrote:
Woodlake wrote: I am currently using 0.03" PEI laminated to 3mm borosilicate glass
have to ask, why glass under PEI? I do get ppl that want smooth finish go with glass and hair spray but under PEI?! I don't get the idea? It's thick, it expands/contracts with heat "a lot" (even borosilicate), it's not readily available in any glass cutting shop and it's thermal conductivity is terrible? Why not go with 2mm aluminium plate? Cheaper, easier to get, easier to cut, easier to machine, thinner, stronger, better thermal conductivity.. I don't get the glass choice at all.. if you were printing directly on glass, ok, I'd understand it (I dislike it, especially with UP!'s puny underpower heated bed), gets super smooth surface, but if you are going with PEI on top all the imperfections of the ALU plate are not present as its PEI sheet that's now "affecting" the surface finish..
Because glass is flatter and it ensures that the PEI is perefctly flat (being quite thin). Others have tried thicker pieces without the glass, but it is not as flat (and expensive).

I have checked the bed calibration when cold and at temperature and it's a non issue in terms of thermal expansion/contraction.

The glass is readily available from Ebay (already cut to size - here in Australia at least), while the PEI and adhesive are from Amazon for around $30 total (with enough to make 4 plates out of). For me at least that is cheaper/better than using aluminium.
Not sure why you think PEI is "affecting" the surface finish? It is a very similar to glass if you want.
The sheet has one side shiny and the other matte. I personally use the matte side as is more closely matches the rest of the print when removed.

The main benefit of PEI is that it requires no prep prior to printing (apart from a wipe with isopropyl alcohol to remove any fingerprints etc).
Raftless prints stick unbelievably well when printing, and fall off when cold. No tape, no glue, no ABS juice.

Plenty more discussion on it here if your interested in reading further:

http://forum.seemecnc.com/viewtopic.php?t=4336

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Tiertime-Jason
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Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Tiertime-Jason » Wed Jul 27, 2016 7:04 am

Woodlake wrote:
Tiertime-Jason wrote:This mod could save majority of the scrapped UP mini. Good work!
Thanks Jason, I hope so! The non level bed was one if its biggest issues (I swapped out he thermistor for an 80deg one - it's other main problem).
I love my mini. For my purposes now that the bed is adjustable, it's close to perfect.
The UP mini 2 is coming, which still has a non adjustable bed. However this time we make sure it is more durable and pre leveled in factory. Well, if bed design failed us again, we can at least ask you for a mini2 version of this mod :lol: :!:

Woodlake
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Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Woodlake » Wed Jul 27, 2016 7:25 am

I'm sure it will be great, but if you want provide me with a free Mini2 I'd be happy to design something up for you :lol:

arhi
Posts: 256
Joined: Sun Mar 08, 2015 10:51 pm

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by arhi » Wed Jul 27, 2016 4:10 pm

Woodlake wrote: Because glass is flatter and it ensures that the PEI is perefctly flat (being quite thin). Others have tried thicker pieces without the glass, but it is not as flat (and expensive).
hm .. either my supply of alu plates is non standard or we have different definition of "flatness", the regular alu board in local store (2mm thick) are +-0.01mm on the 30x30cm sheet, yes glass is "better" then that but "who cares" :D .. where alu is different from glass is "non machined" alu can have scratches that would be visible on the surface when printed directly on alu while glass don't .. but when you put pei on top the scratches on alu become irrelevant :D
Woodlake wrote: I have checked the bed calibration when cold and at temperature and it's a non issue in terms of thermal expansion/contraction.
thickness is too small to matter, I'm talking about XY plane, try to use "fixed" mount from "hard material" and watch that glass shatter when heated .. I used borosilicate glass on my old 35x35cm printer and was not smart enough to give it wiggle room, there was ~1mm breathing room on all 4 sides but was clamped with aluminium brackets so "hard mount", somewhere around 90C it bent one of the holders and then shattered .. so more then 2mm in length..
Woodlake wrote: Not sure why you think PEI is "affecting" the surface finish? It is a very similar to glass if you want.
anything you print on affects the surface finish, on glass and kapton is shiny, on pei is bit more matte then on glass but flat and shiny, on printbite it has very interesting surface (industrial, like small triangles embedded into shiny surface), on alu+slury it's kinda matte .. I didn't say PEI is affecting the surface in bad way, just that since it's PEI touching the print part it's PEI affecting the surface, not what's below PEI, and since it is thick enough the porous surface of alu vs sealed surface of glass make no difference... and here getting 1-2mm alu plate is waaaaaaaaaaaaaaaaaaaay cheaper then getting borosilicate glass ... you can get regular window glass cheap (tried that) if you want but it's too brittle, I cracked more then 10 pieces by mistake while setting the nozzle height so I tend to avoid it...
Woodlake wrote: The main benefit of PEI is that it requires no prep prior to printing (apart from a wipe with isopropyl alcohol to remove any fingerprints etc).
Raftless prints stick unbelievably well when printing, and fall off when cold. No tape, no glue, no ABS juice.
yup, I know, exactly the same as printbite, only printbite requires higher temp to print (95-105C for surface) and is more durable.. now taking into account that ABS "release itself" from both surface when they get cold this durability difference is pretty irrelevant :D
tried pei already, read about it on number of places .. sticking with printbite as it better suits my needs .. I was just wandering why glass and not alu as (for me at least) alu is lot cheaper, and on top of that spreads the heat way better (especially when using crappy pcb heaters) .. not to mention if you need to adapt it (for e.g. to cut a slot for the auto nozzle height sensor on up2plus..) the glass is a killer to modify, while borosilicate is softer and can be machined it's still ugly to work with .. but looking at your pics I see mini has only a simple square..

Woodlake
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Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Woodlake » Thu Jul 28, 2016 2:40 am

arhi wrote: I used borosilicate glass on my old 35x35cm printer and was not smart enough to give it wiggle room, there was ~1mm breathing room on all 4 sides but was clamped with aluminium brackets so "hard mount", somewhere around 90C it bent one of the holders and then shattered .. so more then 2mm in length..
Borosilicate glass has a very low coefficients of thermal expansion of ~3 × 10−6 K−1 at 20 °C (aluminium is ~23 × 10−6 K−1 at 20 °C)
If you had expansion of more than 0.2mm over a 350mm length, then you were not using borosilicate glass...

arhi
Posts: 256
Joined: Sun Mar 08, 2015 10:51 pm

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by arhi » Thu Jul 28, 2016 3:04 pm

Woodlake wrote:then you were not using borosilicate glass...
that would explain shattering! ... got it from ebay I only have "sellers word" :(

GrantWatson
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Joined: Wed Mar 20, 2013 9:53 am
Location: Western Sydney, Australia

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by GrantWatson » Fri Feb 24, 2017 3:00 am

Just thought I'd chime in hear to heap some praise on Woodlake for this ingenious solution to the bed levelling problem on these Minis! You have saved my UP Mini from the landfill!

I've always had issues with my UP! Mini bed calibration being way out of wack. I had almost given up on it after spending many hours shimming various bits and pieces to try and get the bed to be level within software correction tolerances. I ended up with 0.9mm correction being applied to the front of the bed as the best I could achieve. This, of course, ruled out any hope of raftless printing.

Now, after applying this awesome mod to the printer, all nine calibration points are at 0.0mm correction in software. Perfectly flat bed, and I've completed raftless prints for the first time since I've bought it. Very pleased with the results!

Now, I'm not using anything more fancy than the factory perfboards and some painter's tape, but coupled with the heat bed mod to bring it to 80C and it's working a treat on ABS at the moment.

One comment on the design of the end pieces that retain the screws and springs though. I found the little pegs that stand proud on them don't align with the holes in my heat bed. Maybe there's been a revision with slight changes to the dimensions over the years? At any rate, I haven't found them to be necessary for this mod to work perfectly.

Thanks again Woodlake!

My make record is here

Woodlake
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Joined: Sat Aug 22, 2015 6:58 am

Re: Up Mini Adjustable Bed mod for Raftless Printing

Post by Woodlake » Fri Feb 24, 2017 3:42 am

Hi Grant,

Nice to see someone other than me could make use of this :)

Regarding heatbed hole alignment, I'm guessing you're right - there may be more than one version of the hole postions for the heatbed :/
I modelled it on mine and so far you're the only one I know that has tried it, so without more feedback it would be hard to confirm.

As for a printing surface, I settled on a piece of 3mm aluminium plate I had cut to size locally (for $5) and 0.03" PEI fixed with 3M 468MP high temp adhesive (both from Amazon). Works amazingly well. I wipe it down with isoproyl alcohol before a print and it simply "pops" off after it has finished (raftlessly).
One trick I did learn which I use a lot for print removal, is to simply spray/pour a small bit of isopropyl alcohol at the base of the print.
It then "wicks" between the print and board and then removes with ease!

Thanks for sharing your experience with the mod Grant - glad it helped.

Cheers,

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