What Metal Is Used On Print Sheets  

RE: What Metal Is Used On Print Sheets

BTW...Any one of you that are business savvy and have the time, please steal this idea so I don't have to keep making these sheets.  It just better check all the necessary boxes for me to give you my money...

RE:

Posted by: @rock133

Hi all,

I've been using my Prusa with carbon filled nylon filament almost exclusively as of late.  My question is, what sort of sheet metal is Prusa using to manufacture their print sheets??? 

I am making my own sheets using a variety of spring steel from McMaster-Carr and adhering some thin garolite to the metal.  This works great because I can still use the leveling sensor and don't need to babysit the printer when starting a print to wait for a programmed pause.

Problem is...I have, on occasion, sent some temperature to the printer bed (I can print without a heated bed using this homemade sheet) and it will slowly start to warp.  Or, heat soak from a large piece I'm printing can do the same.  Both these situations force me to fabricate another sheet often at the worst time.

The spring steel that Prusa using does not ever warp, so, I'm in search of the same material.  I guess I could TRY to sacrifice one of my old sheets, but thickness was an issue when I was first concepting my homemade sheets and the Prusa sheets are relatively thick.  Also, a part of me just doesn't want to destroy a perfectly good print sheet.

Thanks in advance, everyone!

 

What type and thickness of blue steel are you using? McMaster carries different types, some are hardened and some are annealed. Hardened blue steel should hold its shape pretty well if the material is thick enough. Prusa states 0.03" thickness on their sheets. A hardened sheet on McMaster in similar dimensions is around $36 dollars (not including shipping). After shipping and garolite, it'll be higher. My question is why go this route if you can get a powder coated two-sided sheet from Prusa for $40 plus shipping? 

As for the garolite, I'm not too familiar. However, with things that involve rapid heating, certain materials expand at different rates. Expansion distance could also be varying. I wonder if the garolite is preventing the metal from expanding freely and causing the metal warp? Have you tried printing without the garolite layer? I'm not sure if you tried powder coating your sheets, but the texture definitely increases the surface area which could be aiding to the dissipation of heat and maybe even help the metal heat more evenly. Plus powder coat is likely much thinner than the garolite which probably makes it more flexible. Smooth sheets have some kind of weird multi-layer coating (I know this because I destroyed mine by printing PC on it). The clear layer (probably Garolite) on top of the greenish color has some kind of weird adhesive between it that is extremely sticky. I'm not entirely sure what the green coating is, but maybe the combination of what they use helps with heat transfer. Again, these are just hypotheses'.   

RE: What Metal Is Used On Print Sheets

Hi Ryan,

The metal thickness I am using is .010" (part number 9072K11).  The garolite thickness is 1/32" or .03125" and is high temperature rated (part number 8710K114).  Also, I am adhering a PEI sheet to the bare sheet metal on the side that contacts the heatbed which is .002" thickness (part number 7576K32).  Overall, with the super glue to apply the garolite to the metal my sheet's total thickness is around .050".  Prusa's smooth sheets they sell are about .047" and this was my target thickness so, as previously stated, I could take advantage of the PINDA sensor.

Nylon is a tricky filament, but the results are amazing!  Initially, I did try printing on the textured powder coated sheets from Prusa since I already had one for use with PETG.  First layer adhesion was failing and I was even trying different glues, but it would still fail.  Admittedly, I didn't waste too much time tweaking this method because I already knew how well garolite would work.  If anyone with great experiences with the texture sheet and nylon could fill gaps in my knowledge it would be well received.  Also, nylon prints well on glass sheets, but it requires writing code (which I do know how to do and have done) to add a pause to the start of the print.  Furthermore, printing on glass means I would need to apply several layers of glue stick to the surface prior to every few prints.  All this equals I'm not doing it because it's too much to fuss with.

Hopefully the advantages of garolite are becoming evident and everyone can see why I like it.  It's just too easy!  Apart from the time it takes to make a sheet and the warping issue I experience about twice a year, the process to get a part out of nylon is super straight forward.

1. The nylon filament adheres so well to garolite, zero extra measures are needed.  Just wipe with IPA to remove residue oils from handling and you're good to go.
2. I don't need any heatbed temperatures.  The nylon just won't warp.
3. Startup process is the exact same as if you're using a print sheet from Prusa.  Just program in a custom sheet, name it, calibrate your first layer Z height and you're golden.

Only downfall is the warping.  I'll bite the bullet on making the sheet (although I do wish I could just buy what I'm looking for 😉 ) if it means I save a ton of tedious steps downstream.  As you all know, the sheets from Prusa themselves NEVER experience warp.  Add to that, most users don't ever need to think about warpage.  Turn the temp up to 100°C on thin sheet metal?...sure!  Why not!?  Rip the Prusa sheet off the machine immediately after a print finishes subjecting it to uneven cooling?...no worries!  These are the reasons why I am envious of whoever has the knowledge of this magical metal.

P.S. Ryan thanks for your reply.  Your post made me think if superglue is the best adhesive for the job, but I can add that when I destroyed my first custom sheet, I separated the layers and the garolite returned to flat and the metal looked like a potato chip.  That sheet I did use 3M Super 88, though.

Also, if I could add to your knowledge, garolite is commonly seen as the thick sheet of circuit boards.  It's a layered fibrous material with resin to make it solid.  It's the same material your heated printbed is made from.  The clear layer on your print sheets are known as PEI (polyetherimide) or sometimes referred to as it's trademarked name, Ultem.  It's a super high temperature resistant material and has great electrical insulation properties, which, is why I add it on the bare metal side of my sheets so I reduce the risk of rubbing through the printbed and shorting out on the heater traces.

RE: What Metal Is Used On Print Sheets

What is the part number of the Garolite that you're using? I noticed they have different versions on McMaster. I see they have a high-temp option. Maybe that would help. CMI states that Garolite doesn't expand/contract much with temperature changes, but steel does. However, Prusa's decision to go with 16 individual heat beds on the XL with expansion joints to prevent warpage of the heating bed/sheet makes me think that there's a possibility of Garolite being more mobile than they say. I wonder if using a sheet of Garolite with small individual squares of blue steel (with room to grow between each piece) glued to the bottom rather than one sheet would help. Garolite is also machinable, so I wonder if using a thicker sheet and routing out small recessed areas for steel coins in the location of the PINDA zones would work. However, you'd probably lose that nice magnetic hold down feature.

Thanks for putting me onto this material, it's really interesting and up until now, I haven't ever heard of it! I haven't printed with Nylon yet, but I hear it's a beast to print. I am mostly working with Polycarbonate on a Prusa textured sheet with glue stick and it's worked thus far. 

RE: What Metal Is Used On Print Sheets

No.

buildtak nylon+, not Garolite .  Two sheets to cover both sides.

Get the steel plate from just about anywhere. I think I got mine from Etsy. 

Zero problems after cranking up the bed temp.