[Geschlossen] stickered spring steel build plate durability  

Re: stickered spring steel build plate durability

Interesting question. I use PEI sheets on my glass build plate now, and I'm quite happy with it (although PETG can stick too well sometimes).

Clearly I have no data on how the Prusa assembly will work, but that won't stop me from speculating.

I see two issues:

The thin PEI sheets I apply to my glass build plate are quite flexible. Way more flexible than I would expect a spring steel sheet to be. With that, as long as the sheet is thin and the glue layer is thin I would expect no durability issue. The assembly itself may be stiffer than the powder coated one, but I would not expect delamination or cracking. Having worked to get a PEI sheet off of a glass bed for replacement, if they are using anything like the 3m tape I used, that sheet isn't going anywhere.

I do think the PEI sheet may be more prone to damage from a chisel or scraper (or nozzle) than I'd like. However, hopefully I won't plant the nozzle, and the chisel/scraper should be less needed if I can flex the sheet to remove the print.

Re: stickered spring steel build plate durability

The adhesive part was kind of the lines I was thinking of with regards to the stretch and crease effect.

It's not going to be bent at an acute angle so I wouldn't have thought there'd be an extreme deformation going on there but I'd have thought that any flexing would stretch the outer surface a bit. I've no idea what the elasticity of PEI is.

One other thought is that on the Mk42 beds we've seen the bubbles forming underneath the PEI during certain prints where the glue has been directly affected. If that carries over to the spring steel sheets then it might be that we'll be flexing something that's not fully adhered in places and that's where I would be expecting issues to arise.

Re: stickered spring steel build plate durability

I am wondering the same thing....

Anyone who has replaced the PEI sheet, as I have, knows that the PEI sheet itself in NOT flexible. So, if you are flexing the underlying steel plate it would seem that the PEI sheet will be pulled away from the glue in some areas when flexed in a convex fashion. When flexed in a concave fashion it seems the PEI sheet would be subject to creasing.

Not to mention how the heat will be dispersed when heated.

Has any of this been tested? It was not the initial design so I wonder if there has been any trial and error, or are we the buyers going to be the guinea pigs (of which I would NOT be happy about).

Re: stickered spring steel build plate durability

The factor I am concerned with is the temperature of the heated bed and the adhesive on smooth steel as you flex the plate slipping.

That seems like it is a combination that could potentially be an issue if people are flexing the plate more than a few degrees of deflection...as you would expect a end user to do...

Re: stickered spring steel build plate durability

Anyone who has replaced the PEI sheet, as I have, knows that the PEI sheet itself in NOT flexible.

Interesting. My experience has been different. I've got a PEI sheet in my hand (12x12x0.035", or about .9mm) and it is very flexible. The flexibility of my sheet is comparable to what can be seen at about 2 minutes into this video:

I would expect that thicker sheets may be stiff (and might work better in some situations), but for what I'm applying to a thick glass bed, the thin flexible stuff works best.

I would expect Prusa to use comparably flexible stuff to retain the spring steel advantages, but we'll see. I'm personally not all that worried about the long term durability. It's two sided, which helps, and replacing the PEI on a spring steel sheet shouldn't be harder than replacing it on glass (which I've done twice). If I don't need to, that'll be great.

It will be interesting to see if there are issues with delamination or bubbles. I don't mind them asthetically, but if they start to make the surface not flat, that'll be a big issue.

Re: stickered spring steel build plate durability

I wouldn’t stress about it. Prusa has been doing this quite awhile and I’m certain they have thought through this.

I can’t talk about PEI, but I have used the BuildTak Flexsystem for 6 months. It is simply awesome and makes removing prints a piece of cake. I assume PEI is thinner, but I wouldn’t be worried about the adhesive at least.

If I don’t like the PEI I may switch to BuildTak... I’ll find out Tuesday what it looks like!!

Ron

Re: stickered spring steel build plate durability

They've been producing printers for a while as well but still can't manage an accurate and timely supply line 😀

Nah, seriously though, there have been problems with the adhesive PEI sheets on the MK42 bed and it appears this stickered flexi version is a fallback due to not being able to secure production of the advertised powder coated version rather than a planned implementation.

The glued PEI sheet won't offer the same damage resistance characteristics that the powder coated one was sold with.
It very much seems like a plaster stuck on a delivery problem. Maybe they'll be offering a good warranty on these build plates ?

As for printing on PEI, no problems here, I really like using it and have used it for quite a while on my Mk2. The only issues i've had have been scratched surfaces and the bubbling.

Re: stickered spring steel build plate durability

Anyone who has replaced the PEI sheet, as I have, knows that the PEI sheet itself in NOT flexible.

Interesting. My experience has been different. I've got a PEI sheet in my hand (12x12x0.035", or about .9mm) and it is very flexible. The flexibility of my sheet is comparable to what can be seen at about 2 minutes into this video:

I would expect that thicker sheets may be stiff (and might work better in some situations), but for what I'm applying to a thick glass bed, the thin flexible stuff works best.

I would expect Prusa to use comparably flexible stuff to retain the spring steel advantages, but we'll see. I'm personally not all that worried about the long term durability. It's two sided, which helps, and replacing the PEI on a spring steel sheet shouldn't be harder than replacing it on glass (which I've done twice). If I don't need to, that'll be great.

It will be interesting to see if there are issues with delamination or bubbles. I don't mind them asthetically, but if they start to make the surface not flat, that'll be a big issue.

You are in essence correct. I did say that it was not flexible. What I should have said is that it does not stretch. It will bend, but when flexed in a convex motion over the spring steel, it would have to stretch and retract to stay in place over the flex steel, and I can say for certain that it will not stretch. I should have been more clear.

Re: stickered spring steel build plate durability

Who says you HAVE to flex the build plate..... My current buildplate is solid glass, and that doesnt flex either
So simple solution, dont flex until you get a powdercoated one. I have been using non flexible build plates for years, so a couple more months wont hurt me

Re: stickered spring steel build plate durability

Who says you HAVE to flex the build plate..... My current buildplate is solid glass, and that doesnt flex either
So simple solution, dont flex until you get a powdercoated one. I have been using non flexible build plates for years, so a couple more months wont hurt me

I think this is simply human nature! When I pick that build sheet up out of the kit, the first thing I'm going to have to do is flex it! It'll be irresistible! Now maybe if they built it out of 1/4" sheet steel...

Seriously, I will likely flex it, just keep it quite limited. It doesn't take much flex to pop a flat bottomed object off the plate, and I'm pretty sure the PEI will be fine.

Alternatively, when I try to flex the sheet it will feel quite stiff, and I'll get a quick impression that flexing it might not be the best move, Then I'll live with my old stand-bys of an alcohol squirt bottle and sharpened drywall scraper.

Re: stickered spring steel build plate durability

Unsurprisingly, flexing the sheet with PEI works just fine. You don't bend it 90° anyways.

Durability is the same as on the MK2 x2 as it is double sided. Plus you will never damage the sheet by tools like spatula.

Re: stickered spring steel build plate durability

Good to hear Josef.

Any experience of it suffering the same bubbling effect as the Mk2 under some prints ?

Also a couple more if possible.
I vaguely recall reading that the textured effect aids the part release on cooldown, does the smooth sheet still allow the part to give easily on the flex to remove as well or is the part likely to be stuck stronger ?

How is the surface of the side that is touching the bed holding up. Any scratching or marks from repeated removal and replacement of the build plate ?

Re: stickered spring steel build plate durability

Unsurprisingly, flexing the sheet with PEI works just fine. You don't bend it 90° anyways.

Durability is the same as on the MK2 x2 as it is double sided. Plus you will never damage the sheet by tools like spatula.

May we ask what were/are the specific issues with the Spring Steel build plates that has made them problematic to produce, presumably the same ongoing problems since launch day?

Clearly I have no experience with PEI coating on a steel substrate, but if it's uniformity or adherence related issues, I have had some experience with standard powder coating and had luck bead blasting the surfaces of these rolled sheet metals, airblast and wiping with solvent to give a perfectly uniform and more mechanical bite for the surface on thin flexible sheet which seemed to help with both of the above problems on the as manufactured surface.

Probably unrelated, simply interested in knowing more while we are patiently waiting for that elusive conformation email.

Thanks for all the hard work, we do appreciate it, even if it's clouded by other topics.

Re: stickered spring steel build plate durability

I'm curious to know what process PR uses to print PETG on the new beds, as I print a lot of PETG myself. The MK3 handbook section on PETG doesn't specifically mention the new flexible sheets.

For the PEI sticker sheets, does flexing the sheet solve the issue with over-adhesion like with the MK2? Or do you still need to treat the PEI before printing?

How about the powder coated sheets? Any difference?

Re: stickered spring steel build plate durability

any idea of how you remove flexible print? if it sticks too much flexing the steel sheet wont help too much. specially if the object is low. probably the old way?

Re: stickered spring steel build plate durability

My concern with the stickered sheet was its thickness compared to the powder coated sheets.
Would one have to adjust the z-offset when switching between the two?

For that matter are the two different powder coated sheets (textured and glossy) dimensionally similar enough use the same offset?

If they're all the same thickness and wouldn't require messing with settings I'd probably end up getting all three for variety's sake.

Re: stickered spring steel build plate durability

My concern with the stickered sheet was its thickness compared to the powder coated sheets.
Would one have to adjust the z-offset when switching between the two?

For that matter are the two different powder coated sheets (textured and glossy) dimensionally similar enough use the same offset?

If they're all the same thickness and wouldn't require messing with settings I'd probably end up getting all three for variety's sake.

I should think they will be pretty similar in total thickness.

If there is a benifit to specific settings for each sheet, it would be nice to have a menu entry that would hold the specific setting for individual beds, so we could simply select the bed and confirm the settings associated with it that are saved long term.

Re: stickered spring steel build plate durability

I have been using a BuildTak FlexPlate on my Wanhao Duplicator 6 for several weeks now. No issues with the BuildTak Sheet coming off from flexing.
I may put a PEI sheet on the other side to try it out. It would be nice to have both build surfaces available on the same printer as they each have their strengths with different materials. My MK3 is shipping in February so I guess I will get the powder coated version...

Re: stickered spring steel build plate durability

The biggest change in my mind on the mk3 is the move to make the build plate a consumable part. On the MK2 If the adhesives fail or you mar the surface with tools you will have to go to quite a lot of effort to remove and replace the PEI sheet. On the MK3 you can always put a new plate down and toss the old one for the same cost as a roll of filament.

Although many 3d printer components are certainly long life parts there are some that I don't think anyone should expect to last the lifetime of the printer: The nozzle, bed surface, and to a lesser extent the heatbreak and hobbed gear are all wear items that may require occasional replacement.