[Geschlossen] Thoughts on buying a Prusa i3 MK3  

RE: Thoughts on buying a Prusa i3 MK3

If you treat the standard plate right (don't use knives, spatulas, etc), follow instructions for prep based on material you are printing (adding a separator material like windex for things that might fuse to it, e.g. PETG) and keep it clean (dishwashing liquid - regular posts on it, search here) you have nothing to worry about.

Standard vs PC is personal preference; they are both the same material. If you want the textured effect on your prints then naturally the coated one is what you want. If you're fine with a flat base then the flat sheet will meet your needs.

RE: Thoughts on buying a Prusa i3 MK3

The powder coated spring steel gives a nice texture  but is not fundamentally essential to getting quality prints. I had to wait a year for mine, but Prusa seems to be catching up. They moved production in-house, so that should help.

3rd party sheets are available, but they vary in quality (e.g. AliExpress), willingness of vendor to ship less-than-perfect products and price. 

There are now many options for the smooth PEI sheets. Prusa's is readily available and they just added a reduced shipping rate which makes it competitive with most quality alternatives. BuildTak and Printedsolid.com offer spring steel sheets. BT has PEI as do others. You can also try alternative surfaces if you want to experiment. (Was not impressed with Fysetc.)

In short, spring steel build surface availability should not be a concern. You may wait a bit or have to look for a textured alternative  but that's the case with any printer at this time. 

I damaged one side of my original smooth stickered sheet. Ordered both a full replacement (recommended) and a replacement sticker (more work than its worth, but it worked). Also have several 3rd party sheets now. Not a concern or limitation at all.

RE: Thoughts on buying a Prusa i3 MK3

I would say that the textured spring steel sheet is mostly useful for PETG prints, also, it's not as flat as a plain flat PEI sheet!.

I can get a perfect first layer on a plain flat PEI sheet, yet no matter how much I try, I just can't get the same quality on the textured sheet.

Now PETG, you are generally printing slightly higher (Offset from PLA +0.25 or more, maybe a little less sometimes) and because of this, you can get away with the slight variance found in the textured PEI sheet level. Then once your PETG print has finished, this is where the magic happens on this sheet. Wait for it to cool and your PETG parts just pop off when the sheet is flexed.

I now only use the Textured PEI sheet for PETG and use a plain flat PEI sheet for PLA and find keeping the two materials separate like this, I have no adhesion issues.

RE: Thoughts on buying a Prusa i3 MK3

It took me 5 months to finally damage my standard PEI sheet, and the missing chunk is only about a millimeter square. This happened while printing a small part with a polycarbonate blend (it's small parts that often give me grief with removal; big parts easily flex off). The other side of the sheet is still fine and usable. I have a spare sheet sitting on the shelf that I haven't needed to open yet. The majority of my prints have been PETG with windex as a release agent. 

Treat it with reasonable care and you shouldn't need to worry about it. If you're the type to worry anyway, then just buy a spare.

RE: Thoughts on buying a Prusa i3 MK3

Posted by: londheprachi47

is the standard plate good enough?

Yes.

Is the powder coated really that good?

It gives the parts a nice finish and is more durable (no 3M glue to bubble up when parts exert warping forces), but the 3M glue on the PEI sheet does regenerate when you flip the sheet.

Are there any good alternatives?

I do have TheKkiinngg v4. I don't use it much, unless I need the texture on the bottom of the part. I like the smooth PEI better. Particularly for very small parts the texture is too rough. Funssor sells their own version on Aliexpress cheaper than TheKkiinngg if you really want it.

I'm about to test a 'frosted' PEI sheet from Aliexpress, it's a sheet of PEI that you stick to the flex steel plate. It has a nice, much finer texture. It will not give me the ruggedness of the powder-coated sheet, but may allow for a nicer bottom surface of printed parts.

And finally, should I even be worried?

No. Because even if you damage the PEI sheet, you can always peel it and put new PEI on and it doesn't cost much. If you damage the textured one (which is harder to do), it's not fixable.

RE: Thoughts on buying a Prusa i3 MK3

Mine (smooth) came with some damage at the edges of the print area and Prusa sent me a new one. I've still been printing on the original with no issues.

Based on talking to non-Prusa owners, I think the flexible PEI sheet is the best feature of the printer. Listening to them talking about all the hoops and incantations they go through to get PLA to stick is mind boggling. When I tell them all I have to do is wipe it down with IPA they just don't believe it until I show them video of the prep and how the parts don't budge until I flex the plate.

Now the custom heat break and MMU, I'm not so happy with them at the moment...

RE: Thoughts on buying a Prusa i3 MK3

Posted by: londheprachi47

Hello everyone,

I am considering buying a Prusa i3 MK3, an upgrade from my XYZ DaVinci Jr 1.0, but I am a little concerned about people in reviews/YouTube videos talking about the longevity of the spring steel plate which it comes with.

At this time, the printer is only available with the standard PEI coated spring steel plate and the optional powder coated plate seems suspiciously unavailable, even 3rd party ones from TheKkiinngg.

My questions are;

is the standard plate good enough? Is the powder coated really that good? Are there any good alternatives? And finally, should I even be worried?

Thanks in advance!

After owning an Original Prusa...... You wont see me buying anything else. Its like night and day.   I used to spend HOURS calibrating to prepare for a print. Now I spend a few minutes..... (And my prints turn out far better as well).... I actually enjoy printing things now.

Seriously worth EVERY PENNY. 

One thing... Do NOT use VIVA towels to clean off the print bed...... Ive found it leaves a residue which keeps the print from sticking.... I have since changed the paper towels I buy.  Sticks good now!

RE: Thoughts on buying a Prusa i3 MK3

I agree with justin-V5,

You won't regret buying an original Prûsa printer, it's worth every penny!

Sometimes they are pushing technology a little bit to far too soon, but you will own the 

best 3D FDM printer available and if there are some issues the community is here to help you!

Best,

Dick

RE: Thoughts on buying a Prusa i3 MK3

Quote

"One thing... Do NOT use VIVA towels to clean off the print bed...... Ive found it leaves a residue which keeps the print from sticking.... I have since changed the paper towels I buy.  Sticks good now!"

I use Viva paper towels and have noticed that it does appear to leave streaks but I haven't had any adhesion issues. I used to use methylated spirits to clean my bed but it was less than sufficient to keep things stuck down on the bed. My solution was to use glue and give the sheets a good clean in warm soapy water once in awhile to keep the sheet clean, and on the odd occasion give my sheets a clean with acetone, just to rejuvenate the PEI. I did this for ages and it worked well albeit messy. 

Then one day I decided I had enough of using glue stick and went out to my local hardware and purchased 500ml of 100% Isopropyl alcohol and man what a difference that makes. I use Viva towels with the IPA to wipe down the sheets prior to every print and I have not had any issues since. I have had large footprint prints going for 30hrs+ and not had any issues with the prints separating from the sheet. The only downfall is the price of IPA here in Australia, Its worth more than gold haha.

Can I ask what you use instead of the Viva paper towels?

RE: Thoughts on buying a Prusa i3 MK3

Posted by: tony.s8

Can I ask what you use instead of the Viva paper towels?

Cleanroom Wipes