Glass / PEI bed suggestion for CR-20 Pro

Hi, I have a CR-20 Pro and I am looking to replace the magnetic bed with PEI or Glass. Any suggestions for a specific one to grab? Thanks!

Picking a bed can depend on what you print. I stopped using my glass bed when I print low profile things, because it is harder to remove from the bed without breaking the print. I print in PLA mostly.

One important factor will be what type of finish you want the bed to apply to your prints.

I put a WhamBam PEX flexible build system on my Ender 3 because I really appreciate being able to remove prints from the bed before it has had much time to cool down. As a “bonus”, I discovered that it gave my prints a fabulously shiny finish - just like glass.

I have a powdered PEI bed on my CR-6 SE. That bed gives my prints a rough but sparkly finish. Sometimes I favour one and sometimes the other, so that choice would be personal to you.

If you already have a magnetic sheet on your printer, you will probably find it is fine to hold any flex steel sheet as long as it is in “good shape”. The WhamBam folks claim their magnet holds its strength all the way up to the max bed temp of 110-120C. Some worry that heating up other cheaper magnets that high may actually demagnetize them, but most of us don’t see any issues at least up to the 85C that we use for printing PETG.

You may also find you can just buy an appropriately sized flex sheet and a sheet of PEI with 3M glue on the back and apply one to the other yourself.

I have not enjoyed printing to glass - except for the lovely finish - simply because::

  • I don’t like scratching-up the finish, so scrapers and palette knives are a “no-no” for me
  • I have no patience to wait for the first thing to cooldown before I start printing something else
  • I can’t bend glass to pop small things off the platform
  • PETG can sometimes adhere so strongly that it pulls chunks of glass out of the surface while I try to remove it.

Hi Bill,

Glass is nice for ultra smooth first layers but a couple considerations should be taken into account. As @Phoe says, the adhesion can be quite strong and if you’re not a patient person who can wait for the glass bed to cool down completely before trying to remove your parts, it can be difficult. (When it’s fully cooled down your prints can removed quite easily).

Another consideration is if you plan to print PETG. This filament can actually bind to glass and cause you to break your glass bed. So people with glass beds who want to print PETG often use a barrier of some sort, hairspray, gluestick or painter’s tape so the PETG doesn’t adhere directly to the glass.

PEI gives a nice smooth finish on the first layer and is good for all filaments and provide great adhesion qualities. The Magnetic/PEI Spring Steel bed upgrades are a real treat! I just did so on my Tevo Tornado and the nice thing is you can pop the PEI sheet off and simply flex the spring steel sheet to pop off your print. Also removing the spring steel sheet immediately after the print finishes allows it to cool down faster away from the heat bed allowing easier and quicker print removal as well.

One small consideration with the PEI solution is it does wear out over time. So the Spring Steel magnetic solution is excellent as you can simply replace the sheet after a while.

Recommended:

I bought the Creality glass bed and can’t go back to the magnetic one. PLA sticks very well when the bed is warm and after it’s cooled completely the prints detach themselves most of the time. For larger prints I might stick the glass in the fridge and then it is very easy to remove. I never have to use a tool to remove the print.

The glass is also very flat so the BL-Touch works really well - especially with Marlin 2.x’s unified be leveling enabled.

Thanks for all the feedback!