3D Printing: Can a heatbed PCB (Prusa Mk2) be straightened out? (3 Solutions!)
Channel: Roel Van de Paar
Date: 2019-06-27

3D Printing: Can a heatbed PCB (Prusa Mk2) be straightened out?


The Question: I have a really bent heatbed PCB, the middle is elevated about 3 mm with
respect to all edges.
I have found this thread midibox.org/forums/topic/17599-warped-pcbs/,
where a heating method is applied by baking a PCB in the oven, as described
here: 3.2_Bow_and_Twist_Repair.
Can this help straightening out a Prusa heatbed PCB? If so, can I apply the
heat by the heatbed itself, or do I need to utilize an oven? Will the pressure
from the strongly clamped glass plate be enough or will the glass break at
these temperatures (given that the heatbed can reach them).

Solutions: Please watch the whole video to see all solutions, in order of how many people found them helpful

== This solution helped 3 people ==
Baking PCB in an oven is not a good idea, I would say. I know PCBs are
resistive to the heat (especially heatbeds) but, still, it sounds odd. But the
real question is how baking would help. Let's leave it.
If your heatbed is such bent you can do few things depending on your situation/
environment.
You can:
 1. Add two glass plates (at the bottom and at the top) and clip them all
 together;
 2. Support your HB with flat aluminium or even wood;
 3. Add an aluminium frame, or;
 4. If you use glass plate, clip the HB to the glass using stronger (wider)
 clips.
Ad#1 the thermistor can even stay sandwiched between the PCB and the bottom
glass plate.
Ad#2 If your HB is bent up in the middle, you can use the middle thermistor
hole. Drill it a bit with fi8mm drill (but not too much, I would say halfway
through) and use a cone head screw to screw it flat on to the aluminium/wood
support. Of course you will have to install a thermistor into the new place.
The simplest, and less destructive, solution is #1 and I would recommend that.

== This solution helped 1 person ==
Since aluminium has a melting point at 600?C, you're unlikely to get it to a
state where it flexes much by heating. I would doubt you even manage to aneal
it (release the internal stresses).
Your best option is to construct a jig which allows you to press the distortion
out (or pull, using a screw in the existing holes), whilst also taking care not
to apply pressure (at least with a sharp edge) to the tracks or coatings.
This will only be a partial fix, but might be worth trying with a glass sheet
in addition.
Edit: This might be relevant for a Mk3 heatbed, but not the Mk2 as asked in the
question.

With thanks & praise to God, and with thanks to the many people who have made this project possible! | Content (except music & images) licensed under cc by-sa 3.0 | Music: www.bensound.com/royalty-free-music | Images: stocksnap.io/license & others | With thanks to user Sean Houlihane (askubuntu.com/users/4927), user metacollin (askubuntu.com/users/10295), user kamuro (askubuntu.com/users/168), user Greenonline (askubuntu.com/users/4762), user darth pixel (askubuntu.com/users/1211), and the Stack Exchange Network (3dprinting.stackexchange.com/questions/978). Trademarks are property of their respective owners. Disclaimer: All information is provided "AS IS" without warranty of any kind. You are responsible for your own actions. Please contact me if anything is amiss at Roel D.OT VandePaar A.T gmail.com.