Maybe this is normal ?
Im currently installing a mk3 heatbed but have not recieved the power supply yet. Decided to try it anyway without heat and just print on the aluminium. This did not work at all but only made a mess.
Maybe this is what happens with unheated heatbed ?
i havent tried but i think most people using heated beds also use some sort of glue when printing, depending on what they are printing.
i asume you have it correctly adjusted from the nozzle.
i am in the same boat as you, i have a mk3 heatbed lying here but no powersupply (postal strike in germany) so could you post a picture or 2 on how you did the physical mounting of the heatbed itself ?
i am thinking about rebuilding the intire printbed, because my build platform isnt straigth, it curves up on the middle, and when you use all 4 clips it bends the glass slightly aswell 
[quote=“frich”]i havent tried but i think most people using heated beds also use some sort of glue when printing, depending on what they are printing.
i asume you have it correctly adjusted from the nozzle.
i am in the same boat as you, i have a mk3 heatbed lying here but no powersupply (postal strike in germany) so could you post a picture or 2 on how you did the physical mounting of the heatbed itself ?
i am thinking about rebuilding the intire printbed, because my build platform isnt straigth, it curves up on the middle, and when you use all 4 clips it bends the glass slightly aswell :([/quote]
Today I am going to try to use the original mounting with a MK3 heat bed (The one Marlak have custum made for k8400). A reprap.me piece og cork is 2 thick and flexible, so the mount bends the plate.
I will get piece of gasket sheet in the correct thickness, and cut so the original mount system can be used.
Regards Tommy
Nothing is sticking on the bare alu heated bed even when heated because the surface is not smooth enough. I’m coating the bed with a PVA glue slurry for PLA and with PVC glue for ABS.
Here are a few pictures of my heatbed:
As you can see I have used the original bed as a base. Drilled holes and threaded for the for corner holes of the MK3. I have reprap’s cork insulator but realized soon that since the holes are so close to the edges it’s a very large risk that you over tight them and then the heatbed will form an arc. To minimize this risk I will install small distances the size of the cork insulator and possibly also glue a few in the center. Coming to think of it, I wonder what has the best heat insulating properties: cork or air ? Maybe the cork is not neccessary at all ?
Raby:
What do you make the PVA glue slurry from ?
I read somewhere somone suggested to use a glue stick to fix it to the bed ?!
[quote=“monza64”]Raby:
What do you make the PVA glue slurry from ?
I read somewhere somone suggested to use a glue stick to fix it to the bed ?![/quote]
Glue stick is PVA but also white wood glue (I’ve used both).
Blue painter tape sticks very well too but leaves tiny strips on the object bottom.
Today i printed a small object in PLA. Directly on the MK3 headbed, 50C and hairspray as an adhesive.
Worked very good, and a very clean bottom of the object.
Regards Tommy
Thanks guys.
Cork it is and now with 2 mm distances at each screw and some inthe middle to make sure nothing is overthighted and the mk3 archs.
Raby: What is the blue painter tape ?
Is that a double side adhesive or single sided tape ?
In Sweden blue masking tape is the mark of a tape with quite weak adhesion on the sticky side but on the other hand it does ot leave a lot of residue if you dont remove it quite soon after finishing the job.
Pattex or Tesa tape do the job. The blue tape has a smooth surface so it doesn’t leave residues. Only small marks at the join
