PLA wont stick on printing pad

K8200 3D Printer K8200 - Issues while printing
1

Hi,

over the last days, i assembled my k8200 successfully (hopefully…).

But when i try to print the case as suggested by the manual, the PLA wont stick on the pad. Instead it will stick on the nozzle and the extruder.

Please see the following video:

youtube.com/watch?v=21MpZ4eACKU

Thanks in advance,
Markus

2

It looks like your nozzle is is little bit to high, but there are 3 very important things:

  • level your bed, level your bed, level your bed !
  • regularly thoroughly sand your bed with Scotch-Brite pads till it has a matte surface
  • before printing clean you bed with isopropyl alcohol

If you do this, PLA will stick like hell !
You really don’t need glass, painters tape, hairspray, Kapton, glue stick, …

3

Hi,

thanks for your quick reply.

I managed to get it “kind of” working, but now ive got a different issue:

This is again the case from the manual…something is wrong with the coordinates

4

Hi, set the stepper drivers to 0.55v - exactly the same as you did from the manual during set up but higher voltage. Dont ask me why -it could be changes in motors or drivers but the original setting is to low.

5

Your nozzle is still to high and you are loosing steps.
Did you adjust the stepper motor drivers as described in the manual?

6

Hi,

my nozzle is now leveled right, all motor drivers are at 0.55 V and i cleaned my heatbed with ipa.

Still this:

7

Hi Markus,

Either your bed is not level, either your nozzle is still too high.

  1. Re-level your bed with a piece of paper between the nozzle tip and the PCB on all 4 corners
  2. Adjust the endstop for the Z axis (too low is better than too high)

And did you sand the printbed with very fine sanding paper or preferable Scotch-Brite pads? On the last picture your bed looks a little bit shiny. Mine is really matte.

8

Hi,

thanks again for your awesome help :slight_smile:

I sanded the bed and now it works like a charm.

But now this happens (motor driver voltage is correct set to 0.55 V:

I left it printing for about 3 hours, since the first layers were looking really nice.
It seems that after 5 or 6 layers the whole thing starts shifting.
Do you know why?

thanks in advance

9

Layer shifting, no doubt. Can have different causes:

  • The print carriage is mechanically too stiff, check your construction, use bearing grease (sewing machine oil evaporates)
  • The timing belts are tensioned too hard, it is not the intention that you can play piano on the belts
  • The stepper motor drivers probably will be too warm and skip steps, lower the control voltage a little and use SMD heatsinks
  • The connectors on the control board make poor contact, span the tabs on the headers (I had this problem in the beginning)

You printbed looks very rough, use extra fine sandpaper or (preferable) Scotch-Brite pads in order to make it smooth. Do not make up and down movements, but try to scour circular. And avoid scratches, an equal matte surface will do the job.

Here is a detail how my printbed looks:

1zcpyxe.jpg2047×1426

10

Hi,

  • The print carriage is mechanically too stiff, check your construction, use bearing grease (sewing machine oil evaporates)

    It seems that it slides very nicely (If this is the problem, it would be everytime, right?)

  • The timing belts are tensioned too hard, it is not the intention that you can play piano on the belts

    If a lay a finger on them they easily bend 0.5 cm down, so it seems correct to me.

  • The stepper motor drivers probably will be too warm and skip steps, lower the control voltage a little and use SMD heatsinks

    I also thought about this, so i bought 2 40mm fans and put it right above the drivers. No change…

  • The connectors on the control board make poor contact, span the tabs on the headers (I had this problem in the beginning)

    I inspected every connector and spanned them. No change…

Thanks for your help

EDIT:

I tried a different model. Worked till this point:

11

Check the screws that hold the pulleys on the motors.
Make sure they are tight.
Don’t over tighten them as they can strip.

12

Good one ! This is also a possible cause of the problem.

13

Does your z axis threaded rod wobble around a lot? If it does, this oscillates the height of the print head and it may be going down enough to impact the print. It’s just that the picture shows a waviness in the outline of the object so far.