Hi,
i mounted last week the MK3 heatbed and a second extruder to my K8400.
Printing with the first extruder, original velleman PLA works fine!
But on the second extruder, with PLA from Devil design, it does not work.
Also tried with 190, 195 and 200 degree.
On the PLA Box was written:
Recommendations: Heating bed:60-70 (my bed was @60)
Hotend: 190-205
https://www.youtube.com/watch?v=_my3ZEg-4Ro
https://www.youtube.com/watch?v=FxbeK1v53MM
Any idea?
Thanks
Are you sure the nozzle-bed distance is less or equal to 0.2 mm.
What are you using to get your filament sticking on the bed? (as it usually doesn’t stick very well on the raw surface of the MK3)?
The distance is about 0,2-0,3mm
The PLA from velleman works fine on the first extruder.
Tried PLA and ABS from Devil design on the second extruder, both same problem.
I will recalibrate later today.
Nothing 
Didn’t know this! I thought, only the heated bed is necessary. But anyway, first extruder OK on “naked” MK3 bed.
[quote=“d1nd141”] But anyway, first extruder OK on “naked” MK3 bed.[/quote]Well you got lucky because on mine it never did stick reliably. The surface is too rough. And to get ABS sticking on the bed you need to heat it at about 95-100° and use a 3D fixing spray or you’ll get lifted corners.
For ABS: ok, clear.
But for PLA, here they write:
http://www.k8xxx-3dprinters.crimed.be/w/index.php?title=Installing_a_reprap.me_MK3_heated_bed
Glass plate
Not necessary for the MK3 but required for the MK2
You can use the one provided with the Vertex.
[quote=“d1nd141”]Glass plate
Not necessary for the MK3 but required for the MK2
You can use the one provided with the Vertex.[/quote]OK I did write that and indeed the glass plate is not required which in my mind didn’t mean you don’t need any other means to get the stuff sticking. Many are well known : blue painter tape, PVA glue, glue stick… If the surface of the heated bed was smooth (like the glass plate) it would stick. But like I said it’s quite rough. Some put the glass plate on the heated bed with good results but it must be perfectly clean. The slightest trace of oil and it won’t stick. And it’s valid for every surface and very difficult to maintain when you have oily rods just above.
I use hair spray for PLA.
Also make sure both nozzles are clean before you start printing.
Hi all,
for the Velleman PLA, I do no need any additional glue to get it sticky.
But the glass plate has to be very very clean.
Meanwhile I take the PRITT-Glue-Stick to have thin layer of PVA on the bed.
A nice “installation” is to have the bed heated and put the glue on the glass plate, then take a wet towel to flatten the glue itself.
The water in the towel will smooth the glue on the glass to a very thin layer… the heated bed will dry it within seconds
Works for me.
As good as Velleman PLA runs, that bad the NUNUS PLA performs.
Referring to your videos, I agree on having the wrong distance to the bed.
It is too high… and try to reduce speed of the first layer…
I also got some devil design PLA from reprap, and Im not too impressed by it. I found it needs 210C to extrude properly and the result are not that impressive. I dont think thats your problem though (or not yet), it certainly looks like the nozzle is too from the bed.
To further improve adhesion, use hairspray!