Weak power on extruder heater?

I have recently started to use PLA after having used ABS for a long time. When the cooling fan is running with more than 25% speed, the extrusion nozzle temperature will drop from 185° C to 165° C. At 165 degrees, the filament is not melting, and the extrusion gets stuck.
I hit the pause button and manually lower (or shut off) the fan, and immediately the temperature rises again, and I can continue the print. However the cooling of the printed layers is quite bad.

The temperature control works fine, but to me the power in the nozzle seems to be weak. There is really no problem to to reach high temperatures in “still” air (245°C). The fan is attached to a manifold (that I printed a long time ago) with 3 outlet blowing holes. I cannot remember having issues with manifold before, but I might be wrong. Perhaps the cooling is too efficient.

Is there someone who can tell me if it is normal that the nozzle temperature is so sensitive to flowing air. I can of course reduce the air speed, or move the fan away from the nozzle, but resulting in bad printing quality.

Does the nozzle heater “die gradually” over time. I don’t seem to have any hot (burned) spots on the connectors or pcb. I think that any voltage drop here should show as hot spots.
Any good suggestions?

1 Like

Hello @searope

Have the same issue (on a “recent” freshly mounted one ) … Have also tried a fan manifold http://www.k8200.eu/downloads/files/downloads/k8200fannozzle.stl.zip better but not great … as the PEEK need to by cool down to prevent nozzel jamming …)

For me, this is not a low voltage or nozzle heater deficiency. But a simple physical thermodynamic thing. (construction dessing weakness…)

Have you look https://reprap.org/wiki/3drag ? they are using this kind of protection :

or you could use some “High Temperature Polyimide Film Heat Resistant Tape”
see : https://www.reprap.me/catalogsearch/result/?q=POLYIMIDE

Hopping this help !
Happy to see a fellow K8200 user ! :slight_smile:
Have a good day !

Thanks PPAC. Good suggestion.
I will try to isolate with some gasket silicone. I guess thats what’s in the first picture. It should be able to take the heat easily.
Perhaps I should also order a new heater cartridge (just in case). It is not very expensive. I found someone with this issue in a “Prusa” web forum, that solved the problem with a new heater.
But I will start with your simple solution. Clever.

1 Like

Yes certainly Hight-temperature gasket silicone
On day i think i will make something like that “Mould for making silicone sock” : https://www.thingiverse.com/thing:2785387 but for a K8200 Heater …

If you finaly buy a new Heater cartrige could you tell my where ?
Like from :

or from (lower price but unknown/untested vendor … ) :
(@VEL450 Don’t know your “forum politic” about other vendor links … feel free to edit/remove the next link if this is not allowed !)

or somewhere else.

Thanks !

I just ordered from: https://www.conrad.se/p/velleman-velleman-vaermepatron-effekt-15v-33-passar-till-3d-skrivare-velleman-k8400-velleman-k8200-1555354
(that was before I saw your post). Conrad has representation here in Sweden.
Thanks for the link to the mould. I might use that later. Perhaps with modification to fit K8200.
But at the moment, I will just smear the silicone on the print head. My printer isn’t able to make a good quality mould right now.

1 Like

Success uppdate:
The gasket silicone isolation worked perfectly, and the temperature keeps at a steady setpoint level.

1 Like