Noticing Prusa high temp filament spools tend to come apart after removing from the dryer
So I've now had 2 instances where the plastic end of the spool came off from the cardboard insert after drying a spool of Prusa PP-CF and PC-CF at 80C for 6hrs. The result was a tangled mess on the floor. I think my next project will need to be a filament winder. I suppose maybe the cardboard spool is expanding with the heat? I know Prusa have set these up to be refillable but I might end up having to glue them for next time.
RE: Noticing Prusa high temp filament spools tend to come apart after removing from the dryer
But this is a well-known fact! Before drying, the plastic faces of the Prusa coil need to be connected with three sufficiently long screws threaded through the holes in close proximity to the cardboard center and secured with nuts. In extreme cases, the faces can be strengthened by threading a suitable piece of wire through the holes and tightening it. If you use screws of the appropriate length, these do not matter in normal use of the coils, because the heads of the screws and nuts are hidden in the hexagonal cavities. As you write, you can also try gluing the faces to the cardboard center, but I would not recommend that because there is a risk that the glue will loosen at 80°C and the coil will still fall apart.
RE: Noticing Prusa high temp filament spools tend to come apart after removing from the dryer
Perhaps not as well known as you assume @miroslave-h4) :).
@hyiger, here is a Prusa article about filament drying that discusses this:
Drying filament | Prusa Knowledge Base
Regards,
Steve
RE:
According to Prusa grey spools are supposed to prevent this issue, because the plastic sides are already glued to the cardboard core. I use screws on black spools of Prusament ASA and PC blend, but not on grey spools of Prusament PA11-CF.
For the record, I dried PC blend ( black spool ) and PA11-CF ( grey spool ) at 80-90C for several hours and there were no issues with any of them,
RE:
According to Prusa grey spools are supposed to prevent this issue, because the plastic sides are already glued to the cardboard core. I use screws on black spools of Prusament ASA and PC blend, but not on grey spools of Prusament PA11-CF.
For the record, I dried PC blend ( black spool ) and PA11-CF ( grey spool ) at 80-90C for several hours and there were no issues with any of them,
Both were black spools. I didn't even think to do this because, I have similar high temp engineering filaments from Siraya Tech, MatterHackers etc and have had no such issues so assumed that if Prusa ships a similar filament the spools should have been able to handle a 80 - 90C dryer. They obviously didn't.
Good you didn't have an issue. I did with two spools. So from now, I'll just bind them before putting them in the dryer.
I suppose I have to ask, why on earth would Prusa wind filament onto spools that can't handle the temperature needed to dry it without some sort of hack?
RE: Noticing Prusa high temp filament spools tend to come apart after removing from the dryer
But this is a well-known fact!
Well known fact? By whom? Those who have been in Prusa community for awhile? Obviously not well known because I didn't know it.