Any reason to not use high temp extruder?

[Bikeracer2020]

I have a Qidi XC-Pro which is supplied with a high temperature and a normal extruder.

The normal extruder has problems printing ASA at its rated 250C and I'm having to use it at 240C as recommended by their support otherwise the teflon tube inside burns and deforms because although rated at 250C it should not be used over 240C.

Qidi support tell me that the high temperature extruder is not suitable for printing ASA because it will wear the extruder out and I have to wonder what the problem would be?

[fred_dot_u]

I wasn't aware that ASA was considered abrasive. It shouldn't be abrasive and that means there's no reason to consider that it would cause wear on the extruder. It also makes no sense that Qidi support would recommend against it unless there are other unreferenced factors involved.

[Bikeracer2020]

Thanks.

I can't see any reason for it either, especially when the printer comes fitted with the high temperature extruder with a hardened nozzle for printing carbon fibre filament.

[curious aardvark]

it's always struck me as odd that they and flashforge do the same - supply a hi-temp extruder and then say don;t use it for low temp stuff.

personally I;d just use it for everything.

You can't hurt it by running it at a lower temperature.

The only issue I could see would be the metal throat in the all metal hotend.

I have tried one in my sapphire and flexibkle filaments really do not like a steel tube.
Just would not work. But runs fine with the plastic throat.

But for rigid filaments - just cannot see any problems.

[Bikeracer2020]

Thanks, I think I might just swap the extruders because I've just done two 16-18 hour prints and although they start off okay after a while there are parts with no extrusion where I can see the layer underneath, I think this is down to heat creep because it is not as bad as when I was running 250C on the nozzle.

Just wish that although the specs say 250C nozzle temps it's not sustainable on a longish print time. Of course these things never seem to show up printing calibration cubes or test pieces.

[curious aardvark]

also bear in mind that ptfe liners do not like running for extended periods over 240c.

The liner in my delta needs replacing after using it for petg at 245c for a while.
It's on my 'todo' list lol
(mind you it's been in there for 6 or 7 years, so could just be overall wear and tear)

So if youve got an all metal hotend and you're going to be running over 240c, use the metal one.

The only issue I've come across is the extra friction, and that only effects tpu, which does not like being pushed through a metal tube at all.

That said, I've been running tpu through the ptfe tube at 245c for almost 2 years on the sapphire and only changed the tube once, and that was because I'd damaged it doing something and caused a constriction, not because of heat issues.
And some of those prints have been pretty long.
Never had any heatcreep though, not on any printer that I'm aware of.

But still if you've got a metal setup, just makes more sense to use it I reckon :-)

[Bikeracer2020]

Thanks.

It would be better if, when a useable temperature is specified it was actually useable for longer prints.

Anyway I am now awaiting a new extruder because yesterday I had to stop the print because the silicone heat sock had split and fallen off and the heater block ended up encased in melted ASA filament.

Next print will now have to be with the high temp extruder.

[curious aardvark]

I'djust leave the hi temp one on, unless you wanted to do tpu.
can't think of any other reason to ever change it.

[AlexanderHenry]

The problem with Qidi XC-Pro is not the extruder, but the nozzle. The extruder is designed for printing ABS, PLA, nylon and other generic filaments, but not ASA. The ASA requires a nozzle with a melting temperature of 280-290°C, and most nozzles for Qidi XC-Pro have a melting point of only 270-280°C, which is not suitable for ASA. So when you try to print with a nozzle with a lower melting point than the filament you are using, you should expect the nozzle to degrade over time and eventually fail.

[Bikeracer2020]

There is no reason to not use the high temperature extruders, they are very much useful in the production of a wide variety of products. The sturdiness and the efficiency of these extruders can be improved by using the high quality hardware parts, as well as high quality consumables.

Seems to me you are just spamming with a load of meaningless twaddle with nothing mentioned that is in any way specific.

I think that you are talking out of your own rear facing extruder.