Question for the high speed printers..

Thalios

I just installed a Nova 3D print head on my Railcore II 300ZL.

I can now print at 200mm/s reliably, but to do so, I need to increase the temp to 260°C. Is that normal? (The head can do 500°C, and has a PT1000 on it).

Head is supposed to do 350-400mm/s+ with PLA.

If I want to get faster, do I need to increase the temp even more?

Luke'sLaboratory

Yes.

Pure extrusion rate is limited by heat flux into the plastic and effective pushing power.
If you have enough pushing power, you need to make sure you have enough heat flux - this is primarily done by increasing thermal conductivity, increasing the total area (heat zone) of the heatblock, and by increasing temperature of the block to increase energy transfer to the cooler plastic.

So yes, to go fast, go hotter. FWIW - I reliably print 30mm3/s at 260C for 3D870 based PLA resins. Nothing more than a mosquito Magnum with .6 vanadium nozzle. (lol still a more expensive hotend, rip me)

However - with PLA you may find that instead of volumetric limitations, you may be limited by quality, mostly by how fast you can cool your extruded material. You may need to upgrade cooling as well to lay down more plastic.

As a side note - for high flow/high speed, for any kind of recommendation or diagnosis, I'd recommend sharing volumetric rate, or at least layer height and nozzle size, to get an understanding of just how much plastic you're actually pushing. If you're printing with .4mm nozzle at .1mm layer heights, you can probably push your toolhead past 200mm/s without many issues regardless.

Another side note - this is a simplification. Backpressure and other polymer effects are important here.

Phaedrux

@thalios said in Question for the high speed printers..:

Head is supposed to do 350-400mm/s+ with PLA.

This is a very meaningless measurement though. It's the melt rate that matters. The print speed is arbitrary. What is the layer height and extrusion width being used when printing at 400mm/s?

Thalios

This is a very meaningless measurement though. It's the melt rate that matters. The print speed is arbitrary. What is the layer height and extrusion width being used when printing at 400mm/s?

Sorry for the lack of infos.

Hotend is rated at 60mm^3/s.

100W heater. PT1000. Duet 3 6HC. Bondtech direct drive extruder.

Nozzle 0.5mm, Layer height was 0.28mm, width 0.5mm

Specs to the hotend:

https://3dpassion.com/nova

Luke'sLaboratory

@thalios

At that flow you're in the region of 28mm3/s - assuming their 60mm3/s is true for PLA (I'd personally bet its for ABS/ASA) looks like you have plenty of headroom.

To answer your question, try it? Just go faster and see if you get underextrusion, or run into some other limit along the way, and adjust from there.