Speed!  

RE: Speed!

When you turn on the speed parameter, if you don't keep the printer above 60 mph it will explode... 

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Movie stuff... wipe tower deconstructed halfway, resulting in head-crash, Spaghetti monster incident. Ok, "monster" on a millimeter scale thanks to the 0.25mm nozzle but for Hollywood it's just a question of camera angle... the journey continues...

I don't think there is a 0.25 mm preset for MMU so I may need to look into wipe tower settings. Now here's a new and interesting problem.

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...ludicrous speed. Not yet gone to plaid but some visible red shift (8 mm³ purge volume is fairly low).

RE: Speed!

Posted by: @mnentwig

Is it actually documented what the "Speed" parameter in the "tune" menu does? 

Just for laughs I cranked it up to 300 %, with a finger near the reset button. Laughing stopped when I didn't notice any change in print quality that I could see through the glass door. Only, the print head moves like OD'd on caffeine (I don't believe truly 3x faster but "pretty darn fast").

Is it then so that the parameter accelerates everything, but clips to a safe, known ceiling? That - if so, and the print completes successfully - would be a mighty tool e.g. for quick-and-dirty testprints, without touching the design's slicer settings...

Now, actually wondering, how a 0.25 mm nozzle "taking the white pill" would compare against stock 0.4 mm.

It takes the speed limits specified in the gcode into account, so it will only attain 200% speed increases in slow sections, like ironing.

RE: Speed!

Following up on this, I did a series of (increasingly heavy-handed) experiments. If I pull all the stops, I get a functional print in 15 min (with the 0.25 mm nozzle, let's call this "DRAFT" quality) where the stock profile ("SPEED") needs 31 min. 

Interim conclusions:

- the stock profiles seem conservative and not particularly thorough (I may need a "draft" print while and especially because having the small nozzle mounted)

- setup parameters seem very robust (I didn't touch "machine limits" but cranked up everything else "to 11". Lower speed obviously gives shinier results but no functional issues so far)

- The print head moves like OD'd on caffeine while being encouraged with a cattle prod. Quite impressive, actually.

RE: Speed!

What about vibrations of the printer chassis and acoustic rattling or other noises? Does everything still appear "healthy"? (For context -- do you run a stock Core One or are you using modified feet or reinforcements?)

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I keep ~ 30 kg of floor tiles piled on top of the MMU's "enclosed" cover ... for simplicity, enforcing boundary conditions dx,dy,dz / dt == 0 🙂

(not sure whether it makes a difference. Fight one battle at a time).

RE: Speed!

Posted by: @mnentwig

I keep ~ 30 kg of floor tiles piled on top of the MMU's "enclosed" cover ... for simplicity, enforcing boundary conditions dx,dy,dz / dt == 0 🙂

(not sure whether it makes a difference. Fight one battle at a time).

I live in an earthquake zone. I wouldn't want 30kgs of floor tiles anywhere except the floor. I'm printing something now. I'll do the exact same print again at 300% and see what happens. I expect Keanu Reaves to pop up and take over driving my printer. 

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As background: I'm intending to run this printer for years - putting it through its paces or I'll waste a lot of time in the long run by sub-optimal stock presets. I actually suspect that Prusa is putting in too much margin e.g. for kits without basic tuning (of course, my "LEGO benchie" doesn't exercise the whole gamut of possible print problems but it's a solid start)

Wearing out replacables (possibly belts) I don't care but I wouldn't do anything intentionally that clearly overstresses anything or seems "unhealthy".

Quick video (but, take the audio with a grain of salt... Hollywood effect, larger-than-life...)

RE: Speed!

Not entirely relevant to the thread, but I'll be deciding the life-span of my Core One on the 18th. 

RE: Speed!

OK, right-clicking the .mp4 link, "open in new tab" works. So it has uploaded correctly. It does sound a bit scary with headphones, somewhat less so in reality.

"Lifetime", well, let's hope the machine limits are meaningful, then it's just operation within specs. It's sitting idle 22 h/day when print farms run 24/7. No real concerns on that end.

And yes, I do hope INDX will be a game changer. Still, I'm a late adopter so let's see in a year and then (maybe!) find space for a second printer.

For the multicolor (not "multimaterial") printing I bought it for, I really can't say I'm unhappy. With the ballast tiles on top, the rubber feet also stay attached 🙂

RE: Speed!

Yep, 300% is indeed 3x faster. Quality looks about the same. Ironing is a little rougher but not too bad. I think though, this will depend greatly on the filament type. I'm doing a test print with PLA+. Curious to see if this holds up for TPU, PC etc (my guess is "no"). 

Vibration and noise subjectively seemed the same. I'll probably rely on this now for PETG and PLA prints where I'm not too concerned about quality. 

RE: Speed!

Using a HF0.6 nozzle with 0.32 layers. Overhangs are definitely a lot rougher at 3o0% with the filament I'm using: PolyLite PLA Pro

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300% is not usable for the filament I tried and anything with an overhang. The layer adhesion is non-existent. I guess I'll tuck this away for when I need to do a quick draft of something.

RE: Speed!

I also noticed its possible to print significantly faster than 0,2 fast, especially for smaller prints. I did ran out of extrusion performance on a large print though with the stainless nozzle. Would be nice to have a 0,2 extrafast profile for test fitting, it seems to handle faster printing well. Though this was in the region of 150-175% speed setting.

RE: Speed!

I had a look at the part printed in the video. Layer adhesion shows in the studs, but they didn't rip off easily. So, no obvious issues in that particular print but I wouldn't generalize it (e.g. it's possible that the layer below was still above chamber temperature for the single part but would cool down if I printed lots of them in parallel).

Overhangs (my part is printed without supports but it's small) look as expected. Maybe some tiny noses that weren't there at default speed.

RE: Speed!

Posted by: @mnentwig

I had a look at the part printed in the video. Layer adhesion shows in the studs, but they didn't rip off easily. So, no obvious issues in that particular print but I wouldn't generalize it (e.g. it's possible that the layer below was still above chamber temperature for the single part but would cool down if I printed lots of them in parallel).

Overhangs (my part is printed without supports but it's small) look as expected. Maybe some tiny noses that weren't there at default speed.

I'll print my part again at 300% and attach a photo. I think it depends greatly on the filament type. The filament I'm using for this: PolyMaker PLA Pro is crap to begin with even at 100%. I have to use this filament because it's the only one that comes in a color I need for my project. For sure though, I never thought to try this so it's a good find! I'll definitely use this for my draft projects where I'm trying to gauge fit and then I chuck the part in the recycle bin and then do it again with a smaller nozzle and STRUCTURAL. 

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Following up on "layer adhesion" with the 0.25 mm nozzle: I repeated the print with 6 units so they should have a chance to cool down to chamber temp.

Layer adhesion is as expected from stock prints. I did not provoke any failure ripping off studs with my established "reasonable expectations" test procedure.

This is not to argue that it could not be an issue but it may well be that the 0.25 mm nozzle could run considerably (x2..3) faster than the stock presets.