Print Speeds (Page 1 of 2)

Umm. I'm pretty sure that's an insanely fast speed. The highest I've printed was 3200mm and I think that is pushing it. That's a lot of work for the stepper motor pushing the filament through and other parts. I think that speed would work if you cooled the stepper motor with a fan and had an upgraded power supply. But the davinci stock power supply barely supplies enough power to handle the printer as it is.

Looking at the DaVinci 1.0 user manual (if you can call it that), it says print speeds are 60, 90 and 120 mm/s (3600, 5400 and 7200 mm/m).  Elsewhere in their documentation (before the CES in January) they spec'd it at 150 mm/s (9000 mm/m) but I suspect it was a typo.  Photo attached of current info.

I set it to 5000 mm/m.  Printed 4 parts and zero problems.  Yeah, it moves fast but hasn't shaken the house down, yet.

Common sense suggests lowering and I'll probably set it around 4000 mm/m.

Also, just finished printing a gizmo I designed for loading a pellet gun magazine - photo attached (printed at 5000mm/m)

I figure if they post the spec’s saying 120mm/s the machine can safely do it.  I trust their engineers to have at least tested it for burnout at that speed with margin of safety (I’m an engineer for 40 yrs and have servo control systems flying in space so, I’ve got to have faith - at least  until their marketing dept gets involved).

Video from this morning showing it running at 5000 mm/m.  It’s a circular part so speed isn’t as fast as it would be for a straight line but it clearly shows it running fast.  Screenshot shows settings panel

Should have mentioned: Gcode generators look at current position and next position with respect to the mass (and inertia movement) to calculate proper speed between those two positions.  Thus, reducing the speed as appropriate.
I have a CNC mill and the software for that lets me peak at that percentage and adjust it - for the xyz printer, the only clue to speed reduction is by review of Gcode output.  Save a gcode file from s3d and look at the various speeds (the F command).
Also, you can look at the print preview and the colors show the speeds (and, naturally, that speed legend changes when you adjust the speed settings - you can see that the values do change).

And, running at 5000mm/m = 70% of the 120mm/s (7200mm/m) so, it's comfortably in the range of the spec'd speed limits. As shown on the pellet loaded image (above), the circular geometry is round and the tunnel for the pellets does not have drooping filament or bubbles/etc - the part is perfect and it printed very fast because of so many linear line/positions (as opposed to circular).

If you hang/add mass to the extruder head (such as bigger fan, micro camera...etc, you add mass and the internal (gcode calc's) won't know anything about it and will not correctly calculate speed - that's when you can drive it to failure...

Yes 5000 seems insanely fast to me. I am printing 3200 and the printer can handle it but it's printing fast. Seems something like 5000 would only possibly work for large prints

The Da Vinci 1.0 can just manage 60mm/s if you use stock filament. They have it specially made so it melts at a lower than normal temp of 190. Most third party ABS melts at 220 to 260. The melt temp plays an important role in how fast you can print. The size of the object also plays an important role as small objects must be printed slow to allow each layer to cool enough so you don't get sagging or rubber banding.

Once I changed my controller I found I had to slow the machine to 35mm/s to print third party filament well. If I did not slow it down I would get under feeding or rubber banding from pulling the extrusion too tight.

So although they say the machine can do 60mm/s that is only with stock filament and not aftermarket.

Following up...

After comparing printed parts, actual print times, and my comfort with 5000mm/m,  I dialed it down to 3600 for Print Speed and 5000 for X/Y Rapid Speed.  It increased the print time by only two minutes on the speed-test parts so, I’m going to use that as a default and will adjust as needed.

Thanks for the comments - much appreciated

Those rapid moves are only travel moves though, not extruding. Also the models you've shown in this thread look small enough that the printer may not even have enough time to accelerate to those speeds in most cases.

Anyway, I personally would never print at more than 3600. And like I said, I already experienced some layer adhesion issues at those speeds.

Didn't know that 'rapid moves' was actually a term, thanks

Would you post some close up pics of the same item printed at both speeds? I'd like to see it and like I said, maybe print it myself to compare too.

Yes - "Rapid Move" is Gcoder terminology - here's a quote from Wiki (not that it's a reliable source but it compares with gcode & machine CNC books)
"In the RS274NGC Spec, G0 is Rapid Move, which was used to move between the current point in space and the new point as quickly and efficiently as possible"

1. Speed Compare:
  Photo 1 shows parts & speeds (infill=30% Layer H=0.2, Layers=2 (top&bottom), Shell=1, Temp=230, Shaxon filament).
  Photo 2 closeup
  First photo at top of this post shows two parts - the first of my prints at speed of 5000.

2. Z Offset:
  Photo 3 shows panel where to set it (it's by percentage)
  Photo 4 shows it now set to 0.8  (by setting value to 400%)

3. Adding gcode the easy way:
  Photo 5 shows where to add code (entry panel determines where it goes - hover to see context help)
  Photo 6 shows that it got there

You can leave the " ;layer 1. Z=0.3"  and simply add what you want, via the input panel.  For example, add " ;layer 1. Z=0.0"  if that's the value you want (where and how I indicated "bla bla bla" above).  The machine will respond to it and move before it prints the next line(s).

That way you don't need to edit the gcode.  However, I'm not certain about the machine responding the the H and W values just after the T0 (tool change) -  that functionality could be (should be) dependent on your machine/firmware even though s3d outputs it, since it's a full-featured software for many machines).

First layer height should not be dictated by the software.

Your nozzle to bed gap determines the first layer and should be atleast half of your desired layer height. Once you decide on a printed layer height such as .3mm you then use a feeler gauge or other item of known thickness in this case .15mm and calibrate the bed to that gap.

If you have no way to fine adjust your bed to nozzle clearance which would be very rare and not the case with Da Vinci as it has adjusters, then you would need to do it through an offset in your slicer.

But since the DaVinci has adjusters you should do it correctly and adjust first layer height by hardware, not software.