Hi guys, not “new” to printing but not a veteran either. Had a QIDI x plus for a few months, and have about 320 hours on a bambu a1 mini.
the only setting I do not quite understand what to do with is max volumetric speed.
Is this just another way to control how fast your prints are? For example:
If my print speeds are left stock (way too fast most of the time) and I turn down this number, are my prints going to just slow down? And visa versa if I turn this way up will my printer go nuts and give a bad result?
Could this be a faster way to change speeds instead of turning each speed down manually?
Is there actually a good reason for me to turn this up or down? do I just continue to adjust my speeds as I see fit for the result I want? I got pressure advance and flow rate figured out… just not understanding this settings uses.
Not exactly, although the side effect of its use may make people think that.
It is the upper limit that the hotend can melt and extrude per second.
If this is set too high without knowing the true number, it can cause damage to the printer.
Too slow and your prints will go slower than can be achieved, resulting in wasting time and energy (cost).
Not really, it only changes the upper limit your prints can achieve. You are essentially saying every employee can only be as productive as a random staff member, even though there are more productive staff and less productive ones.
Much of the time, your printer isn’t going at full speed, so halving the value will not halve the print time.
It is often more conservative than it needs to be. However, unless you know what you are doing or are willing to suffer some damage, possibly leading to a fire (worst case), leave it as is.
If too much material is pumped through, this can cause a blockage or material to get stick on the hit end causing a heat build up and the hit end can overheat, resulting in a fire.
Your print speeds and layer height cause a certain volume if plastic per second. The max volumetric flow allows you to limit that volume. Anytime speed and layerheight would cause the printer to exceed this limit, the print speed will be reduced to stay within this limit.
When you set this parameter too high, you could get underextrusion, e.g. holes in your print or completely failed prints. It certainly won’t cause fire.
So perhaps not a fire?
I was mainly looking to this setting to be able to turn down my speed without having to adjust each speed settings individually, I wanted to set my speeds for each filament instead of taking all that time each project.
Max volumetric speed (MVS) only specifies the ability of the hot end to extrude.
If your car can achieve 200 km/h, but your roads are limited to 50 and 100 km/h, you only travel at 50 and 100km/h.
If your car is only capable of 75 km/h, you will still travel at 50 where legal, but only 75 on the 100km/h roads.
You can see the limiting effect of MVS on layer speeds pretty easily. Slice a primitive cube with default settings and use the Speed color scheme in the preview tab.
Compare the colors to the process speed settings. They should match if your MVS is correct.
Double MVS in the filament preset (do not save) and re-slice - if the original MVS was correct the colors and print time should remain the same.
Now reduce MVS to half the original and re-slice - likely some of the layer speeds will be less.
Then reduce MVS to something very low, maybe 2 mm³/s - the layers will probably all be the same colors, the same slow speeds.
There is no setting which can change all layer speeds in proportion.
If your filament preset specifies 10 mm³/s but testing shows that your printer can reliably extrude that filament at 18 mm³/s, you can change the preset. Print time will only be less if the old MVS was actually restricting the layer speeds OR if you also increase layer speeds individually.
MVS settings for Bambu filament are pretty much correct, the preset values for Generic filaments are conservative and can often be increased. Studio has a MVS test built in, but it is hidden. Enable “Develop” mode at the bottom of your Preferences (Ctrl+P) and a new menu on the top line will be available, MVS test is under “More…”. A brief explanation is in the Wiki . A more complete explanation for the same test is available from OrcaSlicer.
Yes, a 3D printing “blob of death” can potentially cause a fire. The primary danger arises when the large mass of molten plastic damages or dislodges sensitive wiring, specifically the heater cartridge or thermistor leads, leading to a short circuit or thermal runaway.
A blob of death is a likely result of setting the value incorrectly.
That works in a way, but as @lkraus has written, it doesn’t proportionally reduce speeds, but caps them depending on layer height and line width.
E.g., line types with wider line width will get slower than line types with narrower line width.
When you reduce the layer height, the speed will increase.
So if speeds are really what you want to control, then it is probably better to save 2 or 3 presets of the process settings and select those depending on filament or object.
The max volumetric flow really is best used to limit flow to a level that still works for the filament and hotend.
The question is, why you would want to control the speed and not the flow?
I want to control speed because the faster a print, the crappier they come out for me, when I slow them down the VFAs are usually a little better. I print a lot of silk and TPU.
I’m one of those people who don’t like owning anything I do not know exactly how to use entirely, not a fan of having this important setting in front of me and not knowing how to make use of it lol.
I did the blob of death like the commenter above on a printer at work. overnight print on an older printer… sat overnight with the entire piece sucked up against the nozzle melting and burning for 24 hours. Didn’t case a fire but sucked. Had a bad tangle in the roll. Learned my lesson about spools… it was a super old one someone gave me.
I calibrate all of my filament manually, and look at them with a magnifying glass, its one of my favorite things to do
I got into this because I fly FPV, wanting to stop buying prints. I am big on tuning things, but I was having trouble understanding the setting this original post is about.
I spent all last summer on filter and pid tuning with the quads… I can’t say it was fun but it was interesting.
Wait a sec… so one time I did select a file without selecting the a1 mini… and it did really alarming things, so what do I do change the printer, open the file then change the printer back to mine before printing the plate perhaps?
I didn’t know about this!
I still don’t get any of those calibrations… just PA and flow when I open that tab
With that background, you really want to set specific speeds. Max volumetric flow is not the right tool for that in my opinion. And I would assume, that VFA-free speeds are independent from filament, right?
So I would create one preset in the process settings that contains the best speeds for high quality and another one for minimum print time.
