Models Printing Smaller Then Model Size in Prusa Slicer
Hi all, just today, the small parts I designed in inventor are being printed smaller then the model size. I have confirmed this now with a number of designs (circles, squares) and despite Prusa Slicer indicating the correct size both visually (on the grid) AND under object INFO, when printing the objects are between 12 and 14% smaller?! (Ex a test square at 30mm both ways printed at 26mm both ways). This is the first time this has ever happened in years of printing with no changes to the printer itself or the slicer software. Obviously I'm not adjusting the scale factors either in Prusa slicer - all at 100%.
Does anyone have any ideas why and how this is happening? Thanks to all in advance!
Please save a sample project as a .3mf file
Files > Save Project as
Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.
Cheerio,
RE: Models Printing Smaller Then Model Size in Prusa Slicer
being printed smaller then the model size.
That's a calibration issue. A stepper motor moves a given number of degrees per impulse, and somewhere in the firmware is a calculation that says "1mm = X number of impulses". For non prusa printers, this often needs tuning because not all stepper motors are the same. For this reason I suspect you may have put the motors in the wrong location.
Here's a post that discusses the process: https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/steps-per-millimeter-correction/
At times you can use gcode commands to do minor adjustments too. Note, I like Prusa printers because this stuff isn't necessary - they come pre-tuned as long as you follow the guides. Your slicer sets printer based parameters, so another typical error is that you have the wrong printer selected on the preset - that the slicer generates code meant for different hardware/motors, steps etc. Ie use MK3S+ instead of MK3. Or someone added customization parameters that overwrote defaults.
So I would create a new untouched printer-preset from the official source. Make sure it matches your printers type including upgrades. Then do the test cube print out - it's relatively quick and should give you a chance to see which axis have the problem. Verify you're using the right motors in the right places, and if so adjust the axis(es) using the methods laid out in the link I provided. You may want to contact Prusa support before you do so - it should not be necessary if you use their motors from the kit.
RE: Models Printing Smaller Then Model Size in Prusa Slicer
Thanks for this feedback however I have used this printer a few thousand times. 100% confident the motors are installed properly! As noted this is the very first time this has ever happened and it started suddenly without any creep (as in a slow deviation from the proper dimensions).
RE: Models Printing Smaller Then Model Size in Prusa Slicer
See attached .3mf file. This was the exact model that printed at just over 24mm (24.04 or something) both directions X and Y. I did not confirm Z. Thanks again!
RE: Models Printing Smaller Then Model Size in Prusa Slicer
As this is happening to a previously functioning printer then it is unlikely to be the steps per mm values. Saying that the steps per millimetre are stored in the printers eeprom memory. While that is non volatile it is possible the values have become corrupted. The current values can be read out using pronterface or similar using M503. The values for a MK3 should all be the same from factory. It didn't start happening after a firmware update did it ?
If it has happened suddenly then it could also be electrical and that your motors are missing steps. It could be the drivers on your einsy or the motor wiring or the motors themselves. Basically anything that results in not all the commanded pulses actually resulting in movement of the motor. I would expect that to happen to individual axis though and not both x/y at the same time.
The steps per MM and eeprom is the easiest thing to check first though. Anything electrical is likely to be a pain in the rear to track down and possibly expensive if it does require replacement parts. New Einsy anyone ?
RE: Models Printing Smaller Then Model Size in Prusa Slicer
ever sort this out?
My printer is now suddenly doing the same and printing approx 85% of the model size. arrrrrghhhhhh
RE: Models Printing Smaller Then Model Size in Prusa Slicer
Mine too. 😣 I have the new prusaslicer 2.6
ever sort this out?
My printer is now suddenly doing the same and printing approx 85% of the model size. arrrrrghhhhhh
RE: Models Printing Smaller Then Model Size in Prusa Slicer
For me I found issues with the bolts holding the extruder in place - one was missing and another was way loose - my bad from when I had to swap over the hot end and hadn’t completed the reinstall properly. Now sorted.