Closed Loop and Prusa?  

I don't see much advantage.  Already positional accuracy is well below an extrusion width and speed/acceleration is limited by the viscosity of molten filament.  They might mean that Prusa could use one size smaller motors or use a fraction less power - most of the power consumption is for heating which won't change.

Cheerio,

RE: Closed Loop and Prusa?

I could see the benefit.  I have been struggling with layer shifts that seem to come and go., Sometimes I just can't seem to get through a particular part no matter how much I lube the bearing, adjust belt tightness and re-slice the model.  Then the problem just goes away. This is of course with crash detection disabled, if one wants to print in stealth mode, layer shifts are an inevitability on larger parts (often when you want stealth mode is when you have a large part that goes overnight, but you don't want to annoy the light sleepers in your house.)  I don't even necessarily think you need full closed loop motors, just some system that can monitor the positional data, compare to what it should be, then trigger am x/y home if it gets out of sync.  This would be able to do crash detection without relying on current detection of the motor. So stealth mode would actually be feasible. This feels like something that could be modded.  Maybe an esp32 monitoring the stepper poles, and if you swapped motors with something like https://www.analog.com/media/en/technical-documentation/data-sheets/QSH4218-x-10k_datasheet_rev1.50.pdf, you would have motors that can still be driven by the einsy rambo, but also have an encoder output.  There are probably also hall effect kits you can slap onto the back of the stock motors.  Would just need some mods to the firmware to get the signal to re-home

RE: Closed Loop and Prusa?

The expense is the problem for our price range. Current XY precision of .08mm or .003" in XY for Core One and MK4 is not good enough in my opinion.
Something like Tesseract Technologies linear motors would be good. Linear motors with closed loop and .0005mm precision. That accuracy is more than enough for FDM printing. No price info yet except "affordable. Also "testing with 3D vendors" currently. Which 3D printers are they testing with? Commercial grade or Hobby grade? Lots of questions yet.
This is the fun of working with machines for hobby/home use. Getting the needed technology affordable. We have a ways to go yet.

RE: Closed Loop and Prusa?

The expense is the problem for our price range. Current XY precision of .08mm or .003" in XY for Core One and MK4 is not good enough in my opinion.
Something like Tesseract Technologies linear motors would be good. Linear motors with closed loop and .0005mm precision. That accuracy is more than enough for FDM printing. No price info yet except "affordable. Also "testing with 3D vendors" currently. Which 3D printers are they testing with? Commercial grade or Hobby grade? Lots of questions yet.
This is the fun of working with machines for hobby/home use. Getting the needed technology affordable. We have a ways to go yet.

RE: Closed Loop and Prusa?

Posted by: @vhubbard

Something like Tesseract Technologies linear motors would be good. Linear motors with closed loop and .0005mm precision. That accuracy is more than enough for FDM printing. No price info yet except "affordable. Also "testing with 3D vendors" currently. Which 3D printers are they testing with? Commercial grade or Hobby grade? Lots of questions yet.

According to https://www.patreon.com/posts/formnext-2025-at-144022833:

In my opinion, linear motors are the future for any 3D printer with a build volume above 500 mm. Long belts introduce stretch, vibrations, resonance, and wear — all problems you can bypass entirely with linear motors. [...]

Now, let’s talk pricing.
We’re in the low industrial segment here. A full gantry will run you somewhere in the mid four-digit range.

Not sure whether that ballpark number for the price is referring to a single axis or a complete XY system.