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Acceleromter and resonance??  

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Bill
 Bill
(@bill-3)
Estimable Member
Acceleromter and resonance??

One of the most fascinating things I find about klipper is the ability to add an accelerometer and supposedly be able to deal with resonance to eliminate print artifacts.  Has Prusa said anything about dealing with this on the XL?

I was big into my Prusa MK2.5s and MK3, but kinda burned out.  This new printer bringing new excitement, but I am still reluctant...  I did place an order on announcement day for the $3500 5 tool kit, but am still leery.

Posted : 21/11/2021 2:29 pm
geekandi
(@geekandi)
Member
RE: Acceleromter and resonance??

if they do the klipper stuff that was mentioned then just add your own accelerometer and do measurements!

Posted : 22/11/2021 4:38 pm
Bill
 Bill
(@bill-3)
Estimable Member
Topic starter answered:
RE: Acceleromter and resonance??

$3500 printer, I expect the latest and greatest.  The accelerometer tech has been around for a minute.  If not I guess we will be force to live with print artifacts that have already been solved on the Voron?

 

Posted : 22/11/2021 11:49 pm
geekandi
(@geekandi)
Member
RE: Acceleromter and resonance??

Posted by: @bill-3

$3500 printer, I expect the latest and greatest.  The accelerometer tech has been around for a minute.  If not I guess we will be force to live with print artifacts that have already been solved on the Voron? 

Well, uh, don't think Marlin has a facility for such items and Prusa only mentioned unofficial klipper support in the announcement. I'd give it time and see what they do. If klipper comes around and there are reasons to check resonance then it will be easy to do so.

Posted : 23/11/2021 1:40 pm
Walter Witt
(@walter-witt)
Eminent Member
RE:

Taking a closer look at the 3D Printing Nerd video, the left hand side of the Nextruder shows quite a bit of PCB area. and given how they've already said it has its own microcontroller, a tiny accelerometer chip on board would just make no sense NOT to have.

Posted : 24/11/2021 3:43 am
Thejiral liked
Bill
 Bill
(@bill-3)
Estimable Member
Topic starter answered:
RE: Acceleromter and resonance??

Good point.  I can't imagine that Joseph and crew have not at least considered this...  Mainly why I posed the question.  I could live with not having it out of the gate, as long as an approach is being worked on I would be happy.  Resonance is one thing I grew to really dislike about my bed slingers (have Mk2.5s and 3).  I have a youtube video up showing a millennium falcon failing due the the resonance of the printer causing the print to break loose from the bed, even with a big raft.

Posted : 24/11/2021 4:56 pm
3Delight
(@3delight)
Moderator Moderator
RE: Acceleromter and resonance??

I think we need to wait and see what they've come up with before fixing things that may not be broke!

Posted : 24/11/2021 6:21 pm
Bill
 Bill
(@bill-3)
Estimable Member
Topic starter answered:
RE: Acceleromter and resonance??

Thanks for the insight.  Very helpful and reassuring.

Posted : 25/11/2021 11:08 am
Mirar
(@mirar)
Estimable Member
RE: Acceleromter and resonance??

I believe running with accelerometer is a one-time calibration thing for klipper to trim parameters, not something that's used live?

Posted : 28/11/2021 5:04 am
GuyH
 GuyH
(@guyh)
Reputable Member
RE: Acceleromter and resonance??

 

Posted by: @mirar

I believe running with accelerometer is a one-time calibration thing for klipper to trim parameters, not something that's used live?

Correct.  Assuming known components then it's conceivable that this could be done in house by Prusa and providing input shaping is supported by the firmware as it is by Klipper and RRF then it could be all part of the profile/fw on the XL.  

In the future accelerometers are used to tune live during a print then it may be something the XL could have.  

Posted : 28/11/2021 11:47 am
burtronix
(@burtronix)
Reputable Member
RE: Acceleromter and resonance??

In  Prusa Live 35, they did not talk about accelerometers, but there was much discussion about force-sensors & how rich & useful the data might be beyond location, calibration, & leveling. They purposefully didn't disclose much because it's still in development, but they did mention that just by looking at the force data they could recreate the model that generated it. So perhaps they could get resonance from the force data.

Whatever you find to do with your hands, do with all your might!

Posted : 28/11/2021 2:46 pm
Neal3d
(@neal3d)
Eminent Member
RE: Acceleromter and resonance??

Just Curious,

From what I have read that current Prusa Firmware cannot be used for Input Shaping. Does anyone know why Prusa Firmware can't support Accelerometers from a Technical perspective (Not Business perspective)?

I'm suspect the old 8 Bit boards can't do acceleration but I would think new 16 Bit boards might be beefy enough to support Input Shaping.

I heard Joe in Podcast indicate some possible future level of Klipper support. Then I wondered why a total Firmware change would be needed and Prusa FW couldn't slowly be upgraded? Maybe a legacy software thing?

Your Thoughts?

 

Posted : 08/12/2021 12:06 am
geekandi
(@geekandi)
Member
RE: Acceleromter and resonance??

From what I have read that current Prusa Firmware cannot be used for Input Shaping.

Relatively correct though in Klipper land, input shaping is done via another process running on the compute MCU (like a PI).

You'd use the accelerometer to get the measurements, do the calculations, update klipper configuration, restart klipper.

I don't know if Marlin itself has anything built in to handle this via the host MCU.

Posted : 08/12/2021 2:37 pm
Neal3d
(@neal3d)
Eminent Member
RE: Acceleromter and resonance??

Thanks @geekandi for the info. I did some more research and found that Nero 3d did a great Youtube Video on Input Shaping. Input Shaping appears to be a one time calibration (Assuming no printer Changes). Fascinating subject.

It will be interesting to see if Prusa will be implementing Input Shaping.

 

 

Posted : 11/12/2021 12:42 am
Thejiral
(@thejiral)
Noble Member
RE: Acceleromter and resonance??

It is a one time calibration ... as long as you don't change your printer setup and don't move your printer either. It would also help if you don't hang the spools directly on your printer but store them on a place next to it (in a perfect world decoupled regarding vibrations). 

You also do not want to do that calibration more often than necessary as it is potentially shaking your printer apart. 

Mk3s MMU2s, Voron 0.1, Voron 2.4

Posted : 13/12/2021 11:04 am
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