I don't get it...

nikscha

I'm trying to tune input shaping on my delta. Could someone help me interpret these results:

Here I'm taking measurements WITH the extruder installed:

And here WITHOUT the extruder (lower inertial mass):

I understand that with the lower mass the resonance frequencies are increasing, but why does the amplitude increase as well? Shouldn't there be less energy in the system?

Am I better of with an extruder? I.e. will I experience less ringing with an extruder? Will the high-frequency ringing be less visible than the low frequency ringing?

dc42

@nikscha the accelerometer measures acceleration, not the amplitude of ringing. Ringing at higher frequencies has higher acceleration, so the accelerometer will respond to it more.

There may be a case for us to scale the amplitude in inverse proportion to frequency when displaying those plots.

nikscha

@dc42 I see, that clears things up. Thank you.

I have another question:
What is the XY option in the 'record motion profile' dialog?
I tried it with the same values I used for just X/Y and had a crash (I have a delta).

And another question:
Does the orientation of the accelerometer matter on the delta? (As long as Z points upwards) X/Y will always have some "random" relationship.

dc42

@nikscha said in I don't get it...:

What is the XY option in the 'record motion profile' dialog?

That should perform an X motion and a Y motion, and record both of them. Please provide more details of the crash, i.e. what the motion profile settings were and what happened.

@nikscha said in I don't get it...:

Does the orientation of the accelerometer matter on the delta? (As long as Z points upwards)

No, it shouldn't matter.