I am a bit confused about input shaping.
I put my printer on concrete pavers recently to have a printer that’s more quiet.
I noticed that this reduced its resonance frequencies, hence it reduces it maximum accelerations using input shaper graphs.
I have not found a conclusion online on this, but am I correct by stating that a heavy frame makes the printer more quiet at the cost of lower acceleration speeds? Am I missing something?
In attachment, you can find my current input shaper graph with the accelerometer in the middle of my bedslinger bed.
Comparing this to other SV06 plus input shaper curves at this forum, I have a lower resonance frequency.
It is indeed true that increasing the mass, dampens the resonance.
But I am talking about the resonance frequency and to my understanding it is the frequency that dictates the max. acceleration dictated by the input shaper, no?
The key aspect is the frequency of the resonances. The lower the resonance frequency, the harder it is to dampen it, respectively, the more smoothing is created.
Note that you will not be able to exceed the recommended accelerations very substantially and still get acceptable quality of the prints, which I think is a common misconception these days, especially in marketing materials of printer manufacturers (claiming that printers could do 10-20k accelerations when in reality a given printer can do 3-5k with a good quality). According to the charts, you have very low resonance frequency and very low-frequency input shaper. So, going with that configuration and 3-5k acceleration will likely produce unacceptable results. I would investigate the mechanical problems that you printer seem to have: whether the Y belt has the right tension, all screws are tightened, especially in the motion system, that Y axis bearings are not loose, etc. Also, I’m not sure about the size and flatness of the concrete pavers, could it be that due to their mass or shape that printer wobble on them, for instance?
You want a solid underground for your frame? (So you only get a single resonance and no added resonances of a wobbly table?)
The frame should be able to move freely on that underground? They are not mechanically coupled? (Such that you get a resonance frequency which is as high as possible, because the mass is lower?)
I did a simple mechanical check and everything seems tight.
The printer seems to be standing flat. I can’t wobble it by hand. Could be a small wobble. But wouldn’t this then also introduce a second resonance and show up in all axis of the accelerometer?
I didn’t get all those points, but the printer frame should stand on a solid hard ground and ideally not move at all. This would allow stepper motors to transfer the force to the moving parts in the best possible manner.
And separately, what I’m saying is that you have suspiciously low resonance frequency that would typically indicate some mechanical issue with the printer. The typical range of the main resonance peak for bed slinger (if the bed is not huge) is in 30-40 Hz, and the chart you showed shows the resonance at around 18 Hz. That is a huge difference in this frequency range.
