Vcore 400
My setup: Funssor CF Tube, VZ-Printhead, Goliath air-cooled, Beacon RevH, BRS M1, Motor Decoupler + FMMM
Have triple check that all my screws on the printhead is secured, tried detaching wire loom from print head without any success. Tried increasing and reducing tension, doesn't help. There seems to be a persistent resonance over a large band in the y-axis direction, from 75hz to 133hz.
Need help from any expert over my terrible skills
9 Replies
You have very small peaks by absolute values, try increase acceleration, like:
There is a lot of noise, and if you have printing problems then you need to check what you have done 😄
As example search for the thing that is creating that noise.
Because as far as I can see you replaced everything and no one without same exact setup can easy suggest solution.
May be your accelerometer placed not on print head but on the nozzle instead?
There is an example of a "normal" v-core 3.1 400
Look at the left side of the graphs for the axes
Mine are bigger - by order of magnitude, so I just don't see any noise below.
And maybe you also don't have any noticeable noise
Appreciate your response, the small peaks that you mean are in the 75 to 130hz range?
I am using beacon with an inbuilt accelerometer
Yea seems like my PSD is rather low. Does that mean i have to tighten the belt further?
Yes, on a scale of 1000~ (1e3) looks like just noise.
No, PSD is not dependent on belts directly, only on vibration amplitude.
About belts, that picture is also for reference, I have them slightly different lengths (RR toolhead Beta2, complicated to tight them right)
(so with the same frequency, I have a different amplitude)
So if you fix your tension, you will just have a similar graph
---
IMHO, exact tension does not matter much if it works, I tension them tactile and my ears.
So if you have a longer belt path, you will have lower frequencies, and if you have a lighter gantry and toolhead slightly higher frequency.
More tension will increase the frequency of belts and have a really small increase in resonance frequency.
But in general why do I have lower PSD even though we have the same Vcore size. Won't we have similar belt path length
If tensioning will only shift frequency, what causes lower PSD ? and how should I fix it
I already said what to do in the first message:
Just increase your acceleration.
Low or high "PSD" is not an issue. Do you have any printing problems? 🙂
We can have a difference there just because I have TMC5160 48V power, and maybe motors just play better with muscles.
Or just because I use different scripts to measure resonances (and they internally modify accel_per_hz), that doesn't matter really
Maybe your gantry and print head are just lighter, and can't create the same inertia. Any way, I already suggested you what you need to do, if you don't like your graphs
If graphs don't work at all, it's also normal.
You can use:
https://klipper.discourse.group/t/new-resonance-testing-method/3215
But this is all if we talk about solving problems here.
Because now it feels like you just don't like your graphs, that's also normal, you can increase accel_per_hz further and they will have a better shape 😄
(I'm not kidding here, this is just graphs, they are great for solving problems, but graphs itself is not a problem)
Hope it helps.
Klipper
New resonance testing method
I’ve spent a lot of time recently trying to improve the speed and quality of my vcore core xy printer recently and much of that time has been spent measuring and improving resonance. To keep things short, I found that using an accelerometer, whether on the print head, nozzle, frame or bed, did not give me the full picture when using klipper’s bu...
And just in case, on your graphs, there is some noise from Y axis on X graph,
So may be your accelerometer is not perfectly horizontal and aligned to the axis, or just wobble.
Anyway, if resonance measurement and input shaping work, that is just circumstances.
ok thanks, I will try it out. grateful for your detailed reply
my prints are actually not that bad at 6k accel