y-axis noise on x-axis shaper
please some one help me, I lost sleep over the past week trying to resolve this
Here are the specs of my printer
Vcore 400 with carbon fibre beam
Recently upgraded to cnc-ed VZ-printhead and brs m1 l3ver tensioner
Vz-hextrudort and Goliath air cooled hotend
Using an adxl345 mounted on the nozzle using mellow clamp mount
Belts are tuned using BRS belt guide to 70hz
The belt tension graph shows almost aligned double peak with some binding perhaps on the lower belt?
But what's interesting is the x/y axis. On x-axis, there is a peak around 85-90hz on the y-axis on the accelerometer. Somehow vibrating left and right is triggering resonance on the nozzle head in the y direction.
If we move to the y-axis graph, there is the same peak.
Solutions that I have attempted :
I have detached my wire loom
I have searched for loose bolts to no avail (though I think the graphs indicates loose bolt?)
I have tighten/loosen the belt
Checked that my gantry is parallel to the front of my printer
27 Replies
I have a vcore 500 , mgn9 vz aluminum printhead with Goliath, and using toolboard on m2 tensioner.
1.) Might be the adxl and how you have it connected.
2.) I loosen my m2 a bit below 1/2 way, connect the belt and make sure they are the same length. Then I tightened with my finger the tension at the same time until I can't use my finger. Run a test and that should be close to where you need to be.
3.)the lower in your picture has higher tension, and if you were to tighten it more that peak that is starting would be the new peak location, that needs to be loosen
@drops_77
1) I can actually visually see the nozzle resonating as those frequency without the adxl, so the accelerometer is likely correctly sensing and not causing it
2)you mean you tightened the nuts with only your fingers ?
3) this video says that the difference in peaks in belt tension graph doesn't matter, only the frequency should align https://youtu.be/M-yc_XM8sP4?si=Nk6rGE2OR0lJrJx3
3D Printers & a Whiteboard
YouTube
How to Read and Analyze Input Shaper Graphs Generated by Klipper
This video is supposed to be a brief overview on what the input shaper graphs can tell us. It is the first video of a series of videos which will give a more in depth view on the kinematic system and input shaping in Klipper.
As always: feel free to jump to those parts, that help you with your problems:
00:00 Intro
00:57 What we can learn from...
Yes tightened only with your fingers, additionally I use a caliper to measure that they are both the same distance. All other things equal.
3.)
The lower belt is a bit too tight , loosen it and your 2nd peak should reduce or disappear in the blue graph
@drops_77 2nd peak ? Shouldn't the graph have 2 peaks? Unless you mean the peak at 110hz
Correct, in the video he says it doesnt matter. In my experience when blue and yellow amplitude dont match, one belt is actually tighter than the other.
The blue in your picture, seem to be too tight. If you tighten it the 110 will become more dominant and the 85 should lower. However If you loosened it , the 110 peak should go lower, and the 85hz amplitude should also decrease to match the yellow.
I think that video is OK and does explain it, but in practice everyone who has a good graph has two peaks, and both peaks amplitude match on each hertz. Of course one peak will have higher than the other and they will never match. T
This is my vcore 500
Two peaks, however both amplitutdes match, and of course one is higher than the other.
I will try it out by loosening, I followed BRS guide on using spectroid to measure the frequency
Additionally in the video the X and Y always confused me
If your belt lengths are equal, just hand tightening and make sure this is the same
And do 1 test
Then slowly start tightening
Once I did this method I got my belts in the picture
The point is to get equal tension. But since there connected you'll end up affecting the other belt when adjusting either one
Also looking at your graph again, its the Y that has something loose
But I can't find anything loose. Tightened every bolt on the toolheadl
@drops_77 loosening the belt to hand tight resulted in this
oddly the x-axis peak increased from 3e6 to 1e7
I mean the graph say there is, also it could be elsewhere in the Y motion. Doesn't necessarily mean just the extruder part.
Keep going, after I hand tighten it creep on the tension. Making sure that both tensioner bolts are even
Unfortunately I never got rid of the 2nd peak on y axis. My prints are not that bad
https://a.aliexpress.com/_mtuCar2
Try this , maybe it will help
Just got mine in today, won't install until the weekend. However weight plus less parts and better alignment Might help your Y
How is this better alignment?
Supposedly more square than the 3d printed one, plus less parts. I'll post my results when I install it this weekend
I've been having low y issues myself
Ooo, nice, await your results
Update : Not much better. I think most of the improvements came from the dual granty and cnc head. However the skew profile came out better after calibration
Before:
xy
AC = 139.74
BD = 141.3
AD = 99.1
xz
AC 140.4
BD 140.6
zx 99.35
yz
140.5
140.82
99.43
#*# [skew_correction my_skew_profile]
#*# xy_skew = -0.011102121166657325
#*# xz_skew = -0.0014234882662185985
#*# yz_skew = -0.002274992741749856
-----------------------------------------------------------------
After:
xy
AC = 140.7
BD = 140.45
AD = 99.5
xz
AC 140.30
BD 140.45
zx 99.25
yz
AC 140.25
BD 140.75
YZ 100.2
#*# [skew_correction my_skew_profile]
#*# xy_skew = 0.001778414998282773
#*# xz_skew = -0.0010685666674418242
#*# yz_skew = -0.003559257385984685
Easier to work with, light, resonance basically the same.
Is dual rail gantry better than CF or lightweight alu gantry?
Dual rail is great for vcore 500. Definitely heavier than the other two options. Just works better against thermal expansion. On smaller some people go gantry-less. Really a mod that you need to do based on your needs and size
I am on 400 not sure if I should go dual rail