vc4 500 core xy for now first resonance
thoughts advice? i know i have a few oose cable ties on the toolhead
37 Replies
after decresing belt tension
so its only core xy currently? I suspect you may be getting to loose as the 2nd spike is not that clean and defined now. You also need to figure out where that noise between 85-90hz is coming from on the lower belt. For the noise I would go into real time analysis tool and pick the correct motion (I forget which is the lower belt) and then move the hz slider till you see a spike at 85-90hz. It could be at another frequency causing it or it could be at 85-90hz as well. When you see the spike I would try to listen first and see if you hear something making noise. If you do, hold it to push it and see if the spike in the real time graph lowers. If you do not hear anything just start pushing and proding on everything to see if you can find where the spike is coming from
have you checked to make sure the m5 bolts that hold the various bearing stacks are tight? those take some torque to get fully tight. One of mine was a slightly loose (<1/4 turn) to fix a spike like that
will investigate thanks for the leads
any idea on seggested belt tension frequency range to aim for?
seen conflicting stements
I have used belt plucking and the real time tool to get them in range. https://discord.com/channels/582187371529764864/1292226831810039909/1292277434187517962
what size printer?
500 as well
Ah I'm only at 70 as I was at 100 and then read something about 60
I'll aim for the 85
DigitalDragon72
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so i redid my tool head wiring and did some cable management looking better should i be happy with this or try for more?
pretty decent. runs shaper graphs and see how those look now as that is the most important thing
I tightened all bearing stacks re threaded the belts ensured same length
Thought's @chicken
something is still causing that ~90hz spike. Go into real time analysis and pick the lower belt and scroll the hz and watch until you get a big 90hz spike and then leave it there at that spike and then start feeling around to see you can push, hold, etc and see if you can get it to go lower.
I suspect it would print perfectly fine as is but something is still rattling
whats your shaper graphs look like
just given it a full go over had a loose screw or two on the tool head and deracked the gantry found that my y carriges were bolted too tight going to run again see where we are at
should this test be ran with filament in or not
It cannot hurt to have filament loaded. Can keep some rattling of the extruder gears at check. Not sure how the orbiter rattles vs some others
sorry traveling this week for work so will be offline a lot
The ball bearing definitely does resonate,
On thing I've noticed when motors are disabled and I move gantry and also present but less so on tool head manual movement is like what I can only describe as a wave like change in resistance which leads me to think somthing is rubbing of bent but I don't know how to identify of if it's normal
ive noticed i have some printed parts vith small cracks which i cant resolve right now
but the spike at 90 on the lower belt ive not been able to isolate
I've also encountered the varying resistance when pushing the toolheads or gantry by hand. The effect increases with increasing belt tension. I believe that my rails are properly torqued and aligned. The resistance is not present with loose or missing belts. I have observed a correlation between the pulsing resistance and stepper pulley rotation. I don't yet know if it's a problem.
This is precisely what I have extra lubricant helped but did not resolve very worried that I over tensioner initially and bend a shafts or something
I think you would have to go REALLY tight to bend a shaft. They are supported at both ends. I suspect that the belts would break first. I'm confident I haven't tighten that much. Anyway, I've taken everything apart again since I can't get a good Y-axis shaper graph.
I hope so
Did this resolve your issue
Still working on it. All graphs look good except Y shaper. I'm beginning to suspect that my issue is not belt-related.
But if it's like mine it's only under tension?
Yes, but that doesn't mean that it is the problem I'm chasing or even a problem at all. As I mentioned, the cyclical change in resistance that I felt tracks motor rotation. When I get a minute I might disconnect a motor from the control board to determine whether the resistance is due to electrical loading of the motor. In other words, when I turn the motor by hand, it becomes a generator. That generator is going to try to drive a current back through the motor driver's output circuit. That circuit has some resistance which may show up as a varying mechanical resistance when back-driven. Anyway, I just broke an endstop switch and I can't get one from RatRig unless I buy $100 US in parts. So I'm looking for other sources. I think I found the right switch at Digikey, but the machine is down for a few days.
This is the same conclusion drawn from other members here
Sorry about your switch
Thanks for the sympathy. I did it to myself by trying to be clever.
Looking forward, after I replace the switch I will tune the belts to the good-as-it-gets point, where I had it a few days ago. Then I will look at other vibration sources, like the enclosure. The Y-axis shaper macro shakes the whole machine, and rather violently. I can hear vibrations from many other sources. So I'll start eliminating those. And I'll post what I learn for posterity and/or comedy.
@Skye Are you still stuck at the same point?
My shaper seems okay for now about to run a benchy to ensure no layer shift seems I may have setup as hybrid and ran the first benchy without the hybrid belts so printer was working incorrectly
Originally I tuned belts to 85.4 however it seems 90 Hz is better for my aetup
That is a good data point. Thank you. Where did your recommended acceleration on Y land?
Mine never exceeded 3900.
4100 after a heatsoak
Sounds respectable. But here again, I don't even know what the target is, or what is considered "good".
I forget did you have layer shift?
No. I have only one, semi-successfully benchy. It had a lot of stringing and some ghosting. It's the ghosting that has me back at shaper graphs and hunting resonances.
stringing would suggest you need to take a look at your filament settings as well
Yeah, I understand. Thanks. I haven't started filament profiles yet. And I tested with PLA, which RatRig don't seem to provide a starting profile for. So I didn't expect much. I made some guesses and was pleased that it actually competed.
Well if it makes you feel any better my first benchy looked like ppop
🙂