Bortimus
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
🙂
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
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.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
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.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
Sounds respectable. But here again, I don't even know what the target is, or what is considered "good".
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
Mine never exceeded 3900.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
That is a good data point. Thank you. Where did your recommended acceleration on Y land?
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
@Skye Are you still stuck at the same point?
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
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.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
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.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
Still working on it. All graphs look good except Y shaper. I'm beginning to suspect that my issue is not belt-related.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
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.
56 replies
RRCRat Rig Community [Unofficial]
•Created by Skye on 1/9/2025 in #fix-my-resonance
vc4 500 core xy for now first resonance
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.
56 replies
RRCRat Rig Community [Unofficial]
•Created by tcsjc on 1/10/2025 in #fix-my-resonance
Whats best to do for this belt tension graph? VC4 500 pre hybrid belts added
Hmm, the belt runs might not be the same length on a single toolhead machine like they are on IDEX. So your belts might be a different frequencies.
4 replies
RRCRat Rig Community [Unofficial]
•Created by tcsjc on 1/10/2025 in #fix-my-resonance
Whats best to do for this belt tension graph? VC4 500 pre hybrid belts added
If your belts are exactly the same length, are routed correctly, and you have no other loose parts vibrating: Are your belts tight enough? I found that if I move the gantry all the way to the rear, with tool heads parked, and I pluck the belts like a string instrument, they should both vibrate at around 100Hz. This is just a ballpark number. Your mileage may vary. A phone audio spectrum analyzer app might help.
4 replies