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I printed a Raspberry Pi camera arm for my Ender 3 V2 as a second camera that's not connected statically to the printer frame but to the printer bed instead. I now have two cameras, both from different angles, each with advantages.

However, the moving bed results in severe vibration. I need anti-vibration or stabilization methods for my very light Raspberry Pi camera. I was thinking about doing something with some rubber bands somehow or making a mold to make a silicon block(s) that I will use to replace some part(s) in the middle of the arm, disconnecting the plastic so it can potentially absorb some vibration.

Below is an example of the vibration viewed from my Raspberry Pi camera. The image is cropped, speed up and compressed to fit in an animated GIF under 2 MB for this site. The original is in higher resolution but the vibration is visible.

Close up of Raspberry Pi camera vibration when connected on arm to 3R printer bed

agarza
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Bob Ortiz
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3 Answers3

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Looking at the project you linked, there is a couple of things you should consider to reduce vibration:

  1. More points of contact. One point gives your arm a lot of freedom left-right, and not insignificant amount of up-down flex. For a 3D construction, ideally you would have N+1 = 4 mounting points.

  2. Camera mount not on rotating axis. This, again, is a point of freedom that can vibrate very well. Glue it up or redesign,

  3. Make it as light as possible. This arm looks way heavier than it needs to, especially at the end. It can very well narrow down towards the end significantly without significant stiffness reduction.

  4. Use wider lenses and shorter arm. Shorter arm will vibrate less.

  5. Make sure your cable is not an issue - it should move easily with the camera. Secure it along the arm so it cannot pull on the camera at all. Make sure it is short enough not to hook on anything. Make sure it's long enough not to pull on anything in any position. If these are contradictory, redesign for them to not be.

Mołot
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Every object or structure has one or more criticals, i.e. frequencies at which it will resonate if excited by a source of kinetic energy vibrating near one of the criticals. A relatively small vibration close to a critical frequency can excite a very large vibration in an object whose physical properties cause it to resonate at that frequency. Resonance occurs when the vibration cycles are in phase and reinforce themselves.

3D printers, with pulsed motors and moving parts operating across a wide spectrum of speeds, will certainly produce a broad range of vibration frequencies. Some of those might excite an object or structure physically connected to them. Common engineering practice for suppressing vibration at or near criticals consists of making changes to one or more of these - excitation frequency, mass or stiffness. Nothing else will be effective.

It's probably impractical to try to change or dampen the myriad vibrations that a 3D printer produces. You'll most likely have more success trying to change the mass or stiffness of whatever is experiencing unacceptable levels of vibration. It should be noted that in some cases reducing mass or stiffness can be as effective as increasing them. The objective is to move the object's critical frequencies away from the frequency of whatever is exciting it. This is often a trial and error process.

allardjd
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  • Meaning that Input Shaping could potentially reduce this too? – Bob Ortiz Jan 01 '24 at 12:28
  • I'm not sure exactly what you mean by Input Shaping but it sounds like trying to manage the vibrations of the printing process. I doubt that will do much good because the process can include a relatively broad spectrum of frequencies. – allardjd Jan 01 '24 at 12:45
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I mounted my Pi camera for Octoprint to the table, rather than the frame of the printer; works fine for me.

If you have a long lever arm it will vibrate. So try for more points of contact with the frame. Three would be ideal, nit one is definitely insufficient.

Another option is to mount the camera directly to the printer head - that seems to be common for super-short focus endoscope-style cameras.

agarza
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Criggie
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    Thank you, but it doesn't answer the question. I have one camera in a static position on the printer already, without vibration. This means that in that picture, the bed moves, but the printer doesn't. This second camera is on purpose bed connected for a different view and focus, static position to the print, instead of the printer. In that picture, the frame is moving instead, not the bed. I'm planning on a third (endoscope) cam focussed closely on the nozzle, which is another purpose again. – Bob Ortiz Dec 11 '23 at 17:56
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    That description strongly implies that there is vibration between the frame and the bed. The camera(s) may be solidly fixed to one or another of them but will still "see" the other part of the printer moving with respect to it. The camera mounting may not be the culprit if frame and bed are vibrating with respect to one another. – allardjd Jan 01 '24 at 12:56