[martin_05]

I am looking into building a dynamic balancer for rotors. Something like this:

Erbessd Instruments - High-precision & high-quality Balancing Machines

Obviously the bearings that support the part being balanced need to be really smooth. In other words, you don't want the bearings to introduce vibrations because they are rough.

What kinds of bearings are suitable for this? It it as simple as going for ABEC 7 or 9 bearings?


Thanks,

-Martin

[underthetire]

Maybe go with ceramic bearings
Radial Bearings Ceramic Hybrid Series

[martin_05]

Maybe go with ceramic bearings
Radial Bearings Ceramic Hybrid Series

I was looking into that. There are some cheap yet seemingly high quality bearings for skateboards. Not sure what their limitations might be though.


-Martin

[rowbare]

Don't over think this. Any decent bearing should do the job. Use shielded vs sealed. If you find the bearings are inducing noise into your measurement system, then upgrade them. Note that a bushing on a polished shaft will be really smooth.

bob

[crazydiamond]

This guys put together a pretty "straightforward" looking balancer.. I think it's more an issue of the software and actual measurement equipment used. He's also using it to balance rotors (for a 4th axis brake) at 5,000 rpm if I'm not mistaken

His explanation starts at 4:10
https://youtu.be/xP_Fc8actok

[martin_05]

Don't over think this. Any decent bearing should do the job. Use shielded vs sealed. If you find the bearings are inducing noise into your measurement system, then upgrade them. Note that a bushing on a polished shaft will be really smooth.

bob

Thanks. You are right, of course.

-Martin

[martin_05]

This guys put together a pretty "straightforward" looking balancer.. I think it's more an issue of the software and actual measurement equipment used. He's also using it to balance rotors (for a 4th axis brake) at 5,000 rpm if I'm not mistaken

Yup, that's basically what I am looking to build, times 2. In other words, both ends would be floating in order to do 2 plane balancing. Also, since I want to be able to balance the rotor out of a spindle motor I'll need to support it with a set of bearings at each end.

I have a bunch of aluminum t-slot (80/20) laying around. Thinking about building most of the frame with that. It makes for quick prototyping.

Yikes, 4,000 RPM! I would have a Lexan box around the thing for safety. If that thing gets loose at 4,000 RPM the damage it could cause is almost unimaginable. Many years ago I built a propeller testing rig for competition carbon fiber RC propellers running up to 20,000 RPM. I had a few fail and get loose in various ways. Let's just say I was glad to have fully encased the thing in Lexan.


Thanks,

-Martin