How to balance rotating plastic drum?
How to balance rotating plastic drum?
(OP)
I'm in the (very early) prototype stage of designing a machine with a rotating plastic drum, specifically a 50 gallon drum. It rotates about the long axis. How would you go about balancing this? I'm thinking take some careful measurements and stick a rod through it, then fine tune it with weights. I don't know if there's a better way though, or how to actually figure out where the weights go. People have been balancing wheels for a long time so I wouldn't think it would require anything too sophisticated. Who's got my slick trick?





RE: How to balance rotating plastic drum?
RE: How to balance rotating plastic drum?
Material is whatever they make those plastic 50 gal drums out of. I'm thinking I'll run a rod through the middle and sandwich the plastic with flanges, so I need a good method of finding the center first.
RE: How to balance rotating plastic drum?
What is going inside the drum?
You have to balance that too!
JHG
RE: How to balance rotating plastic drum?
RE: How to balance rotating plastic drum?
RE: How to balance rotating plastic drum?
RE: How to balance rotating plastic drum?
The last time I watched a mechanic replace my tire, he balanced the wheels statically. This worked okay because a car wheel is a short fat cylinder. Perhaps I got lucky.
In your case, the worst scenario is that your cylinder is balanced statically, but the opposing weights are at opposite ends, creating a centrifugal moment, and a dynamic imbalance. If your drum is longer and thinner in aspect than a car wheel, you could have a problem.
Is your drum symmetric about the axis?
JHG
RE: How to balance rotating plastic drum?
Drum symmetric? It's supposed to be, but nothing ever really is, is it?
RE: How to balance rotating plastic drum?
If the shaft has to be cantilevered to do that, so be it; space the bearings apart, and make the bearing adjacent the drum bigger than the other one. That allows you to taper the shaft in both directions, fat in the middle of course, which can make assembly easier.
If you can keep the drum fairly round, you may be able to make it balance itself once it's rotating, with a partial load of sand, balls, or water.
Mike Halloran
Pembroke Pines, FL, USA
RE: How to balance rotating plastic drum?
Vertical or horizontal construction?
I go with Mike Halloran, but this is also about dimensioning and selecting the right type and strength of ballbearings in additioning to balancing your drum.
With this size you could perhaps use directly same machine and methode as a normal vehicle wheel-balancing machine?
RE: How to balance rotating plastic drum?