How do you go about balancing a spinner? I have the prop balanced but have seen a few posts about balancing the spinner as well and was wondering how you do it.

Thanks

I don't buy spinners that need balancing.
High rpm racing engines have spinner assemblys that are intentionally out of balance to offset the weight of the piston.
If your spinner is wobbling or not running smooth, then it's time to investigate and the problem is likely to be found in other areas.

It's one of those things I don't bother doing. As center mass a bit out of balance isn't going to hurt anything or make the engine vibrate. If however you have one wobbling it is a good idea to just toss it. it's usually a sign of a bent back plate. I do have a couple of prop balancers and if for some reason you just have to balance your spinner you can mount it, let it roll to the heavy spot and remove some material from the inside with a hand piece until the spinner can be set in any spot and not roll. My Dubro balancer works best for this but the GP balancer will work too. I think one of them has the instructions for spinner balancing too? I know no one personally that balances there spinners but I do read of people that do. Whatever floats your boat.

Don't you know, about the bird??...

graybeard has it right...... the closer the imbalance is to the center of the shaft it's on, the less effect it has. spinners don't weigh much to start with, and their entire weight is very close to the center of rotation, so their impact on radial imbalance is negligible. add to that that the process of injection molding produces very even distribution of the plastic they are made of and an imbalance is hardly even probable, much less enough to e noticeable. if you are feeling an imbalance after mounting a spinner, check that the cone is not wobbling,...it's possible the "imbalance" is because the cone is not snapped down all the way because it is making contact with the prop on one side. I have had to reshape the cut outs for some props. as long as you keep the clearance around the prop reasonably even on both blades, there should be no noticeable imbalance.

2012 Again

so what, .....do think people don't have these questions because it's now 2018 ?. with that mindset, there should be no questions on here about setting up servos or covering planes with fabric how to use your r/c radio for that matter,....they've been around for along time,.... everybody should know how to use them ,....right ?.

Yep, old thread but still relevant.
The way you balance a spinner is put it on a DuBro balancer. I do all of mine. I doubt it makes that much of a difference, but it is one less thing to worry about. With my meticulous prop and spinner balancing, if I get a vibration I know it's caused by something else.

Ditto! While I don't spend a lot of time on a spinner, I do check mine. I use mostly aluminum from Tru Turn and can't recall any that really needed anything. But I still check.

However, the bigger the spinner the more important it becomes to balance it. Some of the big models have some good sized spinners. A 1/4 scale P-51 for instance uses a 7 inch diameter spinner. So if you gravitate towards the bigger models, you might want to look into balancing spinners. And start by buying a quality product.

One thing to remember with spinners is the orientation between the cone and back plate. They really need to be indexed in some fashion so they line up the same each and every time. I have seen it make a difference.

That's true. It doesn't do any good to balance a spinner if you install it differently than you balanced it.

In the meantime, has anyone noticed the original question hasn't really been answered?

You balance a spinner much the same way you do a propeller. However, you need a balancer designed to handle spinners. I'd start with the DuBro balancer. If the spinner is too big, I'd use the DuBro design and simply make a bigger one.

To actually balance it, both the nose of the cone and the back plate need to be supported. They also need to be indexed to each other in some way. On aluminum spinners I index with a simple ink marker. Then I put just the backplate on the balancer and balance it if needed. Once done, I then put the whole spinner on the balancer and see if it has a heavy side. I start the process by using little bits of clay on the backplate to offset the heavy side. Once I am satisfied with the balance using clay, I repeat the process using JB Weld on the inside of the backplate and as close to the edge as I can. Without accidently gluing the two parts together. You can put a little Saran Wrap over the edge of the cone to prevent the JB Weld from adhering to it. This way you can get the JB really close to the edge without fear of gluing it all together. Initially I put a little extra JB Weld in place and then, once it sets, balance it again but this time I use my Dremel to grind away the excess JB Weld.

Sometimes just changing the orientation of the backplate to the cone will bring it in to balance. If that works, be sure to make a new index mark and remove the old one.

My process is pretty much the same, except I use medium CA and kicker.