I have a quesiton... More than once I've had to resize the opening where the propeller comes out of the spinner. Fore example, i have a GP RV4 and it calls for a specific size of spinner. The prop that i am using is too big for that opening.

The question is what's the best way to open the holes where the prop comes out of the spinner? i normally just use a knife and start cutting until the prop fits. I am sure someone here has a much better and maybe a "right" way to do it.

Spinners as props do have to be balanced correctly. I normally use the Dubro Spinner Nuts in stead of an actual spinner, so I won't see a balance situation caused by a spinner. These are available at Tower Hobbies or perhaps your LHS has them.

http://www2.towerhobbies.com/cgi-bin...&I=LXE161&P=RF

This one is metric, but the picture shows what I mean. And, they have standard threads as well, and weighted ones, by the way, to help with the CG if needed.

If I recall, someone once posted that the right way to do this is to bring the prop to the LHS and get a spinner that fits the prop.. but I can't imagine that.. opening up all those spinner packages to find one that fits.

I don't have a suggestion for that though, but I'm sure someone out there has run into that situation. RC Ken, MinnFlyer, or Bruce probably can offer a suggestion.

DS.

cutting with knife is the best way to do.but ferst u mark with penor pin onedge of spinner

well thanks for the info guys, i am just afraid that with the knife approach i can leave a microscopic crack that could make it shred into pieces at high RPMs.

Has anybody seen this happen?

use a dremmel and rebalance. mark where you want it .dremmel it close to your mark. use a hobby knife to fine tune or for corners then hand sand the burrs and rebalance. A knife is dangerous with big cuts.

I use a dremmel and rebalance afterwards. I also use spinner nuts on a lot of my non-scale planes where I'm not as worried about looks.

i like the dremmel idea, i do have one of those. only thing holding me back right now is the spinner balancer. i don't have one of those. if i can sneak a few $$ from the wife, i will be visiting the LHS this weekend.

I haven't yet figured out how to mount a spinner on a balancer since all the spinners I have used had no thru hole.

If you get the [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXD712&P=7]THIS[/link] Dubro balancer, you don't need a through hole on the nose cone of the spinner.

You just set up the balancer like this:

pkh, i can't see the pics []

Here you go...

Oh now i see! Thanks for the pics pkh!

When I do it, if it's plastic I use a knife.

Take a bit out of one hole wherever you think it's needed. Then go to the other side and take the same amount from the same place. Check the fit. repeat..........

Once the holes are large enough. Check the balance on a balancer. Balance the backplate first. This bit needs care. You need that backplate right, because then it won't matter what it's orientation when you're checking the cone's balance. Cones seldom take much effort to balance unless you've had to open up the prop holes.

Once that's sorted, if any "whittlin'" cuts need smoothing, do that and check the balance again.

It is worthwhile to check a spinner's balance. You don't have to get that or a props balance absolutely perfect, but it does matter enough to get close.

Gotcha, the balancer will be my next investment. I have one of those that you hold with your fingers, but i doubt i can do it with it so i will get one like pkh's.