How can you tell which spinner is for what? For example, I have 40 sized plane with a 14X7 Prop. What spinner would you get and if you descide to go 3D what spinner would you get and why? Thanks

I usually get a spinner depending on how it would cosmetically look on a airplane. Just, I always check to see if the spinner will acommodate the width of the props.

NJAIRSTRIKE,

It depends on the plane you select. For a profile type plane for 3D choice is so it looks good on the plane. Most spinners in the 2-1/2" to 3" diameter range will work. Brands differ in the amount of offset needed. Du-Bro spinners have the backplate recessed and the Great Planes are flush. If your cowl is close to the prop then that may dictate the choice. For most sport planes these will work. Expect to do some filing on the nose cone to get a good fit especially with the APC props. I just installed an APC 12.25 x 3.75 in a Diablo 3D plane. The back plate also needed to be filed as the prop blade extednds behind the hub. If you want the best then Tru-Turn makes spinners already cut (or cut to order) for specific propellers and/or 3D. Really nice however cost can be in the $30+ range and require an adapter for an additional $8 in the smaller sizes. These are milled from solid aluminum bar stock.

Additional information Du-Bro vs. Great Planes spinners. The Great planes spinners use a phillips screw into the plastic backplate. Du-Bro uses hex bolts into aircraft bolts in the backplate.

EXCAP232

Whatever spinner you choose, be absolutely sure the cone does not touch the prop blades at all. This may require some filing or grinding on the cone.

Dr.1

Dr1, I was told that right away by my Dad when I started getting into planes. Seems like most of the spinners that look right as, in preportion to the model, want to touch the prop, Example: I have a World Models Cap 232-46R. The Castrol Aviator plane of Mike Goulian. It came with a red 2.25 in. spinner which is a dead match for the red cirle on the pre-painted fiberglass cowl. I was barely able to put a 12x6 ( I believe) Master Airscrew on it. While it looks very nice corresponding with the paint on the cowl behind it, the prop looks small for the plane to me. I guess the only way to get the larger cut-outs is to go with the high$$ Dubros that EXCAP mentioned? I'm a little gun shy of taking the Dremel to one. Doesn't it need to be perfectly balanced as well as the prop does?
Thanks.


Mark

Careful work with a Dremel-type tool will not throw the spinner too far out of balance. There are three reasons our spinners and props don't look "scale". Our props are much thicker and wider at the hub than full scale props. Our engines usually can't swing a correct scale size diameter prop. Our spinners are mounted much differently than full size units.

Dr.1

Thanks Dr1.


Mark

I'm still having trouble finding a spinner that would fit a 14X6, 14 X 4 W, 15X6 Props. Please help. Is there any links of spinners maybe even true turn that will work with this. Thanks

did you try cutting the biggest one you found to make it fit ? I have had alter a few to fit my 11x7 props and the also to fit the smaller size props. 8x4 etc.

No matter what prop you are using it's difficult to find a spinner that fits correctly. It's a fact of life in this hobby that you're going to have to trim a spinner to fit properly on given prop. Just make sure that when you trim it up that the spinner isn't touching the prop as this can cause the prop to fail when the engine is running.

Hope this helps

Ken

What size engine are you using on the 40 size plane with a 14x7 prop? must be one honking motor. Unless you call tru-turn with the size and the prop cut outs needed i am sure you will have to be hogging out the spinner.
Dennis

A spinner can improve the efficiency of the prop & engine combo. The spinner hides the grossly inefficient root-transition zone of the prop from the slipstream. This reduces the load on the engine & increases RPM in the working length of the prop -- generating more thrust.

Spinners can be sized up to ~ 25% of the diameter of the prop without causing a loss of efficiency through hiding the functional portion of the prop blades..

So you see, this is about more than just good looks.