2" dubro plastic spinner on fox .35

[DanielGelinas]

Hello,

The 2" dubro plastic spinner seems too big for the fox .35 prop shaft? When all is installed i have hardy any threads to put the nut on. The propeller is a master airscrew gf 10-6. Could it be the propeller is just too thick? Don't have any other propellers to compare.

Thanks!

[John Desrosiers]

Im still new to this. I have a dubro spinner on a os fp 40 with a 10-6 prop and it fits just rite.

[Clancy Arnold]

Daniel
Your problem is the thickness of the spinner backplate, nearly 1/4 inch.  Try using a thinner prop washer behind the prop nut.

The best fix is to use a spinner with a metal packplate on Fox 35 stunt engines.

John
The Prop shaft on the OS FP40 is longer so you do not have the problem, OS 40 measures 1.031 verses Fox at 0.915 inches giving .126 (1/8 In.) extra shaft length.
Clancy

[DanielGelinas]

Hi Clancy,

Thats what I thought....probably a fox thing...
Do you know if suppliers have a specific spinner for the fox 35?

Thanks!

-Danny

[W.D. Roland]

Ran into same problem with older engines. Frustrating to build and finish an airplane around a paticular spinner and then finding the prop nut won't fit! this usually is discovered the day or so before going to fly.

2 ways I dealt with the problem

Use prop nut from spinner adapter with 1/4-20 or what ever the thread is all the way through turned around backwards and a drilled out prop center.

The other way is counter boring the front side of the prop hub so the prop washer is recessed into the prop.
I made a jig to hold prop centered in milling machine and use regular end mill. the O.D. of washer had to be reduced
a small amount to fit bore made by closest size end mill.

I would not use either method in high RPM applications like combat, rat or pylon.

The best fix is the right spinner.

David

[DanielGelinas]

Well, 
I got to thinking, maybe it wasn<t just a fox thing...
So... I pulled out a OS .25LA out of my box, and what do I find???
The  dubro spinner doesn<t fit on the LA either...
I'm a little at lost as to why they make them that way in the fist place The spinners, that is.
I'll try the spinner on my brodak .25 tomorrow and get back.

-Danny

[john e. holliday]

Do it the easy way and use prop shaft extensions.    They are or have the FOX name on them.  I have used the 1/2 inch and 3/4 inch extensions.   On the P-39 I had to J-B Weld the thrust washer to the extension. 

[DanielGelinas]

Hi John,

Can you show me a picture of the propeller shaft extention please?
I have no idea how this setup works or what it looks like. I have read that its NOT a good idea to use them on the FOX 35...

Thanks,

-Danny

[Garf]

You can either use the prop nut part from an extention and ream the prop hole to fit it, or use a backplateless spinner from Hobby Lobby or Kavan. I have both and they help greatly with short shaft engines.

http://www.hobby-lobby.com/1_3_4_aluminum_spinner_993_prd1.htm?pSearchQueryId=1336284

http://www.hobby-lobby.com/spinner_2_white_1092_prd1.htm?pSearchQueryId=1336296

[Jim Thomerson]

I've run both extensions and heavy hubs on Fox stunt 35's for years with no problem.  The usual crankshaft thread is 1/4 x 28.

[JamieHolford]

I put a 2" Dubro spinner on my OS .25LA and it fits perfect....

[W.D. Roland]

So Jamie, that must be a sign that you are close to ready with the Ring Master?

I have drilled some props like Garf has and always worried about all those cut in 2 fibers(grain) in the hub area of the prop.
That was the reason for counter boring face of prop to the Dia and thickness of the prop washer. Much stronger than the boring out the guts.
When drill one for the prop adapter would be wise to not use it on anything more powerful than an older .35 stunt type engine.
Sometimes guilty of not following my own advice.......

Garf, might want to cut the rear of that adapter off or the prop might be free to slip!

David
Breaking props the old fashion way

[JamieHolford]

Nah Dave. I be honest. Only thing Ive done to it so far was get the Leadouts onto the bellcrank. AInt worked on it in a few weeks.  Somehow Ive lost my motivation as i normally do when it comes to models. But once it sparks Its hard to get me away from the table! I jsut dont wanna rush things as easy as it may be.

[W.D. Roland]

Sounds like a Spark Plug change is needed

[DanielGelinas]

Garf, Thanks for the pictures and links!

-Danny

[john e. holliday]

The extension on the engine is made for the excess prop adapter to go into.