Author Topic: Fox 15 (Read 21503 times)

Dave Moritz · « **on:** September 10, 2024, 04:11:27 PM »

To the Cognsceti:

I got one of these (new old stock) for the princely sum of $0 - quite the bargoon, eh? Bench run under my tutelage and mounted on a mini-Ringmaster. Flying it and think it still needs more run time.

I’ve modified the sketchy NV to get a steady run. So far, kinda good. Not sure if I should invest more time in it or consign it to the hurl. What might the future portend for those of you in the know?

Dave Mo…

john e. holliday · « **Reply #1 on:** September 10, 2024, 05:34:37 PM »

If the Fox starts easy and runs to your satisfaction, why worry about it. Some people just don't know how to run Fox engines.

Colin McRae · « **Reply #2 on:** September 10, 2024, 05:42:13 PM »

I acquired a new Fox 15 a few years ago. I decided to give it a try and did some bench running-in, then strapped it to a Jr Flite Streak. It seemed to run reasonably well on the bench, but it did have a few issues in the air. Maybe more running in time was needed. But I decided to abandon it.

I've already sent it to Uncle Jimby to mount on a Hurl trophy. I left specific instructions that it was not to be thrown, but it was only to be used for mounting on the Meet-n-Meat contest trophy.

(He already has one to throw at Meet-n-Meat in a couple of weeks in Napa, CA. I believe the one that is thrown at Napa is highly modified (NVA removed) which allows for less in-flight resistance and longer distances. But I might be wrong!)

Dan McEntee · « **Reply #3 on:** September 10, 2024, 08:03:14 PM »

What prop are you using? People tend to over prop these sometimes.
Type at you later,
Dan McEntee

Dave Moritz · « **Reply #4 on:** September 10, 2024, 09:23:47 PM »

Gents:

Good to hear, John, that these motors can be run. So Collin, likely I’ve arrived at the point when you consigned your 15 to its best (?) possible use. At any rate Dan, the prop is APC 7x6, 50 feet of Spectra lines, small uniflow tank. Might switch that to clunk tank.

Much obliged.

Dave…

Motorman · « **Reply #5 on:** September 10, 2024, 09:25:06 PM »

Which one do you have? Usually a 7-4 apc would be a good prop.

Dan McEntee · « **Reply #6 on:** September 10, 2024, 09:42:21 PM »

Quote from: Dave Moritz on September 10, 2024, 09:23:47 PM

Gents:

Good to hear, John, that these motors can be run. So Collin, likely I’ve arrived at the point when you consigned your 15 to its best (?) possible use. At any rate Dan, the prop is APC 7x6, 50 feet of Spectra lines, small uniflow tank. Might switch that to clunk tank.

Much obliged.

Dave…

Too much pitch. Try some 4 and 5" pitch props, wood if you have them. Lines should not be any more that 20 pound test if that helps any. Same fuel as Fox .35 stunt also and add some fuel line to the needle to seal the threads.

Type at you later,
Dan McEntee

Dave Moritz · « **Reply #7 on:** September 11, 2024, 09:24:13 AM »

I’d already gone from steel to 40-pond line and that helped. Will go with less prop. Thanks, Dan.

Dave…

Shorts,David · « **Reply #8 on:** September 11, 2024, 02:01:02 PM »

I ran my fox 15 on a wooden zinger 8x4. Contrary to the expectation of the hurl commissioner, it ran fine in an acromaster.

Brett Buck · « **Reply #9 on:** September 11, 2024, 11:52:44 PM »

Quote from: Shorts,David on September 11, 2024, 02:01:02 PM

I ran my fox 15 on a wooden zinger 8x4. Contrary to the expectation of the hurl commissioner, it ran fine in an acromaster.

I prefer the term "Maximum Leader".

I note that I am only acting commissioner under The Hurl "Disaster Protocols" (with virtually unlimited powers, which I will gladly relinquish once the current emergency is over). Hurl founder Larry "Joey Jr." Fernandez remains the elected commissioner. We have every hope that he will someday be restored to, er, "normal".

Brett

GERALD WIMMER · « **Reply #10 on:** September 12, 2024, 04:54:25 AM »

Hello I know the basic Fox 15 can be a terrible engine but a good one like a 15X or latter 15 BB can be a very good engine with the right fuel and smallish prop.
If you need to use a muffler on a Junior Ringmaster I would prefer a more modern OS or Enya 15.

regards Gerald

PS why hurl a little Fox 15 when a OS LA 46 will make a bigger hole and exercise your arm more?

Shorts,David · « **Reply #11 on:** September 12, 2024, 05:36:51 PM »

As a second string hurler, I can attest that even a Fox 15 can stress your rotator if you're not careful.

My hurl trainer cautioned me about training with anything larger than collegiate .35s

Dave Moritz · « **Reply #12 on:** September 13, 2024, 07:08:12 PM »

David:

So the winner is the 8x4 wooden Zinger on the Fox. No contest, really, after putting four others to the test.

Thanks to you and the others.

Dave Mo…

Dave Moritz · « **Reply #13 on:** September 13, 2024, 07:12:14 PM »

PS:

Now, another fish or two to fry on this bird. Think I’ll continue the discussion above in “At the Handle.”

Dave Mo…

Dan McEntee · « **Reply #14 on:** September 13, 2024, 08:56:14 PM »

Quote from: Dave Moritz on September 13, 2024, 07:12:14 PM

PS:

Now, another fish or two to fry on this bird. Think I’ll continue the discussion above in “At the Handle.”

Dave Mo…

That's what I thought would happen. I used mainly 8-4 and 9-4 props depending on the size and weight of the airplane. I used the Fox .15 mostly on the SIG Akromaster and it's a bit bigger and heavier than the Ringmaster Jr I think. Using wood props helps here also, but I would not be afraid to try Master Airscrew props in this range. I have been playing with 1/2A stunt models lately, and having fun with them and liking the smaller airplanes. Might be time to revisit the Fox.15. 19 and some models sized for those.

Type at you later,
Dan McEntee

Paul Smith · « **Reply #15 on:** September 14, 2024, 08:04:47 AM »

I have only owned two Fox 15's, both of which were given to me free by wiser men who wanted to get rid of them. I speculate that somebody has a positive thing to report, but that person is not me.

As with any 15, my prop of choice is a 7-4. Over-propping and thus under-revving a 15 is not good.

Dave Moritz · « **Reply #16 on:** September 14, 2024, 04:23:26 PM »

Hello Dan and Paul:

It's perhaps better to continue things here.

To wit: It tips the scales at 18 ounces. Using 50 feet of Spectra, it seems to like the 8x4 lumber. For a decent run (4.6 seconds lap) it has to be launched lean. Tank is a good, home-built small Uniflow at just over an ounce. I prefer short flights at this stage.

Decent enough wingover but the motor slows during hard maneuvers. Likely too lean. Though fore-aft balance seems good, at the handle climb response is slower than dive response. No inverted yet - just too sketchy to try. I just don't see line weight as a problem. Not sure about line length, though.

I've got some ideas but will await anything you gents can provide.

Dave Mo...

Motorman · « **Reply #17 on:** September 14, 2024, 07:16:20 PM »

If you can find one, a Rev Up 8-4 would be infinitly better. The engine is slowing because it's overloaded. The Zinger has more pitch at the tips, wider tips and it's a very thick airfoil.

A 52' radius is pretty standard for 15 size ships.

MM

Dan McEntee · « **Reply #18 on:** September 14, 2024, 08:59:44 PM »

Quote from: Dave Moritz on September 14, 2024, 04:23:26 PM

Hello Dan and Paul:

It's perhaps better to continue things here.

To wit: It tips the scales at 18 ounces. Using 50 feet of Spectra, it seems to like the 8x4 lumber. For a decent run (4.6 seconds lap) it has to be launched lean. Tank is a good, home-built small Uniflow at just over an ounce. I prefer short flights at this stage.

Decent enough wingover but the motor slows during hard maneuvers. Likely too lean. Though fore-aft balance seems good, at the handle climb response is slower than dive response. No inverted yet - just too sketchy to try. I just don't see line weight as a problem. Not sure about line length, though.

I've got some ideas but will await anything you gents can provide.

Dave Mo...

Don't give up until you try some other 8-4 and 8-5 props of other brands. The only ting Zingers are good for is mixing paint, epoxy, or carving them into something you can really use!! Lots of props in the 8-4, 8-5 and 9-4 and 9-5 range turn up reasonably priced on eVilBay. I wouldn't discourage trying Master Airscrew plastic prop. Keep your flying lines where they are for now. Lap times at 4.6 sounds a bit fast, but keep plugging away in that speed range until you get the feel that you are comfortable with. I don't think 18 ounces is too heavy. I am flying a Doodlebug powered with a .061 Norvel that is 207 sq. in. and weighs 12 ounces on 45 foot lines at 4.5 seconds for comparison. Keep at it, take notes and keep us posted.
Type at you later,
Dan McEntee

C.T. Schaefer · « **Reply #19 on:** September 15, 2024, 04:57:18 AM »

I have been flying a Shark 15 with .15x for several years and flew it at Brodak a couple of times in Advanced Profile. My set up. Master scimitar 8x5 and .012x58 lines. Wet 2. GMA 10/22. Some x's come with a thick compression shim. I use two regular head gaskets and remove the thick one if there. Also had to reduce the intake slightly for better suction. Two ounces get me through the pattern. If you have the earlier pre x .15 you are fighting an uphill battle. My two cents, TS

Dave Moritz · « **Reply #20 on:** September 15, 2024, 11:00:08 AM »

Good to hear another point of view, CT. With respect to the diversity of experience here, I suspect there’s something unknowable embedded in the early Fox 15 mills.

Dan and MMan: I’ve got four more props to try out this eve, all 8 inches. Time will tell!

Dave Mo…

Dan McEntee · « **Reply #21 on:** September 15, 2024, 04:13:56 PM »

Quote from: Dave Moritz on September 15, 2024, 11:00:08 AM

Good to hear another point of view, CT. With respect to the diversity of experience here, I suspect there’s something unknowable embedded in the early Fox 15 mills.

Dan and MMan: I’ve got four more props to try out this eve, all 8 inches. Time will tell!

Dave Mo…

Yeah! Try 'em!! You won't know for sure any other way!
Type at you later,
Dan McEntee

Dave Moritz · « **Reply #22 on:** September 15, 2024, 07:23:54 PM »

Just back in after a good time at the field. Props I tested: MAS 8x3, APC 8x4, MAS 8x4, and MAS 8x4 narrow. Hands down, the MAS 8x4 did the job best out of 11 props all told. It worked so well that I’m confident enough to work it through some maneuvers this week.

You weren’t just a whistlin’ Dixie when you said to keep at, Dan! Thanks much.

Dave Mo…

FLOYD CARTER · « **Reply #23 on:** September 15, 2024, 08:00:06 PM »

Long before all the unfortunate Fox 15 jokes (?) I ran one in one of my earliest R/C models (A Midwesr "Esquire") That Fox ran every time, and never gave a bit of trouble. Let's see, that was in 1962 in Chicago's south side. One of the "regulars" at that field was a guy named Carl Goldberg. He was testing a "Shoestring R/C" model at that time./

Dan McEntee · « **Reply #24 on:** September 15, 2024, 10:57:06 PM »

Quote from: Dave Moritz on September 15, 2024, 07:23:54 PM

Just back in after a good time at the field. Props I tested: MAS 8x3, APC 8x4, MAS 8x4, and MAS 8x4 narrow. Hands down, the MAS 8x4 did the job best out of 11 props all told. It worked so well that I’m confident enough to work it through some maneuvers this week.

You weren’t just a whistlin’ Dixie when you said to keep at, Dan! Thanks much.

Dave Mo…

OK, Now!! Don't get rid of the other props!! They may work just fine on a different model/engine, and the MA 8-4 might not!! I have tried some of the new Master Airscrew props since they changed the airfoil on them or something like that, and they have worked pretty well. I will try some more in the future.
Type at you later,
Dan McEntee

Joe Ed Pederson · « **Reply #25 on:** September 16, 2024, 11:05:32 AM »

Quote from: C.T. Schaefer on September 15, 2024, 04:57:18 AM

I have been flying a Shark 15 with .15x for several years and flew it GMA 10/22.

Just to clarify, does 10/22 stand for "10% Nitro/22% all castor" or "10% Nitro/ 11% castor and 11% synthetic oil"?

What does GMA stand for and is that fuel still available?

In another Fox .15x thread someone mentioned Powermaster 10/22. Is Powermaster still available?

Thanks,
Joe Ed Pederson

Paul Smith · « **Reply #26 on:** September 16, 2024, 11:58:12 AM »

GMA was George M Aldrich. He is gone now. Ritch's Brew is the current leader in glow fuel. He has anything anybody needs or wants.

There is a point in getting all fuel sensitive with a new high quality engine.
But an old sport engine has, most likely, been abused in the past and maybe worn out.

Brett Buck · « **Reply #27 on:** September 16, 2024, 12:05:31 PM »

Quote from: Paul Smith on September 16, 2024, 11:58:12 AM

GMA was George M Aldrich. He is gone now. Ritch's Brew is the current leader in glow fuel. He has anything anybody needs or wants.

There is a point in getting all fuel sensitive with a new high quality engine.
But an old sport engine has, most likely, been abused in the past and maybe worn out.

Per the other thread, one thing that stood out in my limited ground testing was that if you are running the 15x with the "spacer", and try to run it on typical stunt fuel, you are going to have a bad experience trying to start it. Fox recommended Missile Mist, which as I recall was 25% nitro, that's what it wants with the extremely low compression.

Brett

Colin McRae · « **Reply #28 on:** September 16, 2024, 02:48:39 PM »

Quote from: Paul Smith on September 16, 2024, 11:58:12 AM

GMA was George M Aldrich. He is gone now. Ritch's Brew is the current leader in glow fuel. He has anything anybody needs or wants.

There is a point in getting all fuel sensitive with a new high quality engine.
But an old sport engine has, most likely, been abused in the past and maybe worn out.

I tried to order fuel from Ritch's Brew like a year ago. I actually talked with him and emailed him wanting to order fuel. Then he just totally stopped corresponding with no explanation. So, I finally gave up. I guess he did not want my $$.

I have been able to source my fuel from others.

Brett Buck · « **Reply #29 on:** September 16, 2024, 06:34:40 PM »

Quote from: Joe Ed Pederson on September 16, 2024, 11:05:32 AM

Just to clarify, does 10/22 stand for "10% Nitro/22% all castor" or "10% Nitro/ 11% castor and 11% synthetic oil"?

What does GMA stand for and is that fuel still available?

In another Fox .15x thread someone mentioned Powermaster 10/22. Is Powermaster still available?

Thanks,
Joe Ed Pederson

Powermaster GMA is still available, it is 22% oil with 50/50 castor/synthetic. As noted, I would not use 10% nitro for a Fox 15x. It worked OK when I tried it with a 15xx (no spacer).

Brett

Joe Ed Pederson · « **Reply #30 on:** September 16, 2024, 06:52:16 PM »

Brett,

Thanks for the clarification, Brett.

I have some Red Max 15/22 (11% syn/11%castor). I'll give that a try.

I've had the same experience with Ritch's Brew (no response). I hear that brings fuel to some contests.

Who distributes Power Master fuel these days?

Joe Ed

Joe Ed Pederson · « **Reply #31 on:** September 16, 2024, 07:23:15 PM »

Quote from: Joe Ed Pederson on September 16, 2024, 06:52:16 PM

Brett,

Who distributes Power Master fuel these days?

Joe Ed

Never mind. I found the VP Racing Powermaster website.

Boy, do they think highly of themselves. $17 a quart and $53 a gallon. Perhaps I'm just behind the inflation curve, but if that's what everyone is charging for nitro fuel, I guess I'll have to retire my IC motors and go electric when my remaining fuel is gone.

The last time I was in Schaeffer' Hobby shop a gallon of Omega 10% nitro was under $30 dollars. I can always add more oil to the Omega if it is still available at that price.

Red Max was very accommodating to five different mixes in small quantities and were quite prompt. But they no longer make/sell nitro fuel.

Joe Ed

Motorman · « **Reply #32 on:** September 16, 2024, 10:08:16 PM »

Don't buy your fuel from VP, you'll pay through the nose. Give Stan a call at S&W fuels 610-252-2024.

MM

Joe Ed Pederson · « **Reply #33 on:** September 17, 2024, 11:18:21 AM »

Quote from: Motorman on September 16, 2024, 10:08:16 PM

Don't buy your fuel from VP, you'll pay through the nose. Give Stan a call at S&W fuels 610-252-2024.

MM

Thanks for the tip.

Joe Ed

Steve Helmick · « **Reply #34 on:** September 18, 2024, 01:38:17 AM »

Been through this thread a couple of times and haven't noticed what version of the Fox .15 the OP is asking about. The earlier "steel fin" is ok with an 8-4 (I used a Tornado nylon), but the slant plug .15X likes smaller props and higher revs.

If you look at the APC line, they have some fractional diameters (like 7.5") and a variety of pitches. It's highly unlikely that your LHS will stock them, but the APC factory is extremely fast and they give excellent service. I got my order in 3 days, but it's a pretty straight shot up I-5.

Steve

Dave Moritz · « **Reply #35 on:** September 18, 2024, 11:58:29 AM »

Steve

It be the simple steel fin version. Yes, APC is top notch service with an outstanding line up. I might lean on them should the MAS change its mind about being a good prop. Thanks for the follow-up.

Dave Mo…

Dave Moritz · « **Reply #36 on:** October 20, 2024, 09:05:45 PM »

Resurrecting this thread. Motorman suggested naphtha for cold weather starts in “At the Handle” above.

Motorman: Assuming fuel is brought up to the needle from the tank, are you shooting this go juice into the venturi followed by a few flips, or does it go directly into an open exhaust port?

I’m vulnerable to cabin fever during Winter here and need to get out for flying. Your advice is appreciated.

Dave Mo…

Dan McEntee · « **Reply #37 on:** October 20, 2024, 09:42:45 PM »

Quote from: Dave Moritz on October 20, 2024, 09:05:45 PM

Resurrecting this thread. Motorman suggested naphtha for cold weather starts in “At the Handle” above.

Motorman: Assuming fuel is brought up to the needle from the tank, are you shooting this go juice into the venturi followed by a few flips, or does it go directly into an open exhaust port?

I’m vulnerable to cabin fever during Winter here and need to get out for flying. Your advice is appreciated.

Dave Mo…

Squirt it anywhere the fuel goes!!! If you have a muffler in place, you have to put it in the venturi. Just a squirt, about as much as you would a prime of normal fuel. In cold weather, make sure you have a hot plug and a good, hot battery for the best glow possible. I have heard of some guys squirting some on the head and cylinder, then lighting it off carefully to heat up the cylinder, or even using a small propane torch if i t's a profile with easy access to the cylinder. For me, it had just better be at least 50 degrees before I'll subject myself to that kind of abuse any more!! Those days are behind me now!!
Type at you later,
Dan McEntee

Dave Moritz · « **Reply #38 on:** October 21, 2024, 10:59:57 AM »

Gotcha, Dan. Don’t blame you a bit in avoiding the freeze. I never thought of a small torch to heat the cylinder. Might be good to have a handful of snow available in case things get out of hand.

Thanks.

Dave Mo…

kenneth cook · « **Reply #39 on:** October 21, 2024, 01:53:43 PM »

Dave , if you do use lighter fluid for cold starts make certain you have hand protection on. It makes the engine really kick back at you. Backflipping is a better way to start your engine using the lighter fluid.

Motorman · « **Reply #40 on:** October 21, 2024, 06:23:14 PM »

Also, keep the lighter fluid off your silicon tubing.

YakNine · « **Reply #41 on:** January 27, 2025, 07:59:24 AM »

This is one of my favorite engines, Larry Scarinzi liked them, I always replace the needle valves with ST clones and it makes them worlds better, Hobby King Turnigy 8x4 is what I use . They like 10/22 GMA fuel, I add a touch of extra castor to it, I have used Glo Devil and Fire Ball shorts mediums or hots, going to try milling out a tongue muffler for it when I get my shop set back up after the move. TJ