Fox 07 R/C

No-that's the engine test-which I'm already familiar wirh...what I want is the actual operating instructions that would have come with the engine when purchased brand new.....normally a double sided pamphlet. Mecoa has most of them in archive form on their website-but they only go down to 09-as the rights to the 049 and 07 engines were sold off by Fox to Richard Rikel and his partner back in the early 90s...H&R Engines-the guys who reintroduced the Fox 049 FAI Special-long before Mecoa acquired the Fox line.... Of course the Fox 049/07 engine residue changed hands several times subsequently.

ChrisM
ffkiwi'

Hello ChrisM, I'm sorry I can't help, I'm just leaving my message to congratulate you on the acquisition, I didn't know about this engine and from the link Eric left, I see a beautiful R/C engine....congratulations and if you want it at some point, of gear to the engine, it will be a pleasure to see it working here. Thank you!

MauricioB wrote:Hello ChrisM, I'm sorry I can't help, I'm just leaving my message to congratulate you on the acquisition, I didn't know about this engine and from the link Eric left, I see a beautiful R/C engine....congratulations and if you want it at some point, of gear to the engine, it will be a pleasure to see it working here. Thank you!

Mauricio-they don't crop up that often-but they do appear on Ebay from time to time....as does the standard 07...also known as the 'Fox compact stunt motor'....the 07 R/C being 15 years ahead of its time-and 25 years ahead of its time in terms of a throttle for its size category-we had to wait till the MP Jet 061 appeared to get a throttle of similar refinement.....its a pity there was no really lightweight gear around at the time-other than cascaded escapement type single channel-that would have allowed it to really make its mark. As the engine test noted-other than capacity, there was very little parts commonality between the 07 and the 07 R/C other than the P/C set and glowhead.

I haven't run either of mine yet-but want to have at least some written backup in the event that the throttle settings have been fiddled with-and Fox throttles-at least of this era -were adjusted a bit differently to modern types and I have to find the correct settings. Powerwise-according to the tests both versions are up there with a Cox Medallion 049 or Black Widow-but capable of turning larger props-7x3 or 7x4-which is no bad thing-about 16% more swept area-which ought to suit some of the classic 1/2A designs from the 60s and 70s. In any case I'm by no means short of throttled 1/2A engines-so if these get used in anger it will be in something period appropriate.

ChrisM

Sorry Chris , I didn't read the whole article till now and see there is no reference to what a starting point would bee for the adjustments . Sounds like a interesting engine to run hope you can get it figured out .

getback wrote:Sorry Chris , I didn't read the whole article till now and see there is no reference to what a starting point would bee for the adjustments . Sounds like a interesting engine to run hope you can get it figured out .

no biggie-Eric and Roddie-the test itself I looked up as soon as i acquired the two examples. I'm just taking precautions in the event that the settings have been fiddled with. If they had, without knowing what the factory suggestions are, any adjustment by me could make things worse rather than better......mainly as regards idle mixture.....the setup as noted in the engine test article is a bit different to what is normal these days-with the low speed jet always in use and the high speed only functioning at full throttle...

As I noted-many years of collecting and using engines have borne out the truism that if something can be unnecessarily fiddled with.....it will be....and especially with diesels. i've lost count of the number of engines that have passed through my hands with the liner in backwards, or the piston 180 degrees out..!

ChrisM

Chris, it's hard to believe this isn't a simple Google search but it isn't. Sadly, we no longer have Bill Mohrbacher to offer his manuals. Bill would immediately know what to do. I know some Fox carbs are much different then others whereas you adjust the low first and then the main. I'm not certain if the .07 carb requires this feature.

Unfortunately I don't have any manual either...

You can get a rough check by blowing into the fuel line, a slight hiss usually works as a starting point. From what I remember the low end setting isn't very critical. Instead one would run the "low-end" well on the rich side, this gives a two-throttle setting, a rich low rpm setting a higher revving lean WOT. One should not expect a true proportional throttle like we have on more modern engines.

Here is a picture of one of my engines and the low-end setting:

Thanks surferkris-that gives me a reference point to work from.

chrisM

I have one but I haven't really paid attention to it Other than I noticed the funny carburetor
Which is simple, two screws to limit opening or closing one serve as an idle screw but the main jet is small The spray bar hole is really small and with a little notch
The carburetor barrel look difrent from What I have already seen I realize that this small carburetor is more complex than it seems
Very difficult to take a photo but I see a flat side and when closed a small hole??? Now I wonder if the barrel is not misaligned with the throttle arms

Here's .07 instructions for fox rc

Hi ,I hope this info helps someone,I would love to try mini mambo rudder/ throttle ,but I'm scared.sam

Rudder and throttle on the Minnie Mambo is easy peasey. I did it back in the early 1980's with Ace R/C Pulse Commander and Adams Stomper Actuator for rudder and KRD Sequential quick blip throttle servo. (A tap on the transmitter push button switch would cycle servo from LO to MED to HI back to LO. (It was how I had it modulate the Cox .049 R/C Bee muffled exhaust throttle sleeve. Sleeve is non-linear versus a regular carburettor. Pushrod forward opened throttle about 1/3rd for middle speed, blip to middle opened throttle wide open, blip to back moved sleeve to idle position where only a notch was exposed.)

The throttle will act as elevator, except that when more rudder is applied, nose will drop and plane will accelerate. Advantage to throttle is you can cut the engine when you think you're having difficulty controlling. When aircraft balloons up after a turn, kicking the rudder temporarily can kill the balloon and you are back to climbing.

I don't know how true, but recall reading someone's comments that the Fox .049 - .07 R/C were non-linear in throttling, basically a HI - LO system. If this is the case, then trim for glide first. Then adjust engine down thrust for a good reasonable climb angle on HI in calm weather. (Corrections to my assumptions are appreciated. I don't have a half-A Fox to know specifically.)

It takes a little getting used to, but with some practice during reasonably calm weather, you'll get the hang. Then it becomes fun. You'll amaze others of how you can maintain perfect control with just rudder.

Once you can fully control the plane, for windier weather, you shim the trailing edge of the wing to decrease its decalage, so plane doesn't balloon in the wind, amount by experimentation. I'd start off with 1/16" of an inch with say a balsa or hardwood shim on each side, then increase or decrease as needed. Over time, you will know how much to shim for the level of wind speed. Basically you can fly rudder only in winds up to 15 mph. Above, best to call it a day.

(Although at higher elevations, 4300 to 6500 feet, I have flown in up to say 22 mph winds.)

Thanks for the reply,can I use proportional r/c equipment.i think this would be a awesome vintage project

Yes of course you can...the only 'but' is that as stated earlier by surfer kris and george above-even using proportional control you probably won't get proportional throttle with the 07 R/c....more like fast and slow...and the idle -if measured will be a typical 1/2A idle of around 6,000rpm...or about 1/3-2/5 of the flat out peaked throttled setting.

my first R/C aircraft-back in about 1974 was a David Boddington 'Tyro'-powered by an OS Max 10 R/C (the early crossflow model)-and Mainstrean Gem Digi 1+1 gear-which gave proportional rudder but sequential throttle-low-med-high-med-low etc. [Just as george describes above with the Ace R/C pulse commander-though my gear WAS digital proportional not a pulse system] It flew well....but i got a fairly stiff neck flying it....its amazing how little power you need to just cruise around

ChrisM
'ffkiwi'

PS Thanks for posting the copy of the 07R/c operating instructions...I've filed a copy for reference.

Thanks Chris for your contributing inputs from your personal experiences. If we ever could meet up, it would be fun to fly with you.

Continuing with what Chris said, the system I was using was one of the last practical rudder only systems available. Prior, reliance was on escapement systems, which the controls were full on or neutral. They were popular, because half A required smaller lighter systems. to fit the planes The proportional systems of the day were much larger and heavier, practical on larger aircraft only.

The Ace system I used was fully proportional, but the rudder kicked back and forth in neutral. It pulsed fast enough that the airplane followed the averages of the rudder throws. I don't remember the exact numbers, but the pulsing was something like 4 to a half dozen times a second. The Adams Actuator made lightweight possible, but it used magnets at the end and the central coil provided the electrico-magnetic "umph".

Moving the proportional stick a little more would cause the rudder to pulse more to one side. At full left or right rudder, it was pulsing to one side and barely returning to the other.

049kid wrote:i think this would be a awesome vintage project

It is. Today, one channel systems still exist, except these inexpensive ready-to-fly small radio control planes use differential motor controls on twin propellers. By spinning up the one motor on one side at a faster RPM than the other, would cause the plane to turn. Full power to both props would cause the plane to climb. An absence of power caused the plane to glide.

But, basically, this is still single channel flying, but by differential motor thrust versus a moving rudder.