Fox .09 Rocket Acquisition

Since we've discussed about people hacking off the rear tank from these engines, get a load of this one!





Currently up for auction.

Rod, that Fox .09 cut away display appears it may have been something that Duke Fox or one of his distributors took to trade shows, to show off this new engine.

It does show how tiny the solid crankshaft is. Most of the crankshaft strength is in the outer diameter. It's smaller diameter substantiates Ken's observations and experiences that it didn't take much to shear it off. (Hence why that Ken mentioned to use lighter inertia propellers. Constant torsional cyclic fatigue (between power on / power off) would eventually work harden and snap the crankshaft in two. Also, wood props break apart easier in a crash, sparing excessive bending of the crankshaft.)

GallopingGhostler wrote:Rod, that Fox .09 cut away display appears it may have been something that Duke Fox or one of his distributors took to trade shows, to show off this new engine.

George.  The seller is from Bulgaria and has quite a range of cut-away engines available.
https://www.ebay.com/sch/i.html?item=185556843243&rt=nc&_trksid=p2047675.m3561.l2562&_ssn=paul_custom

Oldenginerod wrote:

GallopingGhostler wrote:Rod, that Fox .09 cut away display appears it may have been something that Duke Fox or one of his distributors took to trade shows, to show off this new engine.

George.  The seller is from Bulgaria and has quite a range of cut-away engines available.
https://www.ebay.com/sch/i.html?item=185556843243&rt=nc&_trksid=p2047675.m3561.l2562&_ssn=paul_custom

And from the look of some of his other listings-has been doing a bit of amateur anodising on the side.....some of his other offerings never left the factory in those colours.....

ChrisM

Rod and Chris, thanks for the clarifications, I learn something new every day. I would have never guessed it was skilled machinist from Bulgaria making these creative displays. I was using a little intuitive logic, which goes to show that sometimes, there is more to the picture than we see.

I remember a saying about "What You See Is What You Get" (WYSIWYG - referring to software design), one programmer said it was as bad a concept to us as in selecting a woman for a mate based on first appearance and impression.

GallopingGhostler wrote:Rod and Chris, thanks for the clarifications, I learn something new every day. I would have never guessed it was skilled machinist from Bulgaria making these creative displays. I was using a little intuitive logic, which goes to show that sometimes, there is more to the picture than we see.

I remember a saying about "What You See Is What You Get" (WYSIWYG - referring to software design), one programmer said it was as bad a concept to us as in selecting a woman for a mate based on first appearance and impression.

George-give the man his due-he does nice work-especially the sectioned stuff-there one or two other Ebay vendors who offer similar items from time to time-eg 'red-baron2' and 'cutawaycreation'
.... paul_custom's (whoever he is) offerings seem better executed than most.....

ChrisM

ffkiwi wrote:George-give the man his due-he does nice work-especially the sectioned stuff-there one or two other Ebay vendors who offer similar items from time to time-eg 'red-baron2' and 'cutawaycreation' .... paul_custom's (whoever he is) offerings seem better executed than most.....

Chris, I wasn't belittling his work by no means, it is very well executed, what I would expect to see at a tradeshow. Somehow, a little got lost in my expression. That is why when I first saw it, thought that it may have been a first by Fox and a historic relic.

That is what I mean by looks is deceiving. It would also probably be a good way to re-display a well worn engine with a new life as a display.

Sense of humor misplaced. (Not long ago, someone said, "George, you seem to know a lot about many subjects. What is it that you don't know?" I replied to her, "Women." )

GallopingGhostler wrote:

ffkiwi wrote:George-give the man his due-he does nice work-especially the sectioned stuff-there one or two other Ebay vendors who offer similar items from time to time-eg 'red-baron2' and 'cutawaycreation' .... paul_custom's (whoever he is) offerings seem better executed than most.....

Chris, I wasn't belittling his work by no means, it is very well executed, what I would expect to see at a tradeshow. Somehow, a little got lost in my expression. That is why when I first saw it, thought that it may have been a first by Fox and a historic relic.

That is what I mean by looks is deceiving. It would also probably be a good way to re-display a well worn engine with a new life as a display.

Sense of humor misplaced. (Not long ago, someone said, "George, you seem to know a lot about many subjects. What is it that you don't know?" I replied to her, "Women." )

George  I wasn't suggesting-you were belittling him-and yes-I recall photos in the mags over the decades taken at various modelling trade fairs-Toledo, and Nuremberg spring to mind-of major engine manufacturers trade stall with examples of some of their prestige products in cutaway form. So its quite reasonable to assume that Fox might well have done this.

Its very much a standard 'thing' in some other non modelling tech areas-such as military equipment. I have fond memories-40+ years on-during my RNZAC Corps training-conducted of course by the School of Armour at Waiouru-and the driver training side (as distinct from the weapons or comms side) part of the course being conducted by 'D&M Wing'...which was 'driving and maintenance wing'-and they had tucked away in the hangar-but not out of sight-several sectioned tank engines..I recall one from a Valentine, another-almost certainly a RR Meteor-from the Centurion-and another which might have been from a Ferret or Daimler armoured car-all beautifully done-and with the edges of the sectioned portions done in different colours to delineate certain aspects of the design-red, yellow, green. If memory serves-red was just the cut edges, yellow was the fuel pathways, and green lubrication pathways.

These days you tend to only find such items in museums...but in the day they would have been state of the art teaching aids....

ChrisM

Actually Chris, those teaching aids would still be applicable even today. Although computer graphics and videos can help assist education, nothing beats hands on real items. There are still a lot of things that can't be done virtually, best done hands on.

I remember the wind tunnel tests at Douglas Aircraft back in the 1980's, it was thrilling to go actually into the tunnel during down time, and physically see and even touch the 4 foot MD-80 (DC-9 derivative) model (when it was safe to do so ). To visit the model shop shop and see the models being assembled and loaded with instrumentation, fine aluminum tubing being installed ported to various locations along the model's outline. Channels that contained these tubes filled with Epoxy filler and machined smooth to blend it with the aluminum surfaces. Flush mounted screws for the removable access panels to instrumentaiton inside. To actually see this up close instead of photos in a book were an awesome experience.

I can look at photos of model airplane engines, but until I have one in my hands, can turn the crankshaft, feel the compression, feel its weight, experience its compression, it is nothing more than images in a "museum".

I pulled out the profile engine mount I purchased from Cox International, still available. These make for good replacement engine mounts for Sterling Beginner series and Midwest .049 profile fuselage kits (as well as roll your own designs, too):
https://coxengines.ca/building-supplies/cox--049-engine-firewall-mount-control-line.html



An interesting observation I had today is that the Fox .09 Rocket has exactly the same bolt spacing horizontally as the Cox .049 tank engines. One can use #2 sheet metal screws for the bottom two mount holes.

Only thing it is falls slightly short of the vertical mount spacing by about 1/4 inch (6 mm). One could simply drill a hole for the top and use a 2-56 screw with a lock washer and nut on the back. This opens up the possibility for an easy control line profile aircraft retrofit with this engine. A Sterling Beginners Fokker DVII or Beginners Ringmaster Biplane comes to mind.

Today, I placed an order with @Cox International for clear vinyl fuel line suitable for .020 Tee Dee's. This has a small enough wall to fit into the tank holes, but still is large enough to feed the engine. The regular silicon tubing is too thick walled to work with this engine.

A good plane for the Fox .09 Rocket would be the 24 inch 1947 Veron Speedee:
https://outerzone.co.uk/plan_details.asp?ID=10689

Now THAT is one cool looking plane!

Sharing the wealth, @Ken Cook, yesterday I mailed Eric @getback the Fox .09 Rocket spray bar and needle that you gave me, so he can resurrect his .09. Mine has a perfect NVA, so this will help us kick off a Fox .09 renaissance. Thanks, again.

Glad you received the items safe and sound, Eric. When you get time here and there, am looking forward to your Fox .09 Rocket adventures.

Oldenginerod wrote:MECOA use the "We probably have this" line for most of the parts listed for the .099.  Surprisingly they claim to "probably have" quite a bit of stuff, except for the spray bar.    I'm assuming, since Eric's engine has the fuel nipple side, that they use a two piece spray bar similar to the Gilbert.  Fuel nipple screws in one side and the threaded part for the needle screws in the other, leaving a gap in the middle.

Regarding ordering from MECOA, I have yet to do this. I have heard both good and bad, seems mostly on communication. I guess the main thing is as long as one hasn't lost any money.

The one on mine is a single pass through spray bar, same part from Ken that I forwarded to Eric.

These engines are fairly simple. If one lacked the assembly, I think one could probably JB Weld Epoxy one in place from a Sure Start back (available separately from Bernie, https://coxengines.ca/back-end/cox--049-spraybar-oem.html and use a Cox needle and spring. Given their lower power output makes me think that the engines are probably fairly economical in running. Doesn't seem to be anything unusual about their porting to make them thirsty buggers.

(Please don't try this unless you know what you are doing. I have not done this myself and comment thus far is by conjecture.)

Missing a back? The factory tank backplate is so simple, one could even fabricate from hand tools to substitute, use either auto engine RTV or a homemade gasket for sealing.

getback wrote:Not a bad looking engine George , hopefully the glow head works . Are you going to clean it up and give it a spin ? I have a rocket .049 or .09 can't find it at the moment but did find an engine that took me on a adventure  Has no marking but can tell its a Fox from the glow head needs a needle and is a little gummed up but best i can figure its a Fox Comet .049 with the integrated tank . .  

Yep, one of mine had a "hacksaw attack", with the rear of the case (fuel tank) being very roughly hacked off. It runs, but that's about as far as I'll go. My other example presents and runs way better. It's complete and runs ok but you need to be prepared to experiment with different props. Less is more. Over-prop it and and it will refuse to reach any sort of sweet spot. 7 X 3 sounds about right, but I don't remember what I ended up using. Some criticise the Gilberts for being low on power. In regards to performance I'd choose the Gilbert 11 over the Rocket any da

getback wrote:Not a bad looking engine George , hopefully the glow head works . Are you going to clean it up and give it a spin ? I have a rocket .049 or .09 can't find it at the moment but did find an engine that took me on a adventure  Has no marking but can tell its a Fox from the glow head needs a needle and is a little gummed up but best i can figure its a Fox Comet .049 with the integrated tank . .  

Yep, one of mine had a "hacksaw attack", with the rear of the case (fuel tank) being very roughly hacked off. It runs, but that's about as far as I'll go. My other example presents and runs way better. It's complete and runs ok but you need to be prepared to experiment with different props. Less is more. Over-prop it and and it will refuse to reach any sort of sweet spot. 7 X 3 sounds about right, but I don't remember what I ended up using. Some criticise the Gilberts for being low on power. In regards to performance I'd choose the Gilbert 11 over the Rocket any da
Regards:

brookalicja wrote:Yep, one of mine had a "hacksaw attack", with the rear of the case (fuel tank) being very roughly hacked off. It runs, but that's about as far as I'll go. My other example presents and runs way better. It's complete and runs ok but you need to be prepared to experiment with different props. Less is more. Over-prop it and and it will refuse to reach any sort of sweet spot. 7 X 3 sounds about right, but I don't remember what I ended up using. Some criticise the Gilberts for being low on power. In regards to performance I'd choose the Gilbert 11 over the Rocket any day.

@Ken Cook has contributed quite a bit on these engines, pros and cons, things to be aware of while running them, plus he sent me with his compliments parts to help mine be a good runner.

to the forum, @brookalicja ! Please don't forget to introduce yourself in our introduction forum section.

Yes, I have seen a few photos of those hacked .09 Rockets, really doesn't make any sense. Yes, it will reduce their weight a little, but the engine is already lightweight at 3.1 ounces (87.9 grams). If I had one of those hacked engines, I'd probably just carefully use several metal files and dress up the cuts to clean up the hack to make it look more acceptable.

I haven't run a comparison check yet between the A.C. Gilbert .11 Thunderhead and my Rocket, although I have several of those Gilberts.

According to Sceptre Flight Engine Tests, on 15% nitro fuel (Cox standard fuel is OK), engine put out 0.111 BHP at 14,000 RPM, is a very mild .09 engine. (1965 Enya .09-III TV output 0.16 BHP at 14,300 RPM.) A 7x3 prop at 13,000 RPM (would unload in fllight to nearest its BHP) was described as optimal. (In comparison, Cox .049 QZ, forerunner to the Sure Starts output 0.065 BHP at 15,000 RPM.) 6x4 was already at BHP during the bench test, would put it beyond BHP in in flight. I wouldn't be afraid to test other props, say a 6.5x4.5 for thrust checks.

http://sceptreflight.com/Model%20Engine%20Tests/Fox%20Rocket%2009%20%281%29.html
http://sceptreflight.com/Model%20Engine%20Tests/Fox%20Rocket%2009%20%282%29.html

Ken pointed out that it is best to use lower inertia wooden props as the crankshaft on these are of thinner diameter, somewhat fragile, easy to shatter in a crash or blade strike (doesn't stand up well to sudden stops, don't toss a rag into a spinning prop to stop).

Recently I purchased an NOS kit of the 25 inch wingspan Scientific Cessna 170 profile for control line.



This is a correctly sized C/L for flight. another would be Hal DeBolt's 1953 DeMECo (DeBolt Model Engineering Company) 26 inch wingspan full fuselage All American Junior.

https://outerzone.co.uk/plan_details.asp?ID=347


Outerzone photo.

I gather that a control line plane of around 150 square inches wing area would be right sized. Other planes that come to mind are the 27 inch Veco profile Little Tomahawk (140 sq. in.) and OK Model Pilot 27.5 inch Fast.

According to Sceptre Flight Engine Tests, on 15% nitro fuel (Cox standard fuel is OK), engine put out 0.111 BHP at 14,000 RPM, is a very mild .09 engine. (1965 Enya .09-III TV output 0.16 BHP at 14,300 RPM.) A 7x3 prop at 13,000 RPM (would unload in fllight to nearest its BHP) was described as optimal. (In comparison, Cox .049 QZ, forerunner to the Sure Starts output 0.065 BHP at 15,000 RPM.) 6x4 was already at BHP during the bench test, would put it beyond BHP in in flight. I wouldn't be afraid to test other props, say a 6.5x4.5 for thrust checks.
Regards: Pubg Name Generator

The PDQ Circus Prince suggested "A-B" engines for power. Well the Fox 0.099 is considered an "A" engine so I used my Fox to power it. Not a chance it was going to fly! The iron cylinder Fox 0.15 did the trick and apparently that engine has at least double the power of the 0.099.

Whenever a model suggests class engines from such to such as in .19-.35, you always want the larger engine. You can always detune a engine in various methods, you can't extract more power. The Circus Prince isn't out of the question for the Fox .09, the model design and wood choices were terrible. Just like Sterling, all lighter softwoods were discarded due to the die methods used for cutting. The design is from 1948 and ignition engines were still in use with frequency demanding a bit more beef. The dies were essentially spring steel bands which were sharpened. This would totally smash soft wood whereas the harder denser wood would cut even if it looked like it was done with a axe.

          The older profiles used doublers too thick, ribs were generally 3/32", in which none of this was necessary for a smaller model. The Fox .09 is a beginners engine and a good one at that. As long as one doesn't place expectations too high, it does exactly what it was designed to do.

           Jim, when you suggest the Fox Rocket .15 has twice the power, that's quite a statement. The "Steelfin" is a very anemic engine. It is one of my favorite Fox's though. I own quite a bit of them as I do collect them. They're great running small engines. Unlike typical .15's that utilize 52' lines, the "Steelfin" uses more like 48'. They do work well with old timey profiles. The OK .149 is a great comparison.  They fall out of favor with most, I enjoy the heck out of them just watching them run.

706jim wrote:The PDQ Circus Prince suggested "A-B" engines for power. Well the Fox 0.099 is considered an "A" engine so I used my Fox to power it. Not a chance it was going to fly! The iron cylinder Fox 0.15 did the trick and apparently that engine has at least double the power of the 0.099.

https://brodak.com/circus-prince-kit.html

The Circus Prince is 200 sq. in. wing area. This exceeds my observations of 150 sq. in. for the Fox .09 Rocket. Unless it was extremely light, would help to explain why it suffered. This is the same wing area as the Ringmaster Jr., but probably has a thicker wing section for better stunting, which also has more drag. This explains IMO why your Fox .15 (X version?) at least had a chance of flying it bettter.

Kit specifies a .09 to .25 engine. As Ken was alluding to, the larger engine would be the more appropriate one, I think my OS Max .15FP-S would probably be an optimal engine for it (closer to the power of the legacy cross scavenged .25's). This of course would be on the standard longer lines. My Ring Jr. had no problems with 60 foot lines, only drawback was the engine being heavier affected its performance. (It was nose heavy.)

George , the west coast guys fly the full size S-1 using the FP .15. It's pretty impressive for those that can build light. I'm also confusing myself a bit here. The Circus Prince and the Flying Clown are one in the same. I was thinking of the Baby Clown. The original PDQ Baby Clown is nothing like the Brodak version of the Baby Clown. They're entirely different. I had a Baby Clown and it had a K&B Torpedo .09 on it. It flew terrible but it looked great. Too heavy of a engine and no wing area. Bad combo, the meteor on a string.