Tank for a dragonfly

https://www.ebay.com/itm/325161463529?hash=item4bb5222ee9:g:hWwAAOSwSkpiZXjn Black one BIN

That's where I'm looking, on the auction sites.  The tube that the needle valve screws in, can sometimes crack. Tried a little epoxy, maybe some jb weld.  With age not as easy to get and see those places.  Got another question??? The bees, golden bees, black widows, with there tanks have air inlets in the back. Where do the dragonflys rangers and rc bees, get there air from. It also seems like they take more turns open on the needle valves.  Anyhow thanks for answers.

Grf4413 wrote:Where do the dragonflys rangers and rc bees, get there air from. It also seems like they take more turns open on the needle valves.

The air intake for the plastic enhanced capacity tank Bees is located just in front of the needle valve on top of the tank closest to the reed valve assembly.

The finer thread needle valves are the more preferred, were used on the early postage stamp back production engines of the 1960's, also on the Killer Bee I believe.

duaneh wrote:Hey, GRF;

Are these the only parts you need? Found in my Big Box o' Cox. I don't have the needle valve, clunk, or screws. If you're in CONUS, just PM me your address, and I'll drop them in the mail.

Good deal. Nice of you and a tradition on this forum. Did he take you up on it?

getback wrote:This may help , but only 9.50 yrs. to go https://www.ebay.com/itm/265798443990 

Someone got that for a song, Winning bid: US $19.50 + US $5.95 Standard Shipping. Mislabeled, it is an R/C Bee missing the exhaust throttle muffler. One could simply use Bernie's or Matt's throttle ring, and restore the R/C function to it (without the muffling).

rsv1cox wrote:Good deal. Nice of you and a tradition on this forum. Did he take you up on it?

Yes, and the parts are on the way.

duaneh wrote:

rsv1cox wrote:Good deal. Nice of you and a tradition on this forum. Did he take you up on it?

Yes, and the parts are on the way.

Fantastic support, @duaneh. These extended capacity plastic tank Bees were perhaps the best of the last of the lot of reed valves, design of the late 1970's. Being slightly more powerful than the Babe Bee, the extended capacity (20 cc's? never measured it ) were perhaps the best of the Cox sport engines.

Easily giving 4 to 5 minutes of flight time, they were be bee's knees for the R/C sport pilot. I thoroughly enjoyed my R/C Bee. The tank is also very sturdy.

Back in 1983, I plowed mine into the earth at an open field at Little Rock Air Force Base from about 100 feet up burying the engine a couple inches into the grassed soil. The Delrin nylon tank held up very well.

I made a comment here: https://www.coxengineforum.com/t12651-cox-rc-bee-ad-in-rcm-magazine#162409 back in Feb. 2019.

Apparently there was a development version by engineering (@Larry Renger?) that did have a true rotary valve, the next post after mine.

Admin on Oct 27, 2019 wrote:Wow, this ad connects some dots! There is a picture of an R/C Bee with rear rotary induction posted on Mark's 049Collectors Yahoo group. Labeled a "mystery engine".

My 36" Sterling Minnie Mambo fuselage was thoroughly destroyed, but the engine survived. It was already on its second cylinder/piston set. I had already worn out the first set on Sig Champion 25% fuel, a good testament to the usefulness of the engine.

duaneh wrote:

rsv1cox wrote:Good deal. Nice of you and a tradition on this forum. Did he take you up on it?

Yes, and the parts are on the way.

Wonderful, I bought that engine pictured above by George with the idea that if you couldn't I was going to separate the tank and send it to him. But, I don't have that engine either so I'm happy to keep it intact.

i have a dragonfly tank - the needle valve is broken off and stuck in it.

I'll send/trade if anyone wants it.

no clunk.

Some interesting info on these three engines.  It looks like the dragon fly and ranger are the same ,just color of tank. http://www.mh-aerotools.de/airfoils/cox_frameset.htm, is good info on cox engines, but they don't list the ranger. Did cox sell this for something special, or just as a separate engine.  And thanks to duaneh for the great offer and help. Don't post much but do read almost everyday.  Always learning something new..

The Dragonfly is the separately marketed engine for consumers with R/C muffled exhaust throttle control. The Ranger is the product engine used in several RTF's, without throttle control, exhaust muffled only. It's white plastic tank was probably a cost cutting measure, I imagine. However, it is very easily converted to R/C control. If muffling is not needed, a throttle ring does wonders.

The short lived R/C Bee was the predecessor to the Dragonfly. From what I heard, there were legality issues with copyrights on the silicon sleeve used for muffling. Although it was applied to much larger engines, and not in the artful context that Cox used it for, apparently someone thought it worthwhile to approach Cox with threat of lawsuit.

It sort of reminds me of the lawsuit of Jordash with Lardash, a jean made for big women, which Jordash did not have a market for. Seems similarities are enough these days to constitute a lawsuit. But then, a car dealer by the name of Hershey, who used the family name as part of his car dealership prior to the chocolate company, was sued for using the name "Hershey" with his own car dealership. Appears to be a game with the extremely wealthy.

Anyway, screw the lawsuits, the R/C Bee with its unique muffling system (and I heard a few of the earliest Dragonflies used the same muffling system) is still a really nice power system to use. When muffling was not required, I just simply pulled off the silicon cover and used it as a throttle ring.

Isn't this engine the R/C Bee and not a Ranger or Dragonfly. It has the zinc case not aluminum.



I have a similar case that I picked up from CI and attached to a SureStart back end.

Yes, Bob, that it is. If you go 7 messages back, you will see that in my reply to Eric, I copied the associated photo with his link so others could see what auction item he was pointing out.

There's nothing wrong with the cast crankcase used by the R/C Bee. From what I understand, with the quality control issues they encountered, it was more expensive to produce, so they reverted back to the extruded, machined bar stock crankcase with the R/C Bee's successor, the Dragonfly (and derivative Ranger product) engine.

I gather that as a marketing strategy to garner more sales, Bernie had a good number of them powder coated into an array of tasteful colors. I thought often to buy one, as they were very nice eye candy, but living in a windy area, a detriment to half-A flying, forewent them.

Once his last pink bomber horseshoe back engine has disappeared from his website's store, I guess that it was the last of them.

https://coxengines.ca/basic-engines/cox--049-engine-pink-bomber.html


I take that back, Matt has red one crankcases left:

http://www.exmodelengines.com/product.php?productid=18359

Thanks George, I stumbled into that one while looking at the same sellers Cox wrench collection. I do not have a R/C/ Bee.

rsv1cox wrote:Thanks George, I stumbled into that one while looking at the same sellers Cox wrench collection.  I do not have a R/C Bee. 

They are a wonderful engine, Bob. But in reality, if you were to add an exhaust throttle ring to that green bomber of yours, you'd essentially have a tankless R/C Bee, especially with a 2/3 to 1 ounce external tank.

Apparently there was a development version by engineering (@Larry Renger?) that did have a true rotary valve, the next post after mine.

Admin on Oct 27, 2019 wrote:Wow, this ad connects some dots! There is a picture of an R/C Bee with rear rotary induction posted on Mark's 049Collectors Yahoo group. Labeled a "mystery engine".

My 36" Sterling Minnie Mambo fuselage was thoroughly destroyed, but the engine survived. It was already on its second cylinder/piston set. I had already worn out the first set on Sig Champion 25% fuel, a good testament to the usefulness of the engine.[/quote] This is the first time I hear about this prototype engine from larry renger I wonder how many more there are

davidll1984 wrote:

GallopingGhostler wrote:Apparently there was a development version by engineering (@Larry Renger?) that did have a true rotary valve, the next post after mine.

Admin on Oct 27, 2019 wrote:Wow, this ad connects some dots! There is a picture of an R/C Bee with rear rotary induction posted on Mark's 049Collectors Yahoo group. Labeled a "mystery engine".

 This is the first time I hear about this prototype engine from larry renger I wonder how many more there are

I tagged Larry Renger's posting name, but he only posted 1 post here to CEF a while back, so don't know if he gets notices by his E-mail. I don't know if Larry was specifically involved, but I imagine he could have been, why I mentioned him.

If you will notice, the fuel tank appears to be machined out of a block of Delrin nylon, most likely on a several axis CNC mill. It has the rough, non-shiny surface finish of such. They'd do these on very limited production, because constructing a mold for forming is a lot more work. You can barely make out the venturi discharge hole on the top of what appears to be the "reedie" assembly area on the production R/C Bee. Also, the paper gasket also appears to be hand made.

For quick development, they probably went back to the engineering drawings for the RR-1 rear rotary valve, may have even used an RR-1 valve. Regarding quantities, since this was development, I imagine they probably made several, for testing and tweaking by additional machining, etc. Since these were all hand made, they were strictly for concept development.

They probably had a very small engine research and development section (R&D), engineer, machinist, a tech or two. Probably shared their time with other projects.

I guess the reed valve version won out as being the most cost effective with sufficient performance to be considered marketable. From what I gather, the RR-1, as wonderful an engine as it was, didn't have the durability of the other engines and was more costly to produce for the benefit it gave, no advantage over the Tee Dees nor Medallions.

And, reading between the lines, based on Larry's other posts in Stunt Hangar, I gathered that the management side of the company was a difficult bunch to work for. He impresses me as being a very talented and competent, hard working individual (a worker and not a politician).

Wanted to say thanks to duaneh , tank made it to Missouri today safe and sound (USPS).  Also thanks for good info on the dragonfly, ranger and rc bee. I like those engines, just not as common as some of the others.