ajcoholic

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I have allways wanted to try a geared 5 cylinder radial. No where near the one Tanzanos has done (a practical engine) but hey, I had an idea and I ran with it....

Last night and this morning I whipped up this engine, made from 5 geared baby bee Cox 049's. The main part of the engine, which holds the prop shaft, and also carries the 5 engines and acts as the mount was turned by me ( no cnc here!) from a single bar of 3" diameter aluminum. Took a few hours and made a little ball of aluminum swarf

The gears are RC car gears. I wanted to gear down the engines to turn a large prop, so I went with 32 tooth-48 pitch pinions and a 66 tooth spur gear. I wanted a 64 tooth for a 1:2 ratio, but 66 was all I could get. I didnt think the plastic would hold up, and it did not. When I tried to start the engine, right after the cylinders started to come to life the gear quickly lost all the teeth! [X(] Looking for a metal one now....

The rear of the mount also acts as a fuel manifold. Neat design, I thought, but how practical - probably not too well, as the lower wo cylinders seemed to be getting more fuel than the others.

But, for 6 or 8 hours of fun, it was a neat project. On to the next one!

AJC

ajcoholic

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front shot..

phuffstatler

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Good Gawd!!! Aj, You Da Man!


I'm super envious of your machine shop, and your willingness to grind up aluminum, too...


How much does it weigh?

phil in austin

Bipe Flyer

Oh man, another one?!

Amazing! Is there no end to your talents?

ajcoholic

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Never weighed it, but it is not too bad, the parts are very thin, and all aluminum no steel.

Aww shucks Bipe. you get yourself a lathe and start making things too!

AJC

combatpigg

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HI AJC! You look real close to having something there! My son had a COX RC car that kept us busy changing parts all the time. Do you "time" the engines to hit sequentially? In a ring pattern?, or a star pattern?

Bipe Flyer

It looks like there are brass nipples on the back of each engine. What did you do for reed valves? Can you run 5 separate crankcases with reed valves off of one needle?

ajcoholic

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Yes, there are reeds - what I did was take 5 stock babe bee tanks, and turn away the tank portion, and then drill and tap the venturi for a nipple. They all connect to the rear fuel manifold with clear small tygon (see pics) and there is a tarno carb on the top. When I hit it with the starter you could see fuel/air (bubbly fuel) moving in each line, and then it started to come to life. But allmost as fast the gear (plastic) started to shed teeth

I did notice that the lower two cylinders were very wet, and like I said the nipples probably should all be coming out the top of the manifold instead of all the way around.

I am trying to source a 66 tooth, 48 pitch metal gear, if I cant find one then I will just have to grind a form tool and cut one. I have made gears before, but for one-offs its a bit of a pain...

I believe this type of engine has been done many times before, ie, using the cox tanks for the reed valves.

(no one hate me for butchering up 5 good babe bee tanks now please )

The engines were actually very bad, and I also cleanied them up on the lathe, reblued them and rehoned them. I didnt use new engines by any means.

It was a break from my regular stuff, but now I gotta' get back to the Seneca and start on the fuselage.

AJC

flysrc

Andrew,
I'm still working on the geared twin that you posted plans for here on this site. I just have a couple of things left to finish up. When your lathe is from 1948, you have to redo a couple of parts a few time to get them right but I'm having fun just the same. I have already learned alot from this little project. reading this post and looking at the pics, I was wondering. I I removed the tanks on both egines, and used a small ank and a small carb (norvel for the sake of it's all I can think of off the top of my head.) This should give me throttle control as well as my choice of any size tank I want. I f this does work could I use one carb for both engines and if so would I just use a "Y" conector to connect the 2 engines to the single carb. Or should I have 2 carbs. I'll have to go back and look at the pics again. Thanks again for the inspiration!!!!!. When the engine is done I'm thinking of a speedy bee or a Page newbee. I've flown a few non throttle planes and much prefer throttled if I can
Dave

Ragwing

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I have nothing useful to add. But I just had to compliment your work AJ. Its beautiful-very impressive. And all withing 24hrs--wow!

Derek

ajcoholic

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Thanks Ragwing.

Dave, that would work (single throttle) but you will have to use cox mufflers or make some of your own exhaust collector things (like I did for my 040 twins - see my contest plane thread) as the glow plugs need some backpressure to help keep them hot and glowing when throttled down.

An old lathe is a good lathe in my book. Look at mine, it is also circa 1950's and if I can help it, will be going strong in 2050.

AJC

AndyW

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Absolutely fabulous work by Andrew. Another engine genius has been at work and his goal is to make it available to anyone who wants one.

Just to whet your appetite for a small radial, here are some pics of a five cylinder, internally geared radial, made by my good friend, Yiannis Mantheakis of Greece. His first was done with Cox components and looked and ran really well. After some encouragement from me, he decided to try another using Norvel Revlite .06 parts. As you can see, he succeeded in spades. Looks fantastic and runs well. I've tried to download the clip with no luck but the pics still really do it justice.

This one is intended to go into commercial production eventually and I've got first dibs on one of the first. Can't wait.

Yiannis is contemplating trying a bigger version using .074 components. I've advised him that the potential for any size radial is there with the use of the entire Norvel line, .06 all the way to the .40 size. Imagine a 2.0 ci radial using Norvel .40 cylinders. A brute it would be, I'm sure.

BMatthews

Lovely work and a practical answer to the problem.

A few years back someone had one of the old Gmark radials and they brought it to our field to run it. The sound was incredable. I still to this day don't know if I liked the combination of all those little two strokes running in uison along with the shriek of the gearing or not. The sound thrilled the soul at the same time it curdled your bones. A glow powered sewing machine on steroids is all I can think of to describe it.

Looking forward to hearing more about the test runs.

___________________________________________

BTW guys. I'll be away on business for a week so play nice ( like this forum doesn't already do that ) and have fun. I'm going to start on my design contest entry as soon as I get back. Contrary to what I said the Peice O' Sheet is taking a differnt form. More later.....

tanzanos

Just to let you all know that Andy was a big help in my radial project. He gave me very good advice not to mention some parts he made and sent to me. My radial would have stopped at the Cox version were it not for him urging me to try the Norvel cylinders. Modelers are human after all!![&:]

Terbough Bob

My Feedback: (10)

Hey AJ, here's a source of metal gears for you- http://www.wmberg.com/catalog/selectprim.cfm

vauxhall

Nicktu berata and the day the earth stood still! How do you find the ideas and time for this great stuff.Do all the 049's run in the same direction,or does one decide to do the opposite?Maybe you've got a gear stripper in there.

tanzanos

OK! Just to put the gear stripping issue to rest. It is not so much the material used as is the correct centre to centre distance between the gears. To the interested parties involved in geared radials I suggest using the gear formulas available on the web in order to calculate the correct typen of gear. Lubrication is also an issue when high RPM is expected. The wear factor increases rapidly when the centre to centre distance is incorrect. As for one engine trying to run backwards as opposed to the rest is not an issue since each engine does not have the power to strip gears and the total power produced by the rest will force the rogue engine to comply.
I will be happy to calculate the correct centre to centre distance for anyone as long as they give me the gear type.
Keep bashing the aluminium to submission guys!

alex681219

Wow!!! I see your skills and want to share with you this machine...is the TYM award winner ...can you make one of this I´m sure see this linx


http://www.angellabsllc.com/index.html
http://youtube.com/watch?v=_MBYg1NPzMY&feature=related

KidEpoxy

If one plastic spur tooth "X"mm wide doesnt handle the load,
Use a thicker spur gear for wider tooth to tooth contact.

.... or in this case, stack 2 spurs for a much wider tooth surface to lessen the load.
Try it with an on the dot engagement (center to center),
maybe plumb an exhaust line to spray spent castor on the teeth,
and maybe consider it with doubled up gear stacks.

One thing with all metal gearing,
will that RF Interfere with the radios?
It is a metal to metal contact & break buzz. I was looking at this kind of thing (twin) and saw some plastic tooth 1/8th pinions on Tower... deep in the pinion pages.

And maybe start with swinging some smaller lumber to work your way up.

digital_trucker

Use a 2.4 gig radio and forget about interference

DeviousDave

Omagosh! I just ruined my shorts!

I can host the vid on Photobucket and embed it here in the thread.

Man, that's my dream project-I bought my Gmark radial just so I could look inside and make my own out of Norvel parts[8D]

DeviousDave

G-Mark got around this by running the exhaust over the gears to keep them wet and lubed.

MJD

My Feedback: (1)

I bet it runs on water too, and uses a Swarup in the intake to boost mileage by another 90%.

old git

Thanks for showing the Radial, my compliments to AJC for the super work. I have a G-Mark radial still NIB, I haven't dared to run it. I have the model I'd like to use it on but cannot bring myself to sully the lovely aluminium with dirty fuel & exhaust.


As to that Mighty whatever, it looks very difficult to machine. Even worse potential probs than a Wankel rotary or whatever the damn thing was called. I imagine a Deltic would be as good and as compact with the advantage that it has been in use in railways for some long time.

If you don't know what a Deltic looks like, Google it & I'l bet you need an animation to understand how it runs.




old git - - - - -aka John L.

lz-23

Great job! How the intake is made? Can you post more info please?