Cox Fun Model .049 ... flight, flight and flight!!! (page 3 & 5)

After seeing the very good result of the bronze bushing for my Cox Black Lynx, I said: why not make it look attractive and then .... I started making a new bushing and here I show you.
I wanted the gold ring to show on the black carter and that's how I did the job....














this is how she looks with her golden ring

Pretty! And made of the correct bronze, works as a thrust bearing too, if you wanted to use a starter or want to run the engine as a pusher.

Nice work again, Mauricio!

Nice ad To its look Good wit gold ring

Beautiful upgrade to the Lynx. Mauricio.

How about the piston to cylinder fit i.e. compression?

With that ring /new bushing makes her a looker

Thanks guys. I'm glad, the gold ring is distinguished in the black case!
The crankshaft rotates smoothly without brake, this shape is much better than the original hub made from the same aluminum alloy crankcase.
From this, it is not a bad idea to modify engines (crankcase exactly) by placing a bronze bushing, if it is done well, if the adjustment is really perfect, you will notice a better rev performance.
Kari, you're right, that hub shape is also very good as a thrust system, giving the engine a much smoother and more durable friction.
András, you mean the fit between the ball joint and the piston? Or what part exactly, friend? .... I initially reset the piston and the connecting rod ball joint at the beginning, as soon as I disassembled it from this engine to know it, since the play between the ball joint and the piston was excessive in my opinion , now the fit is fine.
If you refer to another point exactly, please tell me, thank you!

¡Buen trabajo! Nice work! By the way, MauricioB, cmulder on https://www.rcgroups.com/forums/showthread.php?2882770-The-1-2A-Channel-1-8A-1-2A-Videos/page21#post45782095 has been asking about you.

GallopingGhostler wrote:¡Buen trabajo! Nice work! By the way, MauricioB, cmulder on https://www.rcgroups.com/forums/showthread.php?2882770-The-1-2A-Channel-1-8A-1-2A-Videos/page21#post45782095 has been asking about you.

Ohh thank you very much! ... very kind.
I went to the link that you leave me here, if that YouTube channel is mine, where I share some of my videos there.
If you have contact with that person (cmulder), tell him that I have no problem in answering him.
In any case, if you do not participate here, you can write to me on the youtube channel, or better to my email address: cvalternativo@hotmail.com
Greetings and thanks again.

Mauricio I meant the compression in rhe cylinder. Is the cylinder-to-piston fit good enough for a good compression?

balogh wrote:Mauricio I meant the compression in rhe cylinder. Is the cylinder-to-piston fit good enough for a good compression?

ahh well, I answer your question Andras, well NO, the compression is not good, you can turn the propeller without much resistance, in turn, you can check the pressure leak between the cylinder and the piston by placing low density oil or you can also do it With soapy water, you will notice many air bubbles, this shows that the fit between the parts is not optimal.
I understand that these engines are assembled from stock parts that do not have a special twinning.
Unfortunately at that point the engine leaves much to be desired.
As always, my views may not coincide with others, but for me it is what it is.

But I know that a clearance is needed for oiling the piston and cylinder. Isn't it?

Thank you Mauricio..while at high rpm the gas blow-by is minimal, I like in old stock engines that they retain good compression with little or no blow-by for many hours of operation.

Levent in my opinion there is enough oil retained for lubrication between the cylinder and piston in the micro-grooves left on the cylinder wall by cylinder honing in the factory, even if the fit is not loose.

Levent Suberk wrote:But I know that a clearance is needed for oiling the piston and cylinder. Isn't it?

Yes buddy, tolerance involves lubrication between parts, but not to the extent that compression escapes between parts.
If you compare Cox engines to Cox engines, you will see that many engines (especially from yesteryear) have incredible leak-free compression.
I take this opportunity to tell you that I have seen your idea of ​​making a supplement with copper sheet, and I want to tell you about it, copper is very malleable, therefore it is pasty, perhaps with friction, it tends to deform superficially, making the crankshaft brake In any case, you can try to make a supplement with a sheet of Spain paper (I don't know what it is called in other parts of the world) ... do the experience and see what results:
https://articulo.mercadolibre.com.ar/MLA-819930068-papel-espana-005-bronce-rollo-15cm-x-80cm-bulguemes-_JM#searchVariation=44873714279&position=1&type=item&tracking_id=9b3cd18e-0887-423b- bf71-60a99b29677c

balogh wrote:Thank you Mauricio..while at high rpm the gas blow-by is minimal, I like in old stock engines that they retain good compression with little or no blow-by for many hours of operation.

Levent in my opinion  there is enough oil retained for lubrication between the cylinder and piston in the micro-grooves left on the cylinder wall by cylinder honing in the factory, even if the fit is not loose.

you are welcome friend!
At high rpm, this engine (my engine) will not have operating problems, as it will work well, but but, if I want to use an acceleration ring and lower the rpm to regulate it, this engine will have to do it above the minimum, otherwise at low rpm it will stop.

Yes, copper is not suitable for this purpose. Papel Espana is bronze sheet, at least I know. Bronze sheet or steel sheet can be used for this. Also a slit can be opened on a steel or bronze tubing lengthwise, then that springy tubing can be inserted in crankcase. But thickness of metal sheet is important, because too much lapping can cause the crankshaft off centered. Yet I don't have lathe, so I thought these.

The piston to cylinder-bore fit of the Cox engines of yesteryear was a good part due to being measured by means of an air-gap instrument that was designed/calibrated specifically for the purpose. It was someone's job at the Cox factory, to assure the fit to be within a specified margin.



It's that kind of attention to detail that made Cox stand-out.

Hey Mauricio, The latest bushing "turned-out" really nice!

Roddie, thank you very much for this valuable input. They have undoubtedly worked hard to ensure quality.
That photo just taken there, talks about an entrepreneur who achieved his goal, to make his product surpass all time.
I feel a lot of admiration for these people, who want to do their best! ... that detail is what definitely makes the difference!

Levent Suberk wrote:Yes, copper is not suitable for this purpose. Papel Espana is bronze sheet, at least I know. Bronze sheet or steel sheet can be used for this. Also a slit can be opened on a steel or bronze tubing lengthwise, then that springy tubing can be inserted in crankcase. But thickness of metal sheet is important, because too much lapping can cause the crankshaft off centered. Yet I don't have lathe, so I thought these.

looking for alternative solutions is great.
Look, I didn't have a lathe, I made many pieces by hand, destroyed some of my fingers until they bled, and I continued doing the work out of pure passion. I achieved many things, many for what I am and one day, a friend from a distance, sees my work and tells me: Mauricio, what do you do your work with ??? .... I answered the methods that I used, right here I placed photos, files, saws, and some elementary tools .... he replied: Friend, you need a lathe! .... At the time I received a message, and that friend had sent me a lathe for his personal use, he told me : you deserve it more than me! I have it as an ornament, and you will give it the true use it needs.
It was one of the best gifts I received in my life .... a gesture from my friend Mario, who has no way of thanking him .... he sees my work and says ...: see! you had to have it that makes me happy!

This is a job that I did entirely by hand .... making a throttle ring and preparing the cylinder surface of a Pee Wee .020 ... I broke my fingers ... yes, a few days without being able to move them due to the cuts received , but I did it ... here is a video:
Cox Pee Wee .020 r / c ... if you see one that works the same, tell me and I'll run a race, hahaha!

many attempts there ... hoops for cox .020, bronze, iron and aluminum alloy ... all handmade, each one took an average of 4 hours of elaboration, then you spent a pinch of a tenth of a millimeter and everything should start!

So today Monday ... the day of the premiere has arrived ...
The "Simple Cox Babe Bee .049 single transfer" and the Cox Fun Model will start.
I hope to achieve the purpose .... meanwhile cross your fingers friend! ... I will keep you informed upon my return! ... have a good day everyone !!

well folks, the Cox Fun has been a success.
A very windy day, but nothing to prevent flying and having fun.
The single-transfer Cox engine is more than enough to enjoy all kinds of maneuvers.
The Cox Fun makes you fly the way you want ... it just depends on your imagination!

Congratultions Mauricio for another successfully completed project!

Ahhh, Mauricio! Beautiful. Thanks for the perfect video too.
It's a joy to see someone enjoy the hobby like you and
others do here.
Bob