Project Cox .049 r/c & Citabrian Champion

Hola Mauricio!!!….. Your finely tuned .049 will be a great match for the Citabria….The plan appears to be an enlarged version that was originally free flight and you will add your own structure method?….Looking forward to another of your finely crafted builds…

Roberto

Hot Darn I am IN  Love your builds my friend !

Thanks guys for joining me!
well, I was thinking about ribs or Styrofoam for the wing, yes, no...finally I'm going to build a foam wing, the ribs are ruled out, the reason is that I will have a very firm and even wing, in turn for previous experiences, I can make it very light, so I go that way.
In the first photo you can see the profile of what could have been the type of ribs, but in the photo that I leave here, you can see the pair of profile sheets that I will use to cut the foam.
I'm excited about this project friends!

Looks like a good plan Mauricio!…. I have tried to make foam wings in the past with a hot wire cutter but with less than best results…. I look forward to seeing your procedure

Dear Roberto, I will do a step by step of foam cutting then...you will see.
In the meantime, I just received a Cox .09 and a Cox .010 from a friend, I'll take a break with the Citabria and tell the story of the engines here:
https://www.coxengineforum.com/t18134-my-friend-ramon-his-cox-09-cox-010#232461

What a beautiful picture Mauricio, poetry in motion. Saved it, I imagine roddie did too.

So, modify the Wen-Mac .049 motor and it is ready to use.
The Wen-Mac .049 and the Cox .049 will share this aircraft model, it is also possible that some more engines will be used on this aircraft.
The idea is to do it without a fairing, so that you can fit engines without major modifications.
I began to cut the wings out of foam, since the profile is biconvex, which means doing some acrobatics too!....

Really nice work on the engines Mauricio…. Well thought out and tested… Great choice for the airplane as well…. Will be scale like and true to the original…. Looking forward to your build of La Citabria

Well, then I already have the Styrofoam core of each semi-wing, by the way the cut with the hot nicron thread turned out very well, I didn't have to throw anything away and start again...so happy!
Thinking about how to veneer those telgo cores, I want the glue not to be on the entire surface and not on the stringers, nor on the wood above and below completely, I only want what is necessary but strong enough to also do some acrobatics. ..then I made these wood coatings, and then veneered the cores...everything goes very well and very light...









All these magazines, which I once read and always look at again..., now act as a weight to compress the sandwuich of styrofoam cores and wood veneers....I hope the result is as expected....now about 24 hours of setting and then I remove the magazines to see what I find....

I love Citabrias.  This is the one I owned and sold just before I got married.  I really wish I hadn't ever sold it.





The Regretful mark

Very nice work on the wing Mauricio!!… The balsa veneer with open bays will provide a very realistic surface…Very stiff and durable because of the lamination as well!!

batjac wrote:I love Citabrias.  This is the one I owned and sold just before I got married.  I really wish I hadn't ever sold it.





The Regretful mark

yes it is a beautiful plane!....
By the way, I was looking for a frontal view, since the plan I am using is that of a rubber-engine model airplane and the fuselage is flat!, so I needed to have an idea of the width of the fuselage in proportion to the wingspan, so I I found this beautiful video, which I share...!

You can see that in the background of the image the magazines are still stacked on the sandwich that will form the wing of the model, so, by the time that has passed, the glue must already be dry, but since other pieces have to be manufactured in the meantime, I prefer leave all that for a while longer....
I cut the fuselage since the original plan is for a flat rubber engine, that is, a board, so I made frames with more or less approximations. The profile, as I mentioned, is also different from the plane, since I want something more acrobatic....so, if you start to see the silhouette of the Citabria, then I'm on the right path!

Beautiful and accurate work as always Mauricio !!….Much attention to detail will produce a fine scale flying machine…. Thanks for sharing your progress!!

Roberto

Making the inserts for the frames and placing the balsa reinforcement in the fairing, by the way, if I manage to coordinate all the engines, then the fairing stays fixed, otherwise, I remove it.





Well!, the semi-wings took the veneer perfectly....then there is leftover material and I put the knife in....it doesn't mean weight or great weight, but in truth all that Styrofoam is not necessary...




I manufacture threaded inserts with stops, they are embedded in the wood and glued with epoxy, this will allow me to place various types of engines...





The towers are initially made with pop rivets, but it is possible to make grilon towers.
This is the idea, some of the engines are presented like this.

Your taking me down a learning road ,very nice build you make it look so easy / giving you have built a lot of planes and do a fantastic job ! Thanks for sharing . love the stand offs for the engines .

getback wrote:Your taking me down a learning road ,very nice build you make it look so easy / giving you have built a lot of planes and do a fantastic job ! Thanks for sharing . love the stand offs for the engines .

Yes... Mauricio.. you have two new students!! Very interesting wing construction. I've never tried hot-wire foam cutting but have always wanted to.

I built these fuselage fixtures many years ago from plans found in my RCM library.. but I have yet to use them.











I wonder if you have fixtures/jigs such as these to build your models?

Roddie, I don't really have that platform like the one you show, sometimes I use the multipurpose work table itself, which has some plastic locks that fit into the holes in the wood, so you can hold some things there. For this case, where the fuselage is so small, I really do everything without the bench, that is, by hand and carefully maintaining the alignment.

Well, the inserts are very close together, so the epoxy itself may not be able to hold them securely and some of them may rotate when you install the motor, to avoid this, then take a piece of sheet metal. They are used for electronics and I soldered all the inserts, that way they are completely fixed and none of them will rotate.
At the same time, I made a central hole in the plate, which allows with a central screw to safely hold all the inserts at the same time and if for any reason any of them have to be changed, by removing the central screw, the plate is removed and one accesses all inserts at once.
I used a little paint to beautify the accessory, although it will not be seen from the outside, I simply want it to look better, even if it cannot be seen.
I couldn't wait to present an engine there and everything definitely seemed to be going very well. Place the Cox EZ Bee with a single tower, just to make it faster and enjoy the presentation....I'm happy with the result.

Mauricio, tu obra dura en el montaje trasero universal para motores diferentes ¡es muy magnifico! ¡Muy profesional!
Mauricio, your hard work on the universal mount for different engines is very magnificent! Very professional!

That looks Great very good on the mounting system , this will bee interesting to witch engine performs better for the stunts . Plane going to bee nice !

Finally, make the holding towers in grilon.
These towers are very safe since they have a good support surface and holding the engine becomes very safe.
Thanks to the arrangement of the inserts and this system, I can then place a few motors to enjoy them.
You can see in the photo that even by modifying the height of the towers, I can also place a Tee Dee .051 and also a G-Marck .061, in addition to of course the Wen-Mac .049 and any Cox engine with a Surestar type rear plate.

I really like the engine mount system Mauricio !!…. Very much like a full size airplane ….. Plus the added entertainment of trying different engines….Beautiful and exemplary work….

Roberto