50% Christen Eagle - RC Groups
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Aug 16, 2012, 10:38 AM
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50% Christen Eagle

Have just aquired the Exclusiv-Modellbou kit and am amazed and perplexed. Certainly amazed at its size, CAM engineering, and welded steel parts, but perplexed by its apparent lack of detailed building data. It may be more data is burried there in the boxes but right off I can see the German to Englsh manual narrative is poorly translated. So far, the included CD is just an e-version of the manual. In quick review, I got right away that "fins " are meant to be ribs but am having real trouble devining what an "absorbsion fin" is, in relation to the empanage! I'm pretty sure it gets worse.

Was also wondering about covering. What material would be best/reccomended? And should same be bonded to ribs or possibly rib sticthed as per actual full size practice?

I will be diving into the two boxes that were passed on to me (are there more?) . One is 6'x2'x16" tall and the other 3'x2'x2' tall. Substantial stack of ply parts appear to have been CNC routered.

Engine is slated to be Desert Aircraft DA-200 Twin (which is actually a 4 cyl!), so engine mounting ideas would be welcomed as well.

My model building experience has been extensive. Some 1/4 scale but mostly smaller and a good measure of full scale construction and repair. Ive even built larger models but nothing this big to fly R/c. So any insights, heads-up's, etc WILL BE VERY welcomed and appreciated.

I am sure there will be a lot of questions that come up as I attempt to "eat this elephant, one spoonfull at a time"!

If I can enhance my inept computer skills, there will be an online build with photos. Sadly, I may need help here, too.
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Aug 16, 2012, 04:34 PM
Bellanca Kruesair
epoxyearl's Avatar
I had poor computer skills also,but the guys here won't let you flounder too much....I became fairly good at it in a short time,and everyone is willing to help,it seems.

We're interested in the Eagle,and I too would like to know what an absorpscion fin is...lol.
Latest blog entry: Rut-roh !
Aug 16, 2012, 06:59 PM
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Got to open the box for real today. Had to stop and recall the proper hobby shop procedure. Pull out each item and place it upside down in front of the box. unstacking, flipping, stacking, til you reach the bottom. Got about 2/3 into the box when the rolled plans appeared. Lots of paper!But just had to look! From them I've determined I will need a building base 30" wide and at least 7' long. Kept the plans out and began to re-pack the box, unstacking from the new pile back into the box. There is a mountain of 1/4", 1/8" ply and some pretty good balsa. Several plastic bags of the latter in approx 5' lengths. Everything appears to be pre-cut to width for LE, TE, etc.

Will just try to assimilate the entire project concept til
Monday, when I dig in for earnest!

First up will be roll around work surface. Will build a wooden framed table top 30" wide and 8' long. Will attempt to make it as flat as possible. 1-1/2" x 5" wide KD pine will make up the front and back rails, machined striaght on one edge, then ripped to 5" final width. intercostals same but only 3/4" thk. This will be trued and covered with 3/4" A/B shop ply (work surface). A post in each corner will sit on industrial grade rubber castoring wheels, for ease of mobility within the shop and all around access. Shelves will be installed below for parts/materials storage. Door skin ply will make for light but all important torsion box, to keep the surface true. I'm shooting for1/64" +/- flatness tolerance, checked with tightly stretched monofiliment thread diagnals touching at center of work surface. Once the torsion box ends and back have been set, it won't move.

Right now, I'm thinking I'll need som sort of jigging to locate spar structures from underneath so as to accomodate the symetrical aifoiled ribs (fins!) over the plans. Have not seen any contruction drawings except outlines but I have to dig further. There's still much to glean from the plans and the last third of that box!
Last edited by packardpursuit; Aug 16, 2012 at 07:04 PM. Reason: to fix the woids
Aug 17, 2012, 07:35 PM
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Big Nuts 181's Avatar
photos man photos!!! you'll find everything you need to know about instillation ideas mounting etc on the flying giants
Aug 20, 2012, 10:36 AM
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Just a quick note this AM to say I've read and re-read the manual several times. Still MANY questions. The narrative is difficult for two reasons: First, as said before terrible English translation!!! Second there are many photos that do not appear to match the narrative! They seem to be talking about one thing or things and show another! Bad captioning? Hard to tell, especially because of the translation.

Speaking of the translation, I now suspect that the "absorbsion fins" are the ply core frames , upon which the balsa strip ribs are applied and form the basis for wrapping the laminated outlines. These are routered so very little ply remains.

In the pictures, I've noted the "absorbsion fin" nailed over the plan, yet when outlines have been added, said outlines do not follow the outline of the plan. ???? so much for CAD/CAM accuracy....or is this just crappy mock up for the manual photos? Or are we seeing paper distortion of the CAD image print ?
I suppose I will find out.

Another gem gleaned from the mess is that jigging strips supposedly included seem to be called "slips". Will be looking up "aglutinated" next! I think I know what it means, but is one of few that have been used that could actually be looked up.

Got some "real work" to do today, but will start the building fixture this afternoon.
Will try to take photos, too.

Aug 21, 2012, 12:39 PM
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Give desert aircraft a call, they carried these kits and may have some info for you.
Aug 25, 2012, 06:43 PM
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I have a friend who built the the same model.....the instructions & plans are not correct for the cabanes as i recall? He had to do some work to get that area correct....also had an effect on the wing incidences....the plans have not been updated to catch some of the errors so this is just a heads up as you go forward.
Aug 27, 2012, 10:06 AM
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Thanks for the info. I saw that the the incidences called out on the plan do not appear to measure correctly as drawn. Will check check closer, now that I have a building surface(after a very long weekend an some $150, I have a work surface trued to within 1/64" in all directions!!) and can get a t-square on the plan.

Are the called out incidences correct? If all else fails, I have ready reference to full scale EAGLE incidence data.

So far, there does not appear to be a top view plan of the fuselage. I will attempt to assemble the fuselage as per photos in the build masnual but center each of the pre-cut formers/upper longerons on a CL drawn direcltly on the buildning surface.

Got to pay some bill this AM. but will start the Stab today. I've taken a few photos of the work surface construction. If I can get a breather, I'll attempt to post them.
Sep 04, 2012, 08:05 AM
Team JR

Go to www.TRCPB.com

Chris is a good friend of mine and a helluva builder....Chris and Barry have built a couple of the 50% Eagle kits from Modelbeau....

Feel free to give him a shout anytime...tell him Casey sent ya
Sep 05, 2012, 10:28 AM
Registered User
Wow!! Where does the time go? Been working for the 'man, selling myself for the sheckles etc. I'm supposed to be semi-retired, but it seems the semi is winning out more lately. It will be better when the rains start and I can't get outside work..
Sep 30, 2012, 10:12 AM
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Have made some progress. The tail feathers are near ready for routing LE/TE's to 1/2round section. I will then attempt to machine hinge slots . My plan is to remove hinge pins and run music wire thru all as epoxy sets for alignment. Then drill for dowel pin (1/8" Birch) sanded flush.

Fuselage is framed. What an exersize in frustration. The instructions are woefully inadiquate in many areas, and the builder is given no clear answers to MANY questions. Thicker ply formers having been enlarged in the cabane area do not fit the milled slots, nor match the plans. Several items mentioned in the building guide/phtos do not match the plan! Where the tail structure is built aound a flimsy ply box, there is no guidence as to how to affix angled gluing surfaces of the longerons to the ply edges. Do I sand one or the other for better match?? or do they sit square, compromizing the established flow of fuselage lines??.. I would have prefered the first choice but as I chose to follow the steps outlined(???) in the instructions, it was too late, installed longerons sort of arriving at that state and in the way. I originally let the spruce tail post run wild, but cut if flush with box sides, as per the build photos. Had I gone with my original idea, the longerons would have a natural terminal with much needed side load strength built in. Having been schooled. I did a better job with the balsa bottom stringers, but again there is scant info as to how it should be done or where exactly they should terminat. How do they say "Kentucky windage" in German?

The light ply side stringers are a bad joke. Several were broken in their carriers, several more broke as they were test fitted. Again, I got into some difficulty by following the directions.. Diagonal and X=bracing is added AFTER side and bottom stringers. I should haver followed my first inclination to add them BEFORE anything was in the way. I suspect the reason for adding them later is to assure a better alinged structure, for the frames are quite springy (easily distorted) without the stringers. I intend to add a 1/8 sq balsa cap to the side stringers for a better/scale covering effect and to strengthen/straighten them between formers!

Speaking of scale, stringer placement is where the model clearly deviates from full size. Again the plan shows one thing and the instuctions show/ indicate something different, although the guide in this case is more scale like than the plan.

I've drilled and mounted the FG tail wheel spring. This is my first experence with composite landing gear. I'm getting ready to mount the mains. This too is FG and am wondering if I can radius the hard edges slightly (scale) without compromising the gear itself?

I swear, I am taking photos at each stage. The roll around building surface is working out great. Will tackle the wings next...

OBTW, I cannot complain about overall balsa quality in this kit. Makes this old Free Flighter cringe to see this kind of wood going into an RC model!
Oct 01, 2012, 01:26 PM
team sleprock
whiskykid's Avatar
so did you send the film out ta be developed? they still have 1hr photo shops lol.
Oct 02, 2012, 09:57 AM
Registered User
The problem is me. I'm not quite sure how to get the photos from my digital into the confuser and then to here. I'll admit I'm a bit befudled by technology and more a hands on kind of guy. Written instructions, even before the tech revolution drove/ drive me nutz!

Speaking of nuts, I took the two bags of hardware from the kit(one large one smaller) and separated each piece by kind and assumtive use into different bins of plastic trays. NOTHING was labeled and although some hardware is specifically mentioned in the guilde booklet,everything else is an unknown, at this point. And there was ax#!!-it pile of loose hardware! Which is now a semi-organized x#!!-it pile.

I have decided to finish the tail surface laminated outlnes before proceeding with the wings. So today will set up a router table /shaper to radius same to constant halfround shape. I will be sing a 1/2"R tool which is slighlu larger than the finished 11.5mm R required for finish. Just want to get them close for final sanding with a custom radiused sanding block. I used similar for the stringers and longerons and it worked great.

Work on the model will be somewhat limited later this week as we are preparing to travel this weekend.
I'm looking for some local help to post photos. Were still rather new to this area.
Last edited by packardpursuit; Oct 02, 2012 at 10:14 AM.
Oct 02, 2012, 10:31 AM
Registered User
Here's a link to photos of an earlier an earlier static project.


Built for a museum in Texas, it now resides in storage, awaiting a better economy and final finish.

Span is 22"3" length is 19' or so ,weighs about 300 lbs Moslty cut out of foam with a hotwire (over a wooden interior structure) although some hand shaping was required at nose and surface tips, etc. Glass cloth anf epoxy overall.

Used NAA parts drawings and or original P-51B fuselage loft for most shape templates. All dimensions were reduced by a factor of .60. It is 60% of full size
Oct 02, 2012, 12:22 PM
team sleprock
whiskykid's Avatar
I hear ya on the tech stuff, I am no geek, are a know it all teenager!

being a hands on kinda guy myself, I learned how by trial and error!

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