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Old Jan 10, 2015, 02:55 PM
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Build Log
Dynaflite Butterfly

So I go the kit for Christmas and after reading many build guides my neighbor and I dug into the kit. Prior to this I did as much reading as I could and looked at the directions a couple of dozen times. Thought I was prepared. But, nothing beats experience. My friend Otto is a great builder, mostly scratch building and he caught things that I just would have flat out missed. We started on the wing, right inner panel as he likes to do wings first. Got the ribs labeled and punched out, bottom spar down and then put the ribs in. After the six starter ribs were in he questions the outer rib on the inner panel. I had it vertical per the instructions but it was obvious that it needed some some angulation to deal with the angle of the outer dihedral. Using tight bond allowed us to solve the problem before it got out of hand. The leading and trailing edges went in and I noted the ribs were longer than the plan demonstrated. We left them as the were all long exactly the same. We placed the wing joiner tube in place to establish a line for the spar webbing and he instantly noticed that the tube was not parallel with the bottom spar. Some minor adjustments and problem solved. Just building myself I wouldn't have known enough to solve that before I went to join the wing halves together.

We got the whole right inner panel completed and now I am going to do the left inner panel myself. Now I know what to look for for issues and am truly thankful to have a skilled builder looking over my shoulder. I've done a laser kit before and it was much better fit and finish but this is fun as we move along. Will try to post photo's soon and keep on the build log. This will be a long build but hope to maiden this summer. Not only is it a good idea to get a mentor to learn to fly but also to learn to build. Scott
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Old Jan 10, 2015, 08:40 PM
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The outer-rib on the inboard panel is vertical. The inner-rib on the outboard panel is angled... per the dihedral angle guide... per the instructs.

Also, where the center wing section joins(center of plane).. both of those ribs are angled(again, using the dihedral gauge, per manual).. pg. 11-12, steps 9-11 in the manual.

Setting the outboard wing-section rib(w-4) is on pg. 14.

The manual is absolutely correct if you want it to turn out as a stock Butterfly... and you were correct in that the outer rib on inboard panel is vertical. The dihedral only comes from one rib on the outboard panels.

There are many reasons also that manuals are written in a certain order, the problem is we don't see those until its too late..

If you follow exactly, you will not have any problems. Its all there. It is a rough cut kit.. but it all goes together correctly... I would consider it much more of a craftsmans kit then the beginner kit they say it is...

I'm all for changing up the build order on some projects.. I say some.. and those would be the ones I've built before, and know inside and out.. If its a first build for me... I study the manual, sometimes for weeks before I start... and I go in the EXACT order they call for. I've been studying the manual for my 33%Extra 330 for a few months now... hah.. I've been building planes for near 40yrs.. and I wouldn't think of jumping out of order on that one.... and I built my Butterfly in exact order called out in their manual.. and you know what... they're right... it does work.. Just an FYI there.

Heres some shots I took of mine that I built last year... I've got a few hundred pics, but this might give some idea.. the angle of the ribs isn't very clear... but just follow my instructs in the first paragraph, as that is the correct configuration of the angles ribs that are so important to the polyhedral of this plane...

If you have any questions, or need more help, or more pics.. I've probably got some. I've actually got a few hundred or so... Check out my blog too.. theres some in there somewhere. Keep pluggin away... you guys will do fine... and there's always help here... Post back with your progress.

Good luck.
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Old Jan 10, 2015, 08:59 PM
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Quote:
Originally Posted by Bariboy View Post
We placed the wing joiner tube in place to establish a line for the spar webbing and he instantly noticed that the tube was not parallel with the bottom spar. Some minor adjustments and problem solved. Just building myself I wouldn't have known enough to solve that before I went to join the wing halves together.
Did I just read this right?.. I re-read your post... and can't believe I missed that part...

That joiner tube IS NOT supposed to be parallel to the bottom spar... or any spar... LOL... so I'm pretty sure he, or anybody would notice that... or at least I'd hope so.. thing is though.. did he know it wasn't supposed to be parallel?...

so what did you adjust?... the wing has a "polyhedral".. so the center sections have a dihedral too... They are not flat. Check it out... This pic shows a pretty good image of the polyhedral..

You might want to double/triple/quadruple check whats going on before your friend sees something else... .......

The manual has the answers.. that and the plans.. its all there bro.
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Old Jan 10, 2015, 10:13 PM
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Thanks DGrant, the spar tube is not parallel to the spar up and down but fore to aft it should be, unless I bend that steel bar to accommodate a cantered fore and aft wing tube. The wing tube, with the inner panel sitting flat has a down angle from inner to outer direction. It is correct, the fore/aft was wrong in that it would not have been straight across to the other tube.

As for the outer rib, I guess it depends on whether the plans are correct or the manual is correct. On my plans the the last rib on the inner panel is not vertical. Rather about 3,5-4 degrees angled inboard. If it is vertical the first outer panel rib will be angled to 7.5 degree's and per the plans that is not correct. I don't think it matters much as the dihedral at that joint will be approximately 7-8 degree's in total per the plans and the directions.

As I mentioned I have built a couple of other kits but this is the first kit that did not identify what the die cuts parts, aside from the ribs, were. So a bit of hunting to be sure we got some of the right parts. I think we will get it to where it needs to be to fly. Thanks again for the interest and comments. I really do appreciate them. Scott
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Old Jan 10, 2015, 10:16 PM
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I've also Read D that these build tail heavy so we are adding a 1.5 inch addition to the nose. Did you do this and if so how did you add it if I could ask. I'm going electric and hope to use Battery for any additional weight issues that might be needed. Scott

By the way thanks for the pic's! My wing tube looks just like yours
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Old Jan 10, 2015, 11:01 PM
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Ok.. I'm glad its working out... whew... I was comprehending it differently... obviously.. So.. the joiner tube didn't line up with the spar "length wise", so it was adjusted.. right?.. ha. Sorry bout that... These things are sometimes tough to describe and interpret ..

The joiner tube does extend past the inner spar, 1/16". Theres a 1/16" ply cap that goes on each inner wing-half... where the wings meet in center. The joiner tube is flush with that cap when the end-cap is installed..... I just extended the tube a few thousandths more and sanded it flush once the cap was in place. Once covered you don't see it.

So.. yeah.. I refreshed myself on a few things.. I looked back in my kit.. and I had 2 dihedral gauges.. one is 6 degrees, one is 7.5 degree. On the plans(I have them in digital format too if you'd like a set.. )... I see the inboard/outer rib is at 7.5 degrees , and the outboard inner rib is vertical to the outboard panel(90degs to the spar).... it is a bit of an illusion it seems... but the point is.. if its 6degs at center, and 7.5degs at outer panels its good to go.. and you're there no doubt. In any case I'm so glad you're doing well with it..

I read alot where these were tail heavy as well... but I didn't have that problem.. for some reason. I did end up putting 3/4oz lead in the nose behind the firewall... and I don't think it even needed that.. it was that close.. I just wanted the nose to tip a little more... and 3/4oz did it. I have the rx battery under the fuel tank.. I probably could put a bigger battery(it has a 1000mah nicad)... but one of my goals was to build the plane with only what I had on hand.. and a 1000ma battery running 3 little servos that barely move will work for a loooong time too... and I had it.

My original plan was to install my Magnum .30 four-stroke.. but a few days before I was going to install it, the throttle body broke.. when I was adjusting the throttle arm, the threads just turned right off with no effort.. they were pretty old and corroded it seems.. The engine was running great too.. as I'd been test running it.. and tweaking.. I tweaked the weak threads right off it.. ha. So I went with my trusty FP.25 two-stroke... Had I put the four-stroke in there, I probably wouldn't have even put the batt under the tank. The whole plane though was built as close to the plans as I could.. and.. if your wing-joiner tube looks like mine.. your good to go.. I think the thing will survive a nuclear attack. So.......
Enough of my plane.. Iets see some pics of your Butterfly....
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Old Jan 11, 2015, 07:18 AM
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Yeah D we are on the same page now, lol. I am going electric with this one and figure if I can get the nose lengthened I can balance where I want with battery size and placement. Will try to get a photo up today if possible. I do have a quick question, I am building the left inner wing panel on my own and I am wondering how do you guarantee that the wing tubes line up perfectly when attached together. Do I build the left wing to that point, measuring tube?and then join the halves? I don't think that will work as excess LE and TE are in the way. I don't want to end up with the tubes being 1/8 inch out of square to each other when I go to join them. Thanks. S
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Old Jan 11, 2015, 09:46 AM
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Very cool... yeah... On getting the wings aligned to each other... I just tried to nail the position of the joiner-tubes to spars... and tried to make sure that lines up. Also, if the sheer webbing in center wing is lined up, thats probably your best guarantee that the joiner tube will line up... as alignment starts at the spars, then the sheer-webs, and if those are lined up, the joiner tube will follow suit.

Don't worry about getting the leading/trailing edges perfect, as those get some work on them anyways.. and thats when those get trued up... Remember the leading edge gets shaped, and the trailing edge(at center of wing) gets notched out for fuselage fit.. thats how those get trued. Shaping the leading edge is one area I didn't follow the manual on, as I left my leading edges square until the wing was framed.. then I shaped/sanded/trued them all together... I have some pics of that somewhere too... For that, get yourself a small razor-plane(Windsor/Master-airscrew brand is an excellent tool, thats only about $5 I think).. the razor plane makes short order of shaping the edges...


I would focus on the spar/joiner area... One thing that you might want to check out is making sure the root rib(s).. w-1, is 90degs to the spar(as your viewing from top).. it sounds like you got that going though. Install the left joiner tube as close to mirrored to the right tube as you can..... again the rest of the structure will be mated/matched in the shaping/sanding stage. Check out the manual again, and refresh your mind... some of it won't make sense at first, and a little bit of it might never make sense, but its pretty close in how to get it lined up.

There will be some slight adjusting (read sanding) to the root/center area once you get that far with both panels. I had a tab bit of a gap, but I just flat sanded the root area on certain spots once I could get them together, to lessen the gap...

One thing I do know on this plane is sandpaper is its friend.. sanding blocks are its neighbors while its being built. Thats part of what makes this more of a craftsmans kit then a beginners kit(as somewhere they even refer to it as such).. but compared to todays "beginners kits"), the Butterfly is far from it... and its really not that difficult of a kit, it just takes a whole lot more sanding, thinking, planning, etc.. then any current "beginner kit". After building that plane, you will pretty much be ready for any balsa based airframe you want.... and you will surprise yourself at what you're learning... as you are learning alot... this kit is pretty much how they all were 35yrs ago.
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Old Jan 11, 2015, 11:30 AM
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Going to try an add a photo...


I was going to leave the leading edge until I had a whole wing as well to make it at least look aligned. Going to try to get some work done this evening.
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Old Jan 11, 2015, 04:21 PM
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There you go!! Very nice start. It will be alot longer before you know it. Plan for some space when it comes to aligning/fitting/etc.. Its a good thing its a 2-peice wing, its pretty tough to manuever in one peice...

One thing I'll mention, when it comes time to install the screws that go into the bottom center... the ones that you put a #10 rubber band on to keep the wing-halves together... pg.19, step 1 calls for #2x3/8" screws...

I wish I would have used 1/2" screws.. the 3/8" length is tough to get a rubber band on, as when the band is looped a few times it bulges over the screw.. so it takes some fidding to get the band to seat.. no biggie really.. but it could be a bit more user friendly with an extra 1/8" on the screws(posts as they're being used in this case...).. Also when those holes are drilled, make sure they center on that sheer web inside there.... that will plant them permanently...

I dare not change mine at this point, as its not worth it the way they're epoxied in there..... I don't have any problem with those posts other then length... and once that band is in place, that small band holds them decently enough to mount the wing on the fuselage... where I use eight #64 rubber-bands to secure it. I've heard of people using a spring in that bottom/center area instead of the #10's.. I thought about that too.. and still could easily... I just grab the small bands from the newspaper every day though and pick the best of them.. something is definatlely needed there, and I wouldn't fly without them, they are part of the system... but all the bands do really is keep the wing stable for mounting, and add strength to hold it all together... the most strength comes from the #64's..

Once its all on, the wing is very tight on the fuselage.. I also used the wing-seating tape it called for... The wing-to-fuselage set-up is very sturdy when done.

You're probably sitting enjoying gluing sticks together, as I did when I was at that stage of the game.. the wing seems to take the longest, as there are 4 sections really to build.. and several steps to them... doing it all 4-8 times.... its all about "doin the time" now.. Have fun... hope to see some more pics.
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Old Jan 12, 2015, 07:03 AM
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Thanks DG. Good advice on the screw, will plan on going longer. I actually didn't get much done as it was family photo evening with the family and I am a slow builder as so much going on in life. Got a small cutoff saw to take care of the inboard extra length of LE/TE/Spar. Going to do those this evening and finish up that inner right side and lay down the left inner side and start on it. My friend and I started with the wing as we find them the most complicated typically and most challenging and redundant. I often find myself getting fuse and tail feathers done then losing interest as the wing drags on and on. lol.
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Old Jan 16, 2015, 01:16 PM
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No photo this morning but got the left inner wing panel completed. Cleaning the work area and thinking of starting the outer panels now. Should be a pretty big wing when done.
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Old Jan 16, 2015, 03:33 PM
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Hey DG, need some advice. I started the right outer wing and trimmed the TE as shown. The leading edge also has a trim but it appears to be on the top surface. Can I leave this intact until the wing is completed and I go to form the whole leading edge? I think I will do a better job of aligning that trim with it all together. By the way the wing joining tubes came out almost perfect for each other and when I do the final fit will get them exactly where they need to be. Scott
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Old Jan 16, 2015, 06:00 PM
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Very cool Scott. Good job! I didn't shape any of the wing's leading edge until the wing panels were framed and sturdy. The wing is obviously flat-bottom, so I think that lends itself well using a flat/square/straight peice of stock for the leading edge(s) to gain the most advantage of the "flat" bottom.. and shaping/finishing the edges(inboard and outboard/top, bottom) when the wing is framed, then you have a whole picture of all edges.. I always try to "mirror" my halves of anything(in this case its wing halves).. by trying to build the second half as an identical mirror/opposite.. it applys here as best you can... and its all a great excercise ... I enjoy it... We modelers are all crazy in many way though. It keeps us out of trouble.. ha.
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Old Jan 16, 2015, 06:36 PM
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OK, going to leave it til the end. Thanks. S
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