J&H Firefeather build

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Charles_McG

Ciderwright
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I’ve long had an interest in boosted gliders and want to move past things like the Tercel and Hummingbird.

I think I’m a fair modeler, but I’m not really an airplane geek. I picked up an Aerotech Phoenix- but it intimidates me. I tried upscaling a Tercel and discovered that I knew less than I thought.

So I chose the J & H Firefeather as a new starting place. With built up wings and fuselage, it looked like an opportunity to learn techniques new to me - without being so expensive it scared me to build or fly.

I’m going forgo the traditional unboxing pictures. I took them, but with enough detail to scan and make cutting files. I don’t think it would be fair to J&H to post them.

One note about the kit: it has as many instructions as a Wildman kit. There are follow-along YouTube videos, but it’s not the same. I’m making my own supplemental notes as I go.

First up, framing up the wings. This is just piecing together the leading spar, the tip piece, the flaperon, and a root edge piece. I started with the tip, making the interior curve smooth.

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That actually leaves a little gap at one end or the other of the root. There’s enough flex in the leading edge spar to close it up and easily.

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I assembled on parchment paper with super gold CA. The table has a protective cover, so has a little give. I held pieces with gentle pressure to keep things even and flat. I redid one root piece.

I built the root edge against a ruler as a straight edge, but the wings aren’t really square anywhere.

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The ribs tuck into slots. I put them in place on a hard cutting board so I could get the bottom (flat) edges even with the frame. I dropped in a drop of thin CA to set them.


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That’s it for the first night. Time for a whiskey.
 
Next up. Shaping the wings.

I got a little $5 mini plane which I’ve never used before. I set it to take a pretty shallow curl that doesn’t take force. I find that doing on a hard smooth surface helps - I rest one edge on the surface and it helps me control the cut. 8A31F02D-C4F9-4529-8579-B109F6C80485.jpeg128200D1-08B2-4270-8A2F-94A33D199E06.jpegF29F4180-9B37-44D0-A6FC-A4D3F00BF865.jpeg

I tapered the tip end, then cut the angles from leading and trailing edge to the tops of the ribs. Josh says to not fret about a specific airfoil.

I used one of the 1/16” pieces of balsa as a reference to cut to.

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The bottom side gets a little cut.

Then smooth with sand paper- still using the ribs as a reference. I didn’t cut to a sharp leading edge - but I ended up with one anyway after sanding. [Lack of] experience, I suppose. If I have to knock the point off to put on the film, then so be it. The tip is supposed to be quite thin.



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That’s it for tonight. Time for Irish coffee- with heavy whipping cream.
 
Then we add stuff to the wing.

Discus throwing reinforcement. Top and bottom of the levo wing, since I’m dexter.
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Then a hold down screw anchor. This one gave me a little trouble - I had to go through Joshua’s video frame by frame to confirm that the little oval in the 1/32” plywood is the right piece. I filed a grove in it before bending to shape so I wouldn’t crack it like he does in the video.

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Ow it’s time to cut out the flaperons. The laser lines make it easy. Then a little sanding cleanup- I pretty much took the burn marks out. As suggested, I used a combination of mini-plane and sanding block to set a 20° throw angle.

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I propped up the flaperon and set the phone on it to check the angle. I think I got pretty close.

I came close to botching the next step, which is fiberglass the wing join. I think I mis-interpreted Joshua’s instructions. I laid out the fiberglass on parchment paper and sprayed it with Super 77. In retrospect, I think I was supposed to spray the paper with the adhesive, and then lay the fiberglass on it (to make it easier to cut) while the Super 77 was tacky. The way I did it pretty much soaked it.
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On the other hand, it made cutting a strip and laying it in place really easy. The parchment paper just peels off, and the super 77 still has a little tack to keep the piece in place on the balsa.
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I added a small second piece to cover the trailing edge. Joshua says not to bother, but with the wood grain the direction it is, it’s pretty floppy.

The biggest reason I think I goofed is that the Super Gold CA behaved really funny over fiberglass w/77. It didn’t dry very hard - it still seemed flexible. Joshua’s video shows him sanding almost immediately, and this would have been gummy. So I covered with super thin CA. Fumey - but it dries fast and much harder. It sanded smooth just fine in the morning. F83166E1-749B-4F4C-96B5-1E8D6DBD9C37.jpeg
 
One more wing doodad, then I have to take a break to get film coating tools and a better color than I got in the kit.

The wing had a leading edge holding hook that’s made by stacking two 1/32” ply parts and then cutting through the fiberglass to re-establish it’s notch. I again went through the video frame by frame to confirm the proper orientation - notch down.

Then I went looking in the videos for later assembly steps to try and get a better idea of the final fit. (In part 5, BTW). It wasn’t very clear in the Part 2 video, but my best assessment is that the hook fits bottom edge flush with the bottom of the wing.

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I expect you folks to tell me if I’ve blown my fiberglass and I need to get a new piece.

I’d have a gin martini - but I’m fasting for bloodwork tomorrow, so it’s just bedtime for me.
 
I was wondering if someone would ever build one of these, the only thing I found was a review on his own site which was a bit of a bummer. I haven't seen any flight video on a D2.3 or what the boost weight is, looking forward to seeing what you wind up with.

Mark C Nye (verified owner) – April 27, 2022

Tonight, for the first time since I have been building R/C, I terminated a partially completed build. The Firefeather would have been my 4th build from J&H. On the three previous builds, I found the build videos to be adequate but not great. On this build I completed the wing and tail sections with little problems but decided to pack it in during construction of the fuselage. The video for the fuselage is entirely inadequate. The camera is pointed at the worktable, but the model is very frequently lifted out of the camera view so much of the video is spent watching an empty table and trying to figure out what is going on off screen based upon Josh’s mumblings. I am an experienced builder, so I know I could have completed the model, but I was not enjoying trying to muddle through the build without adequate guidance. It is a shame, because this looks like a fun plane.
 
I saw that, too, Frank. It’s not so much a criticism of the design, but of the video. Which is one of the reasons I’m taking my own notes as I go.

Memo to me: catch up on my notes.
 
Time to learn a new skill. I’ve never used Monokote before. nor Ultrakote, which is what the Hobbytown had. I decided I wanted a different color scheme than plain white (the film color I got with the kit). I also picked up a Hanger 9 iron, and a sock - which I promptly lost. I watched Joshua’s video a couple of times, and also some others on YouTube get learn some and formulate my technique.

I practiced on the flaperons - nice, flat, and smooth. I worked from the middle to the ends at about 220F, then came back over at 300F, with smooth, long motions. I diagonal cut the corners, then rolled the edges over at the higher temp and then ran the edges flat. I did the bottom first, and rolled the top color over it on the edges. I did trim the excess each time, using a brand new xacto. I found that the slightest ding to the blade was a pain.

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Then I did the bottom of the wing, one half at a time. I did the same technique of setting the edges at lower temperature, then going over again at higher temp. I did the root edge, the worked down the spar. Then I worked leading edge to trailing edge and set the trailing edge.
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Then again at 300F - running along the ribs this time, and rolling the edges over and setting the flat edges.

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Then I got out the heat gun. A Harbor Freight model with a series of LEDs for temp. The bottom setting says 430F - and it worked a charm at about 4” distance to really smooth out the areas between the ribs. I worked the edges, and all the surfaces and watched the wrinkles smooth out. I went back over the trailing edge in a few spots where it visibly lifted adjacent to the inter-rib.

Then trim as before.

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I repeated the process for the other bottom half, and the two top halves. I overlapped about 1/8” in the middle.

The top, being less flat, gave me some trouble just before the tip - either leading edge, or trailing edge. It seemed like I alway wound up with a little excess material that wanted to bunch up, then form a crease. I could work it down to 1, and move it to either edge - but I couldn’t get rid of it. The higher heat and heat gun smoothed it out -almost- entirely.

I want to put a stripe on, but not tonight. And it turns out I need to work on the flaperon clearance. Doing two film layers on all those edge surfaces used up my gap margin, and they catch a little. I sure I can fix it.

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So that’s my first film covering experience. I don’t think I was -too- terrible at it.

That’s a wrap for tonight.
 
The wings finish up by remounting the flaperons with packing tape and gluing in the control horns. I found that a 1/32” gap between flaperon and wing gave full range of motion.

I did have to go back though and carefully remove the orange/top cover that I had wrapped around the edges at the end of the flaperons to get back clearance space. Tedious - but it did work.

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Before I start in on the tail assembly, I’m asking Joshua how the Firefeather in the website photo was colored.
 
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The wings finish up by remounting the flaperons with packing tape and gluing in the control horns. I found that a 1/32” gap between flaperon and wing gave full range of motion.

I did have to go back though and carefully remove the orange/top cover that I had wrapped around the edges at the end of the flaperons to get back clearance space. Tedious - but it did work.

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Before I start in on the tail assembly, I’m asking Joshua how the Firefeather in the website photo was colored.
I'd prefer a live hinge made from the covering material as opposed to packing tape, packing tape can tear easily if there is a little nick, the covering material is much more robust.
 
I'd prefer a live hinge made from the covering material as opposed to packing tape, packing tape can tear easily if there is a little nick, the covering material is much more robust.
Joshua actually uses spare covering for the elevator hinge.

How do you feel about blenderm - I have some of that, too.
 
Joshua actually uses spare covering for the elevator hinge.

How do you feel about blenderm - I have some of that, too.
I only use blenderm hinges in my kits, I like it but it is more visible over covering like this and using covering hinge looks better in this application but blenderm will work well and will absolutely not tear.
 
Time for tail work. By and large, I think the tail video is pretty clear. Mostly - there are two things I’m going to grouse about.

Cut out the horizontal stabilizer. Round the leading edge. Taper the elevator to 1/32”. I used the mini plane some more.

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Cut the elevator free. Plane/sand angle into the facing edge of the horizontal stabilizer.
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And here’s where I made my first, but minor mistake, and I couldn’t tell until the end. You cut the elevator travel angle -in- to the top surface, and which side of the sheet you do that determines which side of the vertical stabilizer the tail boom goes on. I got it backwards from Joshua’s video. But I think it’s really minor. He mentions the orientation, and result, but I didn’t understand it until the end. I didn’t even realize I was inverted from my intent.

Moving on, ultrakote hinge. I find I need a 1/32” gap to get the travel right - I use the plywood piece as a spacer. I can also tell that my sanding block isn’t yielding a straight edge - there’s a tiny curve. It would be easier with a lighter color.

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Then bend and cut the piano wire into a torsion spring. I made the legs different lengths and put the short side into the elevator. It took a little care not to poke through.

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And add the control horn. The design is slightly different as cut than in the video. It’s shorter and wider - the the change wasn’t carried through to the slot in the elevator, so that needed a little hand trimming.

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On to the vertical stabilizer- I. Three pieces. Cut out, round leading edge, taper aft edge. One of these was brittle and was my first part that broke while handling it. Along the grain. That’s what CA is for, right?

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Glue the interior tab into the top. Put on the horizontal stabilizer, and square up.
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Glue on the bottom half and the boom spacer. By eyeball - the bottom doesn’t key into anything to make sure the alignment is right. That’s related to my grouse.

Oops. Out of photo space.
TBC…
 
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Back to the tail assembly before the boom. I did run light fillets in the corners.

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The boom rests against a spacer and is aligned by eye to marks lasered in. I did scuff the boom as described in the video.

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And that’s the tail build.

Now for my grouse: the tail need positive keying in two places, the bottom half of the vertical stabilizer could have had a notch/tab relationship with the horizontal stabilizer just like the top - just moved a bit aft. I’m pretty sure mine has a small angle. Not from vertical (likely- but it won’t affect flight), but from the centerline of the glider.

The second is the tail boom. It could easily have had the spacer run the whole distance back along the top vertical stabilizer. Or a small aft piece keyed into its own slot. As is, mine is glued down nice and tight with a small angle. I’m pretty sure that’s going to give me a small yaw tendency with no way to trim it out in a flaperon/elevator controlled craft.

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That's a nights work. The upstairs liquor cabinet is a little bare. I'll have to go check the archive library in the basement.
 
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Fuselage prep. I built the small, laminated pieces first.

So starting with the wing nut anchor, I pressed the blind nut in place and traced around it with an xacto tip. Then I cut out the depth of the nut flare.


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Then I glued it in flush. It pokes out the back a little, so you can’t do this with the part flat on a hard surface.
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Then cover with the plywood part.
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The nose former and the main former are just simple stacks / laminations, aligned on the central opening.
The nose former gets slight beveled on the long sides. I beveled the lower part using the upper edge as a guide.
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I test fit the wing pin for good measure.

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Then I added to motor mount stiffeners to the fuselage sides.
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And then joined the top forward decking.
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And that uses my 10 photos per post.
 
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Now we start building up the fuselage - and I make my next mistake.

So we start with the side and the main former.
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Then we put in the nose former. I did one side at a time. And I went through Joshua's video frame by frame to make sure I got the orientation right. The thicker end goes down (curved side) and the front is flush end of the side. The front, not the bevel.
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Now for my mistake. The decking goes in basically from left to right as it's laid out in the balsa sheet. I started with the correct (joined) piece - but I was so caught up in getting the front former correct, that I missed the Joshua flips the model over at this point and the first decking is the front -top-. I put it on the bottom. It took a little squeezing and bending, but it went in - over the nose, and inside the sides. Using the hard surave to curl the nose and get the decking nice and flush. Then a little filleting in the corners. I should have put on gloves before this - I'm still picking glue off my skin.
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There wasn't quite enough give (side to side) when I went to do the top - I broke off the tip. If I'd gotten it right from the start, it -might- have fit a little better? The rest went in fine, but it takes fingers inside to make nice and flush. Should've got the gloves...

That gap is the first obvious sign of trouble.

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Here's where I figure out my mistake the next piece doesn't fit.
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BUT... the fuselage it pretty symmetrical top-bottom - so I can recover and keep going by splitting this piece in two, and trimming a 1/16" of an edge or rear here and there. Lucky me.

Next up is the rocket motor mount former and the tail former. Joshua warns about the motor former being fragile - I broke mine the same way he did in the video. Then I broke it a bit more test fitting the tail boom. (I had gotten a little CA in the boom hole during the fix.) For the tail former, the thicker side goes -down-. More frame by frame to check. Joshua holds the parts up to show - but not for long.

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Then the top decking around the motor mount.
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And the tail bottom decking.
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At this point, Josha mounts the tail boom, aligns it visually against the wings (mounted temporarily), and glues is in place.
I discovered That I had not sanded the same airfoil he had.
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He covers this - you sand the fuselage sides to match.

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So, because I couldn't freehand the tail alignment with my bifocals on, I fastened the plane down on my hard surface, then looked at it from the back. Then glue dripped in and set.
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Then the wing fasten down anchor.
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