Scratch Built "Turbo Bushmaster" Build

[Derek]

It has begun and I will try to take pictures and document the build in a better fashion that my usual manner, lol. Hopefully this build won't take me two years to finish...like my 3D plane.

This is a printed image of the plane that I've used for sizing and reference....as well as some doodling and notes

1 initial doodles.jpg (58.23 KiB) Viewed 6434 times

Here is my sketching of the fuselage side pattern...I hope the lines show up well enough

2 sketching.jpg (45.01 KiB) Viewed 6434 times

Here is the general fuselage shaping. That is a 36" measuring stick that I placed next to the plane for size reference.

3 general fuselage shape.jpg (72.41 KiB) Viewed 6434 times

Munchkin is always willing to lend a hand. She isn't sanding a scrap piece. This is one of the pieces for my plane, lol

4 daddys lil helper.jpg (103.56 KiB) Viewed 6434 times

I added some bamboo skewers, in an "X" config, to help give the tail some rigidity. They are glued in place and I used a zip tie on each one to hold them together in the middles

5 tail structuring.jpg (112.74 KiB) Viewed 6434 times

I used some 8-24 all thread and matching T-nuts to help pull the nose into shape. These will be permanent.

6 nose shaping.jpg (93.45 KiB) Viewed 6434 times

Here is a shot that shows the nose is pulled in and the tail, too.

7 nose to tail.jpg (87.71 KiB) Viewed 6434 times

.....more to come.

[Vipertech13]

Great work so far! What glue are you using on that foam?

[Derek]

Great work so far! What glue are you using on that foam?

Thanks! I'm using a combination of hot glue and gorilla glue. Prior to any gluing, I use a hobby knife to ruff up the foam at the glue point. I think that roughing up the foam, quite a bit, will help the finished "hold".

[DOG]

Great work so far! What glue are you using on that foam?

Thanks! I'm using a combination of hot glue and gorilla glue. Prior to any gluing, I use a hobby knife to ruff up the foam at the glue point. I think that roughing up the foam, quite a bit, will help the finished "hold".

Roughing up the foam is a good idea. Watch that gorilla glue, it likes to expand! The bird is looking good Derek.

[Derek]

The fact that the Gorilla Glue expands is one of it's greatest benefits because it will ooze it's way into the tight spaces and then it's really tough stuff. I've been using Gorilla Glue for the past few years and I love this stuff!!!

I appreciate the compliment, DOG! I fell in love with this plane from the first video that I saw. I just hope that I can build a good one.

[cml001]

Nice!

[Derek]

"Attention to detail"??? Hmmm, I must have missed that class, lol.

So, I was building the wings, the other night. Gerald mentioned, previously, that the plane "kit" probably has a 10" wing chord. I built my wings and they look great and then it hits me..........I realized that I build this wings with a 14" wing chord. The wings are 10" from the leading edge to the ailerons and flaps....then the ailerons and flaps are 4", lol. What a moron!!! Instead of remaking, I'm just gonna try these 14" wings out and we'll see what happens. I'll get some picks posted soon.

I did get to the hobby shop, last week, and I bought a steerable tail wheel. I'm not sure the wife was pleased that the tail wheel assembly cost me $30 but she let me have it, lol.

[Vipertech13]

Sounds like you'll need metal gear full size servos on those barn doors! LOL Can you say Turbo Bushmaster on crack!
AWW heck what am I saying I used them too that's what expo is for anyway!
looking forward to the pictures!

[Derek]

Yeah....you're right, Gerald....and I fully planned on using strong metal gear servos. I could always trim down the ailerons and flaps to 3.5" or 3". I just thought that the actual kit had 4" control surfaces....I could be wrong.

But...while I'm waiting for some Gorilla Glue to expand and do it's thing...here are some pics of some progress. Nothing real spectacular.....just a few pics.

The following pic shows the 1/16" Aircraft Plywood that I used to drill a 7/8" hole into to hold the wing spar support tube that will be permanently glued inside the fuselage.

8 wing tube support.jpg (1.4 MiB) Viewed 6408 times

The following pic shows a bit of a triangle shaped bit of 1/8" plywood that I epoxied into place to support the steerable tail wheel assembly. There will be another piece of thin plywood on the outside of the fuselage that the tail wheel assembly will attach to. 3 bolts will go through the bracket and through the pieces of plywood and then there will be a couple of washers and nuts on the inside to tighten up.

9 tail wheel inner support.jpg (1.33 MiB) Viewed 6408 times

The following pic shows the wings being test fitted. From the leading edge to the trailing edge of the control surfaces is 14" and I wanted to see how well the wings looked. I also wanted to check that the wings will sit flush against the fuselage. Let's just go ahead and say it....."Those are some big wings!!!"

10 just checking wings on plane.jpg (1.42 MiB) Viewed 6408 times

[DOG]

It's looking good Derek.

[Derek]

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11 foam skin added.jpg (78.33 KiB) Viewed 6404 times

Here are two more pics of what I've been working on. I fully intended on using my beloved "Dollar Tree Foamboard" on the outside of the green insulation foam. I have taken some of my colored packing tape and I've tested it on the green foam. The base color, yellow, doesn't cover the green as well as I'd like....so, the white foamboard is adhered to the green foamboard. This was another reason why I cut out the circles from the tail in the green foam....trying to keep the tail weight down. Also, in an effort to keep the weight down, I've been very cautious with the amount of glue(s) used and I'm trying to steer away from adding more and more wood.

I do have some wood at the nose for the motor mount, for obvious reasons. I have some very thin plywood on the inside of the fuselage to help reinforce the wing spar tube. There is also some thin plywood on the tail section to help reinforce the spar for the horizontal stabilizer. Let's face it....foam is just not gonna hold a carbon shaft in place for very long, lol.

Also, out of curiosity, I weighed the fuselage, as it is pictured above. As of right now, the 64" long fuselage weighs a mere 2lbs 15oz or 1.3kg. According to the Legacy Aviation website, the weight of their "Turbo Bushmaster" is 7.5-8.5lbs. As I expect, my build will weigh more than theirs....but not by much....maybe, lol.

[Vipertech13]

Looking very Good!

[Derek]

Thanks Gerald! I forgot to mention something else about the added balsa on the tail. That balsa actually serves 3 purposes. One, to give some reinforcement for the horizontal stabilizer spar, as mentioned above. Two, to bring the tail to a point, because the Legacy Aviation "Bushmaster" has a pointed tail. Three, to give me some structure for the servo mounting for the elevator halves.

So far, I think I'm pretty happy with the build. I wish I could take some time off work so that I could keep working on the plane, lol. I am now at the start of my 3 day work weekend so I won't be able to work on the plane again until next week.

[Derek]

Just a bit frustrated, lol. Still in good spirits, but a bit frustrated. I got looking at the left wing and it's got a bit of a twist in it. While holding the leading edge and looking over the wing, the right side of the wing is lower than the left side. I had an idea about what happened, and I had extra foamboard, so I just decided to rip the wing spar tube out and build a new wing. I was careful and cautious with my measurements and lines and, believe it or not, the new wing was just as twisted as the first wing. The odd thing is that all measurements and marks were the same as the right wing (which turned out very nice) but the left side wing has a twist in it. Unbelievable!!!

So, it's probably a good thing that I work the next two nights. I'll just take this time away from the plane and refresh myself.

Also, because I am beginning to get to the point that I'll need to install servos, it's probably a good time to get some servos ordered, lol. I placed an HK order and I got an email, this evening, that my order had been shipped. That being the case, I should have the servos by Friday-Saturday. That's cool! Now I gotta start thinking about linkages. Do I wanna use the usual "pushrod with quik-connects" or do I want to use "ball links and turnbuckles". The pushrod method is cheaper and it's worked on all my other planes. The ball link method costs more but I imagine that this method is more solid.

[Derek]

only got a little done tonight but here are some pics and details

I cut some bamboo skewers down to 2.5". Drilled some holes in a 1/8" plywood plate. Pushed the skewers through the plywood and super glued them in place. Punched the skewers through the bit of foamboard that the vertical stab connects to. I was thinking the skewers would help add rigidity without adding lots of weight.

13 rudder support (1).jpg (1.33 MiB) Viewed 6352 times

Attached the vertical stab

14 vertical stab installed.jpg (1.45 MiB) Viewed 6352 times

The plane now has some color

15 some color added.jpg (1.39 MiB) Viewed 6352 times

I did attach the horizontal stabilizers with a 1/4" carbon fiber tube (25" in length), to act as a spar, and a 1/8" carbon tube (14" in length), to act as a spar and to help prevent rotation.

16 horizontal stab finished.jpg (1.44 MiB) Viewed 6352 times

[Graham Lawrie]

Looking great Derek:)

[Derek]

Thanks Graham! Progress has slowed down, due to the overwhelming mandatory overtime at work, but any progress is still progress. I'm hoping, desperately hoping, to have this plane done by next weekend because there is a Monster Mash Event at my local flying club next weekend. 72" wingspan is the minimum for this event. Both this plane and my large 3D plane might be going to the event.

[Vipertech13]

She's looking GOOD! Ya gotta hate being so close and not having the needed free time! I've been there!

[Derek]

You're right, Gerald! It's quite frustrating to have this build so far along and only have "spare time" here and there....but....some progress is still progress.

No, I didn't get the plane finished as I hoped but....that happens. Nonetheless, I've gotten some more done and I have two pics to share.

I got the front and rear landing gear installed today. The plane can, now, sit on some wheels

17 Landing Gear Installed.jpg (1.56 MiB) Viewed 6309 times

I cut a bit of foamboard for the hood and roof. Since I was running out of time, this evening, I put the wings on so that I could see how she's looking.

18 Really Coming Along.jpg (1.45 MiB) Viewed 6309 times

I do have the two elevator servos and the rudder servo installed. The rudder servo will also have some Kevlar cords running to the steerable tail wheel. I'm sure I'll share some pics of that later on. I have to make a venture to the hobby shop for some parts but I won't be able to do that until Wednesday. I'm thinking the next trip to the hobby shop will be the last trip needed to finish this plane. I have the 6S motor mounted (still needs locktite). I have a 100amp Hobbywing esc that I'll be using. Need to mount the flaps and ailerons, as well as the servos. I need to take my AR8000 and satellite off my Cub (installing a 6 channel rx on the cub) and add the AR8000 and satellite on this plane (I need channel 7 for the dual elevators). I'm sure there are few other things that need done but, in all actuality, this plane is nearly done. I do have a bit of plexi-glass that I'll be using for the windshield and I need to cut out the cabin windows.

[DOG]

Look at you go Derek. She's turning out to be a pretty nice looking plane. Good luck with the rest of the build.