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Apr 24, 2020, 12:49 PM
Foam is my friend!!!
NewZee's Avatar

my next build!


Brett, Thanks for sharing I'll try and use those techniques on my next foamie build! I've been wanting to do a "Bronco / Skymaster" It fits the criteria of a flat wing, and slab sides!! I also plan on making my rear prop just a free spinning dummy! (I think it'll fly just fine with a single tractor motor up front!! I typically use brown kraft paper for covering! it can soak up a lot of water/glue, and stays together! Don't know if its available in "OZ"?? but have it here in many art, kraft, & home stores!
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Apr 24, 2020, 05:29 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Same sort of paper over here. Basically its painters masking paper. Quality is hit and miss and since all that is green is good the recycled stuff must be too.

Broncos make fantastic fliers, and their simple box construction is ideal for this type of model building. Use high Kv motors with 6x4 props and you won't have to worry about counter rotating props. I fly mine often and it never fails to make me smile.

Skymaster looks like a good candidate too. Though I wouldn't pass up that opportunity for another spinning prop. You just can't have too many IMO.
A dummy non driven prop would just add to the drag. Again, use high Kv motors with small props both turning in the same direction. I never had much luck with counter rotating props. Besides the slight amount of torque roll as you go WOT gives a sense of power and the noise is just sublime.
Apr 25, 2020, 07:23 AM
Foam is my friend!!!
NewZee's Avatar

I Love twin boom designs!


Brett, Sorry to go a little off topic, but I love twin boom designs and while my models up to now are not as nice as your "Dream Machine" (and others) I have built and enjoyed several! many of my own design!! they all flew great!! Can't wait to employ some of your building techniques on a Bronco!!! here are just a few of my "Twin Tails"... Now, Let's get back to the "Dream Machine"!!
Last edited by NewZee; Apr 25, 2020 at 07:28 AM.
Apr 25, 2020, 05:24 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
The old funder and lightning. That was first build, and what a mess I made of it too.

Finished covering the fuse. It is so strong now that I reckon I could use it as a baseball bat.
Weight penalty was just 25grams. The tail surfaces added another 13grams.
Not too bad considering.

Now I have run out of brown paper for covering the wings. I have three choices. 1. Use some poor quality paper that I picked up in an art shop, which is heavy and turns to mush when wet. 2. Use newsprint, which isn't as strong. 3. Buy some more and risk the $1k fine for purchasing non essential supplies. I suppose I could claim that I use it as toilet paper.
Last edited by brett.c; Apr 25, 2020 at 07:42 PM.
Apr 27, 2020, 11:53 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
I ventured out and bought a 600mm wide roll of virgin paper. FSC certified no less, so now I don't feel any vicarious guilt over chopping down a tree.

The extra width has allowed me to wrap each wing in one sheet with the seam on the underside trailing edge. Easier said than done.
I have done this with smaller wings and results turn out quite neat, however in this case my ambitions almost outweighed my abilities. The resulting few wrinkles and tears will be easily sanded out and filled.

The fuse has been coated in a surface sealer and rubbed down smooth ready for paint.
Still working on a paint scheme but have settled on bright yellow and red Rutoleum 2x.
Apr 29, 2020, 07:06 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Painting has begun.
I'll wait a few days before applying the red.

Next: Landing gear and wheel spats.
Apr 30, 2020, 08:21 AM
Foam is my friend!!!
NewZee's Avatar
A yellow plane in a bright blue sky looks great!!! Great choice on the color!! It's been a pleasure watching this build come together, Thanks for sharing! Will you be able to get out and fly it when it's done, or are you still in "lockdown"?
Apr 30, 2020, 04:31 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Thanks Zee, they are easing restrictions at the end of this week so hopefully we'll be back in the air soon.
May 03, 2020, 02:25 AM
Foam is where the heart is
brett.c's Avatar
Thread OP
Ok, moving on bit by bit.

1. The windshield took a couple of goes to get right but I think this one is close enough.

2&3. I will share with you my latest method for hinging control surfaces. I no longer use CA as it tends to make the surrounding foam too brittle. Instead I use Gorilla Clear glue which stays somewhat flexible. Hinges are 10x30mm with a hole each end made by a single hole punch. I glue the hinges to the control surface first, wipe off the excess, and let it dry. Then I fit and glue the control surface in place, wipe off the excess and while the glue is drying (2-3hrs approx) I keep moving the control surface to ensure it is free.

4-6. I had no real plan for making up the wheel spats and so just made things up up as I went along. The plywood spine helps to stiffen up the spats and gives me a good guide while sanding the foam. Foam is from my precious stock of 15mm thick Dow Bluecore. I wish I had a lot more of this stuff as it is much nicer to work with. Wheels are 50mm from some long forgotten plane.
Next I have to figure out what to cover them with. Brown paper or expo/glass. I've tried wbpu and glass before but was never happy with the results.

I'm waiting on some 2mm aluminium (correct spelling ) to make the LG legs
May 03, 2020, 07:35 PM
Foam is my friend!!!
NewZee's Avatar
Lookin Good Brett!!
May 06, 2020, 05:42 AM
Registered User
Wow! I am really impressed by your finish. It looks so smooth, no one will think that this bird is made of foam!

Fab
May 07, 2020, 12:11 AM
Foam is where the heart is
brett.c's Avatar
Thread OP
Thanks guys

Finally, I have finished the landing gear.

1. Paper cut ready for covering.
2. Covering finished and looking more like an Egyptian mummy.
3. Sanded smooth and ready for the sealer.
4. All complete.

On some good advice from the minister of domestic affairs I've changed the paint scheme to all yellow with red decals. She reckoned that too much red would cause a clash with such contrasting colours. How would I know when I can't even coordinate the colour of my clothes.

So next is making and adding decals.
May 07, 2020, 08:29 PM
Foam is my friend!!!
NewZee's Avatar
So Cool!..... The paint and decals is always my favorite part of the build!!
May 07, 2020, 11:52 PM
Foam is where the heart is
brett.c's Avatar
Thread OP
Quote:
Originally Posted by NewZee
So Cool!..... The paint and decals is always my favorite part of the build!!
And my least favourite
I'm more of a builder, and when I get to the decorating stage I'm pretty much over it and want to just fly the thing.

Anywayz... Decoration is complete. I used red packaging tape for decals and will need to cover them with wbpu to ensure that they don't peal off in flight.

CG is good with the battery at the leading edge and plenty of room further forward. I'm waiting on some metal gear servos to complete the build.
Thus far the all up weight is 1220grams. Once the servos and pushrods are installed I reckon she'll be just under 1300grams.
That is 95grams more than the donor plane and with much greater wing area, so I expect it to perform the same if not better.
May 08, 2020, 04:27 AM
Registered User
Such a clean Built!


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