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1/24th OV-10D+ Bronco


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I know long time no update. Work has been progressing. I have decided to complete the rest of the sub-assemblies before I do any more painting.

Here are some shots of the FPU-3 external fuel tanks that will be mounted under the wings. A master was created from turned acrylic rod on my lathe. The master was split in half to facilitate the molding process. Rubber molds were created and the parts were made with Castolite. Details were then added, fill ports, fins, joints (aluminum tape) and rivets were added using JB Weld epoxy.

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Next the truly most frustrating part of this build yet the LAU-61 (nineteen shot) and LAU-68 (seven shot) rocket pods. At first I tried to fashion these from solid aluminum with the "tubes" drilled out. While I found a bit long enough, my ability to drill straight holes failed. So next I found thin wall stainless steel tubing the exact size of the rocket tube. I cut these to length and super glued them together to form the right patterns. On the seven shot tube I found brass tubing that the steel tubes fit perfectly into, but the outside diameter was too narrow so I added a second section of tubing, the next size up and soldered the two together. This gave me a diameter that was a little too large so whole thing was turned down to the "right" diameter. For the 19 shot I had to use aluminum tubing that was too narrow on the inside and too large on the outside. So I bored out the tubing to get the stainless tubes to fit inside. Because I could only bore about an inch I had to make multiple section and epoxy the whole thing together. Then the outside was turned to the "right" diameter. Al this work created the center sections (the gray portion in the photos).

The next true nightmare was the aluminum end caps. I turned down small disks that are slightly smaller in diameter than the center section and bored out slightly. These were epoxied to the center section one side at a time. Holes were drilled in the end caps from the open side of the center section using a bit the exact size of the inside diameter of the steel tubes. Once on cap was drilled out a new one was glued on the other end then drilled out life the first one. The problem was, as the drill bit was almost through the aluminum cap it would catch and twist cap right off. I took four or five weekends of trying until I got all the holes drilled without the caps coming off.

The results, however were worth the time. You are seeing them 90% complete. The parts were boiled in water with eggshells to create the burned aluminum color and the center section has a thick coat of primer to conceal my most excellent turned finish.

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lau4rl6.jpg

lau5se5.jpg

More soon!

Timmy!

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Your ingenuity never ceases to amaze me...... Eggshells huh? (shaking my head)

How do you get the JB to make a perfectly round rivet?

Museum quality work.....no doubt.

Full Afterburner,

Scot M.

The JB almost does it by itself. I just apply a small bit with a toothpick. Because the JB is so thick it forms a little ball on its own.

Timmy!

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Great Job on the stores sir!!!

hey that reminds me... Phil. AF OV-10s will be having wing fuel tanks soon...

Great Job on the LAUs!!! I also need to make a couple of sets, since my pop's OV-10 usually slung these underneath, most of the time empty

Another thing, are you planning to add the ripple selection switches on the rocket pods?

Edited by Hans
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Hey timmy, i love this build and have been watching it for quite some time.

Could you explain the thing you mention with boiling water and eggshells, this is the first time i'm hearing about it.

Waiting for more updates :-)

Edited by regevmo
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Another thing, are you planning to add the ripple selection switches on the rocket pods?

Thanks Hans. Yes there will be switches, electrical connector, safe receptacles and ripple switches; plus rivets and raised panels. Like I said a little ways to go yet until they are 100%

Timmy!

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Hey timmy, i love this build and have been watching it for quite some time.

Could you explain the thing you mention with boiling water and eggshells, this is the first time i'm hearing about it.

Waiting for more updates :-)

Aluminum changes color if you put it in boiling water with eggshells. By some magic of chemistry a.k.a. magic, the aluminum changes to dull gray then changes hues like burned metal with bluish color and goes to black. I just boiled my parts until the color was right. If you go to far the aluminum can be polished back to a shiny finish and you can try again. I learned this as, with every other part on this model, I did it twice.

Timmy!

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Thanks Hans. Yes there will be switches, electrical connector, safe receptacles and ripple switches; plus rivets and raised panels. Like I said a little ways to go yet until they are 100%

Timmy!

Now we're talking!!! :D

Keep up the great work sir!!!

Merry Christmas!

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  • 5 weeks later...

Amazing...I thinking you are messing with us and taking pictures of the real thing and calling them your model...seriously, awesome work, can't wait to see more.

Cheers,

Dave

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Nice progress there sir!!!

Also thanks for posting your 3D renderings of the engines!

Um, one thing though, can I ask you to post a photo documentation of your build for the engine later? the T-76 is the part of the OV-10 that drives me nuts...

Thanks!!!

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  • 3 months later...
Thanks fellas!

Your encouragement is always appreciated. More to follow soon - -I keep trying to update more frequently and I will still try.

Timmy!

Yikes looked at the date of my last post.

Not much modeling time, but there has been some progress.

The engine has started to become a reality - model reality that is.

Here is shot of the main engine section. I tried make this as accurate as possible. The Fuel Control Unit was tough as so much of it is coved by lines and wires and engine mount structures that is true shape was tough to get 100% accurate. But, once complete with all the lines, hoses and wires on it should be a good representation of the real thing. There is a shot of the beginnings of the"Hot Section" and the starter / generator.

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The props are nearing completion as well.

prop1dm5.jpg

Spinners were vacuformed over a turned master. Brass tubing makes up the hub.

prop2mp1.jpg

The props themselves were made in left and right hand sets. (The engines turn in opposite directions). They started with a photo-etched stainless steel pattern, with a piece of aluminum tube attached to the hub attachment end. The pattern was glued onto a jig at the root and tip ends. Each end of the jig was angled to impart a twist on the blade. Plastic sheet was then glued in laminations on the pattern. Once enough layers were on the plastic held the curved shape and the blade was removed from the jig. Then the other side was laminated and the whole thing sanded to shape. The steel pattern gave me the ability to keep the trailing edge razor sharp with distorting the prop outline. Once I had left and right blades done I cast duplicates. As might notice the downside of thin props was the difficulty in keeping bubbles out of the casting. A good layer of talcum powder on the molds and lots rejected casting got me to the results you see here. Although all of them had some pin holes that needed to be corrected.

prop3ts0.jpg

That's it for now.

Timmy!

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