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Building Tips and technical articles. => 1/2 A building. => Topic started by: Larry Renger on July 15, 2017, 08:09:12 PM
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Wednesday, after getting home from destroying my Baby Pathfinder, I pulled a Brodak Baby Clown ARC kit off the shelf. It is now Saturday afternoon, and here is my progress. #^
The contest is tomorrow! ~^
With the added flaps, Wing Area becomes 156 sq.in. and the weight came out just a hair under 8 ounces. The Medallion has a Tee Dee cylinder and piston and Merlin plug and extra cooling retainer. Galbreath precision needle valve. The wing becomes an almost perfect scale down of the Super Clown with the addition of the working flaps!
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I like it. H^^
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I like the tri-chromatic, asymmetric, post urban sprawl camo......
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Looks great! If I didn't have way too many 1/2A planes already, I'd be tempted to order an ARC Baby Clown myself. Do the flaps make an appreciable difference in how it flies compared to one without flaps? And, am I correct in that you are using crankcase pressure with the filed down T-nut threaded on the pressure nipple?
Mark
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Yes on the turned down T-nut for a pressure fitting. The hose NEVER falls off! y1
I haven't tuned this plane in yet, but the last one I did, there was a big difference. Both the added wing area and flap action helped. ;D
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Further flight testing results:
Increasing the control throws got it nearly there. When the engine is on peak, it is pretty close. It might use longer lines than the 38' ones, or perhaps more control throw.
The Medallion does not like the Cox glass filled 6x3, and overheats. I will try an APC 5.7x3 tomorrow. It also might be fuel foaming. Whatever, power isn't reliable, and you can't tune in a plane with iffy power.
The landing gear was way too springy, so there is now a cross wire soldered at about half way down the wires. Also, a tall tailskid was added. When I drop the model onto my workbench it only bounces a little, and stays level.
Picky, picky, picky! LL~
This model does have the capability of flying a competitive pattern when all rhe gremlins are tossed overboard.
Going flying tomorrow, so more newsas it breaks!
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Just a question on the APC prop. Years ago I used to love the APC 5.7x3 prop on my Cox engines. I recently ordered one from APC, but the shaft hole was way too big and had inserts, but neither was small enough for the Cox shaft. I verified the package didn't say for electric use. The ones I remember from years ago had no problem fitting the Cox shaft. Any ideas on what I'm doing wrong?
Mark
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I think that some fuel hose will work as an adapter between the smallest of the rings and your prop screw.
For myself, I own a lathe.... ;D
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Just a question on the APC prop. Years ago I used to love the APC 5.7x3 prop on my Cox engines. I recently ordered one from APC, but the shaft hole was way too big and had inserts, but neither was small enough for the Cox shaft. I verified the package didn't say for electric use. The ones I remember from years ago had no problem fitting the Cox shaft. Any ideas on what I'm doing wrong?
Mark
Wait until Melvin gets home from the NATS and talk to him. I think I got some adapters from him for the small APC props. Otherwise I use brass tubing cut to length of sizes to fill the void.
Forgot to say Melvin at MBS Model Supply.
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I think that some fuel hose will work as an adapter between the smallest of the rings and your prop screw.
For myself, I own a lathe.... ;D
Ditto on the fuel hose.
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The Medallion does not like the Cox glass filled 6x3, and overheats. I will try an APC 5.7x3 tomorrow. It also might be fuel foaming.
I ran my Medallion 049 exclusively on Cox 6-3 grays, it was remarkably good and had no problem with overheating. Use more nitro.
Brett
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It is amazing how much better the engine runs with the head tightened down. :-[
Anyway, sneaking uo on the correct trim. Insides and outsides were about equal, but not enough throw. All fixed, going for more testing tomorrow.