Re: Unidentified 1/2A Combat Plane

Ken Cook Mon Sep 14, 2020 4:46 pm

Most kits if that is a actual kit used very poor quality plywood. I only use 1/8" 5 ply which I purchase from Sig. Using blind nuts behind the firewall or nut plates is the best way to fasten the engine. Using good quality ply would also be helpful in assisting wood screws to hold. Whenever a firewall is constructed as your model and many others, a good practice is to wrap the perimeter of the firewall to nacelle with lightweight glass cloth and epoxy. I cut strips of glass cloth 3/4" wide and wrap it around overlapping the strip. If you use blind nuts, the glass will go over the holes for them. I fill the holes with clay and glass right over them. When dry, I poke a hole and the clay prevents epoxy from going into the threads. Slow cure epoxy works exceptionally well for strengthening, I use 30 min for these kind of models. I just hit it with a heat gun just to thin the epoxy to saturate the glass.

TLAnderson Mon Sep 14, 2020 9:25 pm

getback wrote:What i have done before with fuel soaked engine mount holes (not saying U have ) Is to clean up holes good and wood glue some toothpicks in there to refill the holes with a harder wood . What size screws are you using ?

I'm using #3 screws. The biggest ones that will go thru the engine mounting lug holes. Be nice if #4s would work. They're easier to find in the hardware stores around here.
Drilling out the screw holes and glueing hardwood dowels in the holes might work. Thanks.

TLAnderson Mon Sep 14, 2020 9:33 pm

Ken Cook wrote:Most kits if that is a actual kit used very poor quality plywood. I only use 1/8" 5 ply which I purchase from Sig. Using blind nuts behind the firewall or nut plates is the best way to fasten the engine. Using good quality ply would also be helpful in assisting wood screws to hold. Whenever a firewall is constructed as your model and many others, a good practice is to wrap the perimeter of the firewall to nacelle with lightweight glass cloth and epoxy. I cut strips of glass cloth 3/4" wide and wrap it around overlapping the strip. If you use blind nuts, the glass will go over the holes for them. I fill the holes with clay and glass right over them. When dry, I poke a hole and the clay prevents epoxy from going into the threads. Slow cure epoxy works exceptionally well for strengthening, I use 30 min for these kind of models. I just hit it with a heat gun just to thin the epoxy to saturate the glass.

Thanks for the tips, Ken. Now I have some ideas to try out. Winter is coming so I'll have plenty of time to work on it pretty soon. Last night, I tried wicking some thin CA into the screw holes, and turning the screws in and out while it set up. Hope I can get the screws out next time I need to remove the engine. Huh...

TLAnderson Fri Sep 10, 2021 1:11 pm

Got a chance to attempt to fly the Snip today. Did more crashing than flying. Got a few flights in though.
Here it is coming out of the stooge.

Unidentified 1/2A Combat Plane - Page 2 Snip-f12

The only shot I got of it actually in the air.

Unidentified 1/2A Combat Plane - Page 2 Snip-f13

Had some company at the flying field. Those things in the upper right corner of the pic are geese. They're getting ready to get out of here before winter blows in.

Unidentified 1/2A Combat Plane - Page 2 Snip-f14

I finally got tired of crashing the Snip and switched to the 1/2A Skyray. Got a couple of flights in with that, and the wind came up, so that was it for today.

Here are a couple of shots of the aluminum engine mount I came up with to try to avoid breaking the engine off on every hard landing. It seemed to work ok.

Unidentified 1/2A Combat Plane - Page 2 Snip-m11

Unidentified 1/2A Combat Plane - Page 2 Snip-m12

706jim Fri Sep 10, 2021 1:39 pm

I did a Google search last night for Carr's Hobbies in Duluth. I'd heard he closed the store and sold the building in 2020 at the age of 79. And six months after that he died.

Kind of a sad time for me as I had shopped at his store pretty much since it opened in 1970.

But the writing was on the wall as he never brought any new stock in for probably close to 15 years. He also complained about on line sales hurting his business.

RIP Jack Carr, 1940-2020.

TLAnderson Fri Sep 10, 2021 1:51 pm

706jim wrote:I did a Google search last night for Carr's Hobbies in Duluth. I'd heard he closed the store and sold the building in 2020 at the age of 79. And six months after that he died.

Kind of a sad time for me as I had shopped at his store pretty much since it opened in 1970.

But the writing was on the wall as he never brought any new stock in for probably close to 15 years. He also complained about on line sales hurting his business.

RIP Jack Carr, 1940-2020.

I didn't know he had passed. I remember going to the store with my dad back in about 1970. Bought a profile 1/2A Spitfire kit and a Babe Bee.

Edited to add:

I just read his obituary: https://www.doughertyfuneralduluth.com/obituary/JohnJack-Carr

I figured he was ex military by his demeanor, but 82nd Airborne is pretty impressive.

getback Sat Sep 11, 2021 5:51 am

TL that's a pretty wild looking engine mount , have you checked the CG after the application ? It looks heavy ?! Huh...

Sorry to hear of the passing of another model enthusiastic person and Hobby Shop owner .

TLAnderson Sat Sep 11, 2021 7:15 pm

getback wrote:TL that's a pretty wild looking engine mount , have you checked the CG after the application ? It looks heavy ?! Sorry to hear of the passing of another model enthusiastic person and Hobby Shop owner .

CG is about 1/2" back from the leading edge. The mount, engine, and prop weigh about 3-1/4 ounces. The plane with the mount, engine, and prop weighs about 7-1/2 ounces.

I know it looks a little weird, but it beats having the engine break off and the plane being unflyable until it's fixed. Shocked

TLAnderson Tue Sep 28, 2021 7:04 pm

I made several unsuccessful attempts to fly the Snip today. Nothing went right. I finally gave up when the spray bar came out of the back plate on the Black Widow.

Unidentified 1/2A Combat Plane - Page 2 Black-10

Unidentified 1/2A Combat Plane - Page 2 Black-11

What would cause this? If I put it back in, how can I make sure it will stay? Does it need to be oriented a certain way?

Ken Cook Tue Sep 28, 2021 8:01 pm

Vibration is what causes it. I've had it happen many times. I usually use a fine wire wheel and clean the spraybar thoroughly on the outside. I also clean the spraybar with lacquer thinner and the inside of the backplate. I insert the spraybar with the small hole facing the front of the engine. Inside the backplate, the hole of the spraybar will be aligned with fuel pickup nipple. I install the spraybar but I don't push it down all the way, I then use JB weld around the perimeter of the spraybar, I insure it's all the way around the spraybar. I then use a heat gun on the JB weld which liquifies it and I push the spraybar the rest of the way down. I then use a Q-tip with rubbing alcohol which will completely clean and remove any JB weld. I personally like to leave a clean fillet around the top as it seals any air leaks around the perimeter.

TLAnderson Tue Sep 28, 2021 9:08 pm

Thanks, Ken. Great description of the process you use. Thumbs Up

TLAnderson Mon Nov 15, 2021 8:07 pm

Ken's repair instructions seem to have worked. I've flown the Snip a couple of times since repairing it. Thanks Ken.

It was a nice day today, for this time of year, temp about 31f, about an inch of new snow on the ground. So I decided to try flying over snow.

I have to say I don't recommend it. When that hot engine goes into the snow, the snow melts and the engine sucks in water. Makes the engine hard to restart. The plane gets covered in snow, water, ice. It's just not much fun. Won't be trying that again.

I guess I'll wait until Spring to fly again.

getback Tue Nov 16, 2021 6:41 am

On the repair , That sounds like the trick then heating the JB weld to run and mate the parts much better than just dabbing some on it sunny

I think i remember Rusty had shared when gluing the wing in he would heat the glue to get to run in and make a nice smooth bond. TL that's chilling to me to get out the in 31f weather and all but the clean up would be fun Very Happy

Ken Cook Tue Nov 16, 2021 3:26 pm

I flew mine this past weekend for the first time. Very impressive with the TD on it. I was really quite shocked. The last one I built was in the early eighties and it was Black Widow powered. I recall it being short lived. I don't exactly recall what happened to it but I remembered where I was flying it. I just recall being inverted when it hit hard.

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Unidentified 1/2A Combat Plane