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        Build Log Topflite Stinson SR-9 Build

#1 sirzeppu Jan 29, 2013 10:32 PM

Topflite Stinson SR-9 Build
I am really excited for this one. I've never built anything this complex before. Should be fun!


Power will be a DLE30 I have on the shelf (tail will be reinforced, and will be purchasing TNT single piece gear). It might be a little over-powered and may require some weight up front to balance (strange combination, but the research seems to indicate it's true).

Finish will be Solartex with rib stitching from www.pink-it.com, then painted with Rustoleum in the colors of the prototype on the box. I like the looks of the plane on the box, plus this way I get to use the stock decals.

Here we go...

#2 wizard of odd Jan 29, 2013 10:46 PM


There's a really nice build thread for reference, recently completed, by Splinterz http://www.rcgroups.com/forums/showt...ight=splinterz

Good luck, keep the pictures coming!

#3 sirzeppu Jan 30, 2013 07:01 AM

Thanks for the thread reference. I found another thread inside that one as well. So that gives me two really solid pieces of reference material. Thanks!

#4 epoxyearl Jan 30, 2013 03:06 PM

Welcome with your Classic....Man, there's a lot of Golden Age Models being built this winter !

I've built several of those as contract builds.

The tail has options for gas engines- just sheet it when you build.

#5 sirzeppu Jan 30, 2013 05:33 PM

I plan to sheet the tail. I had a question about that:

Since the tail will be completely sheeted, won't the cross bracing be redundant? The sheeting should perform the function of the bracing as well as adding rigidity overall, kind of like a semi-monocoque structure. If that's the case, can I leave the braces out to make it simpler/a bit lighter?

#6 sirzeppu Jan 30, 2013 05:39 PM

Got some stuff done today:

Inventory of wood/labeling pieces:

Building Horizontal Stab:

Sure am enjoying this build. I've done a couple of smaller, easy planes lately, and I had a long somewhat tedious scratch build before that. It's nice to dig into something that is well engineered, easy to put together, but meaty and not over too quickly.

#7 epoxyearl Jan 30, 2013 06:15 PM

Believe me -it won't be over too soon...I build one every so often , then swear I'll never do another....But that was the biggest reward I've gotten, when it WAS done.

The toughest parts were the wing rib "egg crate" slots, which are on a compound angle in the spars.....I fabricated a sanding board with sandpaper on both sides,and sanded vertically the rib openings,which slowly yielded a good fit.

A hand held hacksaw blade cut slots for the thin plywood spar reinforcements and dihedral joiners..which I passed over, originally..

Yes the extra bracing in the stab is redundant, when sheeting the stab.

The extra $100 bucks for fiberglass parts is money WELL spent.
The wing struts are window dressing, unsecured at the bottom (not an omission)...

#8 sirzeppu Jan 30, 2013 06:45 PM

Thanks Earl! I'll skip the bracing, get the fiberglass, and watch those points of the build you pointed out (and build/get the necessary tools).

Thanks again.

#9 TomCrump Jan 31, 2013 07:56 AM

I'm in. A friend purchased the glass parts that Earl suggests. He was very happy with them.

#10 sirzeppu Jan 31, 2013 04:53 PM

Finished the stab today.

Got the top sheeted, removed the pins/jigs and flipped it over:


Sheeting the bottom:


Cutting around the strut mounts seemed simple enough:


But I missed the 1/8" for the TE and cut the hole oversize. Also got the length wrong:



But I used the piece I cut out to add some material back in and got a decent fit:


After that the other side went much better:




It's rough sanded, but per the instructions I did not round the leading edge. FWIW, when I fit the right side, bottom sheet in and it lined up perfectly, I was so excited I yelped. Man I'm a dork. But to see your skills improving with each step really is encouraging. Such fun.

#11 epoxyearl Jan 31, 2013 07:34 PM

Yeee hah !
I just finished sheeting a wing I designed myself..And I know the feeling you're talking about.
I'm making a prototype model of a full scale prototype, and it's under weight and over strength.....just what everyone dreams about.

#12 sirzeppu Jan 31, 2013 07:37 PM


Originally Posted by epoxyearl (Post 23995486)
I just finished sheeting a wing I designed myself..And I know the feeling you're talking about.
I'm making a prototype model of a full scale prototype, and it's under weight and over strength.....just what everyone dreams about.

That's amazing! Congrats...it is truly a dream when a plane is coming out that way. Here's to low wingloading and high strength!

#13 wizard of odd Feb 01, 2013 12:28 AM


Looking very nice, even with the "oops!"


You mean you're actually working on something and not posting pictures??? What kind of a man does that? (Well done mate!)

#14 sirzeppu Feb 02, 2013 05:44 PM


Originally Posted by wizard of odd (Post 23997839)

Looking very nice, even with the "oops!"


Here are some pics from today:

LH Elevator is finished...so much fun build this plane. The structure is so rewarding and the pieces are so much bigger than what I am used to working with. I need a break from balsa dust and CA fumes!


#15 TomCrump Feb 02, 2013 05:50 PM

Nice progress !

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