Re: CEF speed contest Design Discussions (2014)

getback Thu Feb 26, 2015 12:17 pm

Thanks Man Engine off set zero also ? or maybe 2 * Heck by the time I got mine to fly the front had broken off and been epoxied back on 3 times a lot of non intended weight . Got to get off here and go back to building Flying

Eric

roddie Thu Feb 26, 2015 12:57 pm

getback wrote:Thanks Man Engine off set zero also ? or maybe 2 * Heck by the time I got mine to fly the front had broken off and been epoxied back on 3 times a lot of non intended weight . Got to get off here and go back to building Eric

Correct.. no engine or rudder offsets. Now that the rules state landing gear as "optional".. you could build a Speed-Model for a take-off dolly, as I mentioned earlier in the thread. I should make a drawing of the concept I wrote about. I think it might help contestants wrap their heads around it. (of course.. everything looks good on paper..) The only airplane design consideration for use with my dolly design, is that the belly of the profile fuse, fits down between two narrow rails. A single slot/cross-pin arrangement prevents the model's forward movement while taxiing. It will work on a grass field with the fitting of "Pink-foam" (or similar) "main" wheels of say; 3" diameter.

R.O.G.'s are the way to go with a speed model.. Even the best hand-launch is going to require skill, luck and fast reflexes on the pilot's part, to recover control.

I'll draw it out...

JPvelo Thu Feb 26, 2015 9:11 pm

getback wrote:that brings out some interesting ideas , I was wondering what you were thinking , but who am I to ask ? // This hanging the plane from the lead out is all new to me soooo if the plane is pointing nose down that is the outside of the circle it will pull and up is toward the inside so how much ??? Eric

JPvelo wrote:
RknRusty wrote: Well hell, maybe I've just answered my question. Maybe we actually do want a slight yaw-in on a speed ship. I'm in even deeper now.
Rusty
I wasn't going to divulge any secrets but.... That's why my plane has the rudder air foiled on the outboard side, no tip wieght, and leadouts above the vertical cg that can be moved forward of the horizontal cg. I want it to fly in a counter clockwise circle and rely on centrifugal force to keep the lines tight. Or it may just fly into the center of the circle and try to kill me.

Jim

Eric,
That's how I set my Staggerwing up and it was banked into the circle when it flew. I'm pretty confident I could move the leadouts further forward and break 70mph if it was still in one piece.

Jim

stuntflyr Sat Feb 28, 2015 10:44 am

Profile Scale Proto Profile 1972. Trostle Spitfire converted to profile with Latshaw 1/2A Hustler wing and tail. 46 sq in, Kirn lefty prop and fine needle valve on Cox lefty Tee Dee. On red can Cox Racing Fuel, as you can see. It went about 75 to 77 mph usually, had large plastic bellcrank and horns, and thick permanent leadouts or it could've gone faster. We flew on .008 solid lines back then in 1/2A.
Chris...
P.S. Is there another event to be run for 2015?

CEF speed contest Design Discussions (2014) - Page 14 Chris_10

roddie Sat Feb 28, 2015 11:52 am

stuntflyr wrote:Profile Scale Proto Profile 1972. Trostle Spitfire converted to profile with Latshaw 1/2A Hustler wing and tail. 46 sq in, Kirn lefty prop and fine needle valve on Cox lefty Tee Dee. On red can Cox Racing Fuel, as you can see. It went about 75 to 77 mph usually, had large plastic bellcrank and horns, and thick permanent leadouts or it could've gone faster. We flew on .008 solid lines back then in 1/2A.
Chris...
P.S. Is there another event to be run for 2015?

What a GREAT photo Chris!! Yes, there is a contest planned with two Cox engine classes. See here; https://www.coxengineforum.com/t5898-cef-profile-scale-speed-rules

Most 1/2A flyers here are using the "braid" type fishing line. I picked up some 15# Spiderwire EZBraid which has a .2mm (.0079") diameter. The 30# is .3mm/.0118" and is what I used for the first contest; when line-length was 42 feet. The rules now state 35 feet lines.. which makes me feel more comfortable with using the 15# test.

getback Sat Feb 28, 2015 4:29 pm

Come join in the fun , sounds like you know your stuff and you look confident , Nice to look back at the good old days . I never tried to fly anything fast before here and I think I need some lighter glue lol!

JPvelo Fri Mar 06, 2015 11:03 am

And it off to the paint shop....

CEF speed contest Design Discussions (2014) - Page 14 SFvlbTy

KariFS Fri Mar 06, 2015 11:51 am

Looking good JPVelo! The Corsair has been one of my favourite planes ever since I watched that TV-series about Pappy Boyington and the Black Sheep many moons ago.

Just a thought about the bellcrank location... You could keep the lead-out guide above the wing tip, then run the lead-outs through the downward-pointing part of the wing and mount your bellcrank under the belly. You may even be able to modify your cowling so that the bellcrank would be away from the airflow, sort of "streamlined". The rules state that the bellcrank should be visible, otherwise it might even be able to hide it inside the cowl.

Again, just an idea from a novice Smile

JPvelo Fri Mar 06, 2015 5:31 pm

KariFS wrote:Looking good JPVelo! The Corsair has been one of my favourite planes ever since I watched that TV-series about Pappy Boyington and the Black Sheep many moons ago.

Just a thought about the bellcrank location... You could keep the lead-out guide above the wing tip, then run the lead-outs through the downward-pointing part of the wing and mount your bellcrank under the belly. You may even be able to modify your cowling so that the bellcrank would be away from the airflow, sort of "streamlined". The rules state that the bellcrank should be visible, otherwise it might even be able to hide it inside the cowl.

Again, just an idea from a novice

Thanks Kari!
I actually thought about doing just that but decided to tuck it behind the nacelle.

Jim

JPvelo Sat Mar 07, 2015 2:33 pm

Here's a link to the "Tourqette" article and plan. This is a 1/2a proto speed plane designed by Dale Kirn. I'm posting it to show the front leadout located slightly forward of the cg.

http://www.kotrc.org/events/torquette.pdf

roddie Sat Mar 07, 2015 6:50 pm

JPvelo wrote:Here's a link to the "Tourqette" article and plan. This is a 1/2a proto speed plane designed by Dale Kirn. I'm posting it to show the front leadout located slightly forward of the cg.

http://www.kotrc.org/events/torquette.pdf

Oh Man! What a sweet little design that is!!!!! Thumbs Up

getback Sun Mar 08, 2015 8:17 am

That is SWEET !!! and if 10 yr. old Jimmy can fly it maybe I could Laughing

is that a legal plane for building (the race)??

**Cribbs74** Sun Mar 08, 2015 8:22 am

Looks like a Baby Clown Bi-plane!

Cool.

pkrankow Sun Mar 08, 2015 9:43 am

JPvelo wrote:Here's a link to the "Tourqette" article and plan. This is a 1/2a proto speed plane designed by Dale Kirn. I'm posting it to show the front leadout located slightly forward of the cg.

http://www.kotrc.org/events/torquette.pdf

That is pretty cool. The aluminum plate should not scare anybody away from it as it should be an easy cut (not fast, just easy) using a coping saw and a bench pin (a bench pin is a 1x4 clamped to the bench hanging off a bit with a fork cut in the end of it.)

Phil

Ken Cook Sun Mar 08, 2015 11:42 am

I personally see no need for the plate. Dale Kirn's Torquey which is essentially the single wing version same construction didn't use it. Truth be told, the problem with small 1/2A's is keeping heat within them and not trying to dissipate it. The only time the plate would be effective is when the engine isn't running and the upper cylinder heat would quickly heat soak through the case and onto the plate. This in turn in my opinion could assist restarts. Aside from that I see no reason to use it.

JPvelo Sun Mar 08, 2015 12:25 pm

getback wrote:That is SWEET !!! and if 10 yr. old Jimmy can fly it maybe I could is that a legal plane for building (the race)??

Eric,
Unfortunately not legal for the race, just some good speed plane info.

If I were to build a biplane for the Tee Dee class it would be this:

http://wp.scn.ru/en/ww2/f/22/83/0

http://en.m.wikipedia.org/wiki/Avia_B-534

The dimensions are near perfect.

Jim

JPvelo Sun Mar 08, 2015 12:27 pm

roddie wrote:
JPvelo wrote:Here's a link to the "Tourqette" article and plan. This is a 1/2a proto speed plane designed by Dale Kirn. I'm posting it to show the front leadout located slightly forward of the cg.

http://www.kotrc.org/events/torquette.pdf

Oh Man! What a sweet little design that is!!!!!

There may be a 150% version in store for the sportsman .15 I just picked up on eBay.

roddie Sun Mar 08, 2015 1:12 pm

Ken Cook wrote:I personally see no need for the plate. Dale Kirn's Torquey which is essentially the single wing version same construction didn't use it. Truth be told, the problem with small 1/2A's is keeping heat within them and not trying to dissipate it. The only time the plate would be effective is when the engine isn't running and the upper cylinder heat would quickly heat soak through the case and onto the plate. This in turn in my opinion could assist restarts. Aside from that I see no reason to use it.

I wonder if the plate.. along with the 3/8" sq. hardwood beams would help to dampen the tank from vibration/fuel-bubbles? It certainly makes for a sturdy nose and mid-fuse, as well as providing for a nice strong fuse-mounted bell-crank too.

It appeals to me because the design incorporates some thinking outside the box which isn't always a good idea.. either because it's more work than necessary.. than a simple design that accomplishes the same thing.. or it adds weight, when compared to a more conventional design. I like seeing how different modelers design strength into their Speed-ships.

I'd like to see one of your Norvel engines on a Torquette!

pkrankow Thu Apr 09, 2015 9:01 pm

OK, does a "tandem" wing aircraft fall under biplane rules? The span of the forward and aft wings are nearly the same.

Phil

JPvelo Thu Apr 09, 2015 9:08 pm

pkrankow wrote:OK, does a "tandem" wing aircraft fall under biplane rules? The span of the forward and aft wings are nearly the same.

Phil

Go for it!!

Sounds like fun!

pkrankow Thu Apr 09, 2015 9:23 pm

JPvelo wrote:
pkrankow wrote:OK, does a "tandem" wing aircraft fall under biplane rules? The span of the forward and aft wings are nearly the same.

Phil

Go for it!!

Sounds like fun!

Alright. I might have to. 12.5 inch wingspan sounds pretty nice!

Problem is the example I am looking at has fixed LG AND wing struts... just added drag. I could omit the struts I suppose.

Phil

modelbuilder49 Thu Apr 30, 2015 5:03 pm

JPvelo wrote:Mike,
I plan on using an external bladder secured through the spring end of a safety pin.

Greetings JPvelo! I really like your model .... it's sooooo kool! I would like to know where you got your wheels from or if you made them, just how did you do it because I'l like to acquire 3 or 4 sets for my "little birds".

Jim Carter

JPvelo Fri May 01, 2015 7:28 am

modelbuilder49 wrote:
Greetings JPvelo! I really like your model .... it's sooooo kool! I would like to know where you got your wheels from or if you made them, just how did you do it because I'l like to acquire 3 or 4 sets for my "little birds".

Jim Carter

Jim,
Thank you. I believe they are Glenn Lee racing wheels. I put the word out on Stunthanger that I was looking for them and someone came through. It's been long enough ago that I don't remember who it was.

Jim

modelbuilder49 Fri May 01, 2015 4:49 pm

Jim,
Thank you. I believe they are Glenn Lee racing wheels. I put the word out on Stunthanger that I was looking for them and someone came through. It's been long enough ago that I don't remember who it was.

Jim[/quote]Okee dokee!

Jim

getback Sat May 02, 2015 6:52 am

Google ed it http://www.planethobby.com/collections/vendors?q=glenn+lee There are other sites that have them too , mite get me some Thanks Huh...

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