Stuntman 23

Those wheels are super-cool Robert! You got those from Kustom Kraftsmanship? They used to have "all the jazz" for 1/2A flyers../ and lots of Cox "hop-up" goodies!!

yea.. take a good look at those. Nice spun-alum. rims... Lookin' sharp.. with streamlined tires. shyte...

Oh yea!................... I want to see the maiden.. and read the specs. I've been wanting to build one. Please let me know your specifics.., if you fly.

Thanks Roddie!!! I was glad to find the KK box with my 1/2 A engines….. Had a Nelson head adapter and plug in there as well ……Will like to play with that when appropriate….

I ordered some 5 x 3.5 three blade left hand props and a LH starter spring today…. I like the idea of best line tension cause it’s breezy more often than not were I live….Thanks Jim!…..

Will do on specs and maiden…. Trying to watch its weight along the way… .. Here’s a basic layout of its trim color for wing and stab if I can get the white glue and water thing to work…. Will find out soon …. Best!

Getting his color applied….. I’m making this one the “B” model…. Open cockpit

I Likey !! That Looks Great , did you mix white glue w/water to set the (what is that color paper ) your using ?

Excellent work. I really like the tank mounting and finish. Have you figured out what you are doing about the canopy?

Ron

Edit: Nevermind I went back and read a bit if you do ever want to do the canopy it’s probably available from Brodak. You could also just make a small wood form and melt a plastic pop bottle over it with a heat gun.

Thanks fellas!!!

Yes, it’s white glue thinned with water to stick the tissue down… First on the bare wood I wiped on two thin coats of semi gloss polyurethane with a cloth …. The wing has one coat coat of poly over the tissue… I’ll probably add one more….The fuse doesn’t have a top coat yet….The paper is Hallmark just simple red and blue….. Where I was doing it needed to be low odor so it worked out OK…..

I made a faux windshield and will cover it with silver paper….. Trying on this project to use what’s around the shop or easily accessible…. Thanks for the heads up on the canopy though…Fun project, I’m really enjoying it…

Had a little shop time today….. Still a good bit of odds and ends to do…. I ordered some Cox three blade left hand pitch props…. Please advise if I should add tip weight or not with these props…. Thanks!

I forgot to ask also…. Right rudder offset? The plans show 3/8”….. But I’ve read some proponents suggesting no rudder offset?….. What’s the difference?

The difference is how it fly’s I would start with zero offset and give it a whirl. If you have line tension issues and you rule out if the lines are too long, engine underpowered, plane being straight and leadout spacing etc. If all that checks out you can add a little offset. However, I personally would offset the engine before I offset the rudder.

I have busted off several stab/rudders while stunting and they flew the same with or without.  To much offset causes drag and yaw. Neither are desirable. Model looks great BTW.

I have never flew a plane with those kind of props . 3/8" is alot of offset and drag i would go with 1/8" IF it were me and engine offset 2* degrees .. I think that 3 blade is going to bee really slow and that can cause line tension problems . but give it a go and let us know how it does >>>

Wow, that's looking great, Robert!

I don't know what the 'right' amount of rudder offset is, but I used 1/4" on mine. Also 1.5 deg. right thrust.
It seems to be working well.

A very nicely turned out model -- you've done an excellent build.

Hey Robert! Your model looks really nice! Running a L/H prop alone; will negate the need for excessive offsets. This isn't common knowledge.. because there's only a select few model airplane engines that will run in either direction. The Cox reed-valve engines (.020/.049) are among the few.. and IMHO... lend themselves wonderfully to the 1/4A to 1/2A U-Control flyer.

Don't forget; you can also influence how the model "tracks" when you locate the lead-out terminations. You may opt to slightly "rake" the lead-outs rearward from where Goldberg Models specifies that they should be. Remember; nothing is written in stone. All models need to be properly balanced.

I'll mention a few things that you may already know.. but are worth thinking about. You've got a sheet-balsa wing..  Consider fabricating a hardwood bellcrank mounting. (balsa is too soft alone) and be SURE to support the elevator pushrod midway its length, with a "fair-lead" to prevent the pushrod from flexing under a load.

You can (and may need to) add nose-weight. Cox made a "heavy-hub" (prop-hub..) that they used with their "Super-Stunter". You'll need a 5-40 threaded stud to utilize it.. but it's almost 1/4 oz.




... just a detail that could come in handy. Your chosen fuel tank is.. ? 10-12cc's..? and positioned behind the firewall. The engine (as configured) is quite a bit rearward... as compared to a a Cox Golden Bee or Black Widow.. both having the 8cc. integral fuel tank. The heavy prop-hub/nut can be an attractive means of adding needed nose-weight.

Thanks guys on the requests for information….. Wonderful resource here!!! Trying to take all the advantage possible to have a good chance with first flights….. Will go easy on rudder offset and make it easy to reset if needed……. Yes, I think it’s cool too that the reedies can run either way…. I found Dale Kirn’s article on the 290 Special and he recommended a LH prop for line tension…. Course that’s a racing machine but still….

Great idea on the heavy hub… Going to put another order in soon and have found it already… Nice!….That’s one thing I haven’t done yet is check balance point mocked up….The tank is about 3/8 oz or 11 cc’s… I have checked weight though of all components less tail skid, push rod, and bell crank mount…. It’s at 4.5 oz now….. I think I can keep it under 5…..

I was thinking of a couple of plywood discs for BC mount an inch in dia or so…. Think it will crush the balsa?…..Maybe I could add some short vertical 1/8 dowel’s between the discs top stop crushing…. Jim sent a good link for leadout guide placement…. Will utilize that best possible…..

Thanks for all the support and advise  

It was my suggestion a few posts back to run a left handed prop in reverse. And it was mentioned that the Cox reedies were some of the few engines to happily run in either direction.

Then I remembered that my Stuntman from 60 years ago was powered by the Fox "Rocket 0.099".

And guess what? THAT engine with its piston porting was also happy to run either direction!

I had forgotten.

Hi Jim, Yes, That’s what initiated my order for the LH three blade props….. Haven’t received them yet but expect them soon….. Really like that idea!!….. SM 23 will be sort of a re-trainer for me so every little bit helps!!

A SM-23 with the Fox .099 sounds like a hoot!!….. I’m sure it got a little more line length as well…..Love the art work from these old prints….. Brings back a lot of memories….

While the Fox .099 might be a cool looking engine, its peformance is sure to disappoint. Maybe mine's just worn out, but they seem to be pretty asthmatic unless you use a small prop that allows them to wind up a little more.
I noticed on the ad that they mention an Enya .09. There's no comparison with the Fox. The Enya is waaaay heavier than the Fox, but it's also a far superior engine in both performnce a build quality. Too much for a 1/2A plane I'd say.

I haven’t used a Fox .09, but I have used a Fox .10. It was hands down the most pathetic thing I have put in the air. It was light, which was a boon however, the performance was so poor that it wasn’t worth the weight savings.

I imagine the Fox .09 is the same. The good thing is you have an external tank on your stuntman. This opens up other avenues as you can now run Medallions and TD’s. With your AUW being less than 5oz a Medallion is what I would be looking for. Good fuel draw and more power than most reedie Cox engines. You can also swap the cylinder and head to gain some good useable power. A TD doesn’t draw fuel as well, but a bladder can fix that.  You can also modify a TD using a medallion intake. It makes good power with the advantage of adequate fuel draw. The downside is it’s choked down a little and won’t run at full potential.

For now, just see how it goes with what you have. You may like it.

Personally I have never messed with LH props. I have never needed too. They work great on speed planes as there is zero offset on anything as offset lowers speed.

For what you are doing a regular prop is more than sufficient. My suggestion would be the APC 5.7x3 it’s a good choice and can be trimmed down for better performance.

At the time I owned my Fox 09 getting it started easily was more important than power. But it WAS gutless. I had installed it on a PDQ trainer and it flew that well. Then tried putting it on a PDQ Circus Prince rated for A/B engines. Not a chance of that flying. A Fox 15 woke things up for that plane.

The Fox .09 is very anemic but it works terrific for a beginner or a freeflight engine. It's a neat looking engine, just don't expect a lot of rpm's. The Fox .10 Hustler offers more power over the Rocket .09. I have two Fox .10's that actually perform well.

rdw777 wrote:

I was thinking of a couple of plywood discs for BC mount an inch in dia or so…. Think it will crush the balsa?

Thanks for all the support and advise  

Hi Robert, I'm not sure how much more you've done.. but wanted to comment here. I have used plywood discs (top and bottom) on my sheet-wing models. Around 1 inch dia. is fine.. but try to find  some "thin" plywood. If you can find some 1/64" stock (wing-skin plywood-used on model-gliders.. Sig Manufacturing used to stock it) That would be ideal. I would still position the discs' wood-grain "chordwise".. for the most strength. Naturally both top/bottom discs need to be glued-on.



The bellcrank's pivot-screw (machine-screw and nut..) need not be tightened to the point of crushing. Snug-tight is enough.. as long as the nut is either a "locknut".. or can be secured from loosening. I don't recommend mounting a bell-crank using a wood or sheet-metal screw.

I keep a stock of #2 thru #6 machine-screws/lock-nuts/washers (2-56, 3-48, 4-40, 5-40, and 6-32 sizes) for my 1/4A to 1/2A airplane hardware.

An assortment of K & S alloy tubing is also invaluable when you need to fabricate a bushing. Tower used to offer an assortment of K & S cut-offs.. cheap too.

Hi Roddie….I ended up using a piece 1/8 ply 1-1/8 sq with a 1/32 ply 1-3/8 sq for the BC mount…. Kind of like a flanged mount…..I cut completely thru the wing to install….. Glued with 60 min epoxy….



I had a “T” shaped plastic bushing to use for the bearing… I like the brass tube idea too!!
4-40 bolt and nut….. Still need to drill the holes for lead outs and push rod in the BC….Got the LH props today….. I had a Cox Corsair when I was a kid and was fascinated by the three blade props…..Hope they work good here….

Brought the plane with me again to the workbench away from home…. Hopefully get some more done this week…. Thanks guys for the rudder trim advice….. Think I’ll start with minimal…. Cribbs shouldn’t be tempting be with putting a Medallion on it….. Hard not to think about!!!