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-   -   Sheet wing racer revisited (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/11611403-sheet-wing-racer-revisited.html)

gas-flyer 01-02-2015 10:24 AM

Sheet wing racer revisited
 
1 Attachment(s)
Hello fellow speed freaks. So I'm a long time reader but never posted. So here is my version of the Mini Magnum and model I call Tripps (as is triple digits)
The Mini has a built up wing very similar to one posted by CP. I was able to got 89 mph, Galbreth head, APC 1/2a pylon prop on 30% Helo fuel. "Not fast enough" so reduce surface area and weight. This lead to a sheet wing racer that was as clean as possible and came in at 9oz. Although I don't have a good dopler or radar reading on the Tripps we (at the field) are pretty certain the 105 has been topped.http://www.rcuniverse.com/forum/atta...mentid=2059852
Sorry but I will have to resize the Tripps picture its to large. It looks much like the Cheeta that was posted not to long ago. So until then "Fly fast"

gas-flyer 01-02-2015 10:34 AM

Tripps
 
1 Attachment(s)
Well I manage to get the Tripps photo resizedhttp://www.rcuniverse.com/forum/atta...mentid=2059855Same motor from The Mini Magnum, only 2 channel no throttle. She is fast!!

combatpigg 01-02-2015 11:30 AM

Man..!
You did a great job of getting down to the bare minimums.
I'll bet it's good for 105 mph. If you were to do the "Toad Mods" on the AME, you have a plane that will take full advantage of that, too.
Toad hangs out at rcg...but he's got his old RCU posts floating around in CyberSpace. I've found that Google searches can pan out with the right key words.
Basically, the mod improves transfer flow after you notch the skirt of the piston and grind a corresponding notch in the crank's counterweight. At BDC [and a little bit before BDC] the transfer port has an unobstructed path after you do the mod.

I like the color of the leading edge on the red plane....is that paint...?

Your Magnum turned out very slick and I'll bet it looks great while it's zooming around and passing the bigger planes....

gas-flyer 01-02-2015 12:01 PM

Pretty much 2 to1 lap ratio at our field .I mostly fly it with the sky to myself on account it with go right the tail pipe of anything in front of it. By the way take some credit it was total inspired by your post on sheet wing racers. So thanks you.

gas-flyer 01-02-2015 12:04 PM

Its all monokote metallic scraps don't remember the color names

combatpigg 01-02-2015 08:05 PM

It's not easy to get your correct CG with such a long tail...good job doing that.
How did you handle the hook up of the elevator halves...?

airraptor 01-03-2015 09:24 AM

how is this extreme speed? I know its fast for 1/2A but not extreme

aspeed 01-03-2015 11:15 AM

Scale speeds. 1/8 scale from a .40 size pylon racer, makes about 1,000 mph. Hard to see too.

speedracerntrixie 01-03-2015 12:18 PM


Originally Posted by airraptor (Post 11953585)
how is this extreme speed? I know its fast for 1/2A but not extreme


I think ink it's kinda cool, not really fast but a good practice airplane because something that small is challenging at 100 mph. Not what I would think is a club friendly airplane though. Maybe we are just too uptight here in Ca. but the lack of throttle, landing gear and the noise would really get the club old ladies all wadded up. Lots of potential though, think about a sanded out balsa wing glass bagged with skin hinges. Then again, something like this only needs one aileron.

combatpigg 01-03-2015 12:39 PM

I think if we made airraptor the new forum moderator, that would be the "shot in the arm" that this forum needs to make a glorious comeback to it's former glory.

combatpigg 01-03-2015 01:04 PM


Originally Posted by speedracerntrixie (Post 11953693)
............... Then again, something like this only needs one aileron.

I've tried just 1 aileron a couple different times on this size plane and there isn't enough roll control at low speeds in mild wind. You end up bowing to the whims of the Wind Gods and going with the flow until it lands 400 feet away.
The old "Fuddy Duddies" at the local club field enjoyed watching when I brought out a 1/2 A Speedster. This generation of men were the first Ski Jumpers, the first Surfers, the first Drag Racers, the first Motorcycle Hill Climbers, the first Ball Turret Gunners, P-47 pilots, Flame Thrower Operators, the first Oval Track Sprint Car Drivers......in other words, these old "Fuddie Duddies" were actually Men Amongst Men in their day.

speedracerntrixie 01-03-2015 01:14 PM


Originally Posted by combatpigg (Post 11953720)
This generation of men were the first Ski Jumpers, the first Surfers, the first Drag Racers, the first Motorcycle Hill Climbers, the first Ball Turret Gunners, P-47 pilots, Flame Thrower Operators, the first Oval Track Sprint Car Drivers......in other words, these old "Fuddie Duddies" were actually Men Amongst Men in their day.

I don't think we have any of those around here, we have the first code writers, the first CAD engineers, the first clean room operators.........well you get the idea. We have one guy here who has a YS115 powered P-40 set up with a single aileron, it has a bit more cord and he flies on one rate and lands on a higher rate. I've paid very close attention to his flying and at the end of the day I can't tell it only has a single. May be different on a smaller model with lower Reynolds numbers though.

combatpigg 01-03-2015 02:26 PM

Well, I can only speak of the original gang of guys I met when I first got into the local club. Many of them knew each other as kids, then reunited after WWII to become air modelers in this community. Once I got to know them, they turned out to be much different than first appearance...but there were TWO old guys I recall who DID not like seeing the new and strange toys [and toy operators] that were showing up in the 1980s - 1990s.
As a new comer, you usually had to go through a lengthy apprenticeship at the field, then a air-worthiness test where they had you perform a series of tasks with your plane, then they would take your radio from you and hand it back with the trims messed with and the plane flying inverted. Those who passed were given permission to fly solo. I never had to go through that rigamarole. I brought a fast 1/2 A model with me and the reaction was "If you can fly that thing and do the stunts that we call out to you, then you can fly here".

speedracerntrixie 01-03-2015 03:30 PM

Forum participation was brought up earlier. Airraptor and myself race the same warbird series. I for one would be more then happy to share some content and I think he would too if there is interest. We both run 4 strokes but have airplanes that are capable of 180 mph and will be shooting for 200 mph this year.

combatpigg 01-03-2015 03:45 PM

Anything speed related is better than nothing.
Raptor has been signed on at RCU for over a decade and to my knowledge has never contributed a build thread or just a "How To" article about how to prepare an engine.
Yet he feels the need to tell a newcomer to this forum that HIS 1/2 A speed thread isn't qualified to be here.

speedracerntrixie 01-03-2015 03:52 PM

Well, I'm not going to get into that but he is someone I keep an eye on come race day, the has good thumbs and his airplanes are always fast enough to win. He has been a good guy to hang out with. He is somewhat direct but that's just him. Let me dig up my old Macchi thread and add some pictures of the new builds.

MJD 01-04-2015 08:29 AM


Originally Posted by airraptor (Post 11953585)
how is this extreme speed? I know its fast for 1/2A but not extreme

If this forum were filtered down to only the bona fide extreme speed models, it would get pretty thin wouldn't it?

I think anything that is attempting to push it for the engine class or in any other way is legitimate - for survival and a reasonable level of activity.

This 105mph 1/2A effort is far more of a genuine modelling effort and a legitimate attempt at speed, than bolting a Jett .56 to an ARF prop jet and the other sport planes that get posted here. A while ago I sarcastically suggested that there should be a separate forum for prop jets, since so few of them have anything to do with extreme speed, and often don't even qualify for "speed worth reporting".

aspeed 01-04-2015 09:07 AM

www.youtube.com/watch?v=rkWK7CLYefs seems fast to me. It would certainly demand your full attention. Hey, looks like CP.

combatpigg 01-04-2015 10:20 AM

That purple Delta was my very first "1/2 A Speed Trainer" to test fly my very first really hot Russian Combat engine, the FORA .049.
As it turns out, it was a conservative choice to make the plane fairly large and easy to control. At the time, the speed [maybe 90 to 100] was pretty thrilling and that FORA .049 turned out to be a fantastic investment compared to wearing out and breaking a bunch of lower priced 1/2 A engines. I never even had the backplate off that engine. I traded it to a friend for a VA .049 RC engine and that engine blew shortly thereafter.
That Mustang was a bit2ch to launch with the high thrust line. There wasn't enough dihedral to help lower the engine relative to the wing, so even the successful launches were after a short dive to the ground. That model looks like a shriveled up prune now because the cockpit and turtle deck are bare foam covered with Towerkote. It had a lot of flights put on it..[mostly with the FORA .049] and every launch was an adventure. Flying the plane reminded me of the old saying, "I have a tiger by the tail".
Relative impression of speed....about the same feeling and reaction time as flying my Nelson .40 powered delta.

gas-flyer 01-05-2015 07:27 AM

Thank you to CP and MJD for sticking up for the new guy. No its not a 200 mph bird but it was a challenge to build it as sleek and lite as possible. So CP you asked about the elev linkage, its a single pushrod just to the aft section of the fuse and splits (Y) to a couple of small music wire rods and 1/16th ply horns. The aileron servo lays on its side a drives a bell crank to keep the profile down to a min. The rx batt is 4 aaa cells split into to groups of two cells, 2 in front and 2 behind the elev servo to get the cg. The club I fly at thinks its pretty cool and has no complaint about the noise.

MJD 01-05-2015 08:19 AM

I think it's harder to go over 100 with a 1/2A than it is to to crack 150 with a .46. Unless you spend $200 on your .049 that is.

iron eagel 01-05-2015 04:42 PM

Going over 100 with a 1/2a is as doing 200 with a .40 in my book as well.

combatpigg 01-05-2015 05:10 PM

http://youtu.be/a-ZR-lqqWSc?list=UUvajm0pYeG7PvspskjQLq9A Point Oh For Nines, Dude...!

One CC is enough for me, too...!

MJD 01-05-2015 05:28 PM

Visually, that is certainly no less challenging than a bigger model going for the 200 sticker. Is that the model you said the wings still flexed on a bit? Or did you have it licked on this guy. Man - this must be circa 2007?

iron eagel 01-05-2015 05:29 PM

Wasn't that around a buck and a half?


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