CEF speed contest Design Discussions (2014)

I used to use the lid from a 5 gal. bucket staked-down in the center of the circle for a reference, with about 5 feet of clearance all the way around. If I could feel it underfoot.. I knew I wouldn't hit anything.

I got my official flight in the books and on the tube.

Yeah, it was cold here too. I had technical difficulties with my second run with the prop I thought would be fastest. I had cut down an APC but lost the prop screw bushing somewhere along the way. I rough cut a new one that didn't fit quite right. The engine ran faster, but  on the way back to the house my son said he thought the spinner had some wobble to it, so either it or the prop wasn't straight. The flight was one second slower than my official submission. Too bad because I flew level better as the wind had died. When it's all over and y'all can watch, you'll see I'm all over the place altitude-wise. But after the ten laps I did some victory loops and a couple of inverted passes.
Rusty

I managed to get Ian's flight in, albeit a poor one.

I think this is my last contest for a while to include the Tach Race. Too busy to make good on promises and don't wan't to be "that guy"

Jim extended the date twice and I still failed to get my own flight in. Kind of a bummer, but life is hectic. The weather here is crap and that hasn't helped at all. Snow, wind, rain, wind, wind and then we had some days with wind. Did I mention wind?

I'll stop with the excuses, it's just been a busy year.

Congrats to everyone who flew. I think you will all be happy with the prizes!

Ron

Aw Ron, they're not excuses. Like I tell Holley, they're Reasons!
Have a good chill and a Happy New Year.
Rusty

Being road bound for over half the year presents challenges. I have many things that get left behind that when I return my plate is very full.

Couple that with Oklahoma weather and it becomes near impossible to compete/train. Spring/Summer is easier as the weather is less volitile.

I really don't like not making good on things I sign up for. Folks put a lot of work into these contests and when things fall through I feel I let them down.

All I am saying is maybe I should take on less.

Ron

So how many people got their flights submitted?

I'm worried now. I was totally surprised and disappointed to find I was slightly slower this time. I did not expect that, but my over-sized lines were really fluttering in the wind and it spent as much time going up and down as it did round and round.. It looks like the competition is a lot more sophisticated this round.

Maybe I'll try to get some extra revs out of that engine and send it to Kim. I never have polished the crank, and the Tee Dee P/C is still too new and tight. I think I'll try a sloppy #1, sometimes they really turn up good revs.
Slow poke Rusty

We have six entries including mine. I will get them to the judges in the next few days.

Jim

I appreciate the effort by everyone on this forum in the set up and management of all the competitions whether or not I enter them.

Here I must give a special thanks to Ron who devoted the time to flying the "Rocking Donkey" for me. I was a little worried when I saw (quite correctly posted and highlighted) the disasters that entrants had had in flying these. Not worried because of the "Rocking Donkey" being turned into matchwood but that Ron would feel incredibly awkward if it had smashed under his care and attention.

It should be seen now that "scratch building" a "scale" look alike while not difficult does not always result in an easy flyer.

He took on this challenge (with the limited time available to him and at a cost in time available for his own model!).

The "Rocking Donkey" has 14 deg dihedral.

Cribbs74 wrote:Dihedral... Never seen it in CL. Not sure what it will do.  

I am not being negative mind you just genuinely curious.  Looks good though Ian!

It wouldn't be "Spitfireish"  without dihedral but I have now seen it fly and I was "over the moon" at the video Ron sent me.

There were issues with the NVA (my fault - after test running I forgot to put back the tube) and with the tank. Here, as ken has said before, my idea of waggling the plane around with the engine running does not test what will happen when it is on the end of the lines.

I also sent it set up to run on 20% nitro (not 30%+) clockwise propeller. Ron seconded his daughter as launcher and camera girl.

Again, I think he noticed that on launch it would want to climb and need a bit of rapid line tweaking. Dihedral plus semi symmetrical wing.!!!!!

Cribbs74 wrote:I managed to get Ian's flight in, albeit a poor one.

Ron

It flew! . No negative vibes please and your daughter is to be thanked for braving the launch and then switching operating the camera. Not many young ladies would do this!

I managed to enter the competition - don't care about winning or losing but was happy to see a rejuvenated Thermal Hopper take to the air.

Mind you I still reckon mine is the winner have flown the furthest, highest, fastest and landing at its destination in one piece.

Thanks Ron and

I'm REALLY disappointed that I couldn't get a flight done in time for this go-round! But the Conquest Bearcat is already set to go for this year, the Red Baron Mustang is ready for finishing and I'm eagerly looking forward to seeing the Tee Dee rules. I've already got a few ideas kicking around for that!

Best of luck to everyone and I can't wait to see the results!

Mike

Mike Mulligan wrote:I'm REALLY disappointed that I couldn't get a flight done in time for this go-round! But the Conquest Bearcat is already set to go for this year, the Red Baron Mustang is ready for finishing and I'm eagerly looking forward to seeing the Tee Dee rules. I've already got a few ideas kicking around for that!

Best of luck to everyone and I can't wait to see the results!

Mike

Hey Mike, maybe it's a "Bearcat Curse".. I know exactly how you feel Brother. I look at my airplane almost daily.. hanging by it's tail-hook from the ceiling in by basement. We both shared HUGE enthusiasm during our builds. We'll get em' flying!

Rusty, you mentioned having "oversized lines".. just curious what were you using? I had made up a set of 42's for the first go-round using 30# Spiderwire EZ-Braid (.3mm/.012" dia.) and since then; picked up some 15#.. same brand (.2mm/.008" dia.) to try.

30# Spiderwire. It's great and tangle free for fun flying. They were dragging really bad during my speed flight. I had steel lines but got them kinked up. I've got a new set now.
Rusty

I was thinking.. (uhh ohh) about the idea of a CEF "Rat-Speed Fun-Fly" for sometime this Summer. What I mean by "Rat-Speed" is; any airframe, any size, any .049 Cox engine, any fuel and any line-length. Not a contest.. just some radical fun caught on vid if possible. Maybe try and build a launch-dolly for it.. to avoid small-wheels fouling a R.O.G. I'll bet we'd all get better overall launchings if we had good dolly set-ups. At least the model can get up to a decent speed for control input.

more on a dolly... basically a frame/cradle with 3 wheels; preferably 2+" diameter with soft tires. The front axle having 2 wheels spread at least the width of the wingspan.. and the rear wheel is a caster-swivel. Make a fuse-cradle (trough) placed high-enough on the frame for prop-clearance and run a horizontal dowel-pin through the bottom of the fuse.. near the C of G, and cut a slot in the cradle for the pin to locate. This should keep the model tracking forward on a larger pseudo-main-gear and hold it until up-elevator control is given. Rear caster-wheel will allow the dolly to turn around the circle.. and could also be drilled for a pin-stooge assisted launch.

EDIT: If you're having trouble visualizing this.. You'd first need to design a profile fuse that will extend below the wing.. enough to slide down into the grooved cradle (holding the model steady on it's roll-axis) and clean; having no obstructions (no gear on the model.. and short as possible cheek-blocks) only the dowel-pin to prevent forward movement. Building the dolly high enough would allow for making it's tail-wheel bracket adjustable for height. Lowering the dolly's tail-wheel would pitch the model up.. and with enough air-speed, it will rise out of the cradle without any control-input.

If preferred.. reinforce and slot the fuse instead .. and install the dowel-pin on the cradle. A row of holes on the cradle would provide for different pin locations for different models.

Any word from the judges, Jim?
Rusty

Stay tuned....

JPvelo wrote:Stay tuned....

So here's what I came up with today. This plane flew a 30:47 in the contest with a Reed valve space hopper. I flew it twice today with the Tee Dee and an apc 4.75x4, same prop as the contest. I flew it with and without gear. With the gear I got a 27.7 for 66.47 mph. Without gear I got 26.6 for 69.22 mph. My very aerodynamically clean reed valve stagerwing went 26.99 for 68.22 mph. Seems like the most important thing is aerodynamics.

Jim

JPvelo wrote:

JPvelo wrote: Seems like the most important thing is aerodynamics.

Jim

yea... but having a hot 22K+ engine run with that 4.75 x 4 APC prop and holding a dead-level course doesn't hurt! The reduced drag of lines that are 7 feet shorter will certainly raise the speeds of these models for the next round. Jim, your Air-Tractor I'll bet is close; if not over the 75 mph mark with the Tee Dee.. less gear.. on the shorter lines!

roddie wrote:

JPvelo wrote:

JPvelo wrote: Seems like the most important thing is aerodynamics.

Jim

yea... but having a hot 22K+ engine run with that 4.75 x 4 APC prop and holding a dead-level course doesn't hurt! The reduced drag of lines that are 7 feet shorter will certainly raise the speeds of these models for the next round. Jim, your Air-Tractor I'll bet is close; if not over the 75 mph mark with the Tee Dee.. less gear.. on the shorter lines!

I think I'm going to shorten the lines and fly it again on Wednesday. There was a noticeable bow and resistance in the lines today.

Here's video if the flight without landing gear:


Jim