2018 to 2019 CEF Run What YA Brung UNLIMITED speed contes (CLOSED)

I'm still in...just another 10 days left....I know.

I did figure out how to stooge launch. Been blown around by Barry in MS. Was.soaked by him this past weekend.

I did the reedy one but might give the TD a try still. I ran it up at home and it vibrates quite a bit so am not expecting much more than one lousy flight. The Norvel mount is good for a Norvel, but the TD piston must be heavier or something, and it foams up. Really nose heavy too, but I can finger that out. I would rather fly the Conquest, but don't really have a plane besides an F2D combat, and I would need someone useful to help launch. (and a half hour to prepare) Pretty hot here. 110 F with the heat index. Still have some time.

Today, I got out and it was hot. 103 to be exact and I wasn't liking it. The plane is TD powered and I built the coffin style tank. Picture quality isn't great but hey my son was dying in the heat as well. I would've preferred steel lines over the Spectra due to the drag. These lines were old and fuzzy so I was giving up some speed there. Fuel was a bit low on the nitro as this is Fitz fuels 24% Rocket nitro fuel. I estimate about 75 mph. The lines were just a tad over 42'.   https://www.youtube.com/watch?v=4wXLaDmSZXQ

Is this an official entry Ken? Hope so.

Ron, I posted a video earlier for my Black Widow mouser. I will call this last video of my TD flying a official.

Hi Ken what size prop was that?

APC 4.2x4     I really think that was about all I was going to get out of the engine. The engine is quite new and I still have 3 head gaskets in it. The only reason I didn't change it was that I haven't taken out any plugs. I was using Sig 35% early on switching to Cox Super Power fuel. Seeing that Cox Super Power is no longer available and Sig at the time didn't have any 35% I went with Fitz. I'm quite happy with Fitz fuels as I have used 1 qt through various engines and have had good starts and runs. One thing to mention is that this is the thick walled cylinder. I have some really good running thinner walled variants that I was going to try but it was just too darn hot. Certainly higher nitro was in order but this was a decent run.

Thank you for sharing Ken!
I have been using Fitz fuel for the last 4yrs. almost from the date he took
over from Flyboy's operation. Fitz Walker has done his homework and is
offering good fuel. He will mix any design mix you ask for as a option.
17% castor 6% synthetic to help wash away the castor is something I
am trying next for summer time running.
Unloaded RPM readings:
27.6k brief peaks to 28k ish. as the fuel level dropped rpm went into the 26k range.
103 - 104 mph prop pitch speed average take in the drag from the lines from there.
Given the fuzzy older lines it was running great for pulling 42' ish
You would surely fly faster with less line length to drag around.

I'm still in. This week, the weather may provide an opportunity to get the RWYB flying, for an official run. It's been hot, windy and nobody has been out to the circles to go flying. With the deadline approaching, I will encourage some help to document my attempt.
Keep an eye peeled! Thanks!

1/2A Nut wrote:
Unloaded RPM readings:
27.6k brief peaks to 28k ish. as the fuel level dropped rpm went into the 26k range.
103 - 104 mph prop pitch speed average take in the drag from the lines from there.
Given the fuzzy older lines it was running great for pulling 42' ish
You would surely fly faster with less line length to drag around.

 Just wondering if you can get a wavescope reading on it to see the actual speed, and then compare it to an actual stopwatch reading.

Yes Alan I can take that next step with the wav scope software.
Are you going to attempt another vid with a TD on yours?

Data based on temp of 75F / now we can see what collaborates with my rpm gauge data.
If 104 prop pitch speed minus line drag reading show 79.9 mph

Plane lost 24 to 25 mph due to drag. If it was hotter out lets say 83F  would be more like 78 mph.

Note I reviewed 3 passes taking the middle 3rd pass as the average of the three.
The rpm was the most steady at the start of the vid. Also the data is plus or minus
12.82 kph. if so then 115.77 kph or 72 mph worse case.




 

Recap:
Submitted for Alan:

Alan aka Aspeed
Per Alan: Estimated: 63.4 mph or 101.96 kph.
Best 5 laps on 32' lines, .009" dia. at 10.81 seconds
Cox Black Widow with Nelson plug
APC 4.5x4 / 15% Nitro
Average early fast laps per Doppler audio app.
23,821 rpm incoming  / 21,075 rpm outgoing Est. 22.45k rpm
85 mph prop pitch speed

Hmm... The first 5 laps avg ~2.5 seconds, 72MPH on 42ft lines.

You tube shows 13 seconds for 5 laps by just stopping the vid on the 5th pass.
Best I could get with my digital timer was 12.73 / 2.546 seconds per pass.
Ken was cleaver to edit the vid with the plane in front making a pass when you
hit play. No doubt could hear rpm dropping off for the last 4 laps out of ten.

42ft. lines for 10 laps = 1/2 mile
1799.28 ÷ 26 seconds = 69.2 mph

The above information had me take another look at the wav. scope data
I blew up the scope full screen and reset the data lines on the Doppler shift
and seems to make more sense to the lap times.

When I first launched, it was really on. My son had me on the stop watch at 2.38 seconds. The tank is too large and I topped it off. He didn't video the entire flight which I wanted him too. This portion of the video was a little past the 1/2 tank mark. Nonetheless, I was happy with the results.

Yes then most likely averages

Ken 10 laps / 42' lines
1799.28 ÷ 24 seconds = 71.97 mph

Alan 13.125 laps / 32' lines
1799.28 ÷ 28.5 seconds = 63.13 mph

The run was great!!

I just figured time was the easiest way to get the speed.

1/2A Nut wrote:Yes Alan I can take that next step with the wav scope software.
Are you going to attempt another vid with a TD on yours?



 

I have the plane in the van ready to go.  Brought it to the old timer club contest to fly, but really could not stand up any more.  Long day.  I am not happy with the tank mount shaking so much but will try it out.  Maybe get a Norvel on too.  Kind of  interested in comparing the black widow, TD and Norvel all on the same fuel and plane.  Maybe the .06 too if it doesn't break on landings.  I think the wave scope is off a bit, I don't really believe it too much.  Good for estimates.

The wav. scope needs a clean doppler shift reading you have to be
careful when you place the data lines in. My second effort I blew
up the graph full screen to insure good placement.
31 - 32 mph loss in drag is rough with CL.

A HQ carbon blend 4x4.5 speed tip version could be a game changer with a reed engine.
They don't hold up to ground hits, low weight / good airfoil for speed.

GUS THE I.A. wrote:I'm still in. This week, the weather may provide an opportunity to get the RWYB flying, for an official run. It's been hot, windy and nobody has been out to the circles to go flying. With the deadline approaching, I will encourage some help to document my attempt.
Keep an eye peeled! Thanks!

I'm with you Doug. When there's been a window of opportunity; the weather has been at odds. I'd been used to launching my C/L models with a "stooge".. and this event will be no different.

I recently learned of a local elementary school and grounds, that will be completely abandoned for this coming Fall semester. I plan on investigating the site tomorrow. I also discovered another local school-ground this past weekend, which could possibly lend its smooth-paved areas to a satisfactory R.O.G. launch of my C/L airplanes.

I intend to bring several models and support-gear to whichever site gets the green-light.

A paved circle would be so nice. It used to be a free for all at shopping centres on Sundays for the marching bands, 1/8th nitro racers and control line guys. Now everything is open Sundays. Even the factory parking lots are full now with the continental shift work and weekend shifts. Some shopping centres have gone bankrupt and are empty in the US, Toledo comes to mind where there is a good 1/8th track. Around here real estate is pretty hot so there is nothing vacant except Detroit which is another story altogether. I'll take off from the plywood again and crash in the grass. My lovely assistant might not be comfortable hand launching.

Well it survived. Lots of trouble with the TD. Just a parts one I scared up with an .049 cylinder and .051 carb housing. Tubing was falling off the nipple as soon as it go fuel on it. My stooge would point the plane at my head, so I had to call for the wife. Doesn't go lean enough, just cuts out, so this is a rich flight. The lovely assistant was a bit slow and the tank is small with it running so rich, but I got 8 laps here if it loads. Very old 15% fuel and 4 1/4 -4" prop on 42 ft. lines. https://www.facebook.com/tatijana.feil/videos/2518982331517636/