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Lil Speedy II -TD.049 Video 118 MPH Best Pass

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Little crash damage

Post  706jim on Tue Mar 15, 2016 4:31 pm

Probably little damage due to the extremely light weight of the plane. As I mentioned before, fast isn't my thing, but your work is SO impressive!
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Tue Mar 15, 2016 8:36 pm

Thank you guys,

András the ply fuselage was built robust enough to take the TD .020 and just enough wing to
handle the additional 14g weight with the throttle sleeve. If you do make one there are enough photos
to draw up something similar at 19in span. The design will work all the way up the scale of Cox engine classes
the round belly will allow nice landings with less risk to prop strikes. Through the use of ply you can
make a very narrow tail to enhance the speed. The biggest surprise was the effectiveness of the ailerons
with the fully symmetrical airfoil. Note the Lil Speedy in size allowed the engine to unload to
35,186 best pass the more streamlined NANO 36,337 rpm that's a 1,151 rpm increase and the engine
wasn't peaked yet as it was it's first flight and I had it backed off a bit as protocol. Will see about 1,600.

Jim just wet dirt no damage to the plane at 3oz RTF with fuel any field with good thick grass will
allow the plane to live through the worst. My field is a mix of open dirt,rocks and grass its a
toss up what you will hit.
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  cox24711 on Wed Mar 16, 2016 8:17 pm

706jim wrote: As I mentioned before, fast isn't my thing, but your work is SO impressive!

Nah I think it's not impressive. IT'S WICKED!! lol! Also I think brad is more than a 1/2a nut. (because I think we all qualify for that) He is the nuttiest nut of all the 1/2a nuts! lol! did you see the revs on that thing jeez! and the passes HOLEY COW! I have never see a plane move like that! in my life!

Brad ,KEEP UP WITH THE AWESOMENESS! Very Happy
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Thu Mar 17, 2016 8:24 am

Thank you Greg,

I plan to fly this weekend for test number 2 and hope to get much better video of it flying closer
to the video camera. Shamrock Shamrock Shamrock
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  getback on Thu Mar 17, 2016 9:26 am

That's just amazing !! I cant believe that engine can produce that kind of RPMs !! Great maiden even if it didn't do as you wanted I am sure you'll get it worked out . Thanks !! Eric Small Cox Logo
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Fri Mar 18, 2016 9:02 am

Thank you Eric!

Another shocker was when I put the TD .020 on the Lil Speedy see vid on the other page.
I didn't know the TD .020 could generate that much rpm.

30% nitro:
TD .020 / 3.75x3 / 29,554 best level / 31,419 best dive down wind pass
TD .010 / 3x1.25 / best pass 36,337 rpm

The flight ended early do to too much aileron throw but I think
best dive down wind pass will hit 37k

St.Pats Beers
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Tue Apr 12, 2016 8:33 pm



Published on Apr 3, 2016

Lil Speedy TD .020 / 3.75x3 / 31,257 rpm / 148.37 km h / 92.19 mph
Another good reading from a pass about 40ft up / 153 km h / 95mph
Winds 6 to 8 mph. 80 F / Per Doppler and audio app best passes
This is the fastest 3ch TD.020 RC plane currently on video for all to see.








Published on Apr 10, 2016

Cox TD .020 -Static Test Carbon 3x3 / Best Peak 30,764 RPM
88 mph, Est. up to 38,600 rpm unloaded 110 mph down wind passes.
35% Nitro / 20% oil / TD High Compression Glow Plug 1 shim.

Will test fly this new performance carbon prop this weekend and post a vid.
To date  30,764 is the highest rpm ever recorded for a TD .020 and this is just the static rpm!
Get ready to watch the first recorded 3ch TD .020 plane to exceed 100 mph!
It will scream to peak far beyond the average TD .010 momentous moment in the making.

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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  Cribbs74 on Tue Apr 12, 2016 11:26 pm

Nut,

Being a CL guy I don't really understand everything, but I can sure appreciate the amazing engine runs!

Great work and kudos to you for getting those Cox engines running superb and getting them out there for all to see.

Keep it up! I am a big fan.

Ron
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Wed Apr 13, 2016 1:16 am

Thank you Ron,

Yes little different animal but you could use a TD .020 and set up for CL Speed.
The various props I have been testing could adapt to CL to unleash some amazing
results.

Small Cox Logo

I have been looking at the next level for RC use here is a full size rendering.
Will use a single cell 4g 160 mah lipo for single cell 2g servos, over all weight
will be greatly reduce with the smaller RC gear and a simplistic low drag plane.
Servo in pic is the HK 2g. Full scale pic if you have at least a 20in monitor.
Can blow up the pic and match to your engine on hand.

Dart .010 and .020

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Ever heard of slip?

Post  VUgearhead on Wed Apr 13, 2016 8:25 am

Not to burst anyone's bubble, but just because a phone calculated an estimated rpm based on sound, and even if the engine is running at said rpm's doesn't necessarily mean the plane is travelling as fast as the engine rpm's says it's going. There is drag and all that that keeps the plane from ultimately flying as fast as the engine thinks it is.

Just like in electric motors, no motor rated for 1750 rpm actually runs at 1750 rpm. Friction causes what is called 'slip', so the motor only ever actually runs at maybe 1720 rpm.

Remember, there is no perfect frictionless system.

But it's still flying balls out fast!

The only true way to be sure, is to put a speed gun on it.
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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Wed Apr 13, 2016 9:51 am

Thank you, yes agreed the paid app I use give solid rpm readings with 60 rpm.

I have a Bushnell radar gun.

Here is the Doppler analysis verified wave shift,  best pass 95 mph.
Mind you this is down wind so constant speeds are lower.

Prop slip can be as high as 20% but with very low weight very small Reynolds numbers
on the plane the slip is much less, the static and dynamic speeds exceed thrust to weight.
My phone app reads mph within 8 mph of actual do to the plane type. Efficiency
at Wot is impressive.  

23,417 rpm static / .054hp / 40.3W / Actual Unlimited Vertical at about 40 ish mph /
Thrust is rated per the thrust calc 5.4oz and 67 mph static. Plane with fuel 5.28oz / 149.7g

It physically lifts straight up out of my hand this is not your typical TD .020 plane  Eyebrows
35% nitro the E-flite 3.75x3 has beef at the hub and a very thin blade that cobo with
a 50 Sq. In. airfoiled balsa wing 14.5in long fuselage works very well.
Wing is a SIG airfoiled plank sold as 4"x36" sheet Clark Y / airfoil was reshaped to a mild
7mm thick semi symmetrical airfoil.


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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Sun Apr 24, 2016 2:13 am

Update for Lil Speedy 106.48mph

Lil Speedy TD .020 best speeds to date.

Doppler Readings - Carbon 3030 best pass 106.48 mph
taken at 3:08. Low thrust was only good for speed passes.
Best Static 30,684 / 87.2 mph
Static at launch 29,985 rpm best pass 37,304 rpm 106 mph


https://www.youtube.com/watch?v=U7zAyzAawQg







2nd Test:
Per Doppler E-flite 3.5x3.5 best pass 105.12 mph
This one beat prop calc by 3mph. Taken at 4:29.
Best static 24,644 rpm / 82 mph
Best pass 30,742 rpm /105 mph
This one has potential thrust was reasonable so
reworked the prop -more back cut and tips rounded.


https://www.youtube.com/watch?v=BO4Zgvu28zg



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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Sun May 08, 2016 1:50 pm

Update


Published on May 7, 2016
Lil Speedy - TD .049

1 shim and HC Plug / throttle sleeve.
Stock venturi no screen, aluminum carb body. 30% nitro.

4.1 x 4.1N
Static 24,790 rpm / 7.4oz thrust / .127hp / 94.74w / 96.2 mph
Unloaded 30,492 best on Vid 1 / 118.4 mph per prop calc.
Vid 2 best pass 30,361 rpm. 117.8 mph

Doppler has it at 117mph at 1.47mins into the vid



Flies very fast constantly in all directions do to the amount of thrust on hand plane is 6.19oz RTF



4.1 x 4.1N  prop is more narrow with back cut. Carbon nylon mix.

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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

Post  1/2A Nut on Sun May 08, 2016 11:25 pm


Next Prop:
Was a 5x5 now a 4 x 5N / 2.6g weight was saved with more back cut and tapper
airfoil work on the trailing edge to help max the other props rpm.
Should hit 30.5k up to 145 mph this will be about it for the Lil Speedy
it's not made tough enough to endure much more speed.

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Re: Lil Speedy II -TD.049 Video 118 MPH Best Pass

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