Mike Connor

My Feedback: (5)

Yes, the audio can be faked but I think something else is going on here. Feel free to claim a 170 mph Outlaw without a video but aerodynamically speaking, It didn't happen, not in level flight without a tailwind. Just my opinion, but I need more then one audio that, BTW, has not been produced yet. To me this is a matter of common sense, not wishful thinking.

ArthurD

Come on down. It's nice here this time of year.

evan-RCU

What's your landing area like? Smooth grass? I may have to make a trip to this Xanadu land of speed.... where is it so i can google earth it too... If he;s getting 170 out of an Outlaw maybe I can get 270 from my 230mph F5D.... Actually I don't even want to think about that... [X(]

Strykaas

Arthur, OK, you don't have any camera... But don't tell us none of your club mates have one ... I'm pretty sure you CAN post a video of your ship and become FAMOUS (errr on RCU) !

ArthurD

Strykaas,
Not to sound brutal here, but it really doesn't matter what anyone else thinks. And please don't take that wrong; I don't mean it that way. If someone wants to believe, they will. No amount of convincing proof will change someone who doesn't want to believe. I have nothing to prove, claim or gain. I'm way too old to crave recognition and fame enough to lie about it, especially in public. If anyone wants proof, they're welcome to come get it for themselves. If I don't crash it first they can watch a flight and see, hear and video to their heart's satisfaction. I'll even provide all the hospitality they could ever want while they're at it. My goal is not to be king of RCU or any other kingdom. We're just a couple of old country boys having fun with fast model airplanes because we got bored with trainers years ago.

I've given you all the specs on my plane. There's no reason you can't duplicate it and see what you can do. And I hope it's 181 MPH!

combatpigg

My Feedback: (3)

Well, the deal is that the world of model airplane speed is usually so predictable that it is boring. Kind of like setting up a car for the 1/4 mile drags. Experienced observers can tell pretty close what to expect based on seeing the same basic batch of nuts and bolts go down the track over and over. This thread is timely for me because I've been considering which engine to buy when my OS blows up someday. The Heliproz website rates 30 class engines and does not have much good to say about Webra .32-.36. There is a guy at the tach forum who is running a piped Weston .36 at 22,000 rpm with a 8x6 and he loves it. I've seen Nelson .36s turn 8x7 props about 22-24,000 with open exhaust. I don't have a calculator handy [before my post times out] but would need to turn a 9x7 pretty fast to do 169 mph...I'll guess over 25,000 rpm?

Strykaas

Where is the "airflow changes to nose" ? Engine cowling ?
While indeed there is not point in becoming the RCU King, RCU is still the place where we learn from each other and try to share as much as possible to contribute to the community... without teasing too long or too much

Ok, let's start. What is the boca part # ? I think I shall order some soon...

Those ailerons and rudders edges are not that blunt (stock)... so not a lot of room for improvement. [:-]...

Concealing those servos is indeed a big plus to the stock installation...

gofastz

Guys' Guys,
The file is available to anyone that would like a copy..... I ran the test and produced the results.... Please feel free to check my results.... Gofastz

evan-RCU

Remeber this is ground speed. On a 40mph windy day it is very possible....

ArthurD

Strykaas,
BEARINGS: Boca Bearings part number is: ENK-004C-HP. This is a kit of two ceramic bearings. I worked with them to make up this kit since they had not sold ceramics for the .36 Webra before. They had lots of bearings but didn't know what size the Webra needed. The kit identifier was the outcome of that effort. If they have trouble finding it in their records, let me know and I'll call them.

NOSE AIRFLOW CHANGES: Notice the blunt firewall surface extending past the cylinder head? Form a triangle of solid balsa to streamline that area. Shape it as you think best for reduced drag. Mine continues forward at the same angle of the leading edge to about the center of the cyl head. You obviously have to leave room to get the glow plug ignitor attached. Maybe you can design something with a hole in it for the ignitor and make something better than mine.

TRAILING EDGES: The ailerons are fairly well trimmed. The rudder has a very blunt TE; not tapered at all as it comes in the ARF kit. I began by cutting my rudder square so the plane would sit on turf in a three-point stance holding itself upright for launching. (Never got up the nerve to try it) The rudder is about 5MM think at the trailing edge and will take a lot of trimming to make it a smoothly tapered knife-edge. (See below for another idea.)

RUDDER SERVO: This servo is mounted inside the top hatch with just the tip of the control arm peeking out. If I was doing all this again, (and I could crash at any moment) I would not install a rudder servo and all it's hardware. Actually, with the huge vert stab already built into the basic design, it may be possible to leave the hinged rudder off entirely. In that case we'd just taper the stab.

Strykaas

Thx for these details.

evan-RCU

My scratch built Outlaw with as much aerodynamic work done as Arthurs is good for 130 with a full tuned pipe OS .32. I don't have fancy bearings though....

Strykaas

Evan, did you try the 9x7 ? I seem to recall you advocated the 8x8... It won't yield 40 mph though...

pilot man

My Feedback: (1)

Hey ArthurD:

This is Tim. Great thread that you have going here. I can attest to the fact that you are a speed nut. I can believe it based on the setup alone. Speed increase is proportional to drag elimination and weight reduction/or power increase. I cannot wait to drive up the JAX to see your setup. Hopefully, it will still be in one piece by time I get there>


Anyway, you are great at what you do, and that is build fast planes. Keep it up.

Cheers,

Tim
aerospace engineer/model airplane flying nut#2

ArthurD

Evan,
That's a very nice and clean airfram you have. What do you think about getting a .36 Webra and see how it works out for you?

evan-RCU

Looks like I'll have to.....

ArthurD

You'll be happy. Just be sure you cut the header so you'll get the very high RPM's. Longer is Slower. That's probably the single best thing we did to get good speed. So many of the photos we see here shows the header very long. I can't understand why. If you want a photo of my final perfect length let me know. Also, don't forget to reduce the diameter of the pipe outlet. Can pic that also if you like.
If you have trouble locating the .36 I can send you several dealers who say they have them in stock.

ArthurD

Hi Tim, how's the Sikorsky X2 'chopper coming along? We all want a free ride soon, and I'm first.

Thank's for the kind words, and as you certainly know, most of our work is just paying attention to what others have found to work well, particularlly the manufacturers, and faithfully follow their lead. The wheel has been around for a long time; improving it is very difficult.

Come on up to Jacskonville anytime.

evan-RCU

Look at mine in the pic is that too long? Send a pic so I can compare. Sometimes you should not redure the outlet diameter, depends on set up.

So where is your field, I may come down.

ArthurD

Evan,
A few pictures are included here. It's hard to describe exactly so the pictures may help.
Here are the numbers:
Header: 73MM from the weld to the end, measured on it's outside radius.
Coupler: Leave about 1/8 " between the header and pipe
Pipe: 302MM tip to tip. Notice this is about 12MM shorter than stock pipe because I wanted the header to be a little longer and so cut the pipe instead to keep overall length right. You'll be about 12MM too long if you don't do the same thing, or you could just cut the header 12MM shorter. The all-up exhaust system is 377MM from the header weld, through the coupler, to the pipe's reduced tip end.
Exhaust Tip: ID of reducer is 7MM
Pressure Tap: At the rear of the largest diameter. See the pic.

ArthurD

Here's the link to our field:

http://www.gatewayrc.org/ Be sure to let me know when you're coming. I'll be our pleasure to have you visit.

Wiggy

Arthur,

Do you know what the rpm reading is? What prop are you using? I have an Outlaw arf that I was planning to sell because it wasn't fast enough for me. Perhaps I will have to rethink this.

Wiggy

ArthurD

Prop is a 9X7, don't know the RPM, sorry.

drcspeed

Here is a video of a Electric Outlaw I fly  Pulling 2100Watts at 97 Amps on a 5000mAh 6 cell Lipo

 http://www.youtube.com/watch?v=egEWgocvuVo

Flyboy76

My Feedback: (14)

that sounds awesome!!!!!!!  what kind of speeds are you generating with that setup????

Geoff