Author Topic: line tension (Read 1020 times)

bob werle · « **on:** February 12, 2013, 12:33:45 PM »

Not beibg a speed/racing person i apoloigise in advance for this question. Our club holds a modified racing event with 1/2a hollow log type planes and a 1 desigh event with a Dale Kirn designed biplane. *I do not have the skill to modify an engine to a left hand crankshaft and was wondering what would be the down side of large rudder offset or out thrust to keep line tension? We fly on 42' lines 10 laps from a standing start.
Bob Werle

bill bischoff · « **Reply #1 on:** February 12, 2013, 01:05:11 PM »

I would use a bit of extra tip weight rather than lots of engine or rudder offset. A slightly heavier airplane will accelerate more slowly, but be arguably just as fast as a lighter airplane. Lots of offset will slow you down. Of course if you are running a reed valve engine, it will run "backwards" just fine. All you would need is a different prop and different spring starter.

bob werle · « **Reply #2 on:** February 12, 2013, 01:57:58 PM »

Thanks
The one will be a reedee bot the Dale Kirn design will be a TD. Thanks for the info. Never thought about tip weight
Bob

Bruce Van Hoozen · « **Reply #3 on:** February 12, 2013, 09:29:20 PM »

Bob,
Is this a racing event or a speed event? Changing the direction of flight is also a option. (ie:CW). The only problem will be getting used to the direction change-you will get dizzy as if first learning to fly.

Keep your lines tight,
Bruce VanHoozen

GregArdill · « **Reply #4 on:** February 13, 2013, 03:34:10 PM »

The other technique that a lot of stunt and sport fliers don't get, is leading the plane. That means keeping the model behind the handle. Just like whipping only not so much arm.
This will help ensure you always have line tension and the model stays out better.

If it's a proto type event (timed from a standing start) the take-off is crucial. You MUST stay in front of the model. Run with the model and spiral into the centre on release.

Have fun.

Greg

bob werle · « **Reply #5 on:** February 14, 2013, 04:08:04 PM »

It is a proto type event, The plane is Dale's Torquette,a small bi-plane. It timed from a standang start for 10 laps on42' lines (1/2 mile) We have it as a low key thing for stunt flyers in our club to try something different. We run on 10% fuel and suction only. Dale was such a greatdesigner we had to pick one of his designs. One of the Torquettes was modified for a real 1/2A proto and did better than 84mph but on pressure and more nitro. Thats hard core. The stunt flyers were not to happy with less than 2 seconds lap time. See Larryt thread in the 1/2a srction on his Zippy racer.
Bob

Paul Smith · « **Reply #6 on:** February 14, 2013, 06:37:46 PM »

10% nitro is OK for big engines but sort of a killer for 1/2A's. The 42' lines are OK for high performance engines (good TeeDees and above), but also a killer for run-of the-mill 1/2A's.

Joey Mathison 9806 · « **Reply #7 on:** February 14, 2013, 06:57:15 PM »

YES THE LOW NITRO DID SLOW DOWN THE SMALL BORE CLASSES BUT 140 MPH IN 1/2A SPEED IS NOT ENOUGH DROP FROM THE HI NITRO DAYS TO SAY THAT IT IS A KILLER. I SAW ONE OF THEM LITTLE BI-PLANE PROTO PLANES TURN IN A 90 MPH FLIGHT ON 10% NASS SUPPLIED CONTEST FUEL THIS PAST WEEKEND @ WHITTIER NARROWS RECREATION PARK.

Paul Smith · « **Reply #8 on:** February 15, 2013, 09:27:21 AM »

I'm referring to Cox 1/2A's not the modern Russki .049's that easily beat an old .19.

Joey Mathison 9806 · « **Reply #9 on:** February 15, 2013, 06:17:28 PM »

Yes a TD was entered in the 1/2 a speed event also last weekend and it turned in a 75 mph flight. you correct sir.

PaulGibeault · « **Reply #10 on:** February 19, 2013, 09:10:16 PM »

Hi Bob,

For safe proto take-offs you need 4 things: In order of importance:

1. Your lead-out position must be correct. What's correct? Hang your airplane ready to fly w/o fuel. Move the leadouts either back or forwards until the nose points out 2 degrees. This is a great starting point. You can go less, but then the line tension on take-off gets less & less until it rolls in on you...
2. Use of a "SUB RUDDER" really helps keep the lines tight on take-off.
3. Use (initially) 1/3 oz tip weight which can gradually be reduced a bit at a time until the take-offs become too light on the lines. ( I use lead shot pellets + CA glue for this)
4. A handle with less than 2" of line spacing. This produces a smooth flying model & SMOOTHER take off.

You DO NOT need any rudder offset nor engine offset if you follow the above. All those things do is un-necessarily slow you down & that is NOT the idea of going fast in proto when the other above mentioned items will ( very well) take care of you..

I wish you the very best of luck!

bob werle · « **Reply #11 on:** March 02, 2013, 11:06:20 AM »

Thank you all for your information. as a 70+ sport flyer now trying to fly stunt amd proto all info is welcome. I love to buildsnd do more of rhat than fly. As a saide note does anu of you know of a mouse trainer called Burp? Ibuilt one but haven't hadthe nerve to fly it. I still get dizzzzzzy.

PaulGibeault · « **Reply #12 on:** March 04, 2013, 11:09:19 AM »

YES, the "Burp" is a rather nice mouser using a 1/8" ply fuse. It flies well on 26-35' lines. If you use a 5D X 3P (preferably nylon) prop, it will not be too fast. (certainly not too fast on AMA 42' lines)
FLY IT BOB! It's not like you'll have a lot to lose, right? Builds from scratch in a day!
Good Luck.

Cheers, Paul

Author Topic: line tension (Read 1020 times)

bob werle

line tension

bill bischoff

Re: line tension

bob werle

Re: line tension

Bruce Van Hoozen

Re: line tension

GregArdill

Re: line tension

bob werle

Re: line tension

Paul Smith

Re: line tension

Joey Mathison 9806

Re: line tension

Paul Smith

Re: line tension

Joey Mathison 9806

Re: line tension

PaulGibeault

Re: line tension

bob werle

Re: line tension

PaulGibeault

Re: line tension