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Old Oct 25, 2012, 08:02 PM
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Originally Posted by DerekB View Post
Thanks!

I see another one here.

The disadvantage I have is very little C/L flying experience. So I probably don't appreciate how important this device can be. Brodak's description says:

"Adjustable leadouts are an inexpensive way to dramatically improve the performance and handling of your airplane. Nearly every airplane must be trimmed out for flying and to improve performance. In addition, adjustable leadouts enable you to adjust to varying flying conditions, resulting in better overall handling and response. Brodak control-line airplane kits include detailed step-by-step instructions on how to install adjustable leadouts during the construction process."

At least I will be able to do it manually.

Can you describe what I should be looking for during flight to know which way, if any, the guides should be adjusted? How do I know when it's right? What is a good safe "starting point"?

Also, is there a good way to do a pre-flight check for guide location, like hang the airplane from the lines and see how much the nose angles downward. What should I look for?

Also, Brodak says "adjust to varying flying conditions". I just presumed there was one "right" position for a given airplane (other than carrier). I presume they mainly refer to wind (what else varies?). How would you set the guides for calm versus windy? I would guess you move the guides back during higher wind to get more outward pull?

To me, this is the biggest unknown regarding setup.

Derek
1. Hang model vertical from the leadouts with both leadouts put together. Model should have a 1-2 degree nose down attitude i.e. the nose points to what would be the outside of the circle flown. Good starter point. If it doesn't have enough "pull" or line feel, or it pulls too much, move the leadouts back or forward until you are happy with it. You should have a control feel that you know you are flying the airplane- it isn't too much or too little. This is something that is vastly variable. As long as you feel you have complete control all the time, that is where you want to be. Wind gust and the lines go slack, then be prepared to step or RUN back to maintain line tension. It's a lot like playing a game fish I guess.

2. I was told a long time ago that around 17 degrees rake on the front leadout is about right for the average sport model.

3. You need enough tip weight to counter balance 1/2 the weight of whatever control lines you are using.

4. More wind or slower flight needs more leadout rake to maintain line tension. If the wind goes up or the airspeed goes down, the leadouts have to go aft to maintain line tension.

5. Watch the model's side profile in flight. It should be square to you, i.e. one wing not lower or higher than the other if balance and trim is right. Of course it shouldn't be flying with the nose up or down in level flight either.

6. Slight nose heavy is probably best early on, tail heavy is a kaflooey for sure.

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Old Oct 25, 2012, 08:26 PM
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Canada
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Adequate line tension is THE name of the game with CL. Everything else follows.
Inadequate tension or no tension equals no control.. and a model aiming seemingly straight for your head :-)
Less of a personal danger (prop strike) problem with an edf tho.
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Old Oct 25, 2012, 08:38 PM
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Originally Posted by Bare View Post
Adequate line tension is THE name of the game with CL. Everything else follows.
Inadequate tension or no tension equals no control.. and a model aiming seemingly straight for your head :-)
Less of a personal danger (prop strike) problem with an edf tho.
I have had a model turn and come straight in at me twice at different times. Neither was any fun, they tend to follow the line drag and weight and that is right were you are. I didn't get zorked, but they didn't miss me by all that much either, and both motors were singing full bore at the time.
You may not have the prop danger with an EDF, but I bet that pointy nose in an eye or other soft body part is no fun at all...
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Old Oct 25, 2012, 11:04 PM
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Cape Coral, FL
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Originally Posted by JKinTX View Post
Some of the EDF guys cataput the model off the ground like the glider guiders do with a bungee launch.
A very simple adjustable line guide is to make the series of holes as you did, with brass thimbles over the lines a press fit in them. A slot just big enough to allow the lines to pass is cut down the centerline of the series of holes.
To change the line rake, you just press the thimbles out and move the lines to whichever new set of holes you want to use, and press the thimbles back into that set of holes. It is an OLD system.
Aha, I get the picture! Thanks. It may be OLD, but sounds GOOD to me. I could easily adapt my leadout guide to that system. I think just a knife slit might work for me to slide the lines. This 20 lb test PowerPro braided line is quite thin.

Derek
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Old Oct 25, 2012, 11:15 PM
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Originally Posted by Traian View Post
I would like to sugest to install the landing gear. Jets do not have the thrust to get you out of trouble. You need to build up speed to get the bird in the air and that ramp to me is way too short to get the job done.
Put the gear on let it stay on the ground and build up speed and slowly give up elevator and slip it off the ground. Take your time.
And see if you can do it on a paved runway.
I packed the landing gear in the box, so that will be an option. However, there is no paved circle anywhere near my Dad's house. The only option is grass, and rather thick grass at that. If my roller does not work, Dad has a bungee setup that works well for his other EDF control line planes and he has a stooge release trigger so it can be released from the center of the circle (he ends up flying by himself a lot - not very many club members around his area). For my Hawk, all it would take is to embed a tow hook on the underside.

I hear you about taking my time. I have a few "gentle tests" in mind before committing to a full launch.

Derek
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Old Oct 25, 2012, 11:33 PM
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Quote:
Originally Posted by JKinTX View Post
1. Hang model vertical from the leadouts with both leadouts put together. Model should have a 1-2 degree nose down attitude i.e. the nose points to what would be the outside of the circle flown. Good starter point. If it doesn't have enough "pull" or line feel, or it pulls too much, move the leadouts back or forward until you are happy with it. You should have a control feel that you know you are flying the airplane- it isn't too much or too little. This is something that is vastly variable. As long as you feel you have complete control all the time, that is where you want to be. Wind gust and the lines go slack, then be prepared to step or RUN back to maintain line tension. It's a lot like playing a game fish I guess.

2. I was told a long time ago that around 17 degrees rake on the front leadout is about right for the average sport model.

3. You need enough tip weight to counter balance 1/2 the weight of whatever control lines you are using.

4. More wind or slower flight needs more leadout rake to maintain line tension. If the wind goes up or the airspeed goes down, the leadouts have to go aft to maintain line tension.

5. Watch the model's side profile in flight. It should be square to you, i.e. one wing not lower or higher than the other if balance and trim is right. Of course it shouldn't be flying with the nose up or down in level flight either.

6. Slight nose heavy is probably best early on, tail heavy is a kaflooey for sure.

Fantastic list!! Thank you.

For test #1, I did that just before boxing it up. It aimed down a lot more than 2 degrees, maybe 5 degrees. Did not measure it. Keep in mind, I have no "right thrust" like a prop motor, just straight thrust out the back, and I kept the rudder straight also for now, so I am strictly relying on the line sweep. I think I would rather have too much than too little for first test. I will use your advice for judging if the control feels positive or not. If it feels limp at all, I will land immediately (I have that option with the throttle!) and make adjustments.

I will also check #2 test for 17 degrees angle. For #3, that's what my structural engineer intuition tells me also. #4, 5 and 6 - check - makes sense to me. I only crashed one RC plane due to tail heavy - totally my fault - never again. Better to start nose heavy, then adjust slowly.

Derek
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Old Oct 26, 2012, 06:48 PM
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Originally Posted by DerekB View Post
Fantastic list!! Thank you.

For test #1, I did that just before boxing it up. It aimed down a lot more than 2 degrees, maybe 5 degrees. Did not measure it. Keep in mind, I have no "right thrust" like a prop motor, just straight thrust out the back, and I kept the rudder straight also for now, so I am strictly relying on the line sweep. I think I would rather have too much than too little for first test. I will use your advice for judging if the control feels positive or not. If it feels limp at all, I will land immediately (I have that option with the throttle!) and make adjustments.

I will also check #2 test for 17 degrees angle. For #3, that's what my structural engineer intuition tells me also. #4, 5 and 6 - check - makes sense to me. I only crashed one RC plane due to tail heavy - totally my fault - never again. Better to start nose heavy, then adjust slowly.

Derek
You are most welcome. I think all you are doing is well within reasonable and safe parameters and most likely to be a success. Better always too much pull and then back off. If it is too light on the controls and a wind gust comes, you have a problem. Rudder is almost useless- it will yaw the model out and reduce speed- result less line tension. Leadout rake and tip weight have a far greater effect. Some guys use aileron adjustments also to make the model bank outwards and so increase line tension- I haven't tried it so I can only make the observation.

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Old Oct 29, 2012, 09:55 AM
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Make a Video please if you can. It will be fun to watch.
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Old Oct 31, 2012, 01:25 AM
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Hurricane Sandy causes change in plans....

Due to Hurricane Sandy (or tropical storm, whatever it's called), I changed my trip to visit Dad in PA to next Wednesday, Nov. 7th. I'm not sure if a 1 week delay is enough. I live in Southwest Florida and the winds were still very strong here when the storm was 900 miles away! It's a big one.

As I mentioned before, I boxed up the Hawk and shipped it to Dad in PA (it arrived safely) where we will do the final minor assembly and maiden flights, with video of course . My original flight schedule was to go up tomorrow morning (Wednesday flight at 6 am). I realized that was not a good idea. I had to bite the bullet for the $80 change fee.

Derek
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Old Nov 01, 2012, 08:46 AM
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This is a cool project! Thanks for posting!
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Old Nov 01, 2012, 06:58 PM
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I wish I could post something more, but I just have to wait.

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Old Nov 15, 2012, 09:31 AM
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Successful Flights and VIDEO !!!

I had a good visit with Dad and Mom and 2 sisters in PA. I did the Maiden flight of the BAE Hawk and a bunch more. Everything worked as well as I could hope for.

Keep in mind, this is just a first proof of concept and I'm quite happy with the results. At full throttle, it has plenty of line pull, but I don't have enough experience to try a loop or anything yet. And I'm sure it will need flaps for better response.

The plane does one peculiar thing on take-off. After it leaves the end of the ramp, the tail drops - it is NOT tail heavy - and I do NOT have up elevator (we reviewed the videos in slow motion to confirm the elevator is neutral). My Dad's F9F Panther does the same thing. It just drops, so I had to be ready to add a bit of down elevator right away. By the 6th flight, I had a good feel for it. Then it picks up speed and levels out.

You can see on the 2nd Flight, it went waaaay up and I almost lost it.

The R/C trigger for throttle is SUPER. The simple mod's I did to add the lines worked well and the feel of the stock plastic handle was nice. Personally, I don't see a need to go to all the trouble to cut it off and create a custom handle.

I had 2 or 3 cameras filming each flight, and sometimes we had a GoPro on our head for "First Person View". I never got around to mounting the "wing cam".

Here's the video,
Derek

BAE Hawk on control line (14 min 53 sec)
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Last edited by DerekB; Nov 15, 2012 at 07:29 PM.
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Old Nov 15, 2012, 12:09 PM
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Sweet!
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Old Nov 15, 2012, 03:52 PM
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Leadouts

I was using PowerPro braided fishing line 20 lb test for the leadouts. This is not durable enough and broke at the knot after a few flights. Even though it will pass a pull test when newly installed, it's just not durable enough. So I replaced the leadouts with light gauge braided wire from some old control lines. I was worried about the weight of wire leadouts, but this was not a problem.

I will definitely stay with PowerPro control lines to save the weight, but upgrade to 40 lb test or 60 lb test to get better durability.

Derek
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Old Nov 16, 2012, 08:23 AM
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Originally Posted by DerekB View Post
This is totally an experiment. It is a launch ramp made of foam rollers. The foam is from a floaty noodle for the swimming pool. It has a 3/4" hole in the middle. The foam is super light and spins freely on 1/2" water pipe. I did a little test by goosing the throttle while still holding onto the top of the fuselage and let the airplane accelerate along the ramp. I only goosed about 1/4 throttle. It will go!! It has better than 1:1 thrust to weight and will literally jump vertically out of my hand. I have good confidence it will launch from this ramp.

Just a few more things and I'll be ready to box it up for shipping to Dad in Pennsylvania. Nothing is glued together yet so the airplane and the ramp can still fit in the box for shipping, that's why I am still using some blue tape here and there, which will go away of course.

Also, I have the ailerons locked down with dummy pushrods. They still have an adjustable clevis, so it's easy to get them aligned neutral. I will wait to see how it flies before making them into flaps and coupled with the elevator. I'm thinking it won't be needed since the tail moment arm is so short.

Derek
Interesting launch approach. Any reason this method wouldn't work for non control line EDF plane ? I supposed it would need quite a bit of thrust to get off the ramp, stay in the air before if got up on step.
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