Espritmodel.com Telemetry Radio
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Old Oct 18, 2012, 08:28 AM
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Canada, ON, Cottam
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I haven't tried converting one yet, but likely will do an indoor one this winter.(soon) { The dihedral will affect nothing- many of the old C/l designs used it back in the dawn. It was easier to build a flat wing, so it went away. } I found the dihedral makes the plane come in on the lines when it is windy. The wind picks up under the outboard wing.
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Old Oct 18, 2012, 10:42 AM
Mike A.
Des Moines, IA
Joined Oct 2005
364 Posts
Here is my conversion of a HobbyKing cheapo pistol grip mated to an old Fox handle. I wanted to use the Fox handle because it is a steel strap with all the necessary bends already made, plus the adjustable cable. It needed to be lengthened as the grip was too close to the front end to allow enough room to operate the trigger comfortably, so I cut the front end off, and added the 1/8 fiberglass PC board pieces (the green parts), which also saved the work of trying to cut a slot or clearance for the trigger. Then I made my own grip parts.

The radio mods included removing the centering mechanism from the throttle pot and mounting a spring internally to pull it to the full low speed position. Also removed the steering wheel, but not the steering pot. I made the wood fillers behind the trigger to give me a mounting surface. For power, the 8 AA alkalines were replaced with a 3S 1000 mah LiPo, in the box on the bottom. Did some testing to see how much transmitter time is available and it looks like about 10 hours on a fresh charge so would take about 75% of the capacity. So, plenty of time to fly as many events as needed with one transmitter.

Cost was pretty minimal - the transmitter/receiver was about $30 (including $9 shipping) from the HobbyKing USA warehouse. I have a couple of servos already but if bought with the radio, they would cost ~$5 each. The LiPo was about $9 if bought new, but by the calculations above, the 8 AA's would probably last all season. The Fox handle was still new in the bag, but I've had it for 25 years. The rest was just from various scrap bins.
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Old Oct 18, 2012, 01:37 PM
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Cape Coral, FL
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That looks similar to this Transmitter I just ordered yesterday.

Thanks for all your detailed information. I may have a few questions when I perform the surgery!!

Derek
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Old Oct 18, 2012, 04:53 PM
Mike A.
Des Moines, IA
Joined Oct 2005
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Originally Posted by DerekB View Post
That looks similar to this Transmitter I just ordered yesterday.

Thanks for all your detailed information. I may have a few questions when I perform the surgery!!

Derek
Actually, it looks EXACTLY like that Tx. That is the one I got. I got mine from the US Warehouse but they don't have the Rx's to go with it by themselves (at least they didn't when I got mine). I am going to have to put together an bigger order and get a couple more Rx's. I'm probably going to convert all my Carrier stuff to 2-line, with radio for throttle.

Tonight I put the Rx on one of my small electric sport flyer/trainers in place of the normal control-line timer and took it out for a spin at our little city park (where I have just enough room for 42 foot lines). I had to put a clip on the handle leadouts because the line spacing on this handle is way too large for what is essentially a 1/2A size plane, but took off and landed a couple of times, sped up and slowed down - felt pretty natural and comfortable. It's a little bit heavier than a normal 3-line handle, but not too heavy or clunky. I'm quite happy and I'm going to start a new carrier plane - probably electric - for it.
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Old Oct 19, 2012, 01:17 AM
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Cape Coral, FL
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Originally Posted by mikeainia View Post
Actually, it looks EXACTLY like that Tx. That is the one I got. I got mine from the US Warehouse but they don't have the Rx's to go with it by themselves (at least they didn't when I got mine). I am going to have to put together an bigger order and get a couple more Rx's. I'm probably going to convert all my Carrier stuff to 2-line, with radio for throttle.

Tonight I put the Rx on one of my small electric sport flyer/trainers in place of the normal control-line timer and took it out for a spin at our little city park (where I have just enough room for 42 foot lines). I had to put a clip on the handle leadouts because the line spacing on this handle is way too large for what is essentially a 1/2A size plane, but took off and landed a couple of times, sped up and slowed down - felt pretty natural and comfortable. It's a little bit heavier than a normal 3-line handle, but not too heavy or clunky. I'm quite happy and I'm going to start a new carrier plane - probably electric - for it.
So was that your first test flight of the transmitter? I went back to read your post and realized you said you are just now putting this together. I suppose congratulations are in order.

You mentioned 42 foot lines. I have not thought about line length. What line length do you think I should try first on this BAE Hawk? Am I better off trying shorter lines first, then if it performs well enough, go to longer lines (as compared to vice-versa)?

Also, for Electric Ducted Fan, keeping the weight down is critical. I bought these "Tufstrand" control lines. It says they are 1/3 the weight of steel lines and strong as .018 steel cable. What do you think?

Derek
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Old Oct 19, 2012, 01:42 AM
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Cape Coral, FL
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Install elevator and pushrods

Every step of the way I run into some sort of challenge. This time it was how to get a carbon rod embedded into the horizontal stab.

First step was to enlarge the elevators, which was easy. I cut off the stock elevators and made some new ones out of 6mm depron that are 3/4" wider and put 3 hinges each and a control horn.

But getting the carbon reinforcing installed took a bit of creative thinking. Luckily, the geometry was just right and it worked out perfectly.

Again, the pictures tell the story.

Getting closer.....

Derek
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Old Oct 19, 2012, 03:06 AM
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"Also, for Electric Ducted Fan, keeping the weight down is critical. I bought these "Tufstrand" control lines. It says they are 1/3 the weight of steel lines and strong as .018 steel cable. What do you think"?


They also have the drag of a 60 lb rock. Makes a good stooge release line but that is about it.
I'd try Fireline from the tackle shop first, less drag and probably stronger still. The 20 lb test should be more than adequate. Use the 30 lb if you have any concern, there are guys flying full house stunt ships on it.
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Old Oct 19, 2012, 04:13 AM
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I haven't tried converting one yet, but likely will do an indoor one this winter.(soon) { The dihedral will affect nothing- many of the old C/l designs used it back in the dawn. It was easier to build a flat wing, so it went away. } I found the dihedral makes the plane come in on the lines when it is windy. The wind picks up under the outboard wing.
I confess to never having encountered that problem. I note that Al Rabe uses scale dihedral on his masterpiece PA ships.
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Old Oct 19, 2012, 09:27 AM
Mike A.
Des Moines, IA
Joined Oct 2005
364 Posts
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Originally Posted by DerekB View Post
So was that your first test flight of the transmitter? I went back to read your post and realized you said you are just now putting this together. I suppose congratulations are in order.

You mentioned 42 foot lines. I have not thought about line length. What line length do you think I should try first on this BAE Hawk? Am I better off trying shorter lines first, then if it performs well enough, go to longer lines (as compared to vice-versa)?

Also, for Electric Ducted Fan, keeping the weight down is critical. I bought these "Tufstrand" control lines. It says they are 1/3 the weight of steel lines and strong as .018 steel cable. What do you think?

Derek
RE: Tufstrand - As JK said - these are TOTALLY USELESS as control lines. They have a huge cross section, therefore huge drag. Thrust is needed to overcome drag and in Control Line most of the thrust is spent keeping the lines moving. Your DF setup is already marginal on thrust. I can't believe they even still sell these things. I know several people who have tried the Tufstrand lines - I don't know anyone who has tried them twice.

You don't need .018 lines either - as I said above, it is more a question of model weight and flying speed as far as diameter - .012 will be plenty strong enough.

Line length is more of a guess in this case - If you try to start with longer lines and are careful you can cut them down 5 feet at a time but if I had to guess, I'd say start with 52's or so.
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Old Oct 19, 2012, 10:03 AM
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Cape Coral, FL
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Originally Posted by JKinTX View Post
"Also, for Electric Ducted Fan, keeping the weight down is critical. I bought these "Tufstrand" control lines. It says they are 1/3 the weight of steel lines and strong as .018 steel cable. What do you think"?


They also have the drag of a 60 lb rock. Makes a good stooge release line but that is about it.
I'd try Fireline from the tackle shop first, less drag and probably stronger still. The 20 lb test should be more than adequate. Use the 30 lb if you have any concern, there are guys flying full house stunt ships on it.
OK, I'll just donate the Tufstrand to the trash can. Oh well.

Aha! That's exactly what I was hoping to hear about the Fireline and Spiderwire type of fishing lines. I have no personal issues with using it. But what's the official AMA position? When do I need to know when to "hide" them, and use steel lines? This Hawk will be strictly sport flying.

I wouild have total confidence in the 20 lb test. I'm using 12 lb test for fishing around pilings and the mangroves and it is really tuff. To cut this stuff, you really have to try hard, even with a sharp knife or nail cutters.

Now I'm probably pushing it, but what about using swivel snaps to connect the lines? Sure there are cheap kinds, but there are also good ones. If a guy is fishing his $2 million yacht, for prize game fish, he still trusts swivel snaps.

Derek
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Old Oct 19, 2012, 11:41 AM
Mike A.
Des Moines, IA
Joined Oct 2005
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Originally Posted by DerekB View Post
OK, I'll just donate the Tufstrand to the trash can. Oh well.

Aha! That's exactly what I was hoping to hear about the Fireline and Spiderwire type of fishing lines. I have no personal issues with using it. But what's the official AMA position? When do I need to know when to "hide" them, and use steel lines? This Hawk will be strictly sport flying.

I wouild have total confidence in the 20 lb test. I'm using 12 lb test for fishing around pilings and the mangroves and it is really tuff. To cut this stuff, you really have to try hard, even with a sharp knife or nail cutters.

Now I'm probably pushing it, but what about using swivel snaps to connect the lines? Sure there are cheap kinds, but there are also good ones. If a guy is fishing his $2 million yacht, for prize game fish, he still trusts swivel snaps.

Derek
For sport flying, you can do pretty much what you want -- fishing swivels, line types, and connections are not mentioned in the AMA Safety code. Your AMA insurance covers you as long as you fly in accordance with the Safety Code. The code DOES mention "I will pull test my model before flight". And it says that the pull test must be in accordance with the rulebook for the model being flown. It also says that the lines may be GSUMP (an acronym for both Spectra and Dyneema spun plastic fishing lines). Again, for competition and in events where it is allowed, the line must be the same diameter as the steel lines which are called out. For .012's, you are probably talking 40 or 50 lb. test for .012 diameter. Personally, I see no reason to use swivels - regular line connectors are just as easy to connect and I don't see any other advantage to swivels.

We have many sets of .018's flying on Combat planes (the only event where they are currently allowed) - and it takes 100 lb. test to get to .018 diameter. The knots are the weak point and reduce the strength of the line by about 50%. There are web sites which will show you how to tie a Palomar knot, Surgeons knot, Blood knot etc. Phil Cartier - who did most of the development work and got the rules changes which allowed these lines - has a modified Figure 8 knot which he says is stronger than all the others and is easier to get lines tied to equal lengths. (Pictured)
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Old Oct 19, 2012, 01:23 PM
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Cape Coral, FL
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Mike,

You are a wealth of information. Thank you so much. I will use that knot. I can understand the matching line diameters - to create the same air drag. Regarding swivels and such, I only ask because I don't have any of the "normal" control line things. I have to order from Tower or somebody every time I need some little thing, then wait. Whereas I have a box full of various swivel snaps. My local hobby shop is just RC.

This answers a lot of questions where I get into, let's just say, "lively" discussions with my Dad. He is totally old school for the lines and connections, but mostly because he does not have easy access to learn about the latest. He just got his first computer and is becoming internet savvy - let's just say it's a steep learning curve - and I'm impressed with his progress. Otherwise, he has to rely on whatever the few members happen to know at his local club. Nobody is doing electric, let alone a foamie, and definitely not EDF, so he is really out there on the bleeding edge!! I don't fly control line, but I do know the great value of these forums. I started this Build Log for 3 main reasons.

First, so my Dad could follow along and see the photos of what I'm doing (I managed to show him "over the phone" how to find this log. We still need to get him registered, but that's for another day). And second, for exactly this type of great interaction. I want to make sure I am putting the components together so all the rules are satisfied, and so my Dad has enough information so he can be confident to explain to his local guys if anybody were to question it. And third, I enjoying posting the photos and sharing my ideas - that's what these forums are all about.

Thanks again,
Derek
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Old Oct 19, 2012, 02:39 PM
Mike A.
Des Moines, IA
Joined Oct 2005
364 Posts
Like I said, as far as the Insurance/Safety Code goes, as long as you pull test it, it's OK. You could always cut the swivel part off and tie the lines directly to the little safety pin part that is left. Then you would have a disconnect for storage
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Old Oct 20, 2012, 11:00 PM
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Cape Coral, FL
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Car transmitter converted to Control Line throttle

I got the Hobby King transmitter and receiver today. I'll show you what I did to modify the trigger to work. On a Car transmitter, the throttle trigger is sorta centered so you can push away for reverse and pull towards you for forward. Airplanes of course are only forward, and you need that full travel. So it's necessary to reconfigure the throttle centering device.

I'll let the pictures tell the story....

For converting the transmitter to a control line handle, I think I will leave the original transmitter plastic case in tact and simply add an aluminum bar across the front. That will be tomorrow.

The All Up Weight right now is 2 lbs 0.6 oz. and the thrust is 2.2 lbs. The only thing left is the leadouts, which I will use 20 lb test Spiderwire fishing line for the leadouts and the control lines to save weight and minimize the amount of tip weight needed on the outboard wing.

Derek
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Old Oct 21, 2012, 12:03 PM
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I would just leave the throttle trigger as is, and use the push part of the trigger for shutoff on nitro motors. I know this one is electric though. We used to have the push for brakes, as there was no reverse for nitro motors. Even the indoor electrics, push was brakes. Cars are different than planes though. I'll be waiting for the videos.
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