ottogiro58

Hi Gang, Does anyone fly a control-line 1/2A (.074 Thunder Tiger or similar) airplane with 3-line throttle control ?? I have a new TT .074 laying around, and want to build an autogyro with throttle. I have flown Cox .049 gyros successfully for many years, but always wanted a throttle so I could "hang on the prop" and fly slowly, like the carrier guys. Guess I need a special ukie handle. Gyrocopters have their own charms, and challenges, too !!! I'm looking to adapt any successful .074 throttled design...... gyros are a bit "draggy" and need just a bit more power than the Cox could produce. Will the 3-line system work well with a slow, lightweight model ?? Any input, plans or help would be appreciated.....Thanx !!! Charlie Anderson

mikeainia

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Hi Charlie -

I've had some success with Cox engines and the throttle sleeve that some of them had. Regardless of the method of control - whether it's just an exhaust sleeve or an actual carb - you will need a 3-line handle and bellcrank to provide the throttle function. I've had extensive experience with Navy Carrier, so I knew what the basics would have to look like, but I actually made the parts myself, due to the size involved. I also acquired a Cox 3-line handle sometime later, but I never got around to trying it out.

You can get by with a home-made bellcrank - fabricated by bolting the elevator bellcrank to one arm of the throttle bellcrank, which mounts to the normal bellcrank pad. The J-Roberts and Brodak 3-line handles provide the complex motion required to keep the line drag from becoming problematic, but for what you want a simple "trigger" arm, pivoting from the top part of a normal handle will suffice, at least for a first attempt.

I had a shrunk down F4F Wildcat flying with a Black Widow. The span is about 18" and it flew very well. It would actually prop hang and fly around at some pretty extreme angles. One of the problems was that I could only get it off the ground (and back on again) if the circle was paved, and I haven't had access to pavement for flying in many years. Also, the throttle would only idle it down to about 5000 RPM, but even at that it would probably fall out of the sky.

I'll have to dig out some of the old stuff and get pictures for you - a picture is worth 1000 words, you know :-)
I'll check back in later with that. It really is a pretty simple setup, once you see it and I'm sure that it would work fine for your gyro and .074. You may be right about needing a bit more power on an autogyro - I also had a throttled "Otto the Gyro" back about the same time frame and it was a ball to fly also.

L8ter-
Mike (no relation) Anderson

ottogiro58

OK, sounds great, Mike..........thanx for the info. If Cox had continued producing the TD, I might still be using it !!! I also flew an "Otto", with OS FSR .10 ........way too much motor without a throttle control !!! I even have a VCR video of one of my Otto clones wobbling around, crashes included. Gyro success depends on careful rotor design. The 2-bladed Bensen-style teeter head is simple to construct, and provides the necessary stability. My Otto flew, but was prone to shaking, dipping, diving, and rolling............that pesky FSR had a mind of its own........... my most successful gyro was based on Roy L. Clough's July 1962 Popular Mechanix design. I tamed the TD .051 using a one-way check valve to control flooding, along with a stunt-vented film cannister fuel tank. Profile design was easy to modify. Looking forward to more pix/info.....Thanx !!! Charlie Anderson

mikeainia

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My Otto was the .35 size one published in MAN (CA 1978??). Anyway, the motor was an Enya .35, if I recall. It "flew" OK, I guess and the throttle was fun to twiddle, but every time you touched down the least bit hard, the blades would flex down and knock off the rudders - Once it knocked off the whole stab!

As for careful rotor design, well I won't disagree, but I will mention a small gyro that was in our club at one time. As an experiment, we pinned the rotor like a wing and it flew better than with the rotor thrashing about (at least it took off faster and was a little more responsive in climb and dive mode). So we pinned the rotor so that it pointed fore and aft and it still flew (but not as well), which gave us a pretty good laugh.

There is a fellow (Jim Lee) from Topeka, KS that has been flying the same Otto for over 25 years in any event that calls itself balloon bust (lots of different local rules have been used). His has no throttle, but he very nearly ALWAYS wins. And no, the rotor does not bust the balloons - the prop does.

I'll dig out that stuff and see if the camera is charged up.

Mike @

mikeainia

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Here are some pix of the Wildkitty this plane is probably 15 or 16 years old, and hasn't flown in at least 12 years, so the hangar rash is a little extensive - don't have any idea where the fin and rudder went, but the motor and controls still turn over and work easily - I bet I could fly it tomorrow, if I had to ...

First is just a composite of the right and left views - motor may look like a harmless little golden-bee, but it has a TD piston and sleeve and a "killer" crank and with glo-bee heads won mouse racing several times in a different plane. Note that the engine is mounted enough off-center that I could put that fake cowl in front - really stiffens up the front end and eliminates broken chins and brows.

Next are shots of the bellcrank, in high-speed and low-speed positions. Note that a PULL on the throttle line is high speed and a pull on the elevator bellcrank is low speed. The elevator crank is mounted on the throttle bellcrank, and moves whenever the the throttle line moves. The only thing securing the bellcrank assembly to the plane is the screw through the THROTTLE bellcrank.

Next are shots of my home-made handle, which looks quite a bit fancier than it is. It is really just a non-adjustable two line handle, with a pivoting trigger arm. Again, a pull on the trigger is high speed. Then, since you can't PUSH a piece of cable, when you push the trigger forward, the slack line allows the double-drag of the two elevator lines to pull the bellcrank to low-speed position. This handle was inspired by Frank Kelly's EZ-Just Hot Rock, with a coat-hanger wire trigger arm, that WON PROFILE CARRIER at one of the Lincoln, NE Nats.

Finally, a couple of shots of the Cox 3-Line handle that came with one of their plastic Ready-to-fly's. Note that with this handle, as the throttle line is pulled into the handle, the elevator lines are moved out, and vice-verse. This one also applies a pull to the throttle line when the trigger is pulled (to high speed). The J-Roberts and Brodak/LR systems apply a pull to the throttle line when the trigger is PUSHED FORWARD.

I hope this makes it somewhat clearer - I tied my lines all three the same length, and fine-tuned the adjustment with different size line clips.

mikeainia

My Feedback: (1)

I see that the board renamed my pix, so as an explanation, the first is just a composite of the right/left views of the Wildkitty. It spans 16 inches.

The bellcrank shot on the left is the high-speed and the right is the low-speed. Same with both pairs of handle pix - left is the high-speed position and right is the low-speed position. Oops, now that I can see the pictures, I see that the Cox handle pix are opposite - High speed on left and Low-speed on right.

Note on the bellcrank that as you pull the throttle line, the whole elevator bellcrank moves away from the pilot and as you "push" the throttle line, the elevator bellcrank moves towards the pilot. The distance from the throttle-bellcrank-mounting-screw to the elevator-bellcrank-mounting-screw is 1/2 the distance from the throttle-bellcrank-mounting-screw to the throttle line tie-point (Whew! I'm trying to be clear here, but it's getting difficult ) What I am trying to say is that if you pull the throttle line 1 inch, the elevator bellcrank moves 1/2 inch in the opposite direction. That 2:1 ratio is important because the elevator lines have twice the drag of the throttle line (well, unless you use .008's for the elevator and a .018 for the throttle, I guess. If so, make the ratio 1:1[sm=spinnyeyes.gif] ) Dang, now my brain hurts ....


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ottogiro58

Hi Mike, OK, I get the throttle setup and operation now...........thanks for the detailed information. By the way, I saw your older posts concerning electric carrier C/L ...........a throttle controlled electric might do the trick for me !!! Are any of the electric throttles now located in the handle, with a trigger or similar ?? Or are the signals now being sent down the line ?? IR controls ?? It would be great to have all controls located in the ukie handle. Please clue me in on the latest electric technology when you get a chance......Thanx, Charlie

mikeainia

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The way that we are currently using them is to use a 3 line setup exactly like the ones that operate an RC carb. Instead of moving the arm of a carb, you move the arm of a potentiometer. The pot is just the control of a "servo driver" type of circuit (if you are familiar with RC equipment, you can plug in a "servo driver" or tester and use it to center servos and check linkages without turning on your transmitter). Clancy Arnold markets a system called the U-Tronics system for driving a servo. In fact he has a single channel system and (I think) a four channel system, mainly for Scale competition. So we still have the motor/battery/ESC on board the plane, and in additon the U-Tronics unit (it's about the size of postage stamp and weighs a few grams) plus its pot. But you don't need the timer circuit that stunt and sport flyers use.

The U-Tronics systems are actually designed to have the control pots located at the handle, and either send signals down the lines or use the lines as the connecting wires for the pot (in the single channel model). This requires insulated lines, which means our .015 and .018 lines go to over .030. That is one problem with having the controls at the handle. The other is that the single channel unit apparently doesn't work well with an ESC - as some have tried to use it for electric powered planes but were not able to get consistent performance. I really don't know what the specific problems were, though and one of my "back burner" projects is to try out using the handle-mounted pot. I do know of one carrier plane that uses a servo to drive the carb and has the handle-mounted control, so the issue is something to do with the ESC and the Clancy unit. Maybe static electricity or other RF interference on the lines, happening so fast that a mechanical servo doesn't react, but an ESC gets confused.

We also have been exploring the insulated lines issue, in that there have been some inquiries made to a wire & cable mfr., about producing braided steel lines with a much thinner insulation. It looks as though if we commit to a 10000 foot minimum purchase, we may be able to get lines that have a coating similar to the varnish on magnet wire. It is only a couple of thou thick, rather than ten thou. There were five e-powered Skyrays at the Sig contest this year, so I think we can do the 10000 foot minimum order (probably cost us about $75 each, for 2000 feet). My own thought is that a fairly flexible enamel might be enough insulation - something like Rustoleum. Just make a tray of some sort with the enamel in it, and pull the lines through it. Of course, you'd need to suspend them fully strung out for as much as 24 hours to get them really dry before you roll them back up again, or they would dry into a solid ring of plastic coated wire. But since we are doing no loops or maneuvers that would twist the lines together, we don't need perfect insulation - just make sure that no bare spots can actually touch each other.

So many projects, so little time ....

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ottogiro58

Hi Mike, I appreciate the information very much. One more thing.....have you seen in person anyone using an infrared throttle system for C/L, or have links to information regarding IR systems ??? IR could have its virtues.............Thanx again !!! Charlie Anderson

mikeainia

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mikeainia

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Mike Palko - Philadelphia - was the driving force for electric powered stunt models. He is still VERY active with it and posts quite a bit on Stunthanger.com. I would advise that you register there - it is a great site. At any rate, he originally used an IR system for motor control. He now uses a z-tron C/L timer but, of course, he doesn't need a throttle.

As for what is currently available - I really don't know what may or may not be currently available. If you google z-tron IR, you get to some very old posts on various discussion groups but they don't seem to lead anywhere useful. I think that Sergio Zigras has discontinued production of the z-tron system.

I know of several fellows who fly e-powered control-line and just put one of the very small receivers in it and have the transmitter at the handle with them. This would not be legal in any sanctioned event, but for sport flying it seems to work fine. Just be sure you aren't shooting down some RC plane nearby ...

There is also a control-line topic on RCGroups.com, with some electric control-line chatter.

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mikeainia

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Charlie -

Here is a link to an IR control micro-heli -

http://www.ritehobby.com/s.nl;jsessi...&category=2703

I know nothing more about it or if one could cannibalize it to use to drive a control line model of any sort, but it shows that there is SOME development of IR systems ... It only costs $20 so it might be worth messing around with.

The range is quoted as 30 meters/100 feet so that implies that it should be useable for any size control line and also useable outdoors.

Mike

ottogiro58

Hi Mike, OK, thanx for the links......I'll take a look !!! Charlie

clscale-RCU

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I have flown and currently fly Control line models with throttle using these systems:

DSC control using JR radios
Bill Young handle - 3 and 5 channel systems
Converted Radio units (permanent conversion)
Single channel systems - only servo, battery and switch in the airplane (older custome electronics servo driver, 555 timer circuit).
Infered system from Windy

The last 3-line model I had was in 1990 and couldn't wait to cut the third line, My 3-line handles are hanging up as a museum pieces.

THe lightest and easiest system is the single channel systems, Clancy Arnold has a system available that would work well for the smaller models especially if you use the 6 volt dry cell batteries (PX-28) that are the size of your thumb, then hook that up with a small micro servo and the weight will be minimumal.

The DSC system is my favorite, but that gets put into my larger models with throttle and other features due to it's size and weight.

The Infrared system from windy was only tested for a short while, it worked ok but the sensor had to point to the model, and I preferred the DSC and single channel systems

I currently fly CL carrier models (Profile and Class I) with electronic controls, along with my sport and other scale models.

I get my flying lines from this source, get either the 30lb test for small models, 60lbs test for profile carrier, and 80lbs or 140lb test for larger models. The 300 foot rolls are nice, the 1000 foot rolls makes lots of lines.

http://www.americanfishingwire.com/p...nstandard.html

land softly...