Aeronca Old Kit

[davidchoate]

Ended up having to re hinge horiz. stab, and rudder due to binding. But I just got to assemble the pieces and its done. And the decals are too old to use. I have to make them.

[Konrad]

Here are some hinge line profiles and their associated issues.

I like covering film as a hinge as it is flexible and seals the hinge line. But if using tissue or as a result of other concerns I like to use Kevlar as a live hinge.

I like to make my wing struts fully functional. To do this the lower part of the struts need to be tied together through the fuselage with light wire. This will keep the wings on durring most cart wheel landings. Don't ask how I know .

All the best,
Konrad

[davidchoate]

I did your method there on the Rudder,but I always try something new every build. This time I tried hinge tape on the Elevator. It was OK 97% of the time,and with a normal servo would be fine,but once in awhile it would not return to center,And I had lessened deflection due to the carbon rod flexind against the force of the hinge. I considered using fishing string before,and on an old Guillows RC plan they say to use copper wire for hinges. I kinda want to try that. My favorite method as of late is to take an ordinary CA hinge ,scrape off the fuzz, and Ca it on the inside so none gets on the part that moves. These "BRICK" servos are so weak that any resistance at all is a catastrophe waitin to happen.I wish they would make (in quantity) those "X" shaped hinges used on foamies. If they do, please let Me know where to acquire them. . I've been reading up on aerodynamics,(espescially their effects at low speed). The latest MANews issue has a good info. article about recent design changes. For example: it is better to use a rounded,and slightly thicker than the wing aileron. The oldstyle aileron stock is no good.and adding little triangles at certain spots keeps the "dead air" that surrounds the wings surface turbulated or vortexed,and this makes the controls respond at low speeds with only a 4mph loss of top speed. They use this technology on acrobat,and Pylon stuff; Like the EDGE 540. Jeese; How did I digress that far?, But anyway, yes, I reinforced my wing struts with basswood,and made a more solid mounting place for them. Once I glue on the wings, she is done. I already started a Bird Dog to do while the paint and glue dries. I am pleased,and disappointed about some things in the Bird Dog kit, but I'll post em on that thread.

[davidchoate]

Almost done. My 1st ever homemade cowl came out way better than I thought,and I saved 10 or 15 Bucks !And thanx for the hook idea on the wing struts. Its just tacked together now. I wanted to get idea of the finished thing. A School Bus ? I used Cowl dimensions on plan to make 1/64" ply formers,stringers, sheeted it, and spackle. There is no tissue on the front half of the fuselage. AUW inc. Battery is 125gms, and i'm happy with that. perfect for the motor.

[Konrad]

Don't know if you are old enough to remember 3.5" floppy disks. If you are the disk itself makes a good flexible hinge, better than stripped CA hinges.

As I recall copper wire hinges are used as a flex point for Free Flight trim tabs (surfaces). Copper wire makes a poor R/C hinge as the constant flexing will result in work hardening and fracturing of the copper.

I like to encourage experimentation, but on test coupons, not the actual model if one can avoid it.

All the best,
Konrad

[Bill Gaylord]

I use something similar to the floppy disk material Konrad uses, which is a hinge material GWS supplied with their kits. It's a flexible plastic material that never seems to crack, after countless cycles. It doesn't get any easier, since it fits right into an Exacto cut slot, without having to hog out the slot at all. A light wiping of 5 minute epoxy works well for installing them. I'd send you a bit of it, if you want some. For these small models I generally use about 5mm wide x 10mm long strips, so a little bit goes a long way.

You can also just glue it to the top surface of thin sheeted control surfaces like on the 16" Guillows Stuka aileron below. For that model I wanted the ailerons to be mounted below the wing to give the scale slotted aileron appearance. The aileron hinges were then glued to the wing bottom surface.

[David Lewis]

I use ordinary sewing thread for hinges.

[Bill Gaylord]

I use ordinary sewing thread for hinges.

With that thought, the Guillows supplied control line string would be really good. I'm convinced the stuff is somewhere in the neighborhood of 40lb test fishing line. I used it for a pull-pull setup, for the 17" Dumas Peashooter tail surfaces, after pre-stretching it eliminate any further relaxation over time. It also is used to hang about 50 models throughout the house.

[davidchoate]

Thanks guys. I dont think I have any old floppy discs around. And sadly, I am old enough not only to have used them, but I can remember typing in and then recording a program on My Commodore 64 to a cassette tape for storage. Am busy at work this week, but I wanted to allow "Drying Time" for a bit before I permanently Glue anything. I have learned through My many failed attempts that after a week or two things tend to settle out.Espescially when using functionally supporting wing struts. I dont feel bad from My failures, But learn. I saw on TV it took Kelly Johnson 12 failed designs for the SR-71 before they got one right. So that encouraged me a little too recently.

[Bill Gaylord]

Thanks guys. I don't think I have any old floppy discs around. And sadly, I am old enough not only to have used them, but I can remember typing in and then recording a program on My Commodore 64 to a cassette tape for storage. Am busy at work this week, but I wanted to allow "Drying Time" for a bit before I permanently Glue anything. I have learned through My many failed attempts that after a week or two things tend to settle out. Especially when using functionally supporting wing struts. I don't feel bad from My failures, But learn. I saw on TV it took Kelly Johnson 12 failed designs for the SR-71 before they got one right. So that encouraged me a little too recently.

That's the attitude needed, perseverance. You should hear about some of my earlier conversion stories, like a plane doing 4 nearly instantaneous rolls, before getting 50 feet away from me. My first Guillows FW190 turned around like a boomerang immediately after launch and darned near hit me. The DR1 was one of the first where I made practical sense of the situation. I figured if it wanted to loop so badly into inverted flight, that I'd just fly it inverted then. Managed to come in for a nice, soft inverted landing with no damage.

[Konrad]

Thanks guys. I dont think I have any old floppy discs around. And sadly, I am old enough not only to have used them, but I can remember typing in and then recording a program on My Commodore 64 to a cassette tape for storage. Am busy at work this week, but I wanted to allow "Drying Time" for a bit before I permanently Glue anything. I have learned through My many failed attempts that after a week or two things tend to settle out.Espescially when using functionally supporting wing struts. I dont feel bad from My failures, But learn. I saw on TV it took Kelly Johnson 12 failed designs for the SR-71 before they got one right. So that encouraged me a little too recently.

What do you mean SADLY! We have experiences that other can only read about in the history books . It looks like you and I are of the same time.

I have done over a dozen of these "Gummy Band" conversion and I learn something new each time, or wish I had done things differently.

All the best,
Konrad

[WIDDOG]

Even though I'm totally no good at building/flying RC; This Thread has convinced me to give it another try. I have tried and failed to convert a Guillow's kit to RC in past. I decided that a Guillow's conversion to RC is out of my skill level at the present time. I do however hope to in the some what near future attempt a Guillow's RC conversion.

Anyway, what I wanted to share was that I did not have any hinge material so I had to improvise some hinge tape out of a dryer sheet. I cut out the hinge tape from the dryer sheet. Than I rubber cemented it onto my model. Seems to be working out ok.

[David Lewis]

Bill Gaylord wrote: "...Guillows supplied control line string would be really good."

It would also be good for pull-pull cables where you want low elasticity (i.e. high spring constant) and minimum weight. For the hinges themselves, zero stiffness, small diameter and a fatigue-proof material are important. Plain old polyester sewing thread seems to be strong enough, and it's something commonly laying around the house. Nothing against Guillow's control line string -- not saying it's stiff at all (it's not) -- just offering an option.

[Konrad]

Even though I'm totally no good at building/flying RC; This Thread has convinced me to give it another try. I have tried and failed to convert a Guillow's kit to RC in past. I decided that a Guillow's conversion to RC is out of my skill level at the present time. I do however hope to in the some what near future attempt a Guillow's RC conversion.

Anyway, what I wanted to share was that I did not have any hinge material so I had to improvise some hinge tape out of a dryer sheet. I cut out the hinge tape from the dryer sheet. Than I rubber cemented it onto my model. Seems to be working out ok.

I have to ask how did this take a finish? What was the finish dope or iron on film?

All the best,
Konrad

[Bill Gaylord]

Bill Gaylord wrote: "...Guillows supplied control line string would be really good."

It would be good for pull-pull cables where you want low elasticity (i.e. high spring constant) and minimum weight. For the hinges themselves, I need zero stiffness and a fatigue-proof material. From everything I've tried, plain old sewing thread cannot be beat.

I couldn't imagine needing anything floppier than the control line string. I imagine you haven't sampled it. The kit supplied cl string is very flexible and fatigue proof. Remember we're talking rc conversions here also. Plain old sewing threads are known to oxidize over time and break easily. I have a collection of about 500 spools that demonstrate this quite well. Some almost break if you look at them wrong. The thread material would be important IMO.

For pull-pull cables, the control line string requires pre-stretching. It has considerable elasticity, when considering control surface requirements. I used it in the past on several planes, and deemed it best for micros, where the length minimizes the stretch problem. Silver beading wire seems to have less of this issue and also looks good, which is what I've used on a number of pull-pull and rigging setups. The CL string did work well for a Dumas Peashooter pull-pull setup, where you'll do anything to reduce aft weight.