Mustang Fever

My Feedback: (2)

First time using any kind of retracts. I'm building a 60" WS Mustang pattern bird from the 1977 RCM plans. ("Miss Kat Bratt") Decided to use Dave Brown mech retracts as they looked real robust in the picture, and they are.

Questions:

1. Should I use wire push/pull rods, or a flexible type such as the Dubro Lazer Rods? (I have both available.)

2. The Tower retract servo I have does a complete 180 from up to down. What's the trick to keep the pushrods from getting caught up in each other?

Any other suggestions or comments would be greatly appreciated.

Flyboy Dave

My Feedback: (21)

Answers:

1. I don't think there is room for a flex cable. See how the wire has to bend
down to clear the wheel, and see how little distance there is from the
retract to accomplish the bend ?
2. See the offset on these wires where they connect to the servo arm ?
This offset keeps the rods from hitting one another.

Dave.

Mustang Fever

My Feedback: (2)

Thanks, Dave. The pix make it really clear what I need to do. Here I go!

Flyboy Dave

My Feedback: (21)

'Stang....one thing....

....do not cut the wire on the retracts to fit axles, even if they come with axles.
Rather, heat and bend the wire to make the axles....providing they are long
enough.

Dave. [sm=thumbup.gif]

Mustang Fever

My Feedback: (2)

Too late.

I had a fixed gear 51 with a similar setup and had to periodically straighten the axles/wheels out. I'm thinking that once I get this one rolling straight, I'm going to try brazing the axles to the struts. Whaddya think?

Flyboy Dave

My Feedback: (21)

That might work....grind some good flats on them, and hope for the best.

FBD.

Mustang Fever

My Feedback: (2)

I just noticed you're one of the Revvers.

I have a Shrike 40. Most fun I've had since the hogs ate my baby brother. A true "three second" airplane.

Flyboy Dave

My Feedback: (21)

Yep....another Guy came up with the idea, and I started the club. Lots of fun.
I gave myself #4, and some friends 2 and 3. In fact there is no #1....

....no ego trips that way.

Dave.

Mustang Fever

My Feedback: (2)

Dave:

Thanks so much for your help on this project. Everything is installed and works great. The left wheel even hesitates while the right one goes all the way up, then follows, kinda like a real P-51. (I didn't plan it, it's just one pushrod is a bit more flexible than the other.)

Bob Hunt
Cadillac, MI

viper21

My Feedback: (9)

K&S Makes a real great wire bender that you put in your bench vise and its got a good size handle on it. You can bend up to 1/4" steel wire with it and once you get the measuring down pat you will never use another bolt on axle again. No more grinding flats on the struts to fix the set screws on and it always comes loose at just the critical time. K&S sells them for about 30 bucks but they are super heavy duty.
Viper

bubbleboy

Thanks to everyone here as well. I am in the same boat so to speak. Am installing my first set of retracts. I read an article once that I cant find now, that said the distance the cam travels on the leg from full up to full down, is the distance the rods need to be apart on the servo arms? Crikey did that come out right?????[X(][&:]
Can anyone offer any comment on this?

Richard L.

My Feedback: (24)

That is correct. If you stop and think about it, the EZ connectors on the servo arm move the same linear distance from one side to the other as the servo swings 180°:

bubbleboy

Thanks Richard L, that has confirmed it. Thanks for a great picture too. I am on my way again....