Hiatus 2

[Bill Ambrose]

Hello again gents,

Here is number two on the runway.  It's an RSM Shoestring (Bob Whitely design) with a PA 51 on a pipe.  Again don't be too critical, it's been a long time.  Hopefully Willis can help me get it to run like it should.  Basic construction is done.  Much sanding left to do.  I also included one more picture of the GNobler.

I love this site,

Bill Ambrose AMA 880

[Paul Taylor]

Hey Bill,
Looks like you have a adjustable trim tab on this one. Can you post some close up pictures? I am wanting to put one on my new project.

Thanks
Paul

[Willis Swindell]

Bill
No problem. Hope we can fly Sunday at Fentress. Steve and I both have new T-Rex’s to fly Jimmy has to finish adjusting his piped T-Rex. Phil has a new shoulder so he won’t be flying. You do good work, like your dad. The planes look great.
Willis

[Bill Ambrose]

Willis,

The T-Rex looks great.  Dad would be proud.  P-47s rule!

[Bill Ambrose]

Paul,

This is the way I chose to do it.  I'm sure the pundits will rip me to pieces.  I chose to use a spherical joint at the fixed end.  Just good engineering judgement in my view.  The fine adjustability is on the fixed end (screwing the rod in and out).  It also gives you macro adjustability by simply replacing the pushrod with a longer one.

I hope this helps.

Bill

[Bill Ambrose]

Paul,

I would like to slightly change what I said previously.  The "throw" or adjustment can be modified from both ends.  I apologize as it has been awhile since I built this plane.  The pushrod is threaded on both ends, therefore it is adjustable up to a "reasonable thread engagement" (typically 4 to 6 turns for such fine threads) on either end.  Should you find it necessary to shorten or lengthen the "throw", the pushrod can easily be replaced (hence my original thought process).  I failed to state earlier that reinforcement is necessary behind the mounting position of the "fixed" spherical (or ball) jointed end.  The reinforcement is minimal because the aerodynamic forces on such a small "tab" are minimal.

Hope this helps.

Fair Skies,

Bill Ambrose

[Robert Jones]

This is the way I chose to do it.  I'm sure the pundits will rip me to pieces.  I chose to use a spherical joint at the fixed end.  Just good engineering judgement in my view.  The fine adjustability is on the fixed end (screwing the rod in and out).  It also gives you macro adjustability by simply replacing the pushrod with a longer one.

That's a great idea! I'm gonna file that one away for future reference.

[john e. holliday]

That trim tab looks great to me.  Mine are usually external.

[Willis Swindell]

I stole this Idea from some one at the king orange several years ago.
Willis

[Paul Taylor]

Yea I am going to steal both of this ideas and claim them as my own!

[Bill Adair]

Willis,

Neat tab adjustment.

Those continuous hinges are interesting. How are they made?

Bill

[Bill Heher]

Nice , clean and simple- these are 3 of my favorite things.

Only thing I would do different is taper the balsa and ply mount plates to eliminate the straight vertical edges, it wouldn't take any longer to cut them that way.
 Tapering it spreads the load across a bit more rib. The forces on the tab may be slight, but  the load will change with airspeed / attitude.

[Willis Swindell]

Bill

They are monokote hinges. Cut a strip about 1 1/4 inches wide fold it over and cut in half overlap them about 1/4 inch glue joint to glue joint , make sure you iron on both sides of the joint. Then cut them in 1 inch strips. I use them side by side for the entire flap or stab this creates a sealed hinge line. If you use blocks of them use four never three, the odd one will fail.
Willis

[Dwayne]

Thanks Willis, how hot should the iron be when joining the two strips.
Dwayne

[Michael Boucher]

How did you apply the carbon fiber, with dope?  Thanks 

[Bill Adair]

Willis,

Thanks for the explaination. Those hinges looks good! 

I used a similar method on some R/C models, but covered both surfaces with a single sheet of Monokite on top, and another single sheet on the bottom, with the mating LE and TE of
each surface beveled at an angle. The Monokote was then ironed together in the gap, with the edge of a trim iron. Kind of like the crude characters below, are attempting to show.

__________
____/\_____

Bill

[Bill Ambrose]

Michael,

Yes, the carbon fiber is applied with clear dope.

Bill