trim

[hercules]

Hello all,
first i wanna say sorry for my poor english...
We build a trim machanism for my control columns and i want show you the first results.
On the right site of the picture you see the motor. It has a gear (145:1) and drives the plate. In the middle of the plate is a hole. Through this hole comes a pipe that is mounted to the columns. There are 2 dumpers mounted on flexible arms. When the motor moves the plate, the dumpers pressing to the pipe and moves the control columns. This is the trim function.
You can move the columns manuel at ervery time. In this case you work againts the force of the dumpers. The plate wont move, beacause the motor is not turning. So you have manuel control at any time.
Iam not sure yet how i should connect the trim to the sim, beacause there is one poti thats work fo both movements..the trim and manuel.
Any ideas are welcome
Best Ragards
Thomas

[Michael Carter]

Nice work Thomas!

[Mike.Powell]

Yes, I agree, very nice work.

These sorts of mechanisms are not discussed nearly frequently enough. The complexity stops many people from working on them.

I think more pictures, and information about the type of dampers you chose, why you chose them, and the motor configuration would be welcomed by many. I, certainly, would find it interesting.

[hercules]

yes thats right, this kind of sim parts are very rare to find on sim-builder-sites!

Since my english knowledge is not the best in town, its difficult to describe such technical things. I will try it...so dont hit me if it sounds like banana

The problem with trim is to move the control colums with a trim motor without loosing the normal function of the column. The motor will allways blogg the column if you dont find a solution to decouple the trim from normal capability to move the yoke manuel.

So i had the idea to take a plate and link it to a gear motor via a threaded rod. Now you could move the column with the motor in a very fine way, but the old problem is still exist....the colum ist fixed and blogged by the plate or better the hole it the plate.
When the part of the plate thats make the touch to the column isn´t fixed you can move it with your hands. For this "touchzone" i use the dampers (200N). When you move the column by hand, the middle pipe gives this movement to the little arms and from here it goes to the the dampers.

Thomas

[hercules]

Hello again,

can somebody help me to get something clear in my head?! The controls are connected via 2 potentiometers (1 for Ailerons, 1 for Elevator).

When i move the trim motor the elevator poti gives the changes to the flightsim. But i think that the trim need a own poti. I imagine that the trim position works with a needed- and existing position thats registered with a this poti. The 2 values are compared and when the existing position differs from the needed position the motor moves the column to the correct position.

When i use the same poti for trim and normal movements it is not the correct way.

Anybody have some ideas about this??

Regards

Thomas

[Michael Carter]

I don't know how to solve your problem, but this might help understand the system a bit.

When you use the trim switch you are trimming the entire horizontal stabilizer. When you are using the yoke to fly it, the elevator tabs on the horizontal stab are moving.

Two separate but related systems.

[hercules]

Michael,

yes i know the way trim works in real. I guess the problem is easy to solve.

I try to explain my problem on another way (to LA)

Without trim capabilities, the yoke construction needs one poti for each ruder (elevator and Ailerons). It means that the elevator poti catch the movements of the column (back-/forward). The additional trim-motor does just the same...it moves the column for- and backward, so the elevator poti catch this movements also! But this poti is not linked via FSUIPC to the TRIM offset, and will not have effects to the trim-offset inside FS9, but to the elevator offset!
I think its important to use the trim offset additional (takeoff warning and so on). But when i add an additional poti to the construction, i cant prevent that both potis catch the column movements and so the sim wont work correct. It gets nose down /nose up values from boh potis at the same time.

For that problem i need a solution.

Hope my crasy english is good enough to explain it

Regards

Thomas

[Michael Carter]

Youe english is much better than my Deutsch.

[dc6driver]

Hi Thomas,

I believe you need 2 pots, 1 for the primary flight control (Elevator) and 1 for the secondary flight control (Elevator trim). Attach 1 pot to the column movement for the elevator and the second pot to the moving trim plate for the trim function. The aileron will need the same setup.

Fritz

[Trevor Hale]

Your engineering is incredible.

I agree, attach a pot to the trim plate, and attach the elevator pot to the column.

Great stuff.