~S~ all

I've finally taken the plunge and manufactured a control box for handling trim out of an old MS SIdewinder Precision Pro and a (hastily assembled) wooden box...  It was never intended to look like the real thing, just to give the required functionality, which, it appears, it seems to do quite well (though I say so myself. Hem, hem...)

It consists of four rotary controllers - simple knobs (for rudder, elevator and aileron trim and prop pitch) linked via a simple gearing system to the four pots & circuit board from the disassembled stick. I found the gearing system was necessary to scale down the sensitivity - having control input directly into the pots was just too twitchy.

The gearing system uses some plastic cogs I found at a local electrical store (http://www.maplin.co.uk/) and clipped off nails as spindles. The nails are smaller in diameter than my potentiometer spindles (5mm).

I've used some heat-shrink plastic tubing (also sourced from the same shop as the gears) to effect the coupling between the different diameters of the gear system and pots. This is a bit 'jerry-built',  but seems to work quite nicely.

I'm just wondering if anyone else uses this method for handling this issue or whether there is a more elegantly engineered solution... ?

I'd also be interested to hear of how others are handling gear systems such as this - are there any kits available? I found it very difficult drilling accurate holes for the gear spindles with a hand-held drill - even a slight angle or fraction of an inch off true and very soon the gears don't mesh properly.

All working now, but what a fiddle!  

All the best,

Pads

With an extra pully and wrapping a chain round it instead of the thread rods you could also do it this way I think.

http://www.simviation.com/cgi-bin/yabb/YaBB.cgi?board=homebuild;action=display;n...

I might try something like this.

Silcone fuel tubing as used in model planes, boats and cars can be used.

Many model boaters use it in place of  auniversal joint to connect motors to running gear. For best results drill a hole in each of the connecting metal parts and pin the tubing in place so it doesn't rotate.