Spitfire Sim Control project : update N°2

Well here is the full scale replica prototype Spitfire MkIX throttle quadrant for sims, freshly 3D printed, assembled and painted, almost ready for testing.

This is part of a 4 unit set of controls which will include the control column, a trim wheel unit for rudder & elevator, the throttle quadrant (shown) and a radio remote control unit. The other units are currently being printed, but this takes time as one or two items can take up to 30 hours to print.

The throttle quadrant is made up of 36 parts, some had to be divided into halves in order for them to be correctly printed.

The throttle quadrant has a Fuel Cutoff lever which activates a button when it is either pushed fully forward or brought back. This lever is not really used on the MkI’s in Cliffs of Dover, but it is required on the MkIX in DCS.

The throttle lever activates a potentiometer which I had a lot of trouble hiding in between the front and back plates. The lever only rotates through 43° (per the original) so I have developed a gearing system which rotates the potentiometer through 140°. This will help give a sufficiently fine adjustment. The lever also replicates the full throttle max take-off gate movement. To go beyond into WEP, the lever needs to be pushed slightly left and in doing so it activates a button to activate WEP in the sim. When brought back to full throttle setting the button is again activated which cuts WEP.

The MkIX throttle has a button in the grip, which was used for bomb release. In the sim kit, this button will be assignable to any function the player wants.

The airscrew control lever unit is bolted on to the outside of the front plate. This is directly inherited from the MkI when the pitch lever was hurriedly modded in service when variable pitch props were introduced just in time for the battle of Britain. I have had to make some important modifications to this unit which I have managed to do without altering the exterior aspect. I again added a gearing system which drives a potentiometer, converting 55° of lever rotation into 138° on the potentiometer.

For fun, I have added a working friction wheel and lever. This helps to stiffen the controls so that they stay as put, since there are no springs or centering devices.

Next step will be to add the wiring for the two potentiometers and the 3 buttons.

In parallel work has been going on on the Arduino Leonardo programmable chip board.  Initial tests are satisfactory and we have been able to program the chipset using the downloadable software. Next step will be to hook up the wiring from the different elements.

The trim wheel and remote control units are currently being printed and will hopefully be assembled next week.

For those interested is seeing the kit, I will be taking the units that are ready to the following airshows :

Warbird and Oldtimer Day airshow at Bremgarten/Eschbach 24th & 25th June. These will be exposed on the Spitfire Histories booth. NB for those of you in France this is close to Colmar and you’ll have a chance to see Spitfire MkVIII (a pretty rare bird in Europe), P51 Mustang, F4U Corsair and a Yak.

Flying Legends Duxford on Saturday 8th July. I will be visiting this show with other sim flyers from EAF, but will have the items in my car in the car park. If several of you are interested, let me know by posts and I will set up a meeting point & time.