How To add 'Fire' buttons to your transmitter
Status: How To Guide
Date: 8-Oct-2007
Comments: 6
Just a quick guide to show how I added pushbuttons to enable me to fire the main gun and the machine gun without having to do the trimmer-and-stick thing.
I have a Futaba Attack 4WD for my King Tiger, and a Futaba Skysport for the Sherman. Both transmitters have positions for mounting switches or buttons on the shoulders. You will need to drill out holes to mount the buttons and possibly dremmel away a bit of plastic to make them fit. If you have a Skysport you could disconnect and re-use the trainer switch as I have done for the Sherman lights.
The Attack is much easier to access and solder on to.
You will need: 2 x small pushbuttons (normally open contact), fine gauge wire, soldering iron, drill/reamer/dremmel.
***If you don't have any experience with soldering I would not recommend you try any of this!***
As you can see my soldering is not brilliant
The way the MFU works is that normal running requires the trims to be set at the midpoints, and the normal functions operate within the 'trimmed' range. The way firing works is that moving the trim and then the stick will take the pot to the endpoint. The MFU recognises the endpoint as the firing command.
To install a fire button you just need to run a wire from the middle connection on the pot and one from the end that the pot is moved to by the stick. These are connected to a pushbutton (got mine from D i c k Smith).
These need to be connected to the right pot! Make sure it is the 'gun raise/lower' pot that you are connecting to. If your transmitter is not set up to function in the same way as mine then you will need to figure out which is the correct one.
I have also done this for the operation of the lights on my Sherman. I disconnected the trainer switch on the Skysport transmitter, and ran new wires to it for operating the lights. I also moved the switch so that the two 'fire' buttons could sit on the shoulders of the transmitter.
While you have the back off it is a good idea to remove the ratchet off the apropriate stick and install a spring-return on the 4th stick (depends on if your transmitter is mode 1 or 2).
If you liked those pictures, you should see these...
Kellys^ Heros
Comments
DeadLock
Nice tutorial. Do you have a how-to for installing return spring on the attack/skysport ?
8316dart
So I guess you can do the same trick with the big rig MFU? If I send you the transmitters can you sort them out for me??? Just kidding!
Bluefoot
Yes, this should work for the big rig MFUs as well. I haven't installed mine yet, but when I do I'll update this. No problem - I'll do the wiring. Just send it to me here on the other side of the planet!
Bluefoot
It is possible to buy the spare bits needed for the spring return. I made one of mine from a part out of an old 2 ch TX that I butchered, and the other out of a piece of 3mm ally plate that I cut and filed to match one of the existing ones. Not easy, and very difficult to get the springs on!
SMOKE-DOG
Now that's something. Very innovative. You think they would have thought of this.
Crash Cramer
Cool, can I send you all my future soldering jobs??? I couldn't tell what you did to the skyport the soldering was done so well.
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