I make long lever pump action type keys similar to the Amplidan design.
This key is made from Avonite Goldmine. The hardware is brass and gold. The knobs came from a music store from a Fender Telecaster electric guitar.
The feel is superb and in my opinion better than that of a real Amplidan because of the ball bearings. A real Amplidan has coned points on the ends of its axle. Those fit into cups and not near as smooth as ball bearings are.
This type key has a coil spring that adjusts the tension. The Z shaped part is NOT a spring, it is an electrical conductor and only bent into a Z shape to eliminate resistance in the movement of the lever. This part could be removed and replaced with a thin wire and you would never know the difference in feel.
The bottom shows the wiring. I counter sink all the holes, sign it and cut a shelf liner to go with it. The electrical connections are done by grinding the screw heads and soldering them using flux. With a shelf liner, this key will not move around on the desk. I made this key for the SPAR 2008 Home brew key contest and it won 1st place.
New straight key project
Here is a new one in Avonite NewCaldron.
This one will use brass and gold hardware. I plan to make some changes to the design, but the basic idea will be similar to the Amplidan type pump keys. This key will feature my first brass lever and hopefully, my first knob and skirt that I plan to make out of the same material as the base.
I turned this knob and skirt using my cordless drill. Looks pretty rough in this photo.
More hand shaping with sand paper.
Now the knob and skirt are almost good enough.
The lever is cut from a piece of one inch by half inch thick brass bar stock. I get mine from www.speedymetals.com. I use a template to draw the shape of the lever on the brass with a sharpie marker.
I rough cut the lever using a jig saw. I clamp the brass in a vise wrapped in cloth to prevent marring the brass, to cut it.
As you can see, the lever looks pretty rough and has a long way to go.
I shape the lever with a dremel tool and a drum sanding wheel. It doesn't take very long to shape the lever any way you like.
Time to test fit some parts to see how they line up.
I don't make my own adjuster knobs. I like to buy gold knobs from Fender Telecaster guitars. These are nice heavy knobs with deep knurling. The rear adjuster has a 8-32nd screw JB Welded into it. The spring tension adjuster has an 8-32nd nut JB Welded to the inside. The spring screw is 8-32nd and will have its excess threads hidden up inside the knob. The spring is 1/4 od and pretty stiff. I get those from Ace Hardware.
Click on the photo for a larger image of the finished key.
All Finished! - Royal Ruby Pump! 73 Bill NT9K..