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Throttle Quadrant Part 2

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Well-Known Member
Sep 13, 2006
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The MacKenzie newsletters have some good ideas, some not so good. One that I think is good is the throttle quad drawing that is shown. It provides for tension/friction adjustment via a large knob on the outside cover. It is light weight and functional.

I debated using phenolic between the levers due to it's self-lubricating qualities. However, I decided against it purely for asthetic reasons. It would make a fine material for lever spacers, in my opinion.

Once agian, I warn you that this throttle quad is of my own making and I recommend that you make your own decisions regarding construction and safety.....what you see is only my ideas, not THE WAY to make it.

Looking at the drawing, I started by cutting out the spacers from aluminum and brass. The brass is used on the lever side of the spacer, so that the steel levers can slide against them. I cut the front cover plate from 6061 for flexability (friction system) and the rear plate from 2024 (rigid, for mounting).


Now, you can drill the pieces and finish size them in a mill...if you have that kind of stuff. For those builders that don't, after cutting and drilling, bolt the pieces together and finish them with a sander.The brasspieces will need to be laminated to their aluminum counterparts, as I found that they would flex and pull away from the aluminum.I used to spray adhesive and got good results, but some may wish to use epoxy.

You can then bolt the pieces back together and finish them on a polishing wheel, making all of them match and look pretty.


The newsletter drawings are pretty straightforward as tot he tensioner end of the quad. After assembling that end, it looks something like this:


See those rivets? WRONG WAY to do rivets. They have been corrected since this picture was taken. Yea, I make mistakes......that's how I learn.

Looking at the drawings, they show a large aluminum knob on the outside used to adjust the tension screw. I thought making one and knurling it, but I wanted something unique.... Fred Sanford and Son unique. So, I was walking through the garden center at my local hardware retailer and saw this hose adapter:


I bought it and removed the brass and rubber female adapter, then pried the rubber part off:


I then went to the trusty lathe and turned down a duplicate knob from aluminum:



I cut an appropriate length threaded screw for this and secured it to the knob. I used an aluminumspacer to get the knob spaced from the cover plate to avoid interference with the cover plate hardware. I could have machined that spacer into the knob itself, but I really wasn't sure what kind of hardware I was going to settle on (hex bolts, slotted screws, etc).


So, here is the finished body.....I am still working on the levers and will post them later.


I will make only the rear quad a friction-type. The front will be non-adjustable, because I don't want my passengers playing with anything more than the headsets. :)

Comments? Ideas? Questions?

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