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Rodney
03-05-2009, 12:21 AM
Finished!

I started off configuring my real throttle using the existing pulleys and added cable, pots and springs. I need about 5 inches of throw, and the springs gave me too much resistance. So the better option would be to buy already made string pots. After a quick scan for costs I couldn't part with the money for them, $170 USD each. Best option was to build my own. There were many design hurdles to manage. Pot shaft size, spring size, string material, etc. I tackled each problem with a cup of coffee and some serious thought. My goal was to build something that would withstand the movement and a secondary goal of using what I had to keep the cost down. While its not pretty, it certainly is very functional and durable. And at about $65 USD I feel real good about them. I was concerned about the size needed to get the job and not using "string" but metal. I found key reel that fit the build at Harbor Freight http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96589 To mount the pot to the key reel I found some sliding screen door rollers that were from many yeas ago project. They had a 1/4 inch bushing and the roller mounted sideways to the key reel almost perfectly. I had some 1/8" aluminum sheet that I used for the base and brackets. Once mounted in the throttle bottom, all three needed to be aligned with the cables running over the front pulleys before final tightening. No binding is a good thing. They are wired and I foresee no reason that they won't work just fine. Now onto some other small wiring on the throttle and a coat of paint. It is a module that can easily be removed for any type maintenance.

Jackpilot
03-05-2009, 10:50 AM
Hey Rodney,
What are the advantages of a string pot?
Must be some considering the price!
(I'm illiterate about it)
Jack

Gallie
03-05-2009, 10:57 AM
Nice Rodney!

Mike

Rodney
03-05-2009, 02:26 PM
Hey Rodney,
What are the advantages of a string pot?
Must be some considering the price!
(I'm illiterate about it)
Jack

The advantage for me is the routing of the cables and ease of use. No matter how I did it a cable option was prefered by me vise constructing some type of lever to move a sliding pot. So in my 1st interation, I only used pulleys and springs. Springs resulted in too much resistance. One other builder bought the comercial ones and his install and configuration was almost painless. The way I designed and built mine, I created a module that I can easily remove in about 5 minutes to replace worn parts. Of course I don't foresee that happinging for some time. So the ultimate goals were the challenge itself and price. Hope I answered your question.

dnoize
03-05-2009, 05:28 PM
Another advantage on a real trottle is that when you use the same wheel for throttle and reverse the travel is much longer than any stock slider pot. 100 mm just wont do it.

string pots then work perfectly. Mike (gallie on this forum) also made his own using ski-pass holders. He posted pictures too about a month ago. Same idea and a great low cost solution compared to commercial string pots.
Thanks for sharing.

Stef