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Old 11-27-2007, 12:27 PM   #272 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
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Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 51.27 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
Last 3: 66.97 mpg (US)
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02-01-2007, 09:32 Pm

Well, I got some advice & encouragement from an experienced EVer...

#1 salient point was the special Curtis pot that costs so much money is generally thought not to be of particularly good quality. Over priced too.

He encouraged me to mod a $2 Radio Shack 5k pot instead.

Suggested looking at sizing a pulley to put on the shaft that corresponds to the amount of throttle cable travel. Or using some nylon gears.

Nylon gears, I've got.

For some reason, I'd kept an old, dead inkjet printer in my junk pile. I pulled the cover off this evening, and sure enough there were a couple of 1:4 (roughly - didn't measure exactly) gears inside (paper feeder mechanism).

I cut out the chunk of the printer "chassis" with the gear mounts, modified the shaft of my $2 5k Radio Shack pot to fit into one of them, and presto! It works. And bonus: there's even room inside my forklift potbox for this gear assembly to fit on the end of the throttle arm shaft. The ratio matches the stock shaft rotation and coordinates with the microswitches and physical "stops". Perfect!

Of course by now I could have bought the entire Curtis Company with money earned working, instead of spending all this time trying to track down some other solution, or making my own.
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