# Tuning Parma Econo Resistors



## twolff (May 11, 2007)

This started in a thread about the coating on the Parma Econo resistors flaking off:
http://www.hobbytalk.com/bbs1/showthread.php?t=249674

I've destroyed one and "fixed" 3 others. I seem to put too much JB Weld on the face of the resistor and have to sand my butt off. There is still the tinyest notch in the trigger pull when the button rides up the brake and full throttle bands, but it is not much. I'm too chicken to try and sand down the bands enough to make the whole face of the resistor flat. Shaping a little ramp at each end of the windings helps smooth the transition. First pic is the backside where most all of the coating has fallen off. There's not much holding the windings in place. Second pic is the JB Weld smeared on. I need to use less and heat it more so it flows. Third is the high spots taken down by sanding the resistor with a sheet of 400 grit wet/dry on a flat surface. You can really go nuts here. The more you take off the metal bands, the smoother the button transitions on and off the windings. The last one is ready to mount back in the controller after the windings are exposed with 400 and then 600 grit paper. A stock controller feels gritty by comparison.

Anyone have any additional tips?


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## GoodwrenchIntim (Feb 22, 2005)

When I did mine I wet sanded the face with 400 grit and it does wonders. Place the sand paper on a flat surface an rub the face of the resistor in a circular motion on the wetted sand paper till smooth


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## twolff (May 11, 2007)

Did you coat the windings with JB Weld and were you able to expose the windings sanding on a flat surface? That's a LOT of sanding!

I'd also be afraid that I'd sand through a single "wind" that wasn't setting flat on the face of the ceramic.


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## GoodwrenchIntim (Feb 22, 2005)

I sanded mine without jb weld. You can also blueprint the trigger contact by cutting a small piece of 400 grit an placing it on the resistor after installing it an slide the trigger back an forth a few times


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## Hornet (Dec 1, 2005)

Heat the resistor to about 150,then coat the backside of it,not the face.
Let the JB flow towards the face of the resistor.
Build yourself a little coat hanger stand that holds the resistor face down in the oven,then open the oven door and apply the JB while the resistor is still in the oven,the heated JB will flow towards the face of the resistor.
Applying the JB to the backside of the resistor means you won't have as much sanding to do to the face of the resistor:thumbsup:


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