Difalco ball bearing trigger upgrade

[Young again]

My primary controller is a Difalco 30 band unit which I use on our mdf nonmag club tracks. I felt the need for a good dollar value backup. I purchased a 45 ohm Parma Turbo Pro then installed a Difalco brake pot. This system works very well but I missed the smoothness of the Difalco trigger pull. I took the time to retrofit the Difalco ball bearing trigger assembly and am very pleased with the results.

[SpeedyNH]

yeah, i like ball bearing triggers too. but then again, i'm spoiled. and old to boot.
speedy

[scatman]

Photo plz.

Thanks

[SpeedyNH]

if you mean me, i don't have a pic (and never took the time to learn to post 'em yet anyway :(), but here's what i do:

first, i square up and deburr the sides of the trigger (i prefer the Parma type) around the pivot holes and put the ball bearings in with the flanges against the plastic. i use old 1/8" axle bearings (til i run out) as the bronze oem's look like standard 1/8 x 1/4" axle bearings to me anyway. you can check boresight alignment with an old axle.
i use an undersized screw (2-56) because i like to move the pivot point as close to the edge of the frame as i can get it. but that's another story; a 4-40, 3mm or better yet (if you have any) 5-40 screw is a better fit if you only have the bearings. (remember the old threaded 1/8" axles?)
then the critical bit: i shim the inner races apart along the screw inside the trigger body with copper tubing or axle spacers so that when tightened up, it doesn't apply axial loading to the bearings as they squeeze against the plastic.
i also put another tiny washer on each side of the stack so that the screw head and metal frame don't contact the outer races (or the ball retainer/ dust seal) when it's all bolted up. if you can find extended-inner-race bearings to start with, that makes things a little easier.
and if the outer races aren't a tight fit in the holes, i like to glue them in, at least the inner one.
when you're done adjusting the stack, the trigger should be firmly fixed in a parallel plane to the resistor and flop around just like it had ball bearings! oh, wait- it does. :grin:

hope that helps.
speedy

[scatman]

Thanks for the info. I need to give it a try.