i have a b&d rtx rotary tool and love using it but the switch and speed control where so far apart i decided to make a foot speed controller out of a broken sewing machine foot switch.
the good thing is i can set my top speed limit with the controller on the rotary tool so its like a set and forget, also i don't have to turn it off any more unless in changing bits since on my model you have to have the switch off to change a bit.
parts needed are.
1x singer or whatever brand sewing machine foot switch.
1x extension cord.
1x soldering iron.
1x roll solder.
2x 2in pieces of heat shrink.
wire cutters and screwdriver.
total cost was $4 dollars.
Step 1: removing the cables
after you remove the box covering the cables you need to only cut the 2 wires going to the motor.
Step 2: after cutting strip the ends and do the same with your extension cord.
well i have my wires cut on the cord and foot switch so slide your heat shrink over each wire and solder the cord with the outlets to your foot switch.
i used a cheap torch to shrink my heat shrink.
Step 3: after all is together test
after i got it all together i tested it out and it works better than i thought, the low speed on my tool is 15k rpm but with the switch i can go a lot slower than that and max is 30k rpm.
Step 4: enclosure box
i have no enclosure boxes so i was trying to figure out what to use.
well i found a old chew can laying around, (use what you want) and i think it looks ok.
ps; im not a chewer.