Been working on refreshing the motor in the old Monaro. When I was a much younger man I did a lot of engine modification, including porting, and it's been good to revisit this after all this time. The motor is a Chev 350 with a few mods, about 400hp at the crank. I'm swapping out the old "smog" heads with these, double hump fuelies ( those who know will go  "nice!" ), and doing some tidy up work on the ports.





I've been using those electric die grinders. They are a little scary, there is no quick way to shut them off. On more than one occasion the bur got a chatter up while deep inside a port and you need to hold on for dear life and try to get it under control before it destroys the bur or takes chunks out of the port. The bigger grinder nearly drew blood when a extra long bur got out of balance, bent at 90 degrees to the chuck and shook so violently all I could do was hold or drop it, fortunately for me a wire in the motor shook loose and it shut down. I haven't used that one since.

So decided to build a foot operated mains switch. I have a foot pedal for my TIG that I made from a old Singer sewing machine foot speed controller. This had a D9 plug on it where it goes into the TIG box. I made a simple circuit using a step down transformer, bridge, cap, couple LED's, and a 20 amp mains rated relay.

Press the pedal, the mains switch has power, release pedal, its turned off. Tested it with the die grinder, soooo much better, and safer.








Glenn

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The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ

Nice one Gizmo, seems like it would be useful for lots of other things too.
What size relay did you use in the box.
It could be a useful gadget for power tools too, some of them try and get away and strip bark off the user.
I may have to copy your idea and make one too
Pete

Hi Pete

Its just a 20 amp relay, something from the junk pile. I think it may have come from a microwave oven originally, something I would have scrapped for parts long ago. The relay coil is 24v. The transformer has a 18vac tap, so I get about 24 volts once rectified and filtered.

Glenn