100% all the time ESC ?

I got talked into a project for a friend, to make him a small electric chainsaw to replace his gas saw, he's a arborist and has asthma so the fumes are not so good when he is 100 feet up in a tree. I've dug up a couple dewalt 36v packs for the A123s and have a HXT 64-73 from another project I've mated to a spur gear box for a 3.2:1 I have a small 8" bar on the way. So now its just a ESC, I've been looking for one that just on/off, not poportional control since I'm mounting it to a simple push button switch. But I cant find anything, does anybody have a circuit diagram for a 100% all the time ESC?

Since you got "talked into it" talk him back out of it. There are cheap cordless chainsaws available for much less than all the stuff needed to make one. Of course they lack power and do not last long per charge, but I'm assuming that since you are only making it with an 8" bar that it is for small limbs for minimal pruning cuts.

If it really is for minimal cuts, another alternative is a cordless reciprocating saw with pruning blades.

If you had a brushed motor, you could use a simple switch between the battery and motor. With a brushless motor, there's no way around needing a regular ESC and a servo tester. You could wire a switch into the servo tester so it's full throttle or off.

i think the weight of the packs would limit his ability to climb, when the guy climbed into my tree to cut the limbs higher up, he used the smallest but most powerful little chainsaw i have seen, just 16", but it has to be small and light to work with, not gonna work with batteries, imo.

With the right batteries it will! A123 M1 cells have the highest power density in the business! A single 3.3V 2.3AH M1 cell can do 120A bursts!

of course you can just use a simple switch, but that requires running the heavy high current wires from the battery to the switch to the motor. if you really just want a smaller remote switch so you can have a short path between the battery and the motor all you need is one or more FETs. you connect the source of the fet to battery - and the drain to motor - then connect the motor + to battery +. you pull the gate of the fet down to the source to turn it off and up to the drain to turn it on. depending on the voltage you can choose the proper fet. send me a private email and i can send you some scrap parts.