Tool Height Setter

Just got sent a design for a tool height setter using hall effect sensor. A great design that is all shared for the community.


If I understand it correctly, I like that it does not require closing a circuit path through the tool to the touch plate, which means not needing to attach an alligator clip every time I change the tool and want to set the height of the tool’s tip (relative to the work piece).

PRO: This would probably be especially useful for machines that have an automatic tool changer.

CON: Looking at the picture, it seems to be a fixed location device. This means it would be setting the absolute tool tip height relative to the machine–not the work piece. This means the work piece height would have to be set separately (presumably using a touch plate that rests on the work piece like I usually do now). Unfortunately for me, this is not very useful compared to my existing touch plate, because I do not have an automatic tool changer.

But perhaps I’m misunderstanding its intended usage?

I don’t see anything in the design which would prevent it from NOT being bolted down to a fixed location and used to determine the workpiece top surface. Heck, two of these, one fixed and one movable could be wired together to the same circuit and used as you wish.


Agreed. I’m just going by the picture. It is also pretty tall to be placed on the work piece, unless you have a lot of z-axis height to play with–I don’t, I think I only have about 3 inches or so, plus about 2-3 inches to the spoil board (might be less; I’m not sure offhand of my total Z height).

Ah, he’s using it on a mill, not a router. He has a Tormach PCNC440.

I feel like it ought to be possible to create a different mechanical design that uses a hall effect sensor like this but doesn’t take up so much Z.


Hi Michael, agree, I think the design could be shrunk in Z and the electronics housed in a separate small box or just to the side of the sensor. Alan has shared a lot of detail and thus opened this up for further ideas. Best regards, Nigel