Add fuse to router as fail safe? Looking for suggestions


Three weeks ago my 4yr old Makita went toast when the router plunged way too deep and overloaded the RPM governor circuitry. There were a couple of “pops” when diodes overheated/lost its magic smoke.

I bought a new Makita and today I almost did the same, my Z-axis was binding and didnt retract as intended and plunging in too deep. This time I was able to kill power before there was any damage.

However, two bad strikes in a short time has made me anxious and I am considering adding a fail safe if that is viable.

Would a simple fuse, inline with the power cord act fast enough to prevent electronical damage this story tells about?
If so, what kind of amp rating would suffice. The router is rated at 800W (220VAC) so about 4A is a theoretical max.

  • A fuse would kill power to the router but the machine would not notice
  • Perhaps a circuit involving a relay and trigger the abort button should amp draw spike?
  • Or a amp governor circuit, linked to a relay
  • A switch detecting is router plunge below a certain point, triggering an abort/power-off?

I am really interested to hear any ideas you guys may have, or have recommendations or suggestions.

(The Z-axis started to stall out, I have been carving a lot of MDF for a while noe and the dust get everywhere so I assume the screw (1605) and square rails need cleaning, I will need to check these anyways)

In the event that you use a fuse, you should use a fast blow fuse. You can then use a “blown fuse indicator” circuit to trigger the a Feed Hold or E-Stop on the controller.


Brandon Parker