Comments sought on new build: A CNC Router for RC Gliders and Planes

[JAZZCNC]

I'm not going to talk you out of a Pilz style relay as I looked at those as well and was impressed. However, I will mention that a level of safety interlock can be achieved with a cheap multi (4) pole relay - mine was about £8 and has the option of DIN mounting:

I agree pilz are nice to have but not really required at DIY level. Normal relays work just as well provided they are correctly sized.

As stated a latching circuit is easily created and standard 24Vdc relays are cheap and easily sourced for any future problems. Depending on level of safety you'll still probably need a plan vanilla relay or 2 anyway as the pilz won't provide enough contacts.!