i need some one in the melbourne area who can give me information or point me in the right direction for wiring diagrams and components for the control box. to make a cnc mill. all the rest i can do.
Hi Russell. Thanks for the reply
For the moment i think i am ok with pc side of things. I think i will use a parallel port to a break out board then on to motor drivers.
I need things like limit and reference switches, emergency stop details. As well as xyz axis i will need another for a rotary table but i think this will be easy to do after i get use to what is required.
No probs Jim, usually you take the limits and the E-stop to the break out board as well.
There is a lot of different views on how to do this, but here is my take on it :
Wire limit switch pairs (one pair per axis) in series and normally closed contacts. I put two switches in series per axis, so if say the x-axis travels too far either direction the same signal will return, and same for the other axis's.
Generally you will be able to tell which direction the axis has overtravelled, and by the same thinking, you could simply have one signal going to the breakout board for all the limit switches, though with this approach you won't be able to make the machine "home" by itself, I don't use the homing function myself at the moment, so this would work for me as well.
The E-stop is wired with normally closed contacts as well, the theory behind this is that if a cable breaks, the machine will stop on E-stop, and you will know that there is a problem immediately, if it was normally open, you wouldn't know there was a problem until you NEEDED to use the E-stop, and by then it is a little too late and it won't work. You can also easily daisy chain E-stops with the same cabling using this method.
A lot of people that use homing switches prefer optical type instead of lever type of switches for repeatability, again, I don't use em