Wiring loom design questions

[andy_ck87028]

Hi All

Within the head assembly, there might well be a stepper / servo motor, limit switches and the cutting head. (plus others maybe)

The stepper / servo has DC power and control wires; the limit switches the same (?) and the cutting head possible 110V/240V AC.

Given the head assembly is moving on the Y axis, there needs to be a way to get all of those cables to the cutting head.

What guidelines do people have for the management of these cables?

I am looking for rule of thumb guidelines, absolute must do / do not guidelines, shielding guidelines, choice of cable guidelines, cable separation guidelines etc.

Any help much appreciated.

Cheers

Andy
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[OCNC]

"When wiring the electronics to control your motors, the wires should be neatly routed and seperated. By this I mean the wiring from the X axis driver to the x axis motor should not be routed with any other wiring. Same for the Y and Z axes. Board power wiring should be routed independently of all motor wiring. Computer signal wire routing should be independent of all power and motor wiring." This is quoted from PMinMO .

Chris

[andy_ck87028]

Thanks Chris

I have now saved the link into my favorites.

It might be sound advice however at one level it appears to be impractical. (Playing devil's advocate in order to increase my understanding)

I have seen quite a few CNC routers use an energy chain (e.g. Yohudi) and surely those routers must have the wires within that same cradle.

How have they been able to comply with Pminmo?

Andy

[OCNC]

Originally Posted by andy_ck87028 Thanks Chris I have now saved the link into my favorites. It might be sound advice however at one level it appears to be impractical. (Playing devil's advocate in order to increase my understanding) I have seen quite a few CNC routers use an energy chain (e.g. Yohudi) and surely those routers must have the wires within that same cradle. How have they been able to comply with Pminmo? Andy

It happens that I'm just at that point in building my router that I have to address this issue. I would say that it's do-able but since no actual seperation distance is specified my solutions may not be ideal. Time will tell.

Chris

[andy_ck87028]

Thanks Chris

Is the voice of 'been there done that' out there?

Separation makes sense but if separation options are low what are the absolutely must do as distinct from the theoretical should do's?

Assumedly there is a lower chance of a problem if wires run parallell for short distances.

On my gantry, I was thinking of having half my wires come from one end and half coming from the other. That would mean 2 energy chains that would be overlapping for a short ditence in the middle. If I were to do that, what would be the best way of separating the wires. My wires would be for 2 steppers as I have both my head assembly and Z axis motors sitting on the head assembly.

Cheers

Andy

[Al_The_Man]

Originally Posted by andy_ck87028 I have seen quite a few CNC routers use an energy chain (e.g. Yohudi) and surely those routers must have the wires within that same cradle.

Industrial systems rarely use 5v for control voltage (24vdc min.) but if you run 5v control and run separately to motor wiring , I cannot see it being a problem, especially if you make sure the motor feeds are twisted pair and you could run them shielded for extra protection. This is especially important for servo motors where encoders are involved, and personally I have found the benefit of a common ground point for all shields and commons just as important.
Make sure you run a separate ground conductor the the Z axis this is another item often overlooked.
Al.

[andy_ck87028]

Hi all

Well my gantry is pretty well complete and my Z axis is also pretty well complete.

Now it is time to build the hardware for the wiring loom

On my gantry, (which carries two steppers (y and z) plus the router itself), I can either bundle all wires into the same energy chain or I can have up to three energy chains.

Accepting the point below about twisted pair power cables, I was thinking of putting the power cables on one energy chain, all the control wires on another energy chain and reserving the third position for an energy chain type arrangement to carry a vacuum pipe for the dust collector.

What have others done and more importantly what problems have people encountered bundling everything in together?

Andy