Electronics for New Machine + Chinese Spindle + VFD

**Neale** · 29-11-2015

Are those NO or NC?

**mturneruk** · 29-11-2015

So those Prox switches that detect metal does that include aluminum which is non-ferrous?
Or is it ferrous metals only they are looking for . e.g. they contain iron.

Those prox switches your buying don't look to be shielded. Should prox switches be shielded or does it not matter so much?

I have just re-read your advice on the KK01 resistors. Thankyou.

Just to clarify are you certain that no resistors are needed going from the KK01 to the drivers, in the step, enable, dir wires?
I can't see why they would of put that diagram in showing different resistors, and I am certain that getting that wrong could be bad.

It's painting electronics by numbers at this end. Sorry for repeat question.
I'm getting my head round it slowly.

Manual : http://cnc4you.co.uk/resources/KK01.pdf

Cheers
Martin

**Neale** · 29-11-2015

Yes, it could be bad if you get it wrong! But look carefully at the table of resistor values in the diagram. You'll see that for 5V, the required value is zero. That is, a resistor of zero ohms. In other words, a piece of wire! That diagram is slightly misleading and in reality it comes from the data sheet of the driver rather than the BOB. The KK01 BOB is fed from 5V and cannot put out anything higher, so the diagram is misleading and there is no situation where you might need those resistors anyway. However, the drives are designed to take a 5V input and if you use a different BOB running at a different voltage you might need them. Just like the inputs to the BOB, where you need resistors if you use a 24V limit switch system but not if you work at 5V.

**Clive S** · 29-11-2015

Originally Posted by mturneruk

So those Prox switches that detect metal does that include aluminum which is non-ferrous?
Or is it ferrous metals only they are looking for . e.g. they contain iron.

Those prox switches your buying don't look to be shielded. Should prox switches be shielded or does it not matter so much?

Martin

Martin. The leads are not shielded but I tend to cut them short and use shielded cable they also need ferrous ie just a bolt head or washer etc. Neale. I agree that schematic is very misleading you beat me to it

**JAZZCNC** · 29-11-2015

Originally Posted by mturneruk

So those Prox switches that detect metal does that include aluminum which is non-ferrous?
Or is it ferrous metals only they are looking for . e.g. they contain iron.

They will sense Aluminium but you have to get very very close and they are erratic so NO is the answer. Sense to a bolt head or Metal plate etc.

Originally Posted by mturneruk

Those prox switches your buying don't look to be shielded. Should prox switches be shielded or does it not matter so much?

Clive answerd that he does what I do.

Originally Posted by mturneruk

Just to clarify are you certain that no resistors are needed going from the KK01 to the drivers, in the step, enable, dir wires?
I can't see why they would of put that diagram in showing different resistors, and I am certain that getting that wrong could be bad.

They are completely separate and isolated things don't worry.

**cropwell** · 29-11-2015

Originally Posted by JAZZCNC

They will sense Aluminium but you have to get very very close and they are erratic so NO is the answer. Sense to a bolt head or Metal plate etc.

If you run your target bolt head axially on to the sensor, one day you will jog onto it and crush the coil in the head. Put your sensor at right angles to the motion of the axis, so the bolt passes by the sensor. My MD machine was designed with axially mounted sensors. Jeesh !

Rob

**JAZZCNC** · 29-11-2015

Originally Posted by cropwell

If you run your target bolt head axially on to the sensor, one day you will jog onto it and crush the coil in the head.

Rob common sense to me and can't believe MD or anyone would position any switch not to mention Prox switches so they could be crashed into.!

Another reason is the sensing repeatabilty is actually better when sliding over rather than approaching head on. Most Quality Prox switches data sheets will give specs on both types of approach.

**Neale** · 29-11-2015

Common sense because you've researched and tested the answer! I would have thought (probably like a lot of people) that end-on would give better results although I am now quite convinced as a result of your testing demo a while back. I did worry about over-run though, and it's good to know that there's a simple answer.

**cropwell** · 02-12-2015

Originally Posted by JAZZCNC

can't believe MD or anyone would position any switch not to mention Prox switches so they could be crashed into.!

I can, when I consider the design of the rest of the machine !!!!

**mturneruk** · 29-11-2015

OK Great. Thanks Jazz.

So hopefully that's the plan sorted now. Reckon I might get stuck along the way, but i will give it a go.

So am i right in saying I need NC ones. So that when it detects something it opens and breaks the circuit ?
I will have to ensure that the aluminium frame of the router won't cause false triggers then on the prox switches.

Does NPN or PNP matter for my purposes ?

Do these look like they will do the job?
http://www.ebay.co.uk/itm/1-5Pcs-Ind...U0u32s_xiK0nkw

Thanks again for all your help. Couldn't of done without it.

Cheers
Martin