3 Axis 900x500mm

[Wal]

Hi Mikey,

Nice vid - running very nicely..!

Right - regarding the switches, firstly you must understand that I'm an electronics dunce, the little I do manage to learn tends to get overwritten fairly rapidly :(

I'll be setting up my switches on this machine in a largely similar way to how I've done 'em on my mini-mill - the big difference will be in the type of switch - I'll be using three of these (NPN):

http://www.ebay.co.uk/itm/263081103449

...instead of the small red switches - which are great, but fairly fragile...

Each switch, as you know, has three wires, LN and sensing(?) which sends the triggered signal.

Here's what happens in my set-up.

The wires from all switches run back to this black box:



...where they connect to an RJ45 BOB - all L's go to 1, N's go to 2 and sensing goes to 4.

Back inside my main control box there's another one of these RJ45 boards where I've connected a 12VDC supply (don't use a 5V - I understand that the lower voltages are more susceptible to crosstalk/errors) to pins 1 & 2 whilst pin 4 connects to one of the limit switch points on the main BOB. My Linux CNC .ini file is configured to look for a home/limit trigger from just one pin - there's a reason I did it this way, but I can't for the life of me think why, maybe I was just being lazy, which is more than likely... In practical terms what this means is that my axis can't home simultaneously - Z goes first, then X then Y - in all honesty you probably want Z up and out of the way during a homing routine anyway... It also means that if you hit a limit on one axis you'll get three joint errors - it's not the tidiest of set-ups but it certainly works..!

Not sure how helpful my rambling is to you - maybe your issue is more software related - like Clive says, asking on your thread may get you more relevant answers!

All the best.

Wal.

[Zeeflyboy]

I like the idea of the internal cable chains... neat way to do it.

[Wal]

I like the idea of the internal cable chains... neat way to do it.

I merely followed the ways of Clive and Dean...

The only potential drawback I see, is if I use a hugely over-length bolt for fixturing - anything that protrudes 12mm or so below the left underside of the bed could potentially foul the chain.

Hopefully there'll be none of that nonsense...

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