3 Axis 900x500mm

[MikeyC38]

Nice build Wal. Dean's a great guy when it comes to inspiration and great design advice. My machine is up and running very nicely! (see here) It will be good to see some footage of it running when completed.

BTW how are you wiring your proximity switches? are they NPN, Are they connected to a 5v break-out board? I've been trying for ages to get mine to work and I'm stumped!

[Clive S]

BTW how are you wiring your proximity switches? are they NPN, Are they connected to a 5v break-out board? I've been trying for ages to get mine to work and I'm stumped!

Mike best to start and ask again in your thread http://www.mycncuk.com/threads/10262...oes-nt-it-work.

And give us the relevant up to date info.

[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.