3 Axis 900x500mm

[thomashomer1986]

Hi Wal, thanks for the reply. Shame there's no log, I could spend hours reading about other people builds!

Considering it was made in a relatively simple way, it looks a very capable machine. I'm looking forward to seeing the end result of your current project!

[Wal]

Got a couple of jobs done in the last couple of days. Finished the e-chain that runs beneath the bed and is attached to the X-axis - a brief and rather lacklustre vid here:



The fixed end that travels uses a similar spacer as the one I made earlier in the thread - that way the chain stays horizontally level. There's an additional support bracket halfway up the bed, I had to nibble a bit of it away as it fouled the ball-nut housing:



Another thing I thought I'd have a look at is creating a mechanical union between the router and the bench that it's sat on - I was going to screw some strategically placed blocks down to prevent it from walking but thought that I might as well add some mass to the unit as a whole and leverage the weight of the bench (and all the stuff that'll eventually get stored down below) to help hold the router down.

I took the feet off and drilled/tapped a couple of M8 holes in the middle 'foot' - too late to use the corner 'feet' - lack of space notwithstanding, I'm not strong enough to lift the router off by myself - I could have attempted a bit of a balancing act, but laying out on the steel L-section would have been, at best, a very awkward affair...



Next I drilled a couple of 8.1mm clearance holes for the bolts:



And then bolted the router bed down to the bench sub-frame.



There will eventually be a third plank running up the middle of the bench - I'm leaving it out for now so as to be able to get access to the underside when needed.

Waiting for CY cable and switches to arrive now...

[Davek0974]

There will eventually be a third plank running up the middle of the bench - I'm leaving it out for now so as to be able to get access to the underside when needed.

One problem i found with my mini-mill build - the base was almost identical to yours - was that when mounted, you could not get to the screws underneath for service/lube etc. If i was ever to build another i might fit some nylon pipe to the ball nut and run it through the chain to the outside world so it could get a few pumps of grease/oil at service time.

[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.