Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: neptunier on September 18, 2016, 04:16:35 AM

Title: connecting ground from bob to machine for touch plate?
Post by: neptunier on September 18, 2016, 04:16:35 AM

hi all,

i just ordered the 2010 screen set and i want to add a touch plate on my machine.

since i dont want to clip the ground cable with a clamp to the router bit, is it safe to connect the ground from the BOB to the machine ( somewhere on the steel?)

thanks,
neptunier

Title: Re: connecting ground from bob to machine for touch plate?
Post by: Highspeed1964 on September 18, 2016, 04:38:40 AM

The easiest way to check this is with a multimeter or continuity tester.  If you have continuity from where you want to connect the wire through to the tool itself then it should work.  I have the wire passing through the cable track up to the spindle head.  I fastened a 1/4 blade-type lug to the spindle mounting bracket with matching connector on the wire so that I can remove it and hook up a clip if needed for whatever reason.  Before I did this, I confirmed there is continuity from the bracket through the spindle to the tool mounted in the collet.  Then when I need to probe a tool, I pretest (you can use the diagnostics page to check the LED, but I've added one right on the Program Run page) as a final check prior to use by touching the touch plate to the tool.  I usually do a test probe using the Auto Tool Zero button or a manual G31 command from the MDI as well before running the program just to make sure all is in order.

Hope that helps,

Stephen "Highspeed" Kruse

Title: Re: connecting ground from bob to machine for touch plate?
Post by: Davek0974 on September 18, 2016, 06:20:48 AM

I grounded my 0v line to the machine for exactly the same reason, as Stephen says above ALWAYS test the plate by touching it on the tool the instant before you press the button in the 2010 screen set, it gets really messy if it fails ;)

I have the same screen set and its great, the tool change is brilliant.

One other thing i do is ALWAYS wipe the top of the fixed probe before pressing enter after the tool-change - a bit of swarf or muck on there will spoil your day.

Title: Re: connecting ground from bob to machine for touch plate?
Post by: neptunier on September 19, 2016, 03:26:12 AM

thanks for your help, i will try it out today.
michael

Title: Re: connecting ground from bob to machine for touch plate?
Post by: neptunier on September 20, 2016, 05:22:44 AM

now it works, i just had a problem with my probe switch being normally closed and the touch plate normally open.

so i put a 4,7K resistor as a pullup to the probe pin and resoldered the probe switch to normally closed.

now it works like a charm ,-))