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View Full Version : just flicking spindle on and off with a relay



kingcreaky
30-08-2013, 09:46 AM
Maybe not the most elegant of solutions, but ive given up with the usb serial controller and plugin. For now it would be just nice to turn the spindle on and off from the pc

Im using one of those cheapy BOB's from china. Which so far does everything I need, and does it well
(thanks to Wal for photo) - photo for illustration purposes of board, not for wiring

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So what im trying to do is simple.

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but im stumbling at the first hurdle!!! ie just getting the relay to flick

so, in output pins (this is not an actual screenshot of my mach3, but illustrates the screen)

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I have Output #1, set as Port 1, Pin 17, with Active Low not set

In spindle setup (same window different tab) (again picture not my screenshot for illustration purposes only)

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in 'Relay Control'

I have set Clockwise (m3) to be pin 1


Im now running commands like M3 s1000 etc expecting to flick the relay and getting NOTHING

If I take a direct positive from the 5v board feed to the relay it flicks...

ANY help or advice no matter how silly it may be will be greatly appreciated.

thanks in advance.

Jonathan
30-08-2013, 10:22 AM
Are you sure the breakout board can source enough current for the relay? Have you measured the voltage across the relay with the output on and off?

The relay isn't actually necessary - you could just connect the output from the breakout board to the relevant input on the VFD. Just remember to connect the common grounds. Let me know if that's not enough information...

kingcreaky
30-08-2013, 10:49 AM
Thing is, I dont think im even getting a change at Pin 17 let alone there being sufficient to move a relay

Ive just got the voltmeter between pin 17 and ground and jumping up and down on Mach3 and I cant get it the figure on the voltmeter to budge

im clicking at the spindle controls... inventing new gcodes,

M3
M4
MPLEASE

still nothing

so I suspect im either triggering it wrong in mach, have set it up wrong, of ive missed configuration somewhere... or the BOB is incapable of handling outputs?

arent you meant to be at work? skiver!

Jonathan
30-08-2013, 10:55 AM
Have you checked on the diagnostics page in mach3 if the output for the spindle is actually changing state? The diagram of the parallel port showing the pins should light up.

Try something like:
M3 S1000
S sets the speed, might have to set the speed for it to work. I can't remember exactly as it's been a while since I used mach3 and I can't look into it now...

JAZZCNC
30-08-2013, 01:40 PM
It's a simple thing so If you have output 1 to 6 setup with pin 17 then it should work and from what you have posted everything looks correct and it should work.!! . . . So this tells me you either have selected wrong pin on board or pin is knackerd.!! . . . Try different output pin.

EddyCurrent
30-08-2013, 02:58 PM
I don't know what error checks Mach3 does but I can't imagine it would let you select the same output for Clockwise and CCW, have you tried setting CCW to another spare output ? then M3 should operate output 1

birchy
30-08-2013, 04:33 PM
Are you using a digital test meter? I'm just wondering if it's a pulsed input that only an analogue meter would show?

kingcreaky
31-08-2013, 07:17 PM
right... Im now able to turn on 5v and turn off 5v to a pin, by running the m3 command etc.. however it seems there is not sufficient power to pull a relay.... therefore... how do I get from the 5v signal... to flicking the spindle vfd on and off?

i assume an opto coupler?

kingcreaky
31-08-2013, 07:18 PM
The relay isn't actually necessary - you could just connect the output from the breakout board to the relevant input on the VFD. Just remember to connect the common grounds. Let me know if that's not enough information...

its this bit I need a bit of hand holding on...

irving2008
31-08-2013, 07:29 PM
As Jonathan said, you need to find the 'Run' input on your VFD. What model is it?
You shouldn't really switch supply volts to a VFD.


right... Im now able to turn on 5v and turn off 5v to a pin, by running the m3 command etc.. however it seems there is not sufficient power to pull a relay.... therefore... how do I get from the 5v signal... to flicking the spindle vfd on and off?

i assume an opto coupler?

birchy
31-08-2013, 07:43 PM
As mentioned above, most VFD's only require a N.O. contact between 2 pins to trigger the start/run signal, so you'll have to use a switching circuit such as a miniature relay or a semiconductor (transistor, etc).