Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Apples on April 29, 2014, 05:12:54 PM

Title: Relay for Spindle (Plasma torch on) buzzes, rattles, on off really fast
Post by: Apples on April 29, 2014, 05:12:54 PM

The breakout board we have has two relays.  Looks like the relay we use has died.  It will flick on but not flick off unless you unplug the power to the whole cnc controller box.

So I went and moved the two wire to the second relay and reassigned the pins to suit.

Now the plasma torch is firing again and turning off.  On the old relay it would fire and stay on.


I notice that when the plasma is is the relay will rattle fast as in on/off 10 times really fast until the plasma arc is established.  Maybe this was also occurring when on the first really and it just simple wore out.

So what can I do to stop this flicking of the relay?  Is there a debounce setting for an output like this relay?   Or is it just electrical noise from the plasma?

Title: Re: Relay for Spindle (Plasma torch on) buzzes, rattles, on off really fast
Post by: Hood on April 30, 2014, 02:49:49 AM

Make sure the output you are using is not assigned to a pin that is being used for some other Step output.
Hood

Title: Re: Relay for Spindle (Plasma torch on) buzzes, rattles, on off really fast
Post by: BR549 on April 30, 2014, 12:04:34 PM

Sounds like a High frequency start is wrecking havic with the relay when the arc is started. Try running then program WITH the Plasma machine turn off. IF the relay does NOT rattle then there is the problem .

Sometimes adding a capacitor across teh relay input lead can stop the problems with HF starts. DO a search on HF starts and fixes with plasma cutting machines.

Also check as HOOD suggested with crossed or duplicated  ports/pins settings.

(;-) TP