Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Kato on July 29, 2007, 01:02:25 PM
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Hi, I have problem with my lathe. I want to pull a relay when I command M3 or M4.
I hav eunchecked the "Disable Spindle Relay" and choosen Output 1 on both m3 and m4.
Cant make it work.
/Jim
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Hello,
'What pin do you have the output set to? You can check this under outputs (also be sure that the port is set)
Thanks
Brian
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Also check that the printer port output has the power to drive the relay.
I was connecting to my Omron inverter, but had to drive a relay with a simple transistor amp to get it going.
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What do you have for a breakout board?
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Brian - I don't know whether that was aimed at me - I don't have one. I got an old printer lead and identified all the wires in it with the pin numbers and soldered them, in order, on a small piece of copper clad stripboard.
The wires to the stepper motor drives go directly to those boards. The other functions I make the circuit up as required. At the moment it is just the two spindle relays for M3 and M4 commands. I have to do the coolant relays next.
I don't know how to stick a picture on this forum, or I could put one up.
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You will need to do some work to get that output to drive a relay :(
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Hi,
The easiest way to go is, Solid-State Relays , Most of then are 3-30 volt input (Opto-Isolated) and are available in many flavors.
Thanks, Chip
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Getting the parrallel port to drive relays is fairly easy.
The books I have are fairly old hat now, but more modern transistors can be used. I am looking at the design now - which is a BC 549 transistor, fastened to ground, with a relay up to a 12 volt line. It is driven by the 5 volt signal ( or in actual fact the 0v signal ) from the parrallel port via a 2K2 resistor There is a diode across the relay pins (to protect against voltage spikes etc and a 3K9 resistor base to ground. Only four components.
I had suitable values in my bits box to knock up two similar circuits for the spindle motor pins. I have a resistor to cut the 24 volt power supply for my stepper circuits to 12 volt of these relays - and since only one of these is on at once, one resistor is enough for that.The relay outputs go to my Omron inverter.
I can repeat this for the coolant relays - with the advantage that the seperate circuits are completely isolated from one another - via the relays.