[oisyaot]

Hi, I have a Taig CNC http://www.finelinehair.com/home/Taig%20Mill%20CNC.htm controlled via LPT1 pins 16 & 17. The spindle (& mist) are controlled via solid-state relays. When I reboot my PC, the spindle comes on & stays on until Mach3 is started. I have tried changing the LPT1 settings in the BIOS. Normal mode seems to work best (motor on for 1 second on reboot) but then Mach3 loses control over the relays. I know all I have to do is turn the machine off until Mach3 has been started. Certainly the safest way to proceed but it bugs me. Must be a LPT1 thing; maybe looking for a printer. thanks, Alan

[Hirudin]

Hi, I have a Taig CNC http://www.finelinehair.com/home/Taig%20Mill%20CNC.htm controlled via LPT1 pins 16 & 17. The spindle (& mist) are controlled via solid-state relays. When I reboot my PC, the spindle comes on & stays on until Mach3 is started. I have tried changing the LPT1 settings in the BIOS. Normal mode seems to work best (motor on for 1 second on reboot) but then Mach3 loses control over the relays. I know all I have to do is turn the machine off until Mach3 has been started. Certainly the safest way to proceed but it bugs me. Must be a LPT1 thing; maybe looking for a printer. thanks, Alan

I don't know how you can implement this in your system, but probably the most convenient solution would be to add "charge pump" control to your relays.
A charge pump is pretty much a special signal sent by your computer only when Mach3 is active. If the signal isn't present (like when Mach3 is "reset") devices that are activated by a charge pump will not be active.

I'm sorry, I haven't started using my relays yet so I can't recommend specific products, but I bet you can buy a charge pump switch that will only pass a signal when a charge pump is detected.
This is worth a look...
http://www.cnc4pc.com/Store/osc/prod...products_id=51

[oisyaot]

That would do it, I'm sure. I was not eager to add more complexity but I'll check it out. thanks!

[TOTALLYRC]

Hi, I have a Taig CNC http://www.finelinehair.com/home/Taig%20Mill%20CNC.htm controlled via LPT1 pins 16 & 17. The spindle (& mist) are controlled via solid-state relays. When I reboot my PC, the spindle comes on & stays on until Mach3 is started. I have tried changing the LPT1 settings in the BIOS. Normal mode seems to work best (motor on for 1 second on reboot) but then Mach3 loses control over the relays. I know all I have to do is turn the machine off until Mach3 has been started. Certainly the safest way to proceed but it bugs me. Must be a LPT1 thing; maybe looking for a printer. thanks, Alan

What you are describing is the exact reson charge pump was implemented, safety.
Windows will play with the pport and there is no way to know what it is doing.
Boot first and then turn on machine. I would aslo recommend a breakout board with charge pump, but that is up to you.

Mike

[oisyaot]

Thanks for the info. I have a breakout board already, now I'll get the charge pump. The one I need is only $22. what a bargain.

[jallitt]

I had a bunch of spare relay outputs so I wired my spindle in series through the NO contact on one relay and the NC contact of the next relay. This way the spindle can only turn on if one relay is energised and the other isn't - which should only happen if mach has control of the relay board.

[oisyaot]

thanks Jon. but I have no spares to use as you did. I'll just have to use the charge pump relay.

[LeeWay]

I just use manual switches. I flip them on once Mach 3 is started. This works okay, but a charge pump is a much better choice in case Mach 3 gets hung by the computer. If you have a crash, then you will get a wild crash on the machine as well.
Not good at all and a charge pump would likely prevent the physical crash.

[oisyaot]

Lee, thanks, I'm ordering a charge pump this week. I put a scope on Mach3, 12.5KHz output & it was more like, 12KHz. I hope this is not a problem for the pump as it is microcomputer controlled & uses an algorithm to check the range. My Mach3/cpu puts out a perfect 25KHz & I wonder why the 12.5KHz is not as accurate. Alan

[oisyaot]

Works great, thanks for your help everyone. sorry it took so long to follow-up with th results.

Taig Micro Mill Breakout Board, SCHP, Pendant, Tach & Relay Box

Alan