Topics

1

General Mach Discussion / Need help with Mach3 Modbus to BRX PLC

« on: December 14, 2020, 08:45:11 PM »

I am trying to get Modbus communication going between Mach3 and a BRX PLC.  This looks like it should be simple but I am stumped.  On the PLC Ethernet Monitor I can see packets going back and forth as the PLC programming software communicates with the PLC.  I have added some screen shots here that may give someone with expertise here in Modbus to help me.  At the moment the only thing I want to do is send the Spindle Speed S to the PLC as I have 3 different spindles and the PLC can then send the appropriate signals to each device.  That part works just fine already.

Thanks

2

General Mach Discussion / A bad case of stupid

« on: October 15, 2018, 07:59:19 AM »

I’ve been building control panels since I was a kid because I would help my dad build them for his company in our garage. Then I did industrial electric installations for another fifteen years. Ever since I have designed and built control panels for all kinds of machinery. So I know just how important an accurate wiring schematic is.  So what do I do when I build my own CNC machine? I start building and wiring saying to myself I don’t really need a wiring diagram!

Now four years later and I want to add some new capabilites and I am totally confused about how all this stuff works!  I now have almost 5 days of effort cutting wire ties, poking, ringing out wires, and making a wiring diagram.  What a HUGE waste of time this is.  The changes I wanted to make are really simple if you have the correct wiring diagrams.

Broke the rules and I am really getting spanked!

3

General Mach Discussion / A little noise

« on: August 29, 2018, 08:10:07 AM »

I’ve been building control panels for nearly 50 years, so I am well aware of noise issues and very seldom have a problem. Proper grounding, shielded cables, control wires on opposite side of cabinet from power wires, flyback diodes, etc.  Recently I was building a solenoid pump driver. I needed one flyback diode on the coil and with the demise of Radio Shack could not get one quickly. So I took the one on the spindle relay on my Mach 3 mill.

A few weeks went by and I set up job and noticed a large thump noise as I turned the spindle on and off. Then I saw that all 4 axis were jumping a full step every time the spindle turned off!  I’m thinking “Nah, couldn’t be that missing diode.”  The replacement had come in and sure enough that solved the problem!

I’d bet half the troubles we see here are due to simple stuff like this.

4

General Mach Discussion / Selecting a laser

« on: August 08, 2018, 10:30:52 PM »

I want to add a laser to my machine specifically for cutting double faced adhesives and thin materials similar to paper. Can someone recommend a particular laser, lens, and power supply that will give decent results? Don’t want to spend time learning about the laser as I have need to cut prototypes right now.

Thanks,

5

General Mach Discussion / Switches for Home position

« on: January 04, 2018, 12:29:48 PM »

For those of you that want to home your machine very accurately so that you can resume a job after a shutdown for any reason I see that Automation Direct is now offering precision limit switches down to as low as 3 microns repeatability.  That should do it for most of us!  I have sloppy limit switches to prevent crashing into the ends of axis travels and can home to them but the repeatability is very poor. I might add a couple of these so I can home it for position.  These switches might be good for building an accurate tool touch off plate to.

6

General Mach Discussion / How many Mach3, Mach4 users?

« on: February 19, 2017, 12:23:28 PM »

On the pro forums mention of Mach3,4 often brings a derisive response. There are things Mach3 can do that the pro machines often can't, like run a million line program, and store every program you have ever made right on the machine, and tailor the CNC to a configuration that does something special the machine builder never envisioned. The most qouted issue is that it is not a closed loop control. However my homebuilt milling machine was cutting all day yesterday at 200ipm with 300 ipm rapids and when I check position it certainly hasn't missed any steps.

So with that said, I'm willing to bet the number of Mach 3 users may be a really large percentage of all CNCs in use. Anyone know?

7

General Mach Discussion / Mach 3 lathe with stepper spindle

« on: January 26, 2017, 07:02:45 PM »

Can mach 3 lathe drive a stepper motor continuously as a spindle?

8

Third party software and hardware support forums. / Parallel port wiring

« on: November 01, 2016, 10:09:58 PM »

I bought a cnc 3020 for a specific task, not machining. It has a DB25 connector for connection to a parallel port and is set up for Mach 3. I am not using mach 3 for this task, I am using a dedicated controller. I don't want to blow out the driver box so I am wondering what input voltage and current it expects on the axis inputs?  I would guess 5 volts but I have only a 24 volt supply at the moment. If I had a 5 volt supply would I also need to use current limiting resistors in the circuit?
I am a power and industrial control guy not electronics so much.

Thanks,

9

General Mach Discussion / Mach 3 Lathe questions

« on: October 11, 2016, 07:10:07 PM »

In Mach 3 Mill I can't find a way to drive a stepper motor as a spindle using a Xulifeng 4 axis motion card.  I can't program the fourth axis that way.  I was wondering if Mach 3 Lathe can operate a stepper motor driven spindle using this card. I'd have to be able to set up the spindle as an axis drive I believe.  The reason for doing this is I have a stepper driven 7x12 lathe that I use as a fourth axis just fine.  However I would also like to run it as a spindle with the toolpost mounted to the mill head.  That part is done, I can spin it a hundred turns, position but I just can't make it turn continuously.

Can Mach 4 do this?

Thanks,

10

General Mach Discussion / Reset A axis DRO from G-Code program

« on: February 07, 2016, 01:02:01 PM »

Is there a way to reset the A axis (angular) back to zero in a G-code program?  Specifically I want to thread by rotating A axis a specific number of turns, while moving the X axis. Then I want to return X axis at rapid while simply setting A axis to zero for next pass, instead of reversing it back to zero.

Thanks,