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Mach3 USB Homing
« on: August 31, 2018, 06:42:21 AM »
Hello

I have a Mach3 USB board as in the attached picture.
I'm having trouble getting the 3 axis back to their home position. I started with just the x- axis. Home position is indicated by active low limit switches. The signal wire from the limit switch was fed into Input pin 3. Can you please help me with the pin and port configuration for this, or if there is something else that needs to be done as well, please do let me know.

Thank You
Re: Mach3 USB Homing
« Reply #1 on: August 31, 2018, 06:46:51 AM »
Hi,
does the supplier not have a manual?

Do you have any documentation at all? How about the plugin, have you got and installed that?

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach3 USB Homing
« Reply #2 on: August 31, 2018, 07:29:26 AM »
There isn't a manual describing the pin nos. The plugin is installed. I am able to control all the motors, however when the motor reaches its limit (i.e. home), even though the limit switch turns on( gives low voltage signal), the motors do not stop
Re: Mach3 USB Homing
« Reply #3 on: August 31, 2018, 07:36:09 AM »
Hi,
there have been a few people lately who've bought those boards.

http://www.machsupport.com/forum/index.php/topic,38089.0.html
Maybe you could ask them.

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach3 USB Homing
« Reply #4 on: August 31, 2018, 07:48:23 AM »
There is the following picture provided. However I am unclear as to the working of connecting all the home switches to the same pin and all the limit switches to one input.
Re: Mach3 USB Homing
« Reply #5 on: August 31, 2018, 08:16:13 AM »
Hi,
if any of the six limit switches closes the input goes low and Mach will stop. Thus on Machs Config/Ports and Pins/Input Signals
page al the limits (X++,X--,Y++ etc) will get the same port and pin number. Note that if one limit switch closes Mach will know to stop
but it can't tell which switch. It would not know for instance that X++ triggered and if you jogged X+ by mistake and drove the axis even
further out of bounds Mach does not know to stop you.

Likewise all the home switches are paralleled together. On Config/Ports and Pins /Input Signals X Home, Y Home and Z Home will all get the same
port and pin number.

When homing the axes home one at a time in an order you specify, the home order. If the X axis goes first it will drive in the nominated direction
at the nominated speed until the home input activates. We presume as the X axis is the only axis moving it will be the X Home switch, but actually
if any of the home switches operated then the X axis stops and then backs up a bit until the switch deactivates, ie X is homed, the X machine co-ord is
set to zero and the next axis in the order starts to move.

I would prefer to have one input for each home switch, its easier to understand and less prone to errors. But you only have four inputs, you just don't
have enough for all the things you want.

I have an Ethernet SmoothStepper which has as many as 31 inputs so I can have one input per switch no problems. It comes with a very comprehensive manual
and a forum staffed five days a week to answer questions.

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach3 USB Homing
« Reply #6 on: August 31, 2018, 08:57:29 AM »
Is it feasible for me to simply ditch the limit inputs and simply provide all 3 axis homing signals to individual pins.

Are there any issues that may arise...
Re: Mach3 USB Homing
« Reply #7 on: August 31, 2018, 02:13:44 PM »
Hi,
yes that is entirely reasonable. With the machine properly referenced 'Soft Limits' are effective which are a software equivalent
of limit switches.

Note also that as you require three inputs for home switches you will loose the input for limits and also for the probe. There will come
a time when you miss the probe.

Still I think this is a good way to proceed. Having three home switches and three inputs is simple and you will benefit from the learning
experience. You might at a later date change your mind but you will benefit from the experience you have gained.

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach3 USB Homing
« Reply #8 on: September 01, 2018, 02:48:08 AM »
Thank You

Now i simply need to figure out the pin and port nos for the 4 input pins. If you come across anything which might indicate the answer please do let me know
Re: Mach3 USB Homing
« Reply #9 on: September 01, 2018, 03:05:46 AM »
Hi,
this might be the same:

https://www.buildyourcnc.com/Documents/USB%20Motion%20Card%20STB4100%20Manual.pdf

Next time buy something made in the US or Europe that has a manual!

Craig
My wife left with my best friend...
     and I miss him!