plug and play with old machine?

[tomcord]

Hi
I have just purchased an 8 year old cnc router from a school. It all works but runs on some dos based system called pclathe which only imports autocad plot files. Its basically working as a plotter with depth control. So I want to get it up and running on mach 3. But I have no wiring diagram for the stepper motors or the driver board. It is all neatly connected to a power supply driver board and printer cable.  How will I be able to find out which pins do what? Are there standard configurations? Will Mach 3 just figure it out for itself when I just plug it in?

Any advice/help appreciated

tom

[Tweakie.CNC]

Hi Tom,

In answer to your questions it is just about a 'no' to all of them. 

There is no easy solution without knowing more information, it may be possible but most solutions with old DOS machines is to replace the internal driver board.

Does the router operate from a 'parallel port' cable (as opposed to serial) ?.
Do you know the type and model of the router ?

Tweakie.

[tomcord]

hi
its this http://www.hme-tech.com/education/products/cnc_r50.htm  the R70 version I have contacted the manufacturers for more info but they have yet to reply
the software is very basic, its a parallel port
thanks
tom

[Tweakie.CNC]

Tom,

I have never seen one of these machines before and their website doesn't give much away either but if the machine is operated by 'step and direction' signals generated by the PC then there is a good chance that it can be used with Mach without too much hassle.

If,on the other hand, the stepper motor pulses are generated by the machines internal controller then there may be quite a lot of work to do.

A photo of the machines internal electronics might help.

Tweakie.

[tomcord]

hi
pictures of circuit boards with a heat sink removed attached
thanks
tom

[Tweakie.CNC]

OK Tom, excellent photos. This looks like it will be an easy one, well at least not very complicated.

A common convention (but there is no defined standard) is;
LPT Port Pin      2   X Step
                       3   X Direction
                       4   Y Step
                       5   Y Direction
                       6   Z Step
                       7   Z Direction

With pins 18-25 as GND or 0 Volts.

This is the very basic and initial connections required to move the motors but there may be an enable signal (e-stop) to be found also.
If it was me, I would connect the cable to your computers printer port and try configuring Mach with the above pin allocations (2 to 7) as trial and error and see what happens. Once you get axis movement then you need to set the steps per and velocity / acceleration etc. for each axis and get the directions right. (the Mach manual and videos will give you more details of this).

The next step is to find the limit / homing switch, e-stop and spindle control pins (2-9, 1[seldom used], 14, 16 & 17 are all output pins driving the machine functions) (10-13 &15 are all input pins connected to e-stop, limits, safety interlocks etc.) (18-25 are ground)

Good luck with the experiments.

Tweakie.

[tomcord]

thanks
will let you know how I get on

tom

[Tweakie.CNC]

Tom,

Just one point that is very important - do not disconnect any of the motors whilst the board is powered up.

Tweakie.

[tomcord]

on closer examination the pins being used are
1, 13, 25, 23, 22, 16
The rest of the pins dont appear to be connected to anything.
see picture

any ideas?

tom

[Tweakie.CNC]

Tom,

From that information I would think this is not designed to connect to the computers parallel port at all but to a, perhaps PCI, driver card fitted in the controlling PC.

Tweakie.