"Ignoramus27783" wrote in message
...
On 2011-03-09, JB wrote:
Hi Iggy.
I inherited a year or two ago, a nice Shizuoka ST-N CNC mill. This is a
3-axis machine with a nice large CNC rotary table giving it a 4th axis.
It
was given to me by a good friend who couldn't fit it into his workshop.
It
has low hours and was only ever used for machining acrylic.
Awesome! I am envious.
Kirk has a similar mill
http://www.wallacecompany.com/machine_shop/Shizuoka/
He is on emc-users mailing list.
This Japanese machine was originally sourced from and fitted out by a UK
company, Matchmaker, who fitted an unknown control system with arm
mounted
CRT and button panel. The only thing we can easily recognise in the
bird's
nest that is inside the control cabinet is the 4qty, Westamp PWM servo
amp
model no. 30060-3. I take it that this means we have servos rather than
steppers? This makes sense as they (large) motors have 4 brushes.
Most likely servos then.
I think
they have 2-wire tachos built in too. I'm not sure what encoders we have
yet
as they haven't been stripped out for identification.
The control system is dead. The CRT is dead, and I don't trust the
Westamp
boards. However we'd probably keep the big DC PSU, buy 4 new servo drives
and fit a variable freq drive for the spindle.
This brings me to the big question. What controller should we choose?
We'd
like to do as you have done, and use EMC2 on a (Linux?) PC, but don't
have
any idea of what controller we need for the 'bit in between'.
I'd appreciate your advice on this if can spare a moment.
JB, you are on a good track. You have a great machine with a great 4th
axis.
The control is junk.
You need to subscribe to emc-users mailing list at
https://lists.sourceforge.net/lists/listinfo/emc-users
Then you need to go slow and identify your hardware (what servos? What
voltage and current?)
Try to find a schematic of the mill, if you can, pre-retrofit. It will
help you identify wires from all opints like limit switches, valves
etc.
What you want is certainly doable, will probably take a while, but can
be done in steps where the result of each step is verified. For
example, you can hook up one servo motor to one servo drive, and
"drive" it by selding a signal from a battery to the niput of the
servo drive.
Try to identify your servos first.
You may reuse things from the old control, such as relays, power
supply, and possibly even servo drives.
Many thanks for the fast response and pointers. I'll join the mailing list.
I'm already on CNCZone. There is a good section on EMC there too.
http://www.cnczone.com/forums/emc_li...chine_control/
I'll get the servos off later this week and check them out.
Cheers,
JB