On 21 Aug 2005 04:01:38 -0700, "gianlepri"
wrote:


New to this group and new to CNC, but learning fast.

I have purchased a used bobby cnc mill. It's a gantry type with 4 2A
bipolar stepper motors. Two of them are running the YY axes.

I need the controller now. Found a lot of 3 or 4 axes controllers on
the web. But the only XYYZ controller I found is too expensive (1500
usd) for my budget. Is there a way to use a 3-channel controller to
steer the 2 Y's synchronuously ? Any teaching will be much
appreciated.

gianlepri

Crossposted to rec.crafts.metalworking

BTW, Have a make & model number? What became of it's
old control?
There are groups for some specific machines IIRC. And at least
one of the BBS systems has a home-brew hobby section.

HTH
--
Cliff

You *should* just be able to parallel the windings of the two Y axis motors
and run them from the same driver, as long as it's rated at double the
power, though I'm not sure how well micro-stepping would work.

A better idea would be to use a driver for each motor and parallel the
step/direction inputs.

As for a controller, if you don't mind a DOS based program this is a quite
adequate shareware program
http://www.dakeng.com/turbocnc.html
it'll run up to 8 axis, step/direction, or phase output.

--.- Dave


"Cliff" wrote in message
...
On 21 Aug 2005 04:01:38 -0700, "gianlepri"
wrote:


New to this group and new to CNC, but learning fast.

I have purchased a used bobby cnc mill. It's a gantry type with 4 2A
bipolar stepper motors. Two of them are running the YY axes.

I need the controller now. Found a lot of 3 or 4 axes controllers on
the web. But the only XYYZ controller I found is too expensive (1500
usd) for my budget. Is there a way to use a 3-channel controller to
steer the 2 Y's synchronuously ? Any teaching will be much
appreciated.

gianlepri

Crossposted to rec.crafts.metalworking

BTW, Have a make & model number? What became of it's
old control?
There are groups for some specific machines IIRC. And at least
one of the BBS systems has a home-brew hobby section.

HTH
--
Cliff

I am about to retrofit a cnc gantry router.
I decided to go with Pico Systems' "universal stepper controller"
http://pico-systems.com/univstep.html
It sells for $250, and does 4 axes.
Actually, I think you can pair up their boards for even more axes, but I am
not certain about that.
If you write to them, they can probably advise you as to whether you should
parallel the axes, or drive them separately.
For example, if you were to use encoder feedback,
The USC runs under EMC control software, which is open source, and can be
had for free, or a nominal cost, depending on how you obtain it.
http://linuxcnc.org/
EMC runs in Linux, which, again, is open source, and can be had for free, or
a modest price.
I like EMC, because it can control either steppers, or analog sevo drives,
with encoder feedback, if you wish.
EMC does all of the control functions, and sends the control info to the
stepper controler, which in turn outputs a step and direction signal which
needs to be amplified by a stepper driver.
I am going with the Gecko units.
http://www.geckodrive.com/
Gecko's Mariss recommended their G202 for my specific application.

Of course, there's more than one way to skin a cat, but I decided to give
this a try.




"Dave August" wrote in message
...
You *should* just be able to parallel the windings of the two Y axis
motors and run them from the same driver, as long as it's rated at double
the power, though I'm not sure how well micro-stepping would work.

A better idea would be to use a driver for each motor and parallel the
step/direction inputs.

As for a controller, if you don't mind a DOS based program this is a quite
adequate shareware program
http://www.dakeng.com/turbocnc.html
it'll run up to 8 axis, step/direction, or phase output.

--.- Dave


"Cliff" wrote in message
...
On 21 Aug 2005 04:01:38 -0700, "gianlepri"
wrote:


New to this group and new to CNC, but learning fast.

I have purchased a used bobby cnc mill. It's a gantry type with 4 2A
bipolar stepper motors. Two of them are running the YY axes.

I need the controller now. Found a lot of 3 or 4 axes controllers on
the web. But the only XYYZ controller I found is too expensive (1500
usd) for my budget. Is there a way to use a 3-channel controller to
steer the 2 Y's synchronuously ? Any teaching will be much
appreciated.

gianlepri

Crossposted to rec.crafts.metalworking

BTW, Have a make & model number? What became of it's
old control?
There are groups for some specific machines IIRC. And at least
one of the BBS systems has a home-brew hobby section.

HTH
--
Cliff