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I am building a small lathe around a unimat 3 bed and head stock. planning to use a gang tool design, with some live tooling and want to use
the spindle as C axis also. I have been reading on the forum about step direction spindle but having some problems there. but I have seen nothing
on step dir spindle and c axis combined. does any one have some ideas to point me in the right direction.
Thanks steve

Hello,

I would lean toward making two different configurations, one for spindle and one for c axis.

Rick G

Hi
more info on my project
I am using the sherline 4 axis XYZA as starting point. I have commented out Y and changed A to C. Right now I have a 5 axis stepper driver off ebay, that is being used for testing finished project will be servos on gecko g320 drives.
Thanks
Steve

Have you read this?

www.linuxcnc.org/index.php/english/compo...ew&catid=49&id=18116

Rick G

Rick G wrote:Perhaps not the best example, it looks like that chap went off in a huff and switched to Mach.

Hi Thanks for the help so far. I am going to try setting A as my spindle and C as my rotary axis with two seperate stepper drivers and one 1600 ozin motor. I will use m101 to activate the spindle and m102 to activate the C axis using a interlocked relay (reversing contactor) to switch between the drives. with the encoder on the motor tied to the spindle and C axis it should always know its position. Does this sound workable? i just printed some postings on the step dir spindle, I am missing how to link the spindle on and spindle speed to A axis what i have right now loads with no errors. I will include my hal file.
Thanks Steve This attachment is hidden for guests. Please log in or register to see it.

stevestice wrote:
No. Most drives will complain in a puff-of-smoke-and-dark-brown-smell way if you disconnect them from the motor while powered up.

Much better (and cheaper) to have only one stepper drive, one stepper motor and do the switchover in software (i.e. in HAL).

I am convinced that this ought to be moderately straightforward.

It isn't usual to use an encoder with a stepper drive, but it can be done and might help in this case.

Get your machine running with the spindle as an axis, then post your HAL file here and I will sort out a switchover config for you.

Hi Thanks for the help. I will work on the spindle some more. I am slowly making progress my current hal is with my last post. I will post the updated hal probably sunday.
Using a encoder on the spindle for the reason of using the marker pulse for the spindle orientation for threading. After reading here about the pico universal stepper
and gecko interface board I am going that way when I build my mill. I am using step-dir for the gecko drives g320 that I already have and they require encoders. I have a Magmotor pmdc servo with a encoder that may be used on the spindle. The unimat 3 lathe i have now has pittman servo motors with encoders with gecko drives I used it with turbo cnc a few years ago, once i get the bugs out on the bench all my axis and spindle will be servos. I hope this explains for i am working towards. Thanks Steve

stevestice wrote:
Err, no. I am now completely baffled as to what hardware you have on what machines, and which of them this spindle/axis hybrid is.

confused ? me too ,
if your end result is to use servo's then go that route instead of stepper motors
so long as you have shaft encoders fitted to the spindle and axis then all should work fine .

so long as the spindle is a servo motor , rather than a standard invertor driven vfd type then what you propose will work
just make sure the servo motor for the spindle has enough HP of course ,