Jog on a lathe
 

In article ,
lid says...
I bought a VFD and a 3-phase motor to update my semi-crappy lathe.

The VFD supports a jog function and the way I'm going to use it is to
have a switch for JOG on the control panel and then (in JOG mode) the
Run switch moves the motor at a very slow rate until the Run switch is
released.

I never saw a lathe that had a Jog feature. How do they typically work?
Do you press the Jog button and it moves, or is it more like in mine?

Jog seems useful. Never having seen it, I would guess a Jog button with
"move while pressed" would be the way it should work, but can't see any
way to make that happen with the capabilities of my VFD.


Which VFD are you using? The capabilities of the auxiliary inputs
available on most drives, which I assume is where you're connecting your
JOG selector, vary from drive to drive. The quality of the documentation
you need to decipher in order to figure out how to set up the inputs
varies even more. If the drive is from a mfr I'm familiar with I may be
able to suggest things to try.

Ned Simmons

Jog on a lathe
 

In article ,
lid says...
On Fri, 20 Jan 2006 09:46:53 -0500, Ned Simmons wrote:

In article ,
says...

Jog seems useful. Never having seen it, I would guess a Jog button with
"move while pressed" would be the way it should work, but can't see any
way to make that happen with the capabilities of my VFD.


Which VFD are you using? The capabilities of the auxiliary inputs
available on most drives, which I assume is where you're connecting your
JOG selector, vary from drive to drive. The quality of the documentation
you need to decipher in order to figure out how to set up the inputs
varies even more. If the drive is from a mfr I'm familiar with I may be
able to suggest things to try.


Its a Hitachi L200 Series inverter.

I have it configured in 3-wire mode which seems like the sensible thing
for a lathe -- Run, Stop buttons and F/R switch. The default mode is
2-wi F-run, R-run. In either case, the jog function just seems to
modify the operating speed for the normal run/stop controls.

I did figure out a way to wire it so my run button applies stop when
released in jog mode, but can't see a way to get one-button that sets
both jog and movement out of this VFD.


I've never used that drive, but I just took a quick look at the "Quick
Reference Guide"...

http://www.hitachi.us/supportingdocs...s/Support/L200
_QRG_NB6601XA.pdf

Look at Func Codes C001 thru C005 on p.20 and the corresponding option
codes on p.23 . I assume you're using the defaults for C001 and C002
which make terminals 1&2 the RUN/STOP terminals. Try changing C003 to
code 06, which appears to make terminal 3 function as a jog input.

I'm extrapolating from experience from other drives, so you ought to
read the doc about these functions in the full manual, but I'm quite
sure this will get you started in the right direction.

Ned Simmons

Jog on a lathe
 

On Fri, 20 Jan 2006 15:46:56 -0800, xray wrote:

...
I set it up for 3-wire (C001 = 20, C002 = 21, and C003 = 22.) This is
more like the original lathe controls with Start, Stop, and F/R. I set
C004 = 06 for Jog. When jog is closed, the operation of start, stop, and
F/R are modified to run very slow, but there seems to be no sensible way
to get it to move in jog mode with just one button.
...

I had the same issue. The jog was just another preset speed.
Add a diode from the jog button to the run forward.
Then when you push the jog button it will set the speed and
start the motor. I used an 1N4003 because I had them lying around.

Wayne D.

Jog on a lathe
 

In article ,
lid says...
On Fri, 20 Jan 2006 17:02:12 -0500, Ned Simmons wrote:

I've never used that drive, but I just took a quick look at the "Quick
Reference Guide"...

http://www.hitachi.us/supportingdocs...s/Support/L200
_QRG_NB6601XA.pdf

Look at Func Codes C001 thru C005 on p.20 and the corresponding option
codes on p.23 . I assume you're using the defaults for C001 and C002
which make terminals 1&2 the RUN/STOP terminals. Try changing C003 to
code 06, which appears to make terminal 3 function as a jog input.

I'm extrapolating from experience from other drives, so you ought to
read the doc about these functions in the full manual, but I'm quite
sure this will get you started in the right direction.

Thanks for the reply, but I have read the full manual. The defaults for
C001 and C002 set 2-wire mode. I think this sucks for a lathe. One
button is forward-run while closed and the other reverse-run.

I set it up for 3-wire (C001 = 20, C002 = 21, and C003 = 22.) This is
more like the original lathe controls with Start, Stop, and F/R. I set
C004 = 06 for Jog. When jog is closed, the operation of start, stop, and
F/R are modified to run very slow, but there seems to be no sensible way
to get it to move in jog mode with just one button.

The function of jog is described in the full manual:
http://www.hitachi.us/supportingdocs...on_NB660XA.pdf

on page 4-15 (143 of 280.)

That description talks about the default 2-wire control signals, but it
works the same with 3-wire -- just replace the transitions of [FW], [RV]
in the figure with [Start], [Stop] modified by [F/R].

I have used 2-pole switches for Jog and the Run button, so that I can
make the Run button momentary in Jog mode (Stop is applied when the Run
button is released, rather than having to hit the Stop button as in
normal mode.) This seems to be the best I can do unless I burn my own
microcontroller to toggle control lines for Jog.


After looking at the manual I can't see an obvious mode of operation
that will do what you want either, but I wouldn't give up without
talking to tech support at Hitachi. The manual seems pretty good, but
there may be some non-obvious setup that'll get you what you want.

Failing that, I don't think you'd need a uP to get the job done. Set up
a pair of cube relays and 3 PBs to emulate a reversing motor starter and
set up the drive for 2-wire control (p 4-12). Add two PBs that invoke
the jog speed and energize the relays without latching them and I think
you've got what you need.

You may find that you don't need the jog speed at all. It may be more
convenient to adjust your speed pot for jogging rather than having a
fixed jog speed.

Ned Simmons