G32 sync spindle to Z axis lathe

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turbothis
Posts: 150
Joined: Fri Mar 15, 2019 4:07 pm
Location: southern oregon

G32 sync spindle to Z axis lathe

Post by turbothis » Tue Jul 16, 2019 11:35 pm

i remember seeing a video on a guy turning the spindle by hand and the Z axis moving back and forth by this.
i am not finding anything by gooogle
i punch in a " G32 Z1.0 F0.1" in the MDI bar and the feed rate goes into sync mode but nothing happens when rotating the spindle by hand.
i think it might be my M05/off code because it uses the "disableaxis is aat the end.

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TomKerekes
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Re: G32 sync spindle to Z axis lathe

Post by TomKerekes » Wed Jul 17, 2019 3:31 am

Hi turbothis,

How did you configure KMotionCNC | Tool Setup | Trajectory Planner | Threading?
Regards,

Tom Kerekes
Dynomotion, Inc.

turbothis
Posts: 150
Joined: Fri Mar 15, 2019 4:07 pm
Location: southern oregon

Re: G32 sync spindle to Z axis lathe

Post by turbothis » Wed Jul 17, 2019 5:31 am

Image

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TomKerekes
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Re: G32 sync spindle to Z axis lathe

Post by TomKerekes » Wed Jul 17, 2019 5:59 pm

Hi turbothis,

The Threading Parameters look reasonable.

The axis should not need to be enabled to track encoder positions. Does the KMotion.exe | Axis Screen | Axis #2 | Position count when turning the Spindle by hand?

Did you try turning the Spindle both ways? M3/M4 sets the direction the Spindle must move to advance the feed. M5 resets the direction as M3 (CW).

Here are some videos:



Regards,

Tom Kerekes
Dynomotion, Inc.

turbothis
Posts: 150
Joined: Fri Mar 15, 2019 4:07 pm
Location: southern oregon

Re: G32 sync spindle to Z axis lathe

Post by turbothis » Wed Jul 17, 2019 6:20 pm

ok yes. there is no condition where the spindle is not reading movement on the KMotion.exe | Axis Screen
i rotate the spindle both ways by hand and get nothing

with the spindle on and turning i can feed by IPM but not the g32.

if i enter M04 G32 Z2.0 F0.1 in the MDi it appears to work fine

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TomKerekes
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Re: G32 sync spindle to Z axis lathe

Post by TomKerekes » Wed Jul 17, 2019 6:35 pm

Hi turbothis,

G32 may require up to 2 revs to sync to the spindle angle before feeding Z. How many revs are you testing when moving by hand (each direction)?
Regards,

Tom Kerekes
Dynomotion, Inc.

turbothis
Posts: 150
Joined: Fri Mar 15, 2019 4:07 pm
Location: southern oregon

Re: G32 sync spindle to Z axis lathe

Post by turbothis » Wed Jul 17, 2019 6:35 pm

lol!!!! same time

ok i got some progress

if i type G32 Z2.0 F1.0 in the MDI
and then rotate the spindle by hand right about 1 3/4 turns it starts working!
so it needs a bunch of input then sync together?

at F1.0 per rotation and F0.1 the Z axis is real spongy in the sync to the spindle.
like it lags and then over shoots and has to comes back a some
this can be real sloppy too depending on the spindle speed
maybe the motor tuning on the Z axis is weak????
the second video, his looks much more responsive than mine.
thanks

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TomKerekes
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Re: G32 sync spindle to Z axis lathe

Post by TomKerekes » Wed Jul 17, 2019 6:55 pm

Hi turbothis,
if i type G32 Z2.0 F1.0 in the MDI
and then rotate the spindle by hand right about 1 3/4 turns it starts working!
so it needs a bunch of input then sync together?
Yes it must rotate to the "0 degree" position of the Spindle (which is Encoder Position=0 or some multiple of counts/rev) and then do another rev to properly sync.
at F1.0 per rotation the Z axis is real spongy in the sync to the spindle. like it lags and then over shoots and has to comes back a some
this can be real sloppy too depending on the spindle speed
maybe the motor tuning on the Z axis is weak????
Maybe or maybe you are simply exceeding the Z velocity capability of your machine? Do the math and determine from your RPM, Feedrate, and counts/inch of Z what the Z velocity will be in counts/sec. Then test that velocity using the KMotion.exe Step Response Screen. Note make sure you actually test that Velocity and not just set that Velocity but do a small slow move.

Its a good idea to use small Max Following Errors in order to immediately fault if you ever try to do something that the machine can not do.
Regards,

Tom Kerekes
Dynomotion, Inc.

turbothis
Posts: 150
Joined: Fri Mar 15, 2019 4:07 pm
Location: southern oregon

Re: G32 sync spindle to Z axis lathe

Post by turbothis » Wed Jul 17, 2019 7:04 pm

i will play around with the Z axis parameters. it will rapid at 240IPM now.
maybe just needs more accel or jerk

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TomKerekes
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Re: G32 sync spindle to Z axis lathe

Post by TomKerekes » Thu Jul 18, 2019 12:36 am

Hi turbothis,
it will rapid at 240IPM now.
With F1.0 then a Spindle speed of 240RPM should drive Z at 240IPM.

maybe just needs more accel or jerk
Note Jerk doesn't come into play with feed moves. You might read this.
Regards,

Tom Kerekes
Dynomotion, Inc.

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