A axis homing rotary

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
I am using my A axis in rotary configuration, I have a home sensor that works fine.

I am using it to wind motor wingdings on a form, after making say 20 raps i would like this axis to go to the home marker or zero without unwinding 20 times.

On other machines i have built i could set a rotary axis to modulo operation and it would find the shortest path to zero (less than one rev.)

Any help would appreciated.

thanks,

Charles Armstrong

Senior Mechanical Engineer

Rhodan Marine Systems
 

masso-support

MASSO Support
Staff member
will you be able to share a video and explain the requirements so that we know exactly what's required and then try to come up with a solution?
 

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
to start with first homing A axis rotates 4 revolutions to find home marker

second video shows returning to zero

A axis is set up for revs (1.0= one revolution)

after winding 20 revs to set up the next part A rotates back 20 revs, not desirable.

also i tried to use ( G91 G28 A0 ), it did nothing.



thanks for your help



Charles
 

Attachments

  • 20190829_073004.zip
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masso-support

MASSO Support
Staff member
so basically you want to set A to 0.00, as per our understanding you are doing the below:
  1. You home the machine and the A axis homes to the 0 position as picked up by the homing sensor.
  2. Then you run a job and lets say do 20 turns for winding. For this your gcode would be something like G0 A7200 (20 x 360)
  3. Now on the next job if you give the command to go A0 then it would turn backwards 20 times but you want it to go 0.00 on the first turn when it finds the homing sensor? is this what you are after?
 

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
Sorry for not getting right back to you we were dodging hurricane Dorian.

Your scenario is correct the only difference is A axis set up for revolutions not degrees (1.0= one revolution) for ease of long programs not created in CAD.

I move to starting position in absolute then switch to incremental to rotate A axis and move X axis to wind the coil.

G90

G01 x4.5Y2.8Z1.5

G91

G01 A1.0

Go1 X0.03

G90

G01 Z0.0 A0.0
 

masso-support

MASSO Support
Staff member
thanks for the info and hope the hurricane situation is ok.

when you wind a piece and load the next piece, is it possible that the winding can be done in the other direction? I mean the first one is done in CW direction and the next one in CCW, or direction has to be same all the time?
 

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
Yes we do need all coils to be wound in the same direction.

I increased A axis maximum speed and I am using the following code.

G90
G00X0.6 Y3.375Z4.0A0.1
M00
G91
G01A.75F.5
X0.15A5F1
M00
X-0.15A5
M00
X0.15A5
M00
X-0.15A5
M00
G90
Z0F30
M00
A0.1
M30

It works but it also rewinds 20 revs at the end of each coil.

Charles
 

cncnutz

CNCnutz
Staff member
Hi #carmstrong@rhodanmarine.com

This is just a thought but could you just home the machine at the end of each coil? That would find the quickest way to the A0 in less that 1 revolution.

You could set up a button on an input to home the machine when you are ready to start the next coil. You could even add buttons for a rewind and cycle start and have them all next to you on the bench on a little panel. That way you don't even need to look at the Masso at all. Home, rewind, cycle start (rinse and repeat)

I am assuming that you don't have the X,Y &Z set up for something else but even then you can uncheck homing for those axis temporary while winding your coils.

Just a thought, hope it helps.

Cheers

Peter
 

masso-support

MASSO Support
Staff member
@cncnutz another thing that could be done is to add special gcodes to issue homing commands. So there could be a special g/m code for this, for example lets say the gcode is G999 then if we give G999 then all axis home as per the homing axis sequence set in F1 screen, but if we give G999 A then it will only home A axis.
 

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
Thanks guys,

Homing all axis after each coil would not be desirable.

Homing just A axis with a G/M code would make the most sense if I can't set the axis to modulo operation or rollover counts as it is called on other controllers.

Any help would be appreciated.

Thanks,



Charles
 

masso-support

MASSO Support
Staff member
we think resetting with g/m codes will be the way to go. We can start working on this but as we have a new G3 controller release due this month we are not able to do any software changes because of version control issues. So basically we will have to start working on this after the 1st Oct, will that work for you?
 

masso-support

MASSO Support
Staff member
Hi Guys,

We have been discussing how best to implement the feature or more to the point what GCode should we use to do this.

We have come up with G28 A0 or G28 B0 to return a rotary axis to home without having to unwind the entire axis. If the Axis is at A3650 it will return to home in less than 1 rotation .

If you want to unwind the axis quickly all the way then you would use G00 A0 or G00 B0 and it will take the long way home. If the Axis is at A3650 it will return to home in 10 and a bit rotations.

This seems to be in line with what Charles tried earlier on in this thread.
Is there another Gcode commonly used to do this that we don't know about that might be better to use?
If you can let me know your thoughts on this it would be appreciated.

Cheers

Peter
 

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
Good Morning Peter,

Using G28 A0 would certainly work and would be very helpful as we are up to more than 30 revolutions on our coils.

The only other solution would be to set a rotary axis to rollover it's counts after a predefined angle ( G01 A365 would show a machine position of 5.0).

I have used this on machines I designed for the spring industry ,


Again thanks for all your help.



Charles

P.S. all of the shiny machines in the video are mine.
 

carmstrongrhodanmarine-com

carmstrong@rhodanmarine.com
Peter,

Will you be offering any upgrade specials for your G3 units, the extra speed would be very helpful as we have seen some A axis "hanging" issues?

Also what kind of time frame will it take to revise your software to include the G28 command?

Thanks,



Charles
 

masso-support

MASSO Support
Staff member
Hi Charles,

What hanging issue are you experiencing on your rotary axis.

The 2 issues that I know of have now been been found. One was incorrect Gcode and the other was incredibly high pulse per revolution set on the axis.

Could you let us know what issue you are experiencing and share your settings file so we can have a look.

I'm sorry but I don't have a time frame but I am told it is relatively easy to implement so it should not take long.

Regards

Peter
 
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