Need Help!- 4th axis problem

[RP Designs]

finally getting around to using my 4th axis and cutting my first part. I think my problem lies in my post processor editor for my CAM software but while I am waiting to hear back from support I thought I would post here as well. What is happening is that the tool moves up to the clearance plane over the a axis, the axis turns on and then it just hangs there.

Here is the g-code:
O001
N10 M25 G49
N12 G17 G40
N14 G21
N16 G80
N18 G90
N20 G98
N22 ;4th Axis Roughing
N24 G0 Z4.
N26 G0 X17. Y0.
N28 T11 M06
N30 S6000 M3
N32 G1 X-85. Y0. F1829.
N34 G43 Z21.5 H11
N36 A0.F1829.
N38 Z17.5A0.
N40 Z21.5A-360.F3657.
N42 X-80.238A-360.
N44 Z17.5A-360.F1829.
N46 Z21.5A-720.F3657.
N48 X-75.475A-720.
N50 Z17.5A-720.F1829.
N52 Z21.5A-1080.F3657.
N54 X-70.713A-1080.
N56 Z17.5A-1080.F1829.
N58 Z21.5A-1440.F3657.
N60 X-65.95A-1440.
etc..
it hangs up at N36. Any ideas?

[dtown]

No M10 or M11 for clamp / unclamp the axis?

[RP Designs]

Originally Posted by dtown No M10 or M11 for clamp / unclamp the axis?

I don't have locks on my rotary axis so I am limited to light cuts.

As far as the problem goes it only affected the one 4th axis op. If I skipped that op, the indexed ops worked fine and the continuous fourth axis engraving worked fine as well.

[holbieone]

this may be your problem , it's always good practice to put all you axis in a starting position before any other moves

you should have put where you want "A" to start , here "N26 G0 X17. Y0." --> N26 G0 X17. Y0.A0.

your code at "N36" has no direction to travel

[RP Designs]

N26 is a tool change position. And all of the code is being output by the CAM software. Direction changes for the rotary axis are indicated with a - or the absence of a negative in the post. There really isn't a problem with rotary axis movement. When the program gets to N36 the A-axis turns on and spins as it should, the problem is that there is no movement in the z or x axis after that. The a just spins and the tool just hovers over a fixed point on the part.

[holbieone]

"continuous fourth axis engraving worked fine as well."

compare the tap program you are using to engrave with the one that does not work

take a look at this CNC Services Northwest - Rotary Fourth Axis Tips

[RP Designs]

Originally Posted by holbieone "continuous fourth axis engraving worked fine as well." compare the tap program you are using to engrave with the one that does not work take a look at this CNC Services Northwest - Rotary Fourth Axis Tips

This is the engraving:

N21608 ;4th Axis Engraving
N21610 G0 Z4.
N21612 G0 X17. Y0.
N21614 T1 M06
N21616 S6000 M3
N21618 G1 X0. Y0. F2286.
N21620 G43 Z37.027 H1
N21622 A60.F2286
N21624 Z14.A60.
N21626 X-75.A60.F3048
N21628 Z13.4A-60.3
N21630 X0.A60.
N21632 Z37.027A60.F4572
N21634 G0X-6.9A60.
N21636 X-13.8A60.
N21638 X-20.7A60.
N21640 X-27.6A60.
N21642 X-34.5A60.
N21644 X-41.4A60.
N21646 X-48.3A60.etc

Which is essentially the same so I have to scratch my head a bit. one works, the other doesn't and I don't know why.

[cncsnw]

If it remains on N36 with the A axis turning for a long time, maybe it is still busy completing the move to A0. If you start, for example, at A720, you will have two full turns to make before you get to zero. That could take a while.

Do you have the distance-to-go DRO enabled, via machine parameter 143? What does it say about the distance to go on the A axis?

Do you have the revolution count suppressed, via machine parameter 94? If so, the DRO could say A0 when in fact you are one or more full turns away from zero.

The control does not automatically recognize or assume that A0 is the same as A360, A720, etc..

[holbieone]

ok try this , the "A" axis is linear

like from -9999 ,0 , 9999

if you start on the wrong side of A0.0 , "A" axis will count up or down until it passes -9999 or 9999 back to 0.0

[cncsnw]

Holbieone: are you using CNC10/CNC11, or Mach?

The Centroid software (CNC10 or CNC11) will go directly to the given absolute coordinate (in G90 mode), or will go directly the given incremental distance and direction (in G91 mode).

I have no idea what Mach will do. It sounds like it might be trying to apply some sort of rotary axis wrap-around to your A axis, in spite of it being a linear axis.

RP Designs: what control software are you using?

[holbieone]

Originally Posted by cncsnw Holbieone: are you using CNC10/CNC11, or Mach? The Centroid software (CNC10 or CNC11) will go directly to the given absolute coordinate (in G90 mode), or will go directly the given incremental distance and direction (in G91 mode). I have no idea what Mach will do. It sounds like it might be trying to apply some sort of rotary axis wrap-around to your A axis, in spite of it being a linear axis. RP Designs: what control software are you using?

CNC10 , I'm good here , i don't know how his 4th axis is set up so just throwing things out there

[RP Designs]

Originally Posted by cncsnw If it remains on N36 with the A axis turning for a long time, maybe it is still busy completing the move to A0. If you start, for example, at A720, you will have two full turns to make before you get to zero. That could take a while. Do you have the distance-to-go DRO enabled, via machine parameter 143? What does it say about the distance to go on the A axis? Do you have the revolution count suppressed, via machine parameter 94? If so, the DRO could say A0 when in fact you are one or more full turns away from zero. The control does not automatically recognize or assume that A0 is the same as A360, A720, etc..

I don't have distance to go enabled, I will give that a try and see what it says.

Originally Posted by cncsnw Holbieone: are you using CNC10/CNC11, or Mach? The Centroid software (CNC10 or CNC11) will go directly to the given absolute coordinate (in G90 mode), or will go directly the given incremental distance and direction (in G91 mode). I have no idea what Mach will do. It sounds like it might be trying to apply some sort of rotary axis wrap-around to your A axis, in spite of it being a linear axis. RP Designs: what control software are you using?

I am running centroid cnc10 IIRC.