Endless a-axis

[Thompson]

So, I'm running my Fadal with a VH65 4th axis, surfacing a massive 40" ring, I tried punching G1 G91 Z-.015 A1080. F35..The problem is that the machine only lets me spin three revolutions max before erroring out, there is no hidden parameter, just stuck, and I ended up writing a crazy loop program repeating 420 times. Yeah… about 72 hours per cycle..it is definitely one of those days, guys

 

[Tech-bunny24]

Sounds like you nailed the workaround with that mega loop. Some have had luck tweaking macros or nesting loops to push past the 1080 deg cap. Curious, did you try breaking it into smaller subroutines or just forced it all the way?

 

[Titing_]

Have you checked if the A-axis can spin freely without any of those cable tangles? Just want to make sure it won't get stuck or anything.

 

[Arki_Bogs]

Running a 40 ring surfacing is a long haul. What if you tried a few shorter runs instead of a super long one? Might be more dependable.

 

[Ginovirzosa_]

So, I'm running my Fadal with a VH65 4th axis, surfacing a massive 40" ring, I tried punching G1 G91 Z-.015 A1080. F35..The problem is that the machine only lets me spin three revolutions max before erroring out, there is no hidden parameter, just stuck, and I ended up writing a crazy loop program repeating 420 times. Yeah… about 72 hours per cycle..it is definitely one of those days, guys

Try boosting your Z-axis step per rotation. If your project's surface can handle it, upping the step from .015 to .025 or higher could really speed things up.

 

[Kwanda_Rosman]

Fadals just won't let you go endless on the rotary, it's capped. That's why you're stuck looping it. Best bet is to break it into subroutines so at least your code's not 50 pages long. Painful, but that's just how these controls were built.

 

[SGorman1987]

Fadals just won't let you go endless on the rotary, it's capped. That's why you're stuck looping it. Best bet is to break it into subroutines so at least your code's not 50 pages long. Painful, but that's just how these controls were built.

Thanks for the help! I'm new to using a Fadal at our shop and hit the rotary limit while trying a wrap engraving. When you say "looping," do you mean using GOTO or something else? And for subroutines, do you use M98 or is there an easier way on these machines?

 

[hauntedvertigo]

Thompson’s original loop method works but @Ginovirzosa_ was right to suggest bumping the Z-step if your surface finish allows it.

On a Fadal M98 with a subroutine file, this is the cleanest way to handle long rotary runs.

@Thompson since it's been a couple of months, did you end up shortening the runtime or did you run the full-length loops? It would be great to hear how the VH-65 held up after that 72-hr cycle.