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4th Axis?

Posted: Sat Jun 27, 2015 12:09 am
by chrome700
I'm sure this has been asked somewhere before, but anyone tried this with a SO3?

Re: 4th Axis?

Posted: Sat Jun 27, 2015 12:37 am
by CastIrony
You're limited by at least three factors:

1. The carbide motion board specifically, and GRBL in general, don't support a 4th axis, so you'd have to either use a different board or disable one of your axes.
2. AFAIK no cheap CAM software supports generating high quality toolpaths for 4+ axis carving. The extra degree of freedom makes the optimization problem *much* harder.
3. There's only ~3 inches of vertical clearance on the Shapeoko 3, which really limits the diameter of whatever you're carving.

Re: 4th Axis?

Posted: Sat Jun 27, 2015 3:57 am
by WillAdams
there's been some discussion but nothing solid.

Re: 4th Axis?

Posted: Sun Jun 28, 2015 8:10 pm
by James RS
CastIrony wrote:You're limited by at least three factors:

1. The carbide motion board specifically, and GRBL in general, don't support a 4th axis, so you'd have to either use a different board or disable one of your axes.
2. AFAIK no cheap CAM software supports generating high quality toolpaths for 4+ axis carving. The extra degree of freedom makes the optimization problem *much* harder.
3. There's only ~3 inches of vertical clearance on the Shapeoko 3, which really limits the diameter of whatever you're carving.

I too am interested in 4th axis and I found a gentleman on Google + who has installed one on the Shapeoko 3.
From what I could see from the pictures , it's is bolted on the end where the gap is, Also this was mentioned by Edward
in a another post about why the gap was there.I've messaged this person in hopes to get more information on his setup
https://plus.google.com/100117868275643 ... UcEXpQjzQp

Re: 4th Axis?

Posted: Sat Jul 11, 2015 2:47 pm
by chrome700
CastIrony wrote:You're limited by at least three factors:

1. The carbide motion board specifically, and GRBL in general, don't support a 4th axis, so you'd have to either use a different board or disable one of your axes.
2. AFAIK no cheap CAM software supports generating high quality toolpaths for 4+ axis carving. The extra degree of freedom makes the optimization problem *much* harder.
3. There's only ~3 inches of vertical clearance on the Shapeoko 3, which really limits the diameter of whatever you're carving.
CastIrony:
Thank you for your thoughts. A couple of quick responses:

1. Seems like if one was going to do 4th axis work you wouldn't have to use the axis that's perpendicular to the 4th axis shaft.
2. Vectric seems to have some support for it. http://forum.vectric.com/viewtopic.php?t=6449 F360 hints at something in later versions.
3. An SO3 would need some major surgury to achieve this, but if the center of the 4th axis was at the same height of the wasteboard (basically, get rid of the wasteboard) you could create some decent clearance.

Re: 4th Axis?

Posted: Tue Sep 01, 2015 10:50 pm
by James RS
Couldn't you just unplug the one axis and plug in the rotary axis in it's place and clamp the machine?

Re: 4th Axis?

Posted: Tue Sep 01, 2015 10:56 pm
by WillAdams
Yes, but one would then need to use a utility program to wrap the flat G-code around the cylinder for cutting. There are a few utilities for this listed on the wiki.

Re: 4th Axis?

Posted: Wed Sep 02, 2015 10:07 pm
by AnonymousPerson
CastIrony wrote:2. AFAIK no cheap CAM software supports generating high quality toolpaths for 4+ axis carving. The extra degree of freedom makes the optimization problem *much* harder.
Not sure if it helps, but Autodesk's Fusion 360 (free for Hobbyists/Enthusiasts) says it supports 5-axis CNC (already). They also mention on their development roadmap that they're continuing to put develop effort into it:

http://forums.autodesk.com/t5/fusion-36 ... -p/5707378

The Fusion 360 people seem to be fans of Pocket NC (http://www.pocketnc.com), so the 5-axis CNC functionality may have gotten a boost from that (unsure).

No idea if the above means they also support 4-axis stuff. ;)

Re: 4th Axis?

Posted: Wed Sep 02, 2015 10:58 pm
by AnonymousPerson
Looking through the Fusion 360 site, it seems like 4-axis stuff is being worked on:

http://forums.autodesk.com/t5/fusion-36 ... -p/5776887

The comments further down that page by the Autodesk staff mention it's due (roughly) in November.

Re: 4th Axis?

Posted: Thu Sep 03, 2015 1:32 am
by Jimf
Fusion360 4th and 5th axis is indexed and not continuous motion. I can't wait until continuous 4th is available. I have a rotary 4th but have not used it much. Indexed 4th is useful for making gears and such but not for rotary carving.