4th Axis Rotary - First run

[viroy]

Hello,
Over the past year I have had great success with my 3-axis cnc.
Some of you may have seen my 'SaleCNC' thread: See page #4 for pics

I am now ready and eager to fire up the 4th axis rotary on this machine. One thing I should mention, the rotary will be running down the Yaxis, not the Xaxis like in the page1 advert pic.
I asked SaleCNC about how to use this when I purchased, their answer was to unplug the X axis and plug in the rotary instead.
So it looks like I will lose horizontal movement and be replacing it with the rotary. I have yet to test this but I know exactly how to perform the switch.

What I dont know, is how to design for this use.
I have no idea how to tell Solidworks that the Xaxis will now be rotation instead of linear.
I am using SolidWorks 2008 and SolidCam 2008 with Fanuc post processing.
Was hoping I could get some help with design and cam programming.
I have considered one option incase I need to get something done asap... design a flat object with the Xaxis width measured to the circumference of round stock... but I REALLY do not want to do it this way, not sure if it would even work and pretty sure it would be a nightmare to design a round object on a flat panel in SW.
I would like to make a few chess pieces for learning, I believe that will be about as complicated as any object will be and give a solid foundation for programming on the 4th axis.

Looking forward to getting started soon!
Thanks for the help guys!

[PMF]

Hi viroy,

We do a lot of tube work, so I design my tube finished & convert to a sheet metal part and "unroll" it. Our CNC rotates the tube instead of moving the "X" axis. It only "sees a distance" to move. I am sure this doesn't really help, but your SolidCAM software would control the axis, not solidworks.

[shearder]

HOLY MOLY this "unrolling" sounds crazy complicated! I am lost just trying to think about it!

[viroy]

Actually I was just thinking about this earlier.... I imagined a chess piece, stick a long needle through the center, cut one side and 'unroll it'.
Is their a solidworks feature for this?
How do you go about it?

[PMF]

Hi Viroy,

The "unrolling" feature works for tube and "flat" work. You could use it for a pocket feature too. But, draw and extrude a tube. The thickness can be arbitrary, though I usually make mine about .030". Cut the features that you want through the tube. Then cut a slit through the entire tube. I use a .001" wide rectangle. Under the sheet metal tab you can "Insert Bends". Select this and select one of the edges on the slit you cut through the tube. Specify your radius as half your tube diameter, and set your "K" factor to 1. Then go. This should flatten your tube. At this point I create a drawing based on the flat pattern and we then import a DWG into our cam software.

For a chess piece your CAM software should be able to interpret it for you. You shouldn't have to "unroll" it. But if you could it would look like a topographical map.

I hope this helps with at least the tube part.

[awerby]

If you do power your rotary axis with the lead from the X axis, you'll need to make sure you start at the middle of the axis. You'll need to reprogram your control software to call the former X axis "A". And you'll need to lock down the X axis somehow, so it doesn't drift while you're cutting. This isn't an ideal way to go, since there are some machining strategies you won't be able to use, like indexing (running a 3-axis toolpath at one position, then moving the A axis to another position, like 90 degrees from your start point, and running another toolpath.)

Like PME said, the "unrolling" technique only works for things that are basically cylindrical. It might work for a pawn, but I don't see it working for a knight. If you want to try creating a real 4-axis toolpath, which will greatly expand the sort of things you can make, download DeskProto - the demo will work for a month for free.

Andrew Werby
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