I am not sure this is the best place to post this… so admins please feel free to move it if it is better suited elsewhere.
I purchased a rotary attachment for my 1F Elite Foreman last year. I am finally getting around to learning how to use it.
One of the services I offer in my woodworking business is spindle reproduction. So, for example, someone has a stair railing, and it’s missing or has broken spindles that can’t be purchased anymore, I will duplicate turn them. Until now I have done this using a traditional lathe, but I would love to be able to use the CNC to do it, especially when I only need to make one or a few. Particularly with spindles that have small diameters and / or smaller more intricate details on them.
I have spent the last few days experimenting with the first such job, and am looking for guidance / advice from anyone with experience in this area regarding the following:
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The best way to get the profile into the CAD / CAM. I currently use Vectric Aspire. I tried taking a photograph of the original spindle, using a trick from my crime scene tech days. I placed a ruler in the photo. I imported the photo into the software, placed two guidelines 1 inch apart, and then enlarged the photo until 1 inch on the ruler was on the guidelines. I figured that would get the scale correct. I then did a bitmap trace and was able get what appeared to be a good profile, after some node editing of course. I assigned a molding toolpath to it, and sent it to the CNC using a tapered ball nose bit. The result was still not to correct scale. I think part of the issue, or maybe the whole issue, is the parallax error from the camera?? The left and right ends of the spindle in the photo are farther away from and off at an angle from the lens… thereby introducing error when I do the trace? Next I am going to try tracing the profile onto paper with a scribe, and using the Shaper Trace to get it into a vector.
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Speed. It took the machine almost 11hrs to carve 11 inches of spindle. Obviously, this is pretty impractical. I was able to significantly reduce the rounding toolpath time using a technique I found over on the Vectric forums, where you use the spiral gadget to do a continuous rotary movement in conjunction with a continuous X-axis movement. But I cannot seem to figure out how to apply that to the molding toolpath. Would I be better off with a two-rail sweep? Any suggestions on how I can speed up the carve time? I’ve seen videos of CNC’s doing continuous rotary carves and the rotary is turning much faster. Is that possible with my setup? Also, I did try adding a large area clearance toolpath but according to the software it only added more time to the carve.
Thank you.