I've gone to the birds

[jteneyck]

3D objects are possible on a CNC by machining one side, flipping it over, and then machining the other.  Of course, excellent registration is needed for the seam to come out well, but the CNC makes that pretty easy by drilling registration dowel holes in the workpiece and corresponding ones in your spoilboard.  To try it out I made this little bird in cherry from a file on Vectric's website.



it's less than 4" long.  The precision and detail is amazing.  My wife and I liked it so much that I scaled it up to one over 6" long and cut another in Sapele.



The Sapele one has no finish on it yet.  The only places I sanded on either was along the seam and on the tail.  I continue to be amazed with the quality of the machined surface possible with a CNC.  

John

[BrentDH]

Very nice, John.  More details please on the registration method.  I can see how you could drill into the bottom of the bird, but it seems you need holes in each side.  Obviously I am missing something.

[jteneyck]

Very nice, John.  More details please on the registration method.  I can see how you could drill into the bottom of the bird, but it seems you need holes in each side.  Obviously I am missing something.

You drill dowel holes in the top surface, which is cut first.  It doesn't matter how many other than you need at least 2 and 3 or more in some asymmetrical orientation is better.  This is what it looked like after all the machining was done on the top side.  At this point, you remove the workpiece from the spoilboard.  


   
You create an identical dowel hole pattern on the bottom side of the workpiece, using the "Copy to other side" command.  But instead of machining those holes in the workpiece you machine them into the spoilboard.  Put dowels in the holes, line up the workpiece, and tap it down.  If you used an asymmetrical pattern it can only go down one way.  Now the piece is located exactly where it was before, only flipped over, so when you machine side two the edges will line up perfectly, assuming those were copied correctly to side two.  It's amazing how some complex things can be made so easy.  The opposite is sometimes true with a CNC, too, but we'll leave that for a day when I come across something really frustrating that should be easy.  

John

[jteneyck]

I mounted the pair to a piece of spalted maple I found in the woodpile and gave them a home.

[mr_skittle]

I LOVE these little birds! I'd say this is really thinking out of the box on what a CNC can do in a woodshop. It really strikes a chord with me since my business name is Birds and Boards Custom Furniture. Maybe I can get some made locally and give them out to clients as a thank you gift. What a neat idea!

[jteneyck]

I LOVE these little birds! I'd say this is really thinking out of the box on what a CNC can do in a woodshop. It really strikes a chord with me since my business name is Birds and Boards Custom Furniture. Maybe I can get some made locally and give them out to clients as a thank you gift. What a neat idea!

Thanks.  Shipping wouldn't be much for a box of these.  I know how to make them.  

John

[mr_skittle]

Can you find a file for a black-capped chickadee? That's the particular bird on my logo.

[jteneyck]

Can you find a file for a black-capped chickadee? That's the particular bird on my logo.

The lady who developed the file for the little bird started with this photo, an English bird, but it's shape is very close to a black capped chickadee.  




I doubt there will be much difference even if I find a file specifically made from photos of the BCC.  To my eye, the only difference between the two are the colors and those are gone on a carved model.  I can easily make a couple and send to you to evaluate.  

John

[mr_skittle]

The two birds pictured are both from the same family. The old-world species are called ***** (hehehe) and the new-world species are chickadees, along with a couple of ***** and titmouse varieties in there. You see my business name actually reflects the two things I'm most 'obsessed' with, birdwatching and woodworking. My father-in-law does carving and could help me add in some of the distinguishing characteristics to make it a black-capped chickadee. I'll PM you and we can talk a few details.