Wooden Blocks and Other Parts

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One of the challenges with CNC machining is the cutting of perfect inside 90-degree corners. Since the CNC tool is round, the operation of cutting an inside 90 degree angle will always result in a curve that equals the radius of the bit. This can be clearly seen in the photo below. The notches on the left are original CNC cut with rounded corners, while the notches on the right have been squared up manually using knife/files.

notch squaring.jpg

Several months ago, I discovered a technique used by CNC furniture makers to overcome this problem. It is called a Dog-Bone Fillet. It allows for perfectly square fitment of parts of this nature without the need to manually square up the notches. Dog-Bone Fillet functions are available on most high-end CAD software programs today.

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Below is a picture of what I am describing. I have greatly exaggerated the Dog-Bone Fillet to give you an idea of this technique. Once cut this way, the parts will match up perfectly square with the dog-bone hidden after assembly. I have never seen this technique used in any kit I have ever purchased. Have you??

IMG_0247.jpg
 
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Here are three of my old You Tube demo videos for your viewing pleasure:

CNC cutting of shot racks from boxwood:

Quick laser demo:

Demo on the use of 3D tabs on CNC parts. My tabs are small triangles that allow the part to be easily removed from the billet:
 
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Once the CNC job has completed there is a pile of sawdust so fine it is almost like a powder

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Vacuum away the dust and a nice 3D carving of a 1:32 gunport wreath is revealed. This fits the Jeff Staudt Battle Station plans.

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The CNC machining is so precise the part remains attached to the billet via a paper thin sheet of wood that can easily be trimmed away with a knife. This provides a very safe method for shipment.... world-wide.

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Hello Mike- Incredible results! Is Osage Orange better suited than other woods for CNC machining. Would it work just as well with Swiss Pear or more dense woods like Castello Boxwood or Madagascar Ebony (the world's blackest/densest ebony)? Also, I just received an email from woodpeck.com- they have quite a few live edge slabs of Osage Orange!
 
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Hello Mike- Incredible results! Is Osage Orange better suited than other woods for CNC machining. Would it work just as well with Swiss Pear or more dense woods like Castello Boxwood or Madagascar Ebony (the world's blackest/densest ebony)?
We only used Osage on the wreath primarily for it's color. Over time it will actually darken to an almost brown color. For CNC machining we want to use the very finest grain wood possible to get the best results. Pear and Boxwood are my most common choices. I have ebony and can machine it but it tends to be a bit messy. I have also laser cut ebony with no problems.

Dave Stevens and others are more of the wood expert but so far I have found pear and boxwood the best for CNC machining. But that does not stop me from trying anything. LOL.

BTW Robert - that is your wreath. The Admiral should get it out in the mail today. I will PM you the tracking number when she gives it to me.
 
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Thanks Mike! Remember to check woodpeck.com if you need any more Osage Orange- they have quite a few slabs which look like they would probably last a long time for us model makers.
 
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