Dog-Bone and T-Bone Fillets?

[trilobyte]

I'm sorry if this has been covered elsewhere, but in searching the forums, help files, and internet in general I seem to be having no luck.

I'm new to AutoCAD 2014 for Mac, but not new to 2D/3D design and designing for CNC.  In exploring AutoCAD and learning to use the Fillet command, I can't seem to figure out how to create a dog-bone or t-bone fillet.  These are the kinds of fillets very commonly used with designs for CNC machines (such as a ShopBot router), where the cutting tool has a larger-than-zero radius.

I'm trying to design a series of parts and components that will be cut via CNC tools and then fit together  (the attached render shows a few pieces fitting together) - in order to do that the slots need either dog-bones or t-bones in order to accommodate the part that will slide into it.  How can I do this in AutoCAD?

Thanks in advance, I really appreciate any help or pointers you could give me.

[maxim_k · Accepted solution]

Welcome to Autodesk Forums!

There is no such tool in AutoCAD, so you need to use some of 3D commands to create such fillets: for example - UNION. With this command you can union rectangle and circle shapes to create dog-bone fillets: you only need to place circle shape at the right position relative to rectangle corner. In order to use UNION command you need to convert rectangle and circle to regions or extruded 3D solids.
If you need only 2D objects you can use TRIM command after you place circle at right position to trim unnecessary parts.

Maxim

[trilobyte]

Thanks for the info... and what a pain.

Vectric's VCarve Pro is pretty clunky and awkward for most uses (and is Windows-only), but does have the ability to easily create or remove multiple types of fillets.  I had been hoping to be able to use AutoCAD to improve upon and streamline the design workflow, and do all the mechanical drawing.  Then finished drawings could either be sent to C4D (today) or Maya (in the future) for rendering, or machine-specific applications (such as VCarve Pro) to generate the gcode.

I'll take a look at the Union and Trim commands, perhaps I can cook up some kind of shortcut parts or component library that will work.

[Alexrose1942]

There a nice lisp for Dogbone CNC on AutoCAD here 

http://www.kimprojects.com/prepare-your-dog-bone-cnc-transition-automatically/

[maxim_k]

Hi @Alexrose1942

This lisp routine wouldn't work in AutoCAD for Mac as it uses Visual Lisp functions, which are not available in AutoCAD for Mac.

Maxim