Walnut Groot - Cnc Carved From 5 Sides
Introduction: Walnut Groot - Cnc Carved From 5 Sides
I developed an easy system to carve 3d models from four sides on a hobby cnc. Using this system I carved <PERSON>! And because I'm a bit extra, I carved the top of his head and explain how I reached the 5th side.
Supplies
* Any hobby grade cnc (no rotary required!!)
* Fusion360
* 3" long 1/4" endmill
* 1/16" ballnose bit
* Block of wood 2.75"x2.75"x5.25"
Step 1: Setting Up the Model
Grab any model from Thingiverse with high levels of detail. Import the model into Fusion360 as a mesh.
Create a sketch on the X,Y plane, and draw a 2.75" square. Make sure the model is centered, and scaled to barely fit inside the square. Extrude the square down 1.25" to create the base. Next extrude the square up until it covers the top of the model, so we know how tall the stock needs to be.
Step 2: Preparing the Stock
The block of wood to use for the stock needs to be EXACTLY 2.75"x2.75", and approximately 5.25" tall (depending on the model). I cut the chunk out slightly large with the bandsaw, then used the table saw to trim it to the exact size.
Step 3: Carving a Registration Block
A registration block is anything fixed to the cnc bed that forces your workpiece to sit in a precise position. To ensure that my block locks the corner of our stock at the precise X and Y zero of the cnc, I will use the software to cut a slot exactly 2.75" across.
In Fusion, I created the block around the base of the model laying down. Then I defined the origin as the bottom corner of the base (<-- super important point here!), and set up a pocket toolpath to carve it out.
On the cnc, I screwed down a chunk of 2x4. After running the toolpath, the walnut stock fits perfectly and will be in the exact same position regardless of which side is facing up.
Step 4: Adding Clearance
Usually a registration block is all you need before you start. But... I'm going to be using an extra long 1/4" endmill for deep carves, the stock is 2 3/4" tall, and I'm working on top of a 3/4" spoilboard. 431
The cnc just hasn't got the clearance for that, but it's not too far off.
Soooo... how about we just cut out the spoilboard where the block sits, and regain that 3/4" of clearance? Hey, why not?
I used the base and the stock (top of the block) as models, and created a pocket toolpath inside those edges. With the heights set to start at the stock bottom and carve down to stock bottom minus .7" it was happy to carve out that piece of the spoilboard for me.
Step 5: The Secret Sauce
Awesome! So let's get <PERSON> out of this block. Now the only way to get to <PERSON> is to carve him from all four sides. How we gonna do that? Great question! Pay attention, this is how we make the secret sauce!
We're going to create 4 new setups and rotate the orientation of the model 90 degrees each time.
Setup 1, with the right side of his face facing up. The bottom left corner of the base is the origin. It gets carved, obviously, from the top down.
For setup 2, rotate the model 90 degrees counter clockwise. Pick a vertical edge for Z and the new bottom left corner for origin, and carve the left side of his face.
Setup 3, rotate the model 90 degrees again. Pick a vertical edge for z, the new bottom left corner for origin, and carve his left shoulder.
Setup 4, rotate the model 90 degrees again. Pick new z line and bottom left corner for origin, and carve his right shoulder.
Because the X,Y, and Z NEVER CHANGE on the cnc, and the stock is ALWAYS in the EXACT place the carves will meet flawlessly around the model. That's the trick!
Step 6: Setup and Path Details
Ok a couple quick details...
Each Setup uses the 3d mesh and the base for the model. We don't want it to touch the base, so it needs to know that it's there. 116