CNC LEGO Man
This is an introduction to using CNC, lathes and other general shop tools to produce a wooden LEGO man. It will require the use of Fusion 360 and Vetric vCarve desktop software. I will cover the step in which I used to make the project.
Milling rough lumber, turning a 3D model into technical drawing, setting tool paths and working a lathe to produce the head and wrists.
Supplies
Hardwoods I used were Maple (for the legs) Mahogany (arms and torso) and Pau Amarello (yellow heart)(for the head, hands and wrists)
Tools - Jointer, Miter Saw, Drill Press, Lathe, CNC
Software - Fusion 360, vCavre Desktop
Convert Your 3D Model Into Drawings
Follow these steps to create a 2D drawing from a 3D design in the Model workspace:
Open the design.
Click Model and select Drawing from Design.
Select options in the Create Drawing dialog box.
The drawing file can be created from a full assembly or individual components or bodies.
Select the appropriate drawing, template, standard, units, and sheet size options.
Use tools in the drawing workspace to place views and annotation in the drawing workspace.
Note: A drawing can not be created with only sketch elements or surface bodies. The drawing will not auto-populate.
To Print or export the drawing, choose one of these methods:
Select File > Print and choose the preferred output format.
Select the OUTPUT dropdown on the Tool Bar Ribbon and select the preferred output format.
Prepare Your Material
For each body part, I scaled by 10 times.
Material sizes used are as follow (Width / Length / Thickness) in mm:
Head: 115 / 220 / 57
Torso: 170 / 150 / 70 (Cut sides at 10 degree angle on miter saw)
Arms: 76 / 255 / 62
Hands: 60 / 120 / 44
Hip: 90 / 180 / 22
Hip Pivot: 90 / 90 / 16
Legs: 90 / 312 / 65
Neck was turned from left over arm material
Hip pegs were cut from 1.75" maple dowel
Wrists were turned from 1" thick Yellow Heart and 1.5" in length, with the arm peg turned down to 0.75"
Set Your CNC Toolpaths
I exported the arm and hip out of Fusion as an STL file and imported them into vCarve as a 3D model.
I split the arm into the inside and outside half models then ran them as a separate file and toolpaths. This meant you can flip the material over and complete a 2 sided 3D model in the CNC.
Machine the Lumber
The hips and arms were machined on the CNC using the 3D stl files.
The Hip Pivot , Hands and legs were machined on the CNC as a 2D profile and pocket clear toolpath.
Once the hands were cut I Was able to drill a hole to insert the wrists. This was cut at a 20 degree angle and 1" in diameter.
I did CNC the head first off, but found that once glued I didn't like the grain orientation and scraped that version and went the the lathe.
Lathe the Head/wrist
The head was cut to a total length of 117mm, top peg was 19mm in height and 46.5mm in diameter. Neck hole was drilled out at 1 7/8" using a forsner bit mounted in the lathe. Diameter was cut to 65mm.
Drill Holes for Pegs
The make the model true to the original model, I choose to drill out the wrists, neck and torso holes to put a dowel peg in so your can dismantle and swap parts.
Neck was drilled to 1 7/8" and had the neck turned out of the Mahogany to keep the same.
Torso hole drilled out for 1 1/2" maple dowel rod and matched to the hips.
Wrists drilled at 3/4" and turned the wrists to match.
Fit & Finish
Once all part were cut and test fit, they were all finished with a mineral oil finish, once allowed to spoke in and dry coated with a beeswax. I wanted a matt finish, and show off the natural grain in the wood.