Coputer Controlled Machining

For this week we had to make something big, it’s not simple task as it may sound. we had to make this big thing without any nails or screws or even glue, its really an exciting challenge.

Group Work

CAD (fusion 360)

From the first moment, I decided to make some ride on toy for My little nephew he’s 10 month now, and I wanted to make a swing that’s looks like a plane. But after a while I decided that the weight of him and the wood might be large for hanging, so I made it just on the ground toy.

I started the design using fusion 360, drew all the parts together without the joints first and then I added the mail joints only, and using combine option and subtracted the material to form the female joints.

CAM (Vcarve pro )

Since the cuts weren’t in my original sketches, I had to project each face to a new sketch, then I saved all the sketches as DXF files to import them to the job file in Vcarve later.

Until this step, everything was easy and nothing new, but then I had to use the CNC machine, which I have used only one time one year ago, so it was challenging but fun process. We lay down the plywood board on the bed of the machine, I used a plywood instead of MDF wood because we not allowed to use the MDF in the lab since it may cause health problems.

The next step was to start nesting the sketches on the board using Vcarve software. It’s an easy software helps you to create the cutting profile and prepare its settings. I added all my sketches to the plate and selected the thickness of the material 18 mm as my plywood board was.

I have only two profiles for this job (inner and outer cuts), I started selecting the inner cuts.

From the picture, you can see that the cut depth is more than the material thickness by 2 mm, just to make sure that the machine will cut through the thickness even if the board was bended little bit.

The second option in the setting bar is the drill bit options, I selected ¼” straight bit to show as much details as possible. And I named the job Inner and pressed calculate.

And then I selected the profiles for the outer cut and did the same as the inner cuts.

After calculating both jobs, I opened the 3d view tab and new options appears.

Preview toolpaths icon helps you simulate a toolpath for the cutting process as you can see, and toolpaths summary icon gives us a time estimation for both profiles.

The last step in the Vcarve is saving the files in sbp format to open it in the Shopbot, which is the driving software for the Shopbot CNC router.

befor giving the shopbot the cutting order, we have to set the zero for the z-axis for the head, to make sure that the milling bit is touching the wooden board exactly, so when it start cutting it wont be broken. to do that I used the clip and metal plate that attached to the machine head.

I attached the clip to the milling bit and aligned the metal plate on the board exactly under the bit, and gave the machine the order to set the zero for the z-axis. the machine goes down slowly, and when the milling bit touches the plate the machine stops immediatly, and saves its position as the z-axis zero.

after these steps, i just gave the machine the order, and waited near it to finish. when it finished, I removed the parts from the board and sanded them a littel , then I assembeled them.

I was planning to paint it of course, and put on it some decorations and cushions, but unfortunately our lab shutdown because covid19 Circumstances. so this is the partially finished look for my plane.

all DXF files
Fusion 360 file