Make something big

What to do?? Umm.. Animals? Insects? A big press-fit? What?

I choose a press-fit! First, I draw it in real size. I also decide which parts will move and how the structure is going to be.. I want to take it everywhere so it could have some wheels, couldn’t it?

Moving the mouth…Well, I did that in all the parts that move…

Making a test of how the arm would rotate

After defining every detail, I take a picture and import it to Rhino. Now, it’s time to begin to re-draw EVERYTHING! By the way, I scale it to its real rize…

So, after some hours in front of my laptop putting each item in different layers to understand my model, I extrude them to have an idea of how it will look like.

I have to make a prototype to see if it’s really functional and well structured… To do that, I consider the thickness of the plywood (to be cut in the small laser cutter) which is 2.8 mm. If it is more, it would be loose, if it’s less, it’ll be too

tight, so I have to use the caliper.

Now that the file is ready, the next step is to export it as .DXF and open it in EnRouter (the software used for the big laser cutter). It is my first time using it. It feels between exciting and scary, that’s why I keep my

eyes on the EMERGENCY STOP BUTTON in case fire destroys my work.

There are two files: 7mm (for the 7mm MDF), and 10mm (for 10mm MDF). The shown one is for 7mm. It basically has two layers: one for engraving and one for cutting. In the left bottom corner I draw circles for

testing the laser (which means the speed and power the laser requires).

The show begins. LEFT: the test of speed and power. RIGHT: Laser cutter in action

LEFT: detail of the wheel (They have gear shape to avoid it slips on the floor). RIGHT: Laser cutter in action again.

Unfortunately, it was too good to be true. I didn’t realize that the 7mm MDF I took was already used! Its opposite face was cut so 2 items were ruined.

I have to re-do it. Moreover, I opted to cut the 4 wheels again since the holes for the axis were too big. I made an offset of 0.5mm. The picture above shows the parts, and the one below is from EnRouter. The small arrows show

the route it wil take. (ENGRAVING: 100 speed, 80 power; CUTTING: 11 speed, 250 power)

Laser cutting

Now, in this case the drawing is for the 10mm MDF (I measured it and it’s 10.5mm exactly). There is no engraving here. As previously, I made another test on the left bottom corner for the new speed and power

(CUTTING: 9 speed, 262 power)

Laser cutting… again.

Since I want my product to move, I need wheels, and wheels need an axis. In order to do it, I use a wood stick of 6mm diameter which fits in small holes. It fits by pressure. The order is the following: 1- I insert it, 2- I cut it, 3- I use

the hammer to make it fit well, and 4- I cut it in the appropriate size (7mm + 10.5mm + 7mm)

It worked: however, some parts look kind of burned because of the power I set for the laser cutter. I still have to clean it

And this how it looks like. I don’t know how to name it..maybe Biggy or Llamasaur…all press-fit