8. Computer controlled machining

Starting my design.

I first started my design on Corel. I find Corel easier to manipulate things into the shape I want rather than V-Carve (the program we use at school. It’s pretty much identical to Aspire, but I’ll get to that in a minute).

Testing my design

I put my design into the laser and tested it out. I hot glued it just to make sure it was tight enough, but I know i wont really be able to do that for my final, final verision of this chair.

Using the CNC

There are a lot of safety rules that goes along with running a CNC. There are not just there to make your design look good. They’re there to keep you safe!

  • that the mill isn’t running while you are setting up
  • that your X, Y, and Z are correctly set up
  • that your vacuum is on
  • that you’re careful with the tip when it’s not running (its pretty brittle and can be sharp on soft hands. Watch out!)
  • make sure that your hair is tied up even when the machine is not running
  • make sure your clothing is not loose or hanging around the machine

Problems I faced

I had a lot of problems this week. Some of the include:

  • not being able to upload files
  • having to redesign most of my stuff
  • having to refit my material
  • having a poor pressfit

Lets start with uploading files. I wasn’t able to use some of my designs for my make something big project due to some of the updates Corel made. See, I had my files saved on version 20.0 while Lorain only had their Corel system updated to 19.0. This meant that Corel wasn’t able to read the file, therefore I couldn’t export it as a .eps, therefore meaning I couldn’t use my design on Aspire. I had to redisgn one of my parts (it didn’t take to long, but it was probably the reason why my press fit was super loose too.)

Next we have the redesigning part. Now, I didn’t just have to redesign the part I couldn’t open on Corel, I had to redesign the actua seat part of my chair. First, one of the Lorain Fab Lab employees, Chris Leon, helped me get my files into Aspire through .eps. He saw my design and thought that the dog bone slots I put in myself in Corel wouldn’t work (of course he was right. There was way too much circle and not enough dog bone). I took them all out and nudged the pieces back together and used the segment delete tool to clean it up. Then we went back to Aspire and found that we couldn’t use the fillet tool for some reason. There had to be a problem with my design. We went back to Corel and found out that the b-spline I used in my design was not compatible with Aspire. By using a b-spline, my whole design turned into a curve, not a shape. I fixed this by making a border for it, dragging it out, and therefore made a replica of the design. This design actually worked with Aspire since it was a shape, not a bunch of curves.

My press fit wasn’t the best. It was a little wobbly, though that really didnt change the whole integrity of the chair. It still held up, it was still kind of a chair. A bit to avant garde for comfort, but so is everything these days, right? Well, in order to fix my press fit, I have to do a couple test runs to see how the CNC mills and the kerf on it. I also need to use a vernier to measure how thick my material is too. I knew it was 3/4 of an inch, but I didn’t know the exact amount. I think that is why my design failed. I’ll fix it by putting more time into the bottom part of the design and by measuring my material better.

The Final Product

CRV3D File SBP (Milling) File