Make Something Big

I originally planned to create the playatech gizmo as a get-to-know-the-shopbot exercise.

As things went, I ran out of time and did not get a chance to make my own design.

  1. Download and make requisite donation
  2. Recreate in solidworks (with plenty of mirroring and use of equations to link all the width, so I could change the 0.44’’ slot thickness everywhere by just changing one of them)
    Yes, it’s all one giant sketch. Terrible practice, I know.
    I had to create this file several times because I was
    slack on adding Dimensions, instead just placing points where I wanted them (specifying when I created the point without going back with a “smart dimesions” tool).
  3. Make shopbot path in partworks
    This is where I learned that generally, you don’t make designs that us ALL of the stock on the shopbot. You really want a margin
    However, being silly, I thought it wouldn’t hurt to go ahead and try anyway (sorry everyone who politely tried to make things easier for me). I figured that I could cut without detaching any parts, score the remaining lines, and then finish things up on the bandsaw / using a jigsaw.
    I thus put 9 holes where I knew there was a wide margin of error where the shopbot tool should not come anywhere near and carefully zero’d all the axis to be as accurate as possible. Yay tape measure + sharpie!
    I minimized the amount of measuring I needed to do by picking each x with 3 different y-values, instead of my haphazard 9 values with all different x’s and y’s originally.
    Interestingly, I had some major issues getting closed vectors in partworks. I used “Mirror” in solidworks to create parts of my design. The original parts recognized themselves as connected vectors. The mirrored lines didn’t. I ended up deleting the mirrored portions in partworks and copy-pasting the lines I needed.
    To do this without messing up the dimensions, I took advantage of the fact that
    Partworks copy-pastes in place. I would copy the ones I wanted (the “closed-vectored” lines), paste, then hit the up arrow key to move the copied lines over the solidworks lines-which-won’t-close/allow-me-to-fillet, zooming in to make sure the copy was exactly over the solidworks lines since it doesn’t seem to snap. Then I would hit Ctrl-C again. Then I would hit delete, then delete the solidworks lines as well. Finally I would hit Ctrl-P and the lines would be pasted in the correct place.
  4. Cut
    Material used: One 4’x8’ OSB sheet, 7/16’’, provided by the class.
  5. Then I realize that with the lines scribed, I could see exactly where the shopbot tool would go if I just reran the same path but deeper, cutting through instead of scribing. So I added more screws (at least 2 in each part) and then cut again.
  6. Assemble

  7. Some notes:
    I measured ~0.45’’ thickness and cut to 0.46’’ depth. This worked out well as the board was not perfectly flat in some places for the first cut.
    In the design, I didn’t compensate for the width of the tool. As a result, there were minor differences in the “identical parts” but the slack in the design allowed me to assemble it anyway. When I put it together, I realized two pieces were longer than the other two and made sure to put them on the outside. You can see the two pieces hovering @ ⅛’’ off the floor (half the tool radius) below.

    On some parts, I put a t-bone fillet for a ⅛’’ (see left pic below) instead of a ¼’’ tool (right pic below). Later, I couldn’t fix this because I couldn’t delete old fillets. This worked out okay due to the leeway in the design.

Files located in this directory: (contains sldpart, dwg, crv, and sbp files: solidworks part file, CAD drawing file, partworks file, shopbot path file)