I also noticed that the larger, forked openings in the image above were lopsided. Both “fingertips” should be the same length, but the one on the left is clearly longer than the one on the right. I decided to go back to VectorWorks and widen those fingertip tenons, as well as elongate the inappropriately rounded tenons per a classmates suggestion.
Interestingly enough, though MasterCam hadn’t projected this in it’s preview, the same thing happened to the fingertip tenons of my two long pieces as had happened with the fingertip tenons for the smaller end. These would require sanding to remove the excess material.
Regrettably, even if the fingertip tenons hadn’t been left out in the cutting process, the pieces didn’t fit together. This was because I grouped each fingertip tenon too closely, making it so tenons on one end couldn’t nest with openings on another.
I went back to VectorWorks to widen the fingertip tenons to solve this problem. There were so many tenons to check and I was running out of time for the assignment, so I simplified things: instead of cutting long walls, a floor, and short side walls, I shrunk my file down to six side walls with wider fingertip tenons. Then I took my file to the CNC machine, to which I had already mounted my new material: maple plywood.
After three days of battling VectorWorks, MasterCam, and my prototypes, I wasn’t able to finish milling before I was kicked out of the shop. I have another 30 minutes of milling time to finish the pieces above. Hopefully they fit together!
When I presented this projects back in February it was still just a bunch of ill fitting parts. Up until that point I had been frustrated with the amount of time it took to refine my models in Vectorworks and had spent the bulk of my productive time for this project battling the software.
However, within a few days of presenting I was feeling significantly more confident with Vectorworks and had decided to simplify my CNC joinery approach to make it less…arduous.
I still ended up going through TONS of iterations to get the joints to fit.
To test the joints without cutting out every piece at once, I focused on just testing fit for the right and left walls of the box, since the joint was essentially the same for each side. Eventually I got the sides to fit really nicely.
With the joints seemingly in a good place, I proceeded with the rest of the piece. During milling of the top panel, my plywood started to peels and split along where the slide rail would go. Oh well: can’t stop now.
When this first pass at making each part of the project was complete, I discovered that I hadn’t made the slide rail track long enough (note how the rail doesn’t sit well in the track – the joint looks good though!).
I ran the job just for this piece once more after lengthening the track, but soon realized that I needed to dog bone the corners of it as well to accommodate the sheer corners of the slide rail. Rather than run the CNC again, I used a Dremel to sand out the dog bones. Not the most elegant solution, but it got the job done.
Dog bones in place, it was time to add mounting holes for the pulleys. I turned to the drill press for this.
I then assembled the piece.
To my horror, I realized I miss-sized the back wall, so I needed to cut off the joint fingers on either side with the bandsaw to complete assembly. Here’s what it looks like when viewing straight on. Notice the gaps on either side: that’s because of the missing fingers. Not great, but again, gets the job done. At least I was able to assemble everything.
And here is the rowing machine simulator working!