One of the first things I ever tried to mill was this ‘Grunblau soap dish’ design I found by accident on the interwebs. It turned out that the project had too steep of a learning curve for me at that time. The fact of the matter is I was just getting to know my machine and had yet to understand all its quirks. Also, there were some issues which I won’t elaborate on, but suffice to say that I think the Arduino/Gshield setup wasn’t calibrated properly, which caused me a lot of headache.
Yesterday, I made a new attempt, of which you’ll see the result here. But first things first:
The design is available for purchase on his website, should you be interested. Obviously, I can’t make the source files available for download as I usually do.
I won’t go too much into detail about the process itself, because the video in the link above explains everything really well. But one thing I do want to elaborate on is why I like this project. First of all it looked like a beautiful design. From a technical point of view, there’s also quite a lot to keep track of (hence the steep learning curve). There’s multiple tool changes on the 2 sides, the flipping jig is really really clever and the organic shape is ideal for testing machine settings, such as stepover and general feeds/speeds. Because the dish is only a few millimeters in thickness, the process is quite unforgiving.
If you purchase the files, there’s a readme included with most of his cutting parameters and used endmills. If you’re confident your machine can handle his speeds/DOC’s, there’s even ready-to-go gcode included for all machining operations. But the objective for me was learning to make a relatively complex part from start to finish, so I made my own toolpaths. Moreover, I work in metric, and don’t own the specific endmills the designer used. I also had to re-work the flip jig to match my endmill diameter.
Roughing side 1:
Finishing side 1:
Cleanup of the holes side 1:
I don’t have pictures of the ‘side 2’ operations, but it’s basically the same thing. I do have a video though that’s kind of an overview of all the machining operations, and shows the awesome flip jig in action.
I used different stepover values for different sides: 5% and 10%.
And off course, with soap 🙂
Now, did everything go as planned? Hell no! I actually started with a piece of scrap bamboo that was just smaller than what I had anticipated in the software. And that was the first of several concessions I made. Now, let me give you one piece of advice: NEVER make concessions when it comes to a CNC project. It will always bite you in the ass sooner or later. Therefor, always prepare 100% and always make sure everything is exactly as planned in the designing and toolpathing stages. But I am a stubborn SOB, so I proceeded, hoping it would all work out in the end. And it kind of did … i guess … 🙂
Stock material was slightly undersized (because I used a piece of scrap, bamboo is expensive you know…). This caused my working zero to fall outside the stock box (which is a pain for zeroing after a toolchange). Stock material was also 0.5mm slimmer than it was supposed to be, and had some glue gaps that I didn’t like (can be seen in ‘side 2’ close-ups). Also, I underestimated the total cutting time, so I had to do it in 2 times. I powered off my motors in between, so my flipside zero wasn’t spot-on anymore.
But all things considered, I think i’d call it a success!