I bought a great car a few months ago, but it is *not* a new car. It’s a 2005 Porsche Boxster S and is a profound pleasure to drive. I’d much rather buy a great used car than a new car that I wouldn’t love. One down side to buying a car from the middle of the previous decade, though, is that it lacks some of the more modern electronics. In my case, I have to toss my iPhone in the passenger seat and connect it to the radio via an FM transmitter (there’s no aux input jack). The phone slides around all over the place in the passenger seat becuase there’s no good place to attach a holder on the dash. Honestly, though, I could go without music entirely if I had to because the driving experience is superlative.
Given a choice, though, I won’t go without my music, and as a maker I don’t have to! Since this a wonderful car, I want an iPhone mount that won’t take away from the car’s appearance. Fortunately, there is a conveniently-placed ashtray (and I don’t smoke!). Unfortunately, it’s too small to simply drop my phone into it (and I couldn’t press skip/pause/replay if it did fit). However, that ashtray can serve as perfect location for an iPhone mount if such a thing existed.
That’s where rapid prototyping comes in to play along with 3D-print-on-demand that’s available to me as a builder of a 3D printer. First I made a few quick measurements of the ashtray and the phone (in its case). I then did rough designs for the mount and the bracket. Save and print and I have “rough sketch” real objects. No surprise to me that they wouldn’t fit/work — I didn’t expect the sketches to be the final product. What this rapid “idea to model to object” process does is let me quickly and easily determine what changes I need to make. It didn’t have to be perfect from the start. In this case, the grip for the phone was too thin, the ashtray turned out to be smaller on the bottom than the top and the slot for the grip was too shallow. I ran through a few more iterations before getting it exactly as I wanted. You can see the progressive changes here:
Rapid prototyping (model –> build –> repeat) is a fantastic real-world equivalent to the agile programming methodology. It’s also a lot more fun than having to get everything right on the first go. Once I was satisfied I had exactly what I wanted, I changed out the filament feeding into my printer from white to sky blue to make it prettier. The final product is two pieces that come apart so that I can store the grip in the center console and close the ashtray when I’m not using it — this keeps the original design of the car’s interior intact. Here’s the final version:
I may purchase a spool of grey plastic in the future and reprint it so that it matches the grey interior. In the meantime, though, I now have a custom-made, rapidly-prototyped secure mount for my iPhone that’s a perfect fit for the ashtray in a 2005 Boxster!
Yeah, yeah… I’m late posting again. You get a full refund of all the money I made off your viewing of my blog up to today (3/16/12). :-)
The biggest progress I made was on linear bearings:
My old version and my new…
The longer version on the right is the new one. Being longer, it has much less play than the shorter, old version. However, it also produces LESS friction. What’s the secret sauce? The “teeth” you can see that touch the rod taper away along the inside of the bearing so that the only touch near the ends where they are needed. Negligible play, low friction: best of both worlds!
The other cool aspect of this design is that you cannot make these parts via a mold — they require a 3D printer to create if you want to make them out of a single piece. Traditional manufacturing processes would find this design to be problematic to say the least.
I’m hoping to have Week Eleven up in a timely fashion — with a nice bit of SketchUp + 3D printing in the works!
Yep… didn’t get last week’s update up. Better late than never! Not much to say about it, though. I worked on creating linear bearings (picture below) and found that I need to add a LOT more infill for that design to work properly. In the process I decided to upgrade my 3D printer’s software — which in turn requires firmware upgrades which in turn proved difficult. Hopefully I’ll have the new firmware/software up-to-date this weekend.
Yay! This week was productive! More experiments with Sketchup and my 3D printer: printable universal joints (click that link if you don’t know what a Universal Joint is — the animation will make it clear). There are a LOT of ways to create a universal joint, but this is my own design (version 0.1) working under the constraint that it had to be printable (and that’s a big constraint that I won’t go into here). Here is the result:
I did this for a couple of reasons. First, I wanted the challenge of making this beast with NO screws, bolts or nuts. It’s strictly snap-together and can sustain very large forces acting on it (which means it was really, really hard to put together!). Also, u-joints + wire + servos + arduinos = animatronics! This will end up in either a cool robot or costume. It can be used in robotic tentacle-type grips or robotic tails.
For those of you that might not know what 3D printing is all about, here’s a 30 second video of the my “Kevbot 3000″ printer in action. The universal joint took over two hours to print in total, so this really is just a tiny sample:
3D printers like mine melt a plastic filament (a whole lot like what you feed into a weed-eater) and extrude it layer by layer into whatever shape you want. We really are living in the future for anyone that wants to expend the time and energy to get there!
I call that a “Snap-It”. It’s a laser-cut design that snaps two pieces of 5 mm (1/4 inch) plywood together without screws. I designed several cuts before I found one that snapped together without breaking and would then hold the pieces together. The idea is to be able to build boxes and other items with no screws or glue:
Here you can just such a box. However, I’m finding that if two tabs are too close to each other this design is still very hard to snap together without breaking something. I also spent a bit more time with Sketchup and my laser.
The goal was to make a holder for glass IKEA candles, but after all was said and done I found that I had made a mistake somewhere along the way: some of the pieces are slightly the wrong width and won’t fit together. Oh well, measure twice / laser once, right? I’ll have another go at it this week. It’s all about getting better, so I consider it time well spent.
You see, I decided a couple of days ago that 2012 would be my personal “Year of the Maker”. I’m going to see just how much make-y stuff I can design, build, teach, publish, etc, etc, etc in hopes of tremendously improving my skill set over the course of the year. In fact, what I really want to do is follow JoCo’s example and do “A Thing A Week” and try to accomplish at least one maker activity each week. Not every week may yield a successful build, but I’d like every week to yield SOMETHING. Let’s see how this goes…
This is Week One. My goal is to design and build a filament spool for my Makerbot by the end of the week (weeks will end on Sundays since that gives me the week to plan and the weekend to build). I’ll publish the results here. Version 0.1 of the spool is done as of last night — and a miserable failure. The filament drives the whole thing like a clock’s mainspring and since I designed it to look like a gear it even has TEETH with which to BITE THE OPERATOR. Looks pretty, though.