I asked my girlfriend what she wants for the holidays. She smiled, saying she wants something sexy, colorful, that comes in a small box, something the perfect size and shape. Naturally, I fired up a 3D editor, warmed up my awesome PolyPrinter and made a … 3DR Pixhawk mass model!
My girl is very smart, and when she figured out what I was up to, she was curious about why I'd make a mass model for her. I admitted that, of course, I have a few Pixhawk autopilots on order, but the printed mass model was something we…. errr… she could use right now. I guess she could see how excited I am about the Pixhawk because she told me I could keep it!
Which is really fortunate, since I suspect that I have the greater need for a mass model of the Pixhawk. I've got a new plane, not yet trimmed, Given that the new autopilot release is expected very soon, I figured I would go ahead and layout the plane with the Pixhawk in mind. After all, I don't want to risk the real gear on my dodgy piloting skills in an unbalanced plane. I also don't want to complicate PID tuning with balancing and trimming at the same time. Besides using the mass model as an aide to help balance my new plane, I am already using it to help outfit and test other vehicles, including a boat, some of my new multicopter designs (strictly physical layout and balance right now) and for a rover project.
My girlfriend asked how things might unfold if I had correctly figured out what she wanted for the holidays. I reassured her by admitting that if she had really wanted the Pixhawk mass model, I probably would have simply printed another one for me. If you don't already have a 3D printer (and even if you already do) I recommend checking with the guys over at PolyPrinter. They are fellow makers, and regulars with the Dallas Makerspace, where a PolyPrinter has been precisely and quickly laying down plastic (and evolving) almost non-stop for at least long as I've been a member.
A few minor disclosures:
- This model is based on publicly available specs and art. I don't have a Pixhawk yet, and that is another reason I made the model. When I get my hands on the actual gear, I'll update the mass model because it is still very useful for designing and testing, even when I have the real thing.
- I'm not affiliated with 3DR, other than as a customer. So this model is not "official." I just like to share.
- I'm not affiliated with PolyPrinter, other than as a customer. I have experience with other 3D printers, and this is simply the happiest-making printer I've ever used. No DIYer or self-respecting prototyped should be without a good 3D printer, and the PolyPrinter is a great printer.
In the spirit of sharing, I'm posting the Sketchup and STL files for this (draft) Pixhawk mass model. I recommend slicing with wall thickness of 2.5mm, 33.3% infill, circular. This produces a model that is around 40.5g. I printed at the lowest quality, but I think it still came out looking very nice. Please ignore the rough spots in the photo, even at the lowest quality, those are actually from me messing about with a dremel tool, and are not from the printer.
Once the model was printed, I shaved a bit of the plastic off to bring it down to about 39 grams. The spec reports 38 grams, but I'm going to leave it a bit heavy until I can measure it myself, with SD card and extra connectors. The servo, USB, reset, and SD slots are great places to drill out excess plastic to get the weight exactly right. I added a bit of color by hot flowing some crayon to meet the girlfriend's original requirements, and I think it really helps to bring detail for this photo.
I have the best girlfriend. And soon, I'll be swapping out my PX4s for 3DR Pixhawks, and more safely thanks to this model. Here's wishing you get a Pixhawk or two in your stockings this season!
STL Model: PixHawk-MM.stl
Google Sketchup: PixHawk-MM.skp