On 3D printable quad copters

Recently I became interested in building my own multirotor UAV, often called Drones and other stigmatized names. Specifically I wanted to build my own quadcopter from the ground up, the type with 4 upward facing propellers atop high powered brushless motors.

Design of the UAV took place in Solidworks, which enabled me to size everything correctly and check clearances and such.

Before starting the design phase I looked around at a  few existing 3D printable designs and chose one to base the initial design.

Some of the specs

  • ArduFlyer 2.5.2 to be used with APM flight planner for real time telemetry w/ GPS module
  • 2200kv motors
  • Afro 30A ESCs
  • 2x 2200mah 3s lipo packs

V1

The quad came together pretty quickly after I had finalized the design, 3D printed the body+arms, and received all my parts from different sources online.

Then I took it on it’s maiden flight: and this was the result.

IMG_0712About 1 second after liftoff two of the motors ripped themselves free taking part of the arms with them. Obviously the arms weren’t strong enough to combat vibrations from the motor and props as well as lift forces generated by the props nearby the motor.  I also realized the motor/ESC combo I purchased was quite a bit more powerful then I realized and would need to beef up the rigidity of the frame accordingly.

V2

After the first flight and ensuing catastrophic failure was witnessed by my engineer friend Drew, he took measurements from my previous design CAD files and created a new arm design that he felt would be able to take the motor’s vibrations and torsional forces.

I took that arm design and modified it to use lofts a little more smoothly around the motor mount area and added mounting points for the arm to the body. The body was designed by me to be able to fit most of the electronics inside with the controller and reciever plus other control hardware  on the top. The body splits in two for easy access to the power electronics. The arms are attached to the upepr and lower parts of the body via small aluminum mounting tabs I made out of 4x5mm aluminum bar stock.

final cad

The arms were printed with very low infill as it was designed to distribute most of the forces around the outside surface. After printing, holes were drilled on either side of the arm for the motors wires and ESCs to fit through.

Assembly took a quite bit longer than the first version as feeding the ESCs through the arms to get the motor leeds out the other side for connecting the motor proved quite troublesome and tedious. Mounting the arms and making sure clearance was good between multiple 3D printed parts required a little bit of sanding and forcing certain parts together.

Can you guess what happened when I flew it for the first time?

maiden flight damage.

Conclusions

3D printed sturdy quadcopter and multirotors are possible, there are tons of working designs out there, you just need to print them thick enough.

My V2 design may have been more successful if I took advice from nature and filled the arms with foam after running the motor wires.

Design, crash, learn, repeat I guess.

V3

It’s in the works.

It’s going to be made out of aluminum square tubes.

And when I crash it, It will probably be able to fly shortly after.

 

The argument for a Tulsa hackerspace

You may be staring at this wondering “What is a hackerspace?” Will allowing a hackerspace in Tulsa open me up to war drivers and people getting freaky with bubble wrap?  Are these the questions you’re asking yourself? Then I’ll try to explain it as succinctly as possible :

At it’s simplest, a hackerspace is a building that allows creatives and nerds to hang out and build things and share information.  It really can be almost anything you need it to be;  within reason of course.

Please no death beams.

Some of the cool things about hackerspaces

  • They can be open 24/7
  • You can leave WIP projects in a member storage area
  • Access to some pretty cool tools
    • You can also petition/fundraise for new tools!
    • Donate/leave your own tools while you’re at it!
  • Nerds are usually helpful and nice
  • Creatives can usually tell you if your project is ugly
  • Run your own classes, maybe even charge for them!
  • Use it as a co-working space for your next million dollar startup!
  • It’s not just for nerds-n-geeks! Do you enjoy hobbies such as: knitting, sewing, crafting, painting, building instruments, cooking, and lost techniques from a different era? You’ll probably be accepted with open arms. ( especially if you bring cooking skills and food )

Let’s stop there before I promise too much. Seeing as everything is yet to be decided.

To learn more about hackerspaces visit http://hackerspaces.org/ and http://en.wikipedia.org/wiki/Hackerspace

Also here’s a good intro video given by Mitch Altman a founder of one of the first hackerspaces in america:

Did you watch the video? This is a safe place, we can be honest here. Go back and watch it again.

Starting a hackerspace in Tulsa

You may be thinking “why start one in tulsa?” I already have my : garage and tools,  fab lab tulsa, automated manufacturing facility ( eg. iron man movies), laptop and 3D printer.  Or you may just like working alone in your man garage… alone.  If you do, that’s fine. You’ll always be welcome at a hackerspace if you wander in.

Over the course of the past year I’ve been gathering support for a local hackerspace.  And have peeked enough people’s interest to have a large enough founder base to get this thing started. That doesn’t mean you can’t join in early.

Some may argue that since we already have a Fab Lab here in tulsa why have something similar?  If you read the section above and are actually familiar with the concept of Fab Labs you’ll have noticed a few differences. A lot of these difference revolve around the mission/charter.  Hackerspaces are usually community owned, where those members decide what to do with their resources. Whereas the Tulsa Fab Lab’s charter is centric around community development and STEM young adult education. Both of which are awesome.

Did you know many cities have multiple hackerspaces?  Maybe it wouldn’t hurt if there were more than two similarish things in one town?

Starting our own in tulsa will give creatives like you and me a 24/7 space they know will attract many others with complementary and similar skill sets. Seriously, who doesn’t like nerding out over programming industrial sewing machines, involute gear meshing, plasma torch CNC hacking, DIY pick-and-place machines, 3D printers, welding techniques, motion transfer systems, autobots, decepticons, Unmanned jousting competitions, trek wars, automated m&m sorting and eating, and probably a few more things.

I hope you will join me.

What you can do to help

Share this post with friends who you feel may benefit from such a place.
Join and participate in the mailing list!

https://groups.google.com/forum/#!forum/tulsa-hackerspace

Come to the planning meetings!

The latest planning meeting will be posted on the mailing list.

As of this posting (May 29th) the next (first!) planning meeting is on June 4th at my house. ( comment or message me on whatever social network you saw this on for the address)

More Resources

3D printable mecanum wheel rollers using two materials

For version two of my mecanum robotics platform I’ll be providing a 3D printable version of the rollers for dual extruders. The outer shell of the roller can then be printed with a flexible rubbery filament to aid in increasing the friction between the roller and the ground. Otherwise you’ll have to spray or coat the roller in a material like plastidip.

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Hopefully this will speed up the process of getting rollers ready, a total of 56 individual rollers.

However printing a full bed of radial items doesn’t go as quickly as one would hope.

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