Monday 27 May 2013

3D printed Raspberry pi camera case updated to v0.4

I have made some changes from v0.1 to v0.4, these are mainly:
  • Rounded edges to the case giving it a better look and making it lighter.
  • Addition of closing features that make the case more dificult to open.
  • The cable slot.width has been reduced.
  
 Also following some users advice I have created a variant to the plain case by adding a M3 nut attachment location to the bottom and top of the top case so as to be used as a tripod attachment.


Let me know of your sugestions.
These files are now available at http://www.thingiverse.com/thing:92208 or if you do not have a 3D printer available you can buy one of these cases from me at http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=121114273917.

Tuesday 21 May 2013

3D printed Raspberry pi camera case

I received my Raspicam yesterday from Premier Farnell/Element14 (you can also order one from RS Components). It surelly looks like a very nice piece of kit, light simple and sensitive to static.The camera is based on a OV5647 module (see http://www.ovt.com/products/sensor.php?id=66) and the camera PCB is about 25x20x9.7mm. The camera module is a fixed focus 5MP sensor capable of 2592x1944 stills, but also 1080p30, 720p60 and 640x480p60/90 and capable of  faster frame rates.


I am eager to start tinkering with the camera, as I bet it will lend itself to a nice still shot platform or to an affordable network home surveillance option. Also see all the stuff available on http://www.raspberrypi.org/archives/3890. But before the tinkering begins I felt the urge to protect the sensitive electronics onboard the PCB from my electrifying touch hence I came up with a very simple case design made of a base where the camera board is inserted and a top lid.



I have shared the initial version of the case on thingiverse and I am also selling some of the cases in ebay for everyone without access to a 3D printer.



Weekend weather forecast is bad so weekend will be fun.

Friday 17 May 2013

Crazyflie frame v1.7 assembly instructions

Get a Bitcraze Crazyflie from Seeed Studio.




Download the Crazyflie frame v1.7 files from http://www.thingiverse.com/thing:90566.


Print:
1 of Crazyflie frame v1.7 (frame in).stl
1 of Crazyflie frame v1.7 (frame out).stl
4 of Crazyflie frame v1.7 (motor mount).stl
2 of Crazyflie frame v1.7 (junctions).stl






After printing, start with the motor mounts. Make sure you bundle the motor cables close together on your flie so as to prevent them to be accidentally clipped by the motor mount walls.

 


Insert the motor mounts in the motor base as shown below. Note that the motor mount part has a channel that should allow for the motor cables to pass through, be especially carefull because a clipped motor cable means an unhappy Crazyflie.


 Fit all four mounts into the motors, these should fit tightly into the Crazyflie plastic motor supports you can use some double sided adhesive tape to help adhesion, I have not used any adhesive im my case.


Pass the flie between the Crazyflie frame v1.7 (frame in) part, align the motor mounts bottom notches with the inner frame part and press down until the frame snaps in place on the motor mount notches.



The frame should snap in place into the motor mount notches as depicted below.



The assembly should look like depicted below. Make sure the propeller stays clear of the top of the frame by carefully pressing the motors into the mounts.




Pass the Crazyflie frame v1.7 (frame out) part on the outside of the current assembly and align with the motor mounts bottom notches. Press down onto the free motor mounts until the frame snaps in place into the mount bottom notches.




You should now have something that looks like a frame. All you need to do is to add the 2 Crazyflie frame v1.7 (junctions) parts to the top an bottom frame intersections so as to add strength and keep the frame square.



You can glue the junctions and motor mounts to the frame  using some fast contact glue or some acetone in case your parts are printed in ABS.
The frame should now be able to provide you enough crash protection to your Crazyflie.


By the way I have used a diferent colour for one of the motor mounts because it helps as a reference orientation when in flying.

Tuesday 14 May 2013

Crazyflie frame v1.7 finished

Finally finished the flie frame v1.7, here is a quick snap I took earlier.
After test first test flight the frame proved to be too heavy and the flie responded very slowly, so I decided to remove the loops around the props to reduce the frame overall weight and improve flight behaviour.


After removing the prop loops the flie performs a lot better and the loopless v1.7 frame seems to be a good compromise between protection and weight whilst still providing reference orientation to the pilot. I will be posting the files in thingiverse by the end of the week. Please do let me know of your thoughts about flying this frame.

Friday 10 May 2013

Crazyflie frame v1.7 early concept.

Ever since the last weekend I have been thinking of a better way to protect the Crazyflie rotors and board whilst combining lightness and resistance. Version 1.6.5 of the frame does offer some crash protection and it has been reinforced from v1.6 as some flie users have pointed out that v1.5 can end up being too flimsy. Although stronger v1.6.5 it is still not the best solution to protect the rotors from ground collisions when the quad is flipped, and several flie owners have already complained that flipped flies crashes may end up with impacted motor bearings.
As a response to this problem I have thought of a combined frame. Early tests show that the concept is viable. Unfortunately I am not going to have a lot of time this weekend to develop the concept fully... stay tooned.


Sunday 5 May 2013

Crazyflie frame evolution


I have gone through quite a bit of PLA to get to a Crazyflie frame design that I am happy with.
Here is a list of some of the designs I have been through.



Crazyflie frame v1.0 to 1.2
A simplistic frame concept, simple configuration and easy to fix to the flie arms using dual sided adhesive foam. Strong frame but offers only protection in the XY plane. Weight 2.5g.




Crazyflie frame v1.3
Start of the motor mount attachment method as a means of attaching the frame and to use the frame as the battery cradle. Frame was very weak and flimsy and counted on parts deformation and release so as to dissipate the collision energy. Frame made up of 4 separate parts fixed to the side of the stock motor mounts. Weight 4 x 0.35g.

 


Crazyflie frame v1.4
Same as v1.3
Frame was very weak and flimsy and counted on parts deformation and release so as to dissipate the collision energy. Frame made up of 4 separate parts fixed to the side of the stock motor mounts. Weight 4 x 0.26g.


 

 


Crazyflie frame v1.5
Motor mount attachment joined together as a means of attaching the frame to the flie. The frame itself has a battery cradle underneath the flie that allows the battery to be attached to the frame rather than to the flie board so as to improve flight stability.
Frame was very weak and flimsy and counted on parts deformation so as to dissipate the collision energy. Weight 1.72g.




Crazyflie frame v1.6
Integral loops around the rotor so as to improve protection. Frame was very weak and flimsy and counted on parts deformation so as to dissipate the collision energy. Weight 1.51g.




Crazyflie frame v1.6.5
Based on the experience from the community, frame thickness was increased from 0.6mm to 1mm.
Loop around rotors kept and reinforced with extra side bars.
Frame is more rigid than previous versions and relies on increased stiffness as protection, top of rotors remain unprotected. Frame provides additional stability to the quad because it allows for the battery to be mounted underneath the quad. Weight 2.76g.

                                   


Crazyflie frame v1.6.6
Same as v1.6.5 with modified clamping method to the flie stock motor mounts. Loop lateral bar reinforcements thickened from 0.6mm to 1mm. Weight 3.23g.





Crazyflie frame v1.7
Major redesign from previous versions of the frames.
Attempt to provide an improved protection on the Z plane as well the XY plane.
Frame is too heavy and the thick wake of the struts on top of the rotors decreases the aerodynamic efficiency of the props. Weight 8.085g.



Crazyflie frame v1.7.1 (loopless)
Same as v1.7 but without the rotor loops. Decrease in XY plane protection to the flie. Weight 4.885g.


Crazyflie frame v1.8 (ongoing)
Based on v1.7 frame without the struts upstream of the rotors, hence better aerodynamic efficiency.
In order to keep the frame weight down the protection loops have been made quite thin and somewhat fragile but it is one of the best frames I have flown.
Weight 5.12g.






Crazyflie frame v1.8.5 (TBD)
 Weight reduced version of v1.8

Frame weight history




Now I am selling a few of these frames in ebay to feed my 3D print addiction.

Saturday 4 May 2013

Crazyflie arrives

It's Saturday and the most eagerly awaited parcel made it just in time for the bank holiday ahead.
Inside the parcel is a Crazyflie.
The flie is a micro quadcopter weighting approximately 19grams developed by Bitcraze (http://www.bitcraze.se/about/) and distributed by Seeed Studio (http://www.seeedstudio.com/depot/bitcraze-m-64.html).

The box opening reveals the components that will need to be assembled to make the flie.
  • Crazyflie quad board
  • 4 mini motors + extra
  • 4 motor supports + extra
  • Crazyflie battery
  • CW and CCW props
  • CrazyRadio + antena
I have ordered for additional batteries and props in anticipation of all the wall banging that is going to occur over the weekend.