2012-07-31

Joining 3d printed parts

Nophead posted a link to a video about a simple connector to connect 3d printed parts via friction.
I suggest a tried and true method that requires even less precision: a Tusk Tenon

Why?
Because with the proposed locking joint hole and pluig have to highly very similar dimensions and shape. If one is wider, longer or deeper, the other will either not fit at all, have too little friction to stay put even under stress and vibration or will fit but both parts will have a tiny gap between them.
With a Tusk Tenon all 3 parts can have any tollerance in any direction. You just choose an allowance wide enough so they still fit into each other. No matter how large the gap created by the allowance is, they will always align and lock in the same position, orientation and strength.
Why create something new if we already have a solution that has proven to work very well for 500 years?

2012-07-27

No 5DtoRGB anymore

Looks like we have a fix for the AVCHD problems (incorrectly mapping 0-255 to 16-235 color space) on the Mac issue with footage from 5D Sony FS100 and GH1/GH2 that doesn't involve transcoding in 5DtoRGB .

I linked to the comment with the numbers for . The posting itself has the numbers for .
 

2012-07-26

YN460II modification with 3d printed parts

Brainstorming 

  1. Replace both front and back. 
  2. Make it slightly longer to have a hole for an umbrella mounting between battery compartment and electronics.
    Use the free space left of the umbrella for a 12V DC plug and on the right for a battery/mains power switch.
  3. That power level LED mod looks great. Better integrate that into the case right away.
    http://www.flickr.com/photos/malow/5948108074/in/photostream
    http://www.flickr.com/photos/malow/5948112440/in/photostream
  4. Integrate the PCB of a remote trigger. Later to be replaced by an Arduino Nano+RF (to not only trigger the flash but also remote control the power.)
    1. Looks like thee are 3.3V and 5V for the RF-trigger PCB already present:
      http://www.dslr-forum.de/showthread.php?t=819870
      http://www.dslr-forum.de/showthread.php?t=967445&page=2

Design

TODO

Final object

TODO

Mapping again

     Due to the fact that I am a Mentor in Google Summer of Code for a student improving Vespucci (and doign a great job at it),
    I finally found my way back to doing some actual mapping.
    Should have done this much more often. There are so many small details not present in OpenStreetMap...

2012-07-25

3d printing again

 After a long time of having the printers sitting in the corner I'm  back to designing and printing again.
Will do the upgrade to Alibre Design 2012 in the next days and am currently constructing some special purpose GoPro mounts.
(Yes, there are thousands of them but all just uneditable STL files and none of them do what.)
I'll of cause publish technical drawings too. So other then the many STL-only versions you can look up the dimensions comfortably to design your own without using a tool like Netfabb Studio to meassure inside an STL or get a GoPro first.

7/16 inch imperial ********

Needed a 7/16" pipe fitting for a vacuum pump yesterday.
Nobody seems to have something like that.
Certainly not one with a seal made to work fine with very low pressures.

Luckily 7/16" seems to be a "standard" pipe fitting for beer kegs...

The nice thing about standards is that there are so many of them.
I want my SI back!

2012-07-24

Paid reviews

I advise to ignore androidmag.de and other such publications of the cda-verlag like ANDROID MAGAZIN and ANDROID APPS.
They just cold called me and offered to make Vespucci (the OpenStreetMap editor) an app of the week for  490,- euro plus taxes including a video review.
I have to assume all their existing reviews and apps of the week are paid for as well.

2012-07-18

Rebuilding an existing camera

I recently found an announcement and later a story about the final product on EOSHD.
The product is a modification to the NEX 5N camera. Producing an entirely new case for this camera with active cooling (because the camera has overheating issues),  locking HDMI sockets, reinforced USB connector, huge monitor,...
This fascinated me. Having taken apart one Panasonic GH2 already in the past, I though about what it takes to do such a thing for this camera too and what options this provides.
In the end I settled to do an alternative case for something much simpler first. For the YN460 II flashes. The point being to integrate umbrella holder, external power socket, and my existing radio triggers into one flash body.
Then I found a posting on DVXUsers.  It seems that back in april a user named "rigs" got the idea of a custom machined new body for the GH2 with an incredible array of planned features. So it seems like someone else not only though of this but actually started for the GH2. The discussion is still going on, so the project seems to have not died in the last few month.
I'm not sure if I should do such a think. Printing objects of that size is ...difficult on the ThingOMatic lately. In a month the GH3 will be relased. I'm selling my two GH1 to replace one of them with a  GH3 and the other with a second GH2. Difficult to decide on a project.

I guess I'll offer Rigs my help but all on my own I'll work on these modified flashes and cool mounting options for the GoPro.  ...and on actually editing the video clips I already made.

Got a GoPro

Having already 3 DSLR bodies and an expensive collection of lenses for them, I convinced myself to not get an action cam myself.
....until I just got the chance to help myself to a GoPro Hd Hero II outdoor edition for much less then the usual retail price.
Having a huge number of cool mounting options on Thingiverse to 3d print for this helped a lot to justify the expense. After all, this caters to two of my hobbys. Filming and 3D printing/CAD.

So here it is...my fourth and (as my wallet tells me) hopefully last simultanous camera angle.


2012-07-08

Panasonic GH2 powered via USB battery

I'm already using a 3600mAh external cellphone battery that outputs 5V USB power to run my Zoom H4n audio recorder for extended recording times.
Recently I found a 10'000mAh battery that not only has 2 USB outputs but also a third output that can be switched to 12V or....9V.
Perfect to run the GH2 camera!
It turns out that even the proper adapters are already included and have the polarity required.
Here is what I used:
The original batteries are 7.4V 1200mAh. The power bank is 5V 10000mAh.
This is about 5.6x the capacity of a Panasonic battery for this camera.
Of cause it will be significatly less of this device also powers the Zoom H4n and 1-2 phantom powered microphones through it.
...or multiple GH2 cameras from one power bank.
...or something else that runs on 5V USB power from the second USB port. (Arduino? Video light? ...) 

2012-07-04

Rode Stereo Video Mic Pro - evaluating the most ugly microphone ever

When I started doing video with a DSLR (actually with EVIL cameras), I quickly found the in-camera sound to be unacceptable and got myself a Sennheiser MKE400. I wanted to have a tiny shotgun that would get me the sound of whatever was in front of the camera and ignore everything else. It seemed a reasonable choice at that time. However it turned out that very often I find myself in one of two situations:
  • Having the time to prepare the right kind of equipment to record one special kind of event using as much and as specialized gear as I find necessary and practical.
  • Recording ambiance and B-roll with whatever I have in my pocket at that time.
For the first occation I have my trusted Zoom H4n and a small collection of micropones. A large diaphragm and a headset for voice overs and commentary, a pair of shotguns for stages and booming, dynamic handmics for interviews.
It would seem natural to use the H4n with it's great internal microphones to collect B-roll. It it nearly perfectly suited for this job. Just place it in a corner or on a camera with a wide angle lens and keep rolling.
Why would I choose not to?
Because it is inpractical and with time you tend to avoid inpractical things.
  • It is large and heavy.
  • When used before, it's batterys are often quite down already.
  • You need to sync the sound to the camera later. (Syncing is trivial but identifying what sound belongs to what picture takes time and organisational effort.)
So here I am, evaluating the Rode Stereo Video Mic Pro.
The purpose being to have it on camera for wide shots to capture ambience right in the camera. This need not be B-Roll. It can very well be a sound performance or a groups of people standing close together. Anything that does not require a directional pattern.
So what did I find?
  • It is lightweight and small enough to just keep it on the camera. It doesn't even affect the center of gravity even of a small mirrorless camera like the GH1 and GH2.
  • Contrary to the H4n it is practically unaffected by wind. The 2 microphones are mounted inside a round blimp below a foam cover. I did not even feel the need to unpack the deadcat I got for it.
  • It picks up lower frequencies much better then the H4n. I'm not sure yet that this is a good thing or if they are overrepresented.
  • The low-cut is useless. Even the lowest frequency rumbling of a bus you're sitting it are reduced at all.
  • I still have to test the +20dB gain on the GH2 and GH1 cameras.
  • The hotshoe has an incompatible threading. It's 1/2" microphone threading and not 1/4" as for camera equipment. This would be fine for booming except that an purely omnidirectional on-camera microphone with a 3.5mm stereo-jack is not reasonable for booming at all.