fangin.com RC, photos & tech

17Jul/130

rctimer brushless gimbal settings for GoPro 3

These are the settings I'm using with "BruGi_049B_r77.zip". They seem to work well for me. Sample video from the gimbal on the hex to follow soon.

https://code.google.com/p/brushless-gimbal/downloads/list

 

Brushless-Gimbal-Tool (for v49)_2013-07-16_22-46-28 Brushless-Gimbal-Tool (for v49)_2013-07-16_22-47-07 Brushless-Gimbal-Tool (for v49)_2013-07-16_22-46-58

28Jun/120

Stabilise Filter Example – Telstra Tower

 

On the left is the original footage from the DJI Naza F450 GoPro. On the right is the "stabilised" version. By uploading the original to YouTube, applying the stabilise, then downloading the MP4 and running it back through YouTube you're able to see a side by side comparison. 

The stabilised filter has some funny side effects where it appears as though the video is suddenly zoomed in and out. The blurriness of the RHS probably isn't a fair representation because that side has been uploaded, compressed, and downloaded.

The process does crop the video slightly and uses the edges as a buffer to remove the sudden  movements from side to side or up and down. 

The videos are in pretty good time sync but you may notice the RHS looks like it's behind the LHS. This lag is due to the smoothing effect of the filter and sudden movements take a little bit more time to catch-up with the RHS.

I've since changed the mount that the GoPro uses and without any post-processing the video is quite smooth. It will be interesting to see how smooth a video would look from the new mount after applying the stabilise filter.

Overall for this type of video, the stabilise filter does a pretty good job.

 

20Apr/110

Tricopter vibration mount testing

 

This clip shows sample footage from four different camera mounts on my tricopter. The aim was to counter the effect of vibration on the quality of the video and remove the "jello" effect as much as possible. 

The best result achieved so far was probably the simplest and cheapest: a HD keychain (#11) velcroed directly to the frame. 

The biggest improvement was can probably be attributed to using an accurate prop balancer as you might notice the noise in the last two videos is significantly reduced.

The next test will be with a GoPro.

Tricopter vibration mount testing

29Dec/104

Tricopter Flight test

I've got a couple of flights under the belt now but there's a persistent problem with the front right motor. It keeps stopping dead. This isn't so bad when its 30cm off the ground but when it's a few meters in the air there's potential for more damage. I caught one crash on the trusty little keychain camera, one mounted on my hat and the other mounted on-board the tri when the motor failed.

I checked all the connections, added padding to the gyros for vibration dampening and re-calibrated the throttle and tried again. Unfortunately the same result with that motor stopping mid-flight. I pulled out the trusty iPhone 4.0 and captured some video to help diagnose the problem over at rcgroups.

I've decided it's probably a dodgy motor or maybe the ESC. The motor is out of stock at HobbyKing so I ordered a virtually identical one from lowpricerc.com. At about six bucks each, I considered ordering three to make sure I have identical motors all round but when trying to order them, I got the "out of stock" error here as well! Turns out they had two left so I snapped up both. I'll replace the dodgy motor and keep one spare.

Just in case I grabbed a replacement ESC to help troubleshoot the problem. I went with the Turnigy Plush 18 Amp ESC because I already have the programming card and when I originally bought all the parts, this is the ESC I wanted to use but it was out of stock, surprise surprise.

So now I wait for my replacement motor until I try again. In the meantime I'll go learn some Arduino programming so I can get rid of the 4 HK401B gyros and use the Wii sensors instead. Apparently the Arduino controlled TriWiiCopter is more stable.

15Dec/103

How to remove the timestamp from keychain camera video

808 keychain spy camera The cheapest and easiest way I've found to get onboard video footage would have to be the 808 Keychain camera. Anything and everything you need to know about these great little cameras can be found here. While the quality isn't the best, it's good enough and until I save up the $380 to buy a GoPro HD, these $20 cameras are great to experiment with. By default video from the keychain cam includes a date and timestamp overlay that is encoded with the video. Sometimes that's ok but other times I'd prefer a nice clean image without the timestamp. There's a VirtualDub filter available here http://www.aircommandrockets.com/md80clone.htm direct download here. This page also has instructions how to install and use the filter. I'll go into a bit more detail including compressing the output and optimal settings for uploading to YouTube. The screenshot below shows a still image showing the original footage next to the version with the filter applied in VirtualDub. All the filter settings have been left to the default values. Note the overly blue haze across the top of the screen is because I filmed this through the blue tint at the top of the windscreen driving to work. You can see from the still image, it does a pretty good job. How about for a moving version. To apply the filter to the video, in VirtualDub;

Video, Filters (Ctrl F)

Add, Scroll down and select "Timestamp Remover", click ok

The default settings work fine, click ok again.

The source video window on the left has the timestamp where the processed version on the right has no timestamp.

Now if you you were to select File, Save as AVI...(F7) then the processed version would be saved as a rather large, uncompressed AVI file. For the source quality coming from the keychain cam, a bit of compression isn't going to hurt. One codec I like to use is the Xvid codec. If you don't already have it, grab it here. Back in VirtualDub;

Video, Compression ( Ctrl + P)

Select Xvid MPEG-4 Codec

Configure, if there's a button labelled 'Target quantizer', click it to change it to 'Target bitrate (kbps)' and enter 900 in the input field.

Click ok, then ok

Experimentation will go a long way here in figuring out what's best. These settings are merely a reference point to get started.

 

 

17Aug/100

time lapse build video – extra 300

What started out as an instructional video on building a foamy, turned into a time lapse video of the build. I used Vegas Pro to capture, resample and speed up the playback to condense a few night work into about 90 seconds video. I built it out of 5mm foam core artboard which overall I think comes out too heavy. During the build, I used a heatgun to remove the cardboard layer from the ailerons and rudder. This came to about 45 grams of weight removed from the plane. Imagine how much I could save if I skinned all the cardboard from the foam and used a few CF rods for stiffness instead.
My suspicions about the weight was confirmed with a maiden flight on Sunday past. It flew ok and would hover but needed about 90% throttle to do so. I think I'll try to lighten this version and build another one without the cardboard skin.

23Apr/100

VMAA Trophy 2010

The VMAA trophy was held at the state field, Darraweit Guim outside Wallan. It's a two day event open to all clubs in the VMAA. This video shows a few short clips I grabbed between flying and calling for others. Towards the end of this video is some keychain cam video from my Precedent Fun-Fly. I mounted it with velcro and cable ties, vertically on the rudder and rotated the video in software.

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10Aug/080

4WD to Crows Hut



4WD to Crows Hut, originally uploaded by mattmc.

Well the photos are up on Flickr of our adventure to Crows Hut and the video is currently uploading to YouTube. Check em out.

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27Jul/080

Tour de France – Crash Compilation 2008

Check out at about 57 seconds - the impatient support car almost drives over the riders leg!

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20Jul/070

The Great Internet Crash of 2007

If you can read this, then the Internet has rebooted. Phew! For a moment there I was gonna get the null modem cable out and fire up Doom. old skool.... uhu huhuhuhuuhuhu... huh.

Please let me know you're safe - leave me a comment below.



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