7 replies to this topic

[Kilrah]

After giving up with my attempts at getting a small MK-based quad (<35cm between axes) to work well mainly for FPV (i.e without GPS and other bells and whistles), and not wanting to spend any more hours and days trying to configure and tweak something for nothing good in the end, I went for... the oldest "serious" quad around, an X3D-BL.

Quite expensive, but reliable, simple, perfect size, and great performance... and quick to build!

So I got it last friday, built on Saturday evening, and first FPV flights on Sunday morning after less than 6 hours of work... that's how I wanted it!
2 more hours, and there we are

[Mr.RC-Cam]

Beautiful area, awesome piloting. The cat spotter/helper was a nice touch too.

[Terry]

Cool !
looks very steady, thought you were going to short out the electric at one point


Terry

[Old Man Mike]

After giving up with my attempts at getting a small MK-based quad (<35cm between axes) to work well mainly for FPV (i.e without GPS and other bells and whistles), and not wanting to spend any more hours and days trying to configure and tweak something for nothing good in the end, I went for... the oldest "serious" quad around, an X3D-BL.

Quite expensive, but reliable, simple, perfect size, and great performance... and quick to build!

So I got it last friday, built on Saturday evening, and first FPV flights on Sunday morning after less than 6 hours of work... that's how I wanted it!
2 more hours, and there we are

Wow! Since vimeo does such a poor job on these types of videos, I downloaded the file and played it back in Quicktime. As a multiple MK quad owner, I'll say that your video so impressed me that I'm considering buying the X3D-BL. Could you post a picture of your quad and how the camera is mounted?

Again, VERY impressive!

OMM

[Kilrah]

Thanks!
I must say I'm impressed myself, this quad was mainly intended for "fun FPV", but it turns out it's actually making better video than any of our other bigger ones...

But I did have a try before buying... My colleague actually bought one back in 2007 when it went out, still has it, never flew it much especially because it couldn't lift any of our cameras and camcorders back then... We didn't think of it again that much until recently, and now with that GoPro cam the problem is solved. We did a very quick test an evening a month ago or so, and I could instantly see the potential with the smoothness of movement. There were some vibrations but that would just be a question of spending more than 3 mins with a bit of tape to attach the camera... I hesitated a little and finally decided to get one for myself... and very happy about it!

Here are a few pics, not very complicated either, some threaded rod as feet and a bit of foam and velcro...:

[Old Man Mike]

I'm even more amazed after seeing the photos. Maybe the smoothness comes from such a light weight system for HD video. And although light, the GoPro cameras are quite sensitive to vibration and will often produce a jello effect in the video. But certainly not noticable in your system. Also, those props look similar to the old Draganflyer props. Plus they look like the tips have been cut off. Did you do that or did they come that way?

I like to carry extra items on the quad for my long distance flights so I wonder how well the system scales to a larger payload capacity. Guess I'll have to start reading up in some of the forums. Are there any groups you would recommend to start with?

OMM

[Kilrah]

the GoPro cameras are quite sensitive to vibration and will often produce a jello effect in the video. But certainly not noticable in your system.

There's a "secret" to know about this. The jello effect is dependent on the exposure time. On longer exposures required when there is less light, the effect disappears, possible vibrations leading to no more than a pretty unnoticeable blur. It was the case with the light available for that video... and in full daylight it's as simple as removing the excess light with an ND filter.

Maybe the smoothness comes from such a light weight system for HD video.

I'd rather say it's mostly due to the optimizations in the whole chain. Unlike most quads where you will throw random motors with random ESCs on a random frame, the X3D-BL is a single platform that has everything tuned to work in that precise configuration... response is very very fast.
But the conditions there were also ideal, you will still get a bit of shake with wind like there was today. Maybe some regulator tuning could help adapt to the added weight...

those props look similar to the old Draganflyer props. Plus they look like the tips have been cut off. Did you do that or did they come that way?

They are from the (now long discontinued) Silverlit X-UFO. I sanded them to try and balance them as well as I could to reduce vibration and eliminate the wobbles on the gopro image after the first couple of flights. That's where I learned that the ND filter is the only solution, as even when vibration is so low you barely can feel anything it will still wobble...
Draganflyer props were much larger, and really awful too...

I like to carry extra items on the quad for my long distance flights so I wonder how well the system scales to a larger payload capacity.

I wouldn't have too much hope. That thing was never actually designed to lift anything, and the standard config uses a 850mAh lipo for a total flying weight of 350gr. I'm already at 550gr with the gopro, legs and a 1300mAh pack. It flies well as you can see, probably would with a bit more stuff but I wouldn't really try more than another 50-100gr...

Are there any groups you would recommend to start with?

I think there is a loooong thread on RCGroups... but I didn't do much reading really.

Edited by Kilrah, 09 April 2011 - 01:18 PM.

[Old Man Mike]

Thanks for the detail response, especially the jello prevention approach. I would have thought just the opposite with less jello from more light rather than less light.

What makes your video remarkable is that you posted nearly the entire flight. It is easy to get super smooth video when the quad is slowly ascending which is why that is the type of quad video so often posted. I've done hundreds of hours of quad FPV flying and I can tell you that you've got something to be proud of with that nice portable system. After a bit of reading I also came to the conclusion that the stock configuration is too small for me and that upscaling it would likely diminish the performance. Later this month I'll be trying larger motors and props with my normal MK system in the hopes that the extra power and lower response time will help emulate the small platform flying experience.

OMM