Mike Thorlin's Posts (6)

Sort by

Quadcopter Park Flight with video...

I took the quad out the a nearby park for a more extensive flight.

All went very well, got 10+ minutes of great video.  The quad was carrying a 5000mAh battery and my Contour video camera.  I still am having difficulty identifying the orientation of the quad when it's quite a ways off, you can tell in the video where I am trying to establish which way a given control will move it.


Alignment of the video camera was poor, it was a last minute strap-down with velcro and zip-ties.  I'm working on a more practical undercarriage for the quad that would allow me to better mount/balance the battery and the camer.  This should also allow me to clean up the video, keeping the aircraft out of the frame as well as ensuring that the video is oriented squarely.  As you can see in the video, I've got the camera tilted a bit.





Read more…


After the Latest Skywalker crash I decided that the build-fly-crash-build-(repeat) process was too slow, and I wasn't learning as fast as I'd hoped. 


I'd seen an ad at Hobby King for $20 Quadcopter frames... sounded like a good deal and I already had a matched pair of motors/ESC and APM2 so I decided to take the plunge and order the balance of the components needed to build a basic quad copter.

The motors were Detrum 810kv's with 25A ESCs from HobbyPartz.  I'd picked them up to experiement with twin fixed wing stuff and small wings...

Assembly was easy, though I was short on bolts/screws.  No big deal.

HobbyKing 550mm Quadcopter frame

4x Detrum 25A ESC

4x Detrum 810kv



Below are pictures of the finished quadcopter and then some videos from today.  My 11 yr old was cameraman... kinda shakey...  Yes, the "fuselage" is a potato salad tub from a local deli.




Read more…

3689456980?profile=originalSo my buddy Shad and I headed out to my flying spot to fly the Skywalker.

This time around I used my new roof-top antenna mount, with VTR and Planner PC mounted inside the SUV in the back seat.  I found a mount designed for an iPad which worked to hold the ASUS tablet behind the passenger seat headrest.  Worked perfectly. 3689456935?profile=original I set the VTR on the console between the driver seat and passenger seat with the screen tilted so that I could see the video output.  3689457007?profile=originalWhile I have two video cameras sending video to the transmitter, I haven't yet recieved my video switch, not have I cracked exactly how to activate the switch, so I just hard wired the side looking camera in to see how mounting angle and field of view were.  Besides, the idea is to record the forward view in HD with the Contour camera, right?

Before we left for the field I also finished up my pre-flight checklist.  I have a terrible memory, and have forgotten to complete important steps before flight before (set home) so I wanted to establish a more repeatable procedure.

Once at the site we got all setup, mounted the antennas and pre-flighted.  Of course, my memory being what it is, I forgot to use the checklist.  Well, we used the checklist, but actually just to stabilize the wing of the plane as we calibrated the gyro...  I'm a knucklehead.

During the pre-flight, all was good except that when in FBW-A and STAB modes the lelevator seemed to have very very little control authority.  The servo pitch gain (P) was set to 300. Thats higher than the what others seem to be using, but I doubled it to 600... it was an improvement though still provided less deflection that the other surfaces seemed to have.  I need to look at the control horns and servo arm to see if perhaps I have set it up improperly.

After a brief mis-start Shad launched the plane and started recording with his iPhone.  I remembered this time to start the VTR to capture video from the flight... but although I turned the ContourHD camera on, I entirely forgot to set it to "record".  Crap.

So this time I was able get the plane into the air and gain altitude. I flew for 2-3 minutes, initially on manual then in FBW-A and STAB.  All worked very well, though the wind picked up and I was seeing some effects on the plane.  Once I was confident, I threw the switch to auto and the APM took over.  I was very happy, it flw in a very stable manner.  I had defined a very basic square shaped course.  3689457034?profile=originalI'm not sure that I'd say it followed the course, I'm still looking at the log data, having trouble developing an overlay so that I can see it output on google earth.  The telemetry data is showing me history that doesn't strongly suggest the waypoints were followed.  I seem to have lost telemetry at a certain point prior to "landing" as the kml terminates way prior to the "landing".  I'll post those files.

When the plane was at it's furthest point, I got worried that it was wandering off out of control, so I started nudging it home. Things were ok for a bit, then I noticed I was having less influence, it wasn't responding well to the TX.    Then shortly thereafter it started heading in, in a spin.  I gave it full up-elev, but it dropped below bush-tree level and that was it. 

Shad and I identified an azimuth to the plane and hopped into the SUV and drove over the the site - or tried to.   The terrain was too dense with bushes, we tried for 45 minutes or so to get to the site without scratching the hell out of the SUV, but couldn't find it , even after dismounting and seraching on foot.  The telemetry had halted and I didn't trust the indicated last position.  I haven't been able to build a kmz using the logs pulled from the APM, just from the tlogs.  I'm actively working this - any help????3689456944?profile=original

We ended up heading back to the launch site, regained the azimuth to the "landing" site and started walking.  Found the plane just a few minutes later, we had been searching in the right direction, but too far from launch.3689456980?profile=original

The plane was in surprisingly good shape when we found it. I would never have believed it.  I was able to identify the impact point (below). It hit the ground somewhat hard, but was upright, wings level and could not have had more that a 15 degree nose down attitude.3689457041?profile=original

The wooden camera pod was damaged, more from the CountourHD (not recording) being popped from it's mounts and the safety wire shearing through the wooden from. 3689457168?profile=original 3689457056?profile=originalThe telemetry unit looks to be toast.  The high mass of the 900mHz antenna wrenched the RP-SMA connector off the circuit board.  I think it is repairable, but not by me.  I'm seriously considering dropping the whip antenna and picking up a 900mHz cloverleaf antenna from ReadyMadeRC.com.  I've very happy with the 1.3GHz cloverleafe I use for video.3689457184?profile=originalI'll give it a shot at resoldering, but I'll have to do the work under a microscope and I think I'll have one shot at it.  That was a shame, of all the parts of this plane, the XBee's have been the most difficult to get.  I finally gave up on 3DR and bought directly from Digikey.  Maybe this is a good excuse to go with the new 3DR radios...

The vertical stab is torn a bit, but thats an easy fix.3689457201?profile=original

Overall, after only 6 minutes of flight I'm still very happy to have another success.  Every time I have flown, even for the shortest flights, I have learned something.  I'm a big believer of lessons learned. 

I still haven't been able to download the video from the VTR, I have no Firewire capability, gotta get an adapter.  When Shad sends me the iPhone vid I'll edit and post.

Here's the YouTube video...


Read more…

Ground station antenna mount...


I had previously setup my video receiver and telemetry set on a tripod with a PVC "mast" to establish height and antenna separation.  Xbee on one side, video receiver on the other.  My ASUS tablet PC hung in a case on the cross-bar between the two masts.  Video runs down to a Digital-8 video tape recorder, sitting on the ground because it's weight was difficult to balance on the wooden platform between the tripod and the PVC frame.  Power is provided by an AC inverter in the SUV,

I setup the tripod right next to my SUV.


Unfortunately, the tripod was pretty unstable.  I've had the whole assembly fall over due to wind and even with a stable tripod, the pan/tilt assemble is a weak point.  With the PVC frame it was quite top-heavy and it required me to run an AC cord out from an inverter in the cargo area to power the video recorder, tablet PC and video receiver.


After thinking that one through a bit more, I decided to rig up an antenna mast with a magnetic base that I could mount on the roof of the SUV.  3689456363?profile=original


It's bigger than it looks.  I built it from 1-1/4 inch PVC rather than the 3/4 inch PVC the prior apparatus is made from.  The magnet base is about 6 inches in diameter and quite strong.  With this setup, I can get the antennas up as high as with the larger, more cumbersome tripod arrangement, but with a simpler, smaller apparatus.


I was able to identify a number of additional advantages:

- I can pick-up and chase an runaway plane without having to load equipment back into the SUV, maintaining video/telemety contact on the move.  This might be a bit sketchy.  I would never intentionally "operate" in this mode, but if moving the ground station (with a designated driver) will allow me to regain control, I think thats a good thing.  If I seriously ever want to do this, I'll have to examine just how strong the mount would need to be as a function of the possible speeds the SUV would be moving at.  Dirt road at the flying area - easy.  65mph on the adjacent freeway while the plane tries to fly to Tucson - not so easy.


- After launch, I can take a seat inside the vehicle, benefitting from AC (it gets hot here) and shade (tablet display is hard to read in bright light.) I'll have to ease into this to ensure I truly know what I'm doing here.


- Affords better protection to the video recorder and tablet PC.


- I believe that being mounted on the roof will provide the antennas a source of reflection that would benefit them in terms of additional gain.  There won't be any electrical connection to establish a true ground plane (at least not intentionally), but just reflection alone should help a bit.

I'll come back and post more photos as I actually assemble the various components onto the SUV.


Read more…

Skywalker #2 Camera pod

Almost finished with Skywalker fuse #2.3689456191?profile=originalI used liberal application of velcro to attached each camera.  The ContourHD also uses a removable velcro/adhesive mount.  The good part is that now I can turn the cam power on and set to record without having to remove the camera from the canopy ("cam-opy"?).  As you can see from the photo below, I cut the hatches rounded instead of following the hatch lines moulded into the fuse by the manufacturer.  This was based upon the realizing that the  sharp corners on the previous hatch weakened the structure.  After the first crash I had to glue/reinforce the structure that failed at the corners, totally shearing the foam between the canopy and the fwd/top hatch corner.  I wish I had taken pictures...3689456211?profile=originalAdded 2 video cameras and an HD camera to the pod that now comes in lieu of the foam canopy.  Below you see the fwd facing HD and video cameras.  The HD camera does NOT provide NTSC output to the video transmitter, unlike the GoPro.  Thats the primary weakness of the ContourHD (in addition to weight).  You can see here the side looking camera.  This camera, with video switching (waiting for units from nghobbies.com and flytron.com) will allow me to switch from fwd looking to side looking whenever the UAS is circling in loiter, "fly to"/guided, RTL or on command.  The aluminum mount can be bent to adjust the angle as I make some test flights.  Starting position will be 90deg. 3689456138?profile=original Looks like its going to work out well... 3689456239?profile=original

Read more…

Just posted photos and video of my Skywalker.  After the third(last) flight, the fuselage is a write off.  Lots of work went into it.  On the brighter side, the only electronic (expensive) item damaged was the $30 video camera for the video downlink.  The ContourHD camera in the nose not only captured great HD video but also survived the crash (actually two crashes, two deployments to Afghanistan and the Warrior Dash on Saturday).

Read more…