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Archive for September, 2017
Posted by KristofferR | Sep 30, 2017 @ 11:14 AM | 2,973 Views
Below is a post I made today in the Multiplex Heron thread.

The day before I maidened the Heron, right off the slope edge. I just had not gotten around to try it on the flatland and brought it to the slope on a whim. It flew really well.


Today I went to the slope again with the Heron. Wind was stronger, 12-14 m/s. I needed to sleep in and did not make it in time to meet my flying buddies; I met them on the trail on my way up and they were done.

Dan had crashed his Intention and Seppo stayed on the ground. Dan told me the turbulence took him and despite applying full power he could not recover. The Intention is a fast ship and his prime pick in difficult conditions. He warned me where not to fly and I am grateful for that.

Up top the wind was hard and it was difficult to walk. I decided to assemble the Heron and wait for the wind to drop a bit. I live near the coast, today the wind came from the inland and combined with sun that means thermals.

Launch was easy but the bumpy air was appalling. Basically, I needed to fly all sticks all the time to keep the Heron level. Venturing left I understood what happened to Dans plane, a weird wave/turbulence effect made sloping impossible and I powered up early to avoid repeating Dans crash.

I endured and eventually found a narrow corridor of lift to milk for altitude. Sometimes the wind died down a bit, indicating thermals upwind in front of the slope and then lift was very good. Problem was that...Continue Reading
Posted by KristofferR | Sep 28, 2017 @ 02:35 PM | 2,814 Views
First, I got thinking about a song by the Replacements called Bent (all?) out of shape that I think it was a cover version that I really liked. Can't find it anywhere.

The ZenMuse is not pointing straight and I watched a bunch of videos first and then started by removing it from the quad. I noted that the "plates" were slightly bent and the colour change indicated plastic deformation. Then some odd scratches caught my eye. Upon further inspection, the whole gimbal arm has taken a big hit and was 4-5 mm bent. Now I am impressed that it still works!

I went ahead straightening the thing with pliers, kids bedtime stopped further progress but I am hopeful to get it sorted!
Posted by KristofferR | Sep 27, 2017 @ 02:02 PM | 2,732 Views
The last coupe of days, I used the Phantom a lot.

First off was a bachelor party. I used all my little cameras, from hiding the Möbius to record the grooms' surprise, using the Phantom to do aerial videos of the guys, SJCam for gokarting, slowmo for beachvolleyboll etc.

A few days later I took some photos of my parents house and adjacent build sites. The weather was warm, windy and very gusty, occasionally 10 m/s according to the local meteorology reports. My thermal/slope glider mind noted great thermalling potential.

The Phantom performed really well in the dirty air, and after I set my Futaba T10J dual rates at 45-50% and added about 35% expo on top to tame the yaw sensitivity, videos get very smooth. Thats a definite Ooooh!

Flying FPV with the Fatsharks is also an Oooh, especially when I let the guys at the bachelor party have a "ride".

Bringing the Phantom 2 along for "work", ie not RC hobby but trying to deliver photos, highlights the improvements made in the later models. Lots of different items, lots of batteries and a general unability to adjust things on the fly limits the usability of the 2.

Judging by the way I constantly need to use forums to find answers, and that there is no proper DJI FAQ to help with all known issues highlights how DJI lacks support and documentation as well as a general SW robustness: Things like startup order or compass calibration procedures are unflexible, and old firmwares are deleted and...Continue Reading
Posted by KristofferR | Sep 12, 2017 @ 02:59 AM | 2,735 Views
For non-followers: I bought a damaged Phantom. The GoPro was broken. I fixed it. The GoPro battery showed 0V.

It made no sense as the Phantom batteries were behaving perfectly fine.

I opened up the GoPro battery to look inside. Sure thing, there was a little protective control circuit and two cells in parallel. They showed 1.7V which means they might be less dead.

I put 0.1 A into them using my B6 NiMH setting and they quickly got to 2,5V. During the next days I was increasing the amperage gradually as the voltage went up to 4.2V. Lots of pauses and checking for swell or heat. I got approx 1150-1200mAh into it and it says 1180mAh in the spec.

Next up is to try a discharge-charge cycle and see how it fares.

NOTE: All of this was done with me sitting at the desk, battery in a glass jar inside a LiPO bag and the whole setup made so I could easily unplug and throw it out the window onto the stone tiles. I have great respect for LiPO batteries and fires in general and I do properly discard of any puffed or otherwise damaged LiPO batteries. I have two smoke detectors and I have also trained/instructed my kids and my wife what to do in case there is a fire while charging.
Posted by KristofferR | Sep 11, 2017 @ 02:15 PM | 2,372 Views
I am so late getting into FPV. I was close pulling the trigger for a while bit decided to sit back and wait a few years to let the new and used market catch up and wow, it felt good to finally cross that border!

The mix of Phantom, GoPro, Immersion+OSD and a set of Attidude V2 goggles worked pretty fine even in the dusk.

I already have a smaller camera/transmitter kit on the way from Banggood to put on my Magnum Reloaded.
Posted by KristofferR | Sep 10, 2017 @ 03:55 AM | 3,978 Views
My CC01 Pajero is starting to resemble a car! Ther are a lot of details left before the correct Rally Raid look is in place.

The body did not fit perfect, the wheels sat about 3-4 mm wrong in the wheelhouses so I got my drill out and moved the rear brackets - from looking at other builds that seem to be a standard issue.

The front body supports are magnets, maybe I will drop it a few mm.

I have filed and cut most suspension and chassis parts for more flex, more steering and more ground clearance. The rims are original, but redesigned with a Dremel.

Next up is to do the scale thing. Never did that before so looking forward to trying and learning!

My blog about RC and other things:
Posted by KristofferR | Sep 08, 2017 @ 09:28 AM | 2,991 Views
Recently I bought a used and broken DJI Phantom 2. In the package of parts was a GoPro Hero 3+ Black edition action camera. This is about the camera.

The camera has taken a minor hit. It does not have any case sitting on the Zenmuse Gimbal. The front cover had a small chip in it near the USB port. First, I tried to start it. No success. Battery was dead. Being a LiPO and showing 0V on my multimeter it was definitely done. The USB connector felt sort of friction-less and I heard a rattle inside. I opened up the camera - pop the front plastic cover with a "spudger" and unscrew four screws. Careful here as there is a flat-cable attached. For these steps, I recommend "iFixit" instructions - they are very good, but not entirely complete.

The USB port was broken off the motherboard and with ten tiny arms soldered to the motherboard I decided to not try to reattach it. Neither my soldering skills or equipment are not good enough to handle micro-repairs. On eBay, I ordered a spare motherboard / main board and it came in the post some days later.

Dismantling the camera was done without issues. If you ever did work on a smartphone this is easy. The Hero3 camera is huge in comparison to an iPhone 4, 5 or 6. The only particular care is needed with the flatcables. They connect to the board and have with little locktabs which needs to be opened and closed with the plastic spudger or metal tweezers if you feel more adventurous.

The replacement board came without...Continue Reading
Posted by KristofferR | Sep 07, 2017 @ 01:54 PM | 2,784 Views
The V24 is now fully kitted with Banggood items.

My homemade motor mount was actually the result of an ordering mistake - the one I ordered was for a smaller can. As I already went ahead with the glue gun I used that for the propshaft.

The rudder fit really nice and I used a pushrod from my aircraft. Next is to mount the servo and the electronics and try it!
Posted by KristofferR | Sep 06, 2017 @ 10:26 AM | 2,975 Views
I went crazy with the glue gun!

The result is not very pretty but I think it will hold up as long as the motor stays within reasonable temperatures.

I don't have any experience with RC boats. Maybe I will not like boating. Maybe this conversion needs big adjustments. Quick and dirty is the theme so far.
Posted by KristofferR | Sep 05, 2017 @ 09:47 PM | 2,458 Views
A friend gave me a hull.

This v24 tech toys / victory / syma / stealth ep700 is "good toy grade level", powered by dual 380 motors. It has no rudder. Turning is done by cutting power to one of the props.

Hardware and electronics were badly rusted. One motor was stuck. Props broken. Spares and props are close to non-existent and the prop shafts have a unique, or unusual dimension.

I decided to take everything out and install a single center motor and a rudder. The motor is a Racerstar 540 brushless, shaft and rudder from Banggood.

There was a looong thread on by a guy in Sweden who tried to make this boat fast and well, it was in the end but it cost him a lot of money and time.

With that in mind I'll be happy if it moves in a reasonably brisk way.

There are some really sweet paintjobs for this boat and I might try to make it shelf-worthy.
Posted by KristofferR | Sep 05, 2017 @ 02:51 AM | 2,253 Views
The Phantom is in the air again. The GoPro Hero3+ is still off duty waiting for parts, but I put my SJ4000 camera on the ZenMuse gimbal and went flying. A few coins got the SJcam up to the weight of the Hero3+ and it worked decently well until a coin fell off in the air.

The Phantom is fascinating to watch in the air but honestly quite boring to fly. It is intended to be a camera platform and it does very well in that role of course!

The SJ has no live video out so I could not run fpv, it has the Wifi though so I could view through the phone but only from close range. I did a short edit from the first flights.

Short video, DJI Phantom2 with SJ4000+ test flight (0 min 47 sec)

Posted by KristofferR | Sep 01, 2017 @ 12:24 AM | 2,177 Views
So far, there is slow but steady progress with the Phantom 2!

I spent a lot of time getting the firmware sorted. While I cannot tell exactly what worked, the "Hard Reset" procedure on the Naza seemed to help. After twenty or more attempts - PC restarts, DJI program restart, connects and disconnects - magic happened and the upgrade went into the Main Controller and the Flight Controller.

In total about six hours went into that activity (another four searching and reading). In my line of work, embedded sw development, bricked units and firmware flashing issues is a common and we have methods and tools to do it. In this case, I had no tools and I dont know exactly what I managed to do but the order of activities seems to matter greatly (drone power cycle, usb plugin, app start etc).

When the Phantom talked to the PC, the rest was straightforward!

I set the Futaba T10J up with a Multicopter preset, this means that Ch1-4 are normal sticks and CH5 and upwards are defined as AUX and switches can be freely assigned. The T10J is very nice and "better" than my old Multiplex Cockpit SX in some aspects.

The setup is familiar to anyone who has RC aircraft experience. Instead of actual servos, servo arms, pushrods etc it is all virtual.

After assignment, reversal, subtrim and endpoint adjustment things were ready for GPS calibration which went smoothly. Next up was to go outside - by now it was dark - where I found that the elevator needed to be reversed. Motors on and they seem to respond to stick movement!

No props attached yet, but a re-maiden flight could happen this weekend!