søndag den 31. maj 2015

10x4.5 SF Props For DJI Motor CCW Rotation

I bought a stack of these off a seller on Ebay, and initially thought they were the usual props I always purchased. Upon receiving i noticed that they looked very familiar with Hobbykings Slowfly props. The Ebay version has a slightly different hub designThey both have the same designed hub and design, are the same. I must say i was very very disappointed with this product both the hobbyking and the Ebay version. 90% of the props that I have used have broken in exactly the same spot. As you can see in the pictures, all the props have a weak link where the hub and propeller shaft meet.
The Hobbyking version (green) has a slightly different hub.

The prop design and pitch seem identical.

The light green prop is the Hobbyking version and it shares the same characteristics as the Ebay version though they do fare a bit better, but they are not impressive. 

These props break very easily often just small twigs and light crashes will cause the prop to break, just in a single 30 minute session, i have had to change three of these props.

The Hobbyking version has the same weak spot.

This is the version I thought i was buying, 10x4.5" 1045 Nylon CW CCW Propeller Prop Multicopter QuadCopter Black&Red these props i notice are more expensive, but I have always enjoyed using them, they coup much better than the recent ones i purchased. Despite them being much thinner and flexing more, they can take a bigger beating. They get tacky on the edges or the nylon rips on the prop arm. If you hit something hard a small peice will break off, but never had one break at the hub.

The no name prop is much thinner, causing it to flex more.

I hear alot of people talking positive about the Slowfly props from Hobbyking but for me that was the last time i purchused these, i would prefer to stay with the no name Chinese version of props.

torsdag den 28. maj 2015

Hobbyking H4 Quadcopter frame remodelled

You can also check this article Hobbyking H4 - Tuning for better flight & videos

As mentioned in an earlier article on the Hobbyking H4, some of the cons were the landing gear and the thin alu booms and the carbon motor mounts. After a few what i would call relatively normal landings, the landing gear bent and after som time of benting i opted to dismantle the gear. The carbon motor mounts are relatively thin and broke. I replaced these with som alu mounts from hobbycnc. The booms also bent relatively easily so i replaced them with a stronger and more relaiable version.

If you are looking to do the same on your H4, check out how i went about it.

I went to my local hardware store and purchased a electricity box, they come in all shapes and sizes. I grabbed one with the thin rubber pods on the side so the I lead the wire into the box.
I purchased 6 of these alu booms both for the booms and the landing gear

I had to resize the booms to the desired length and redrill the mount holes for the body section. The motor end has the the right size holes if you purchase the motor mounts mentioned above from hobbycnc.

The speaker wire is poked through one of the rubber pads and can be hotglued to keep it in place

The landing gear was made using two motor arms/booms. I measured the distance between the two middle holes on the carriage and drilled a 3mm hole all the way through. I redrilled the top hole to a 10-12 mm so the stand-off screw could pass through. I tightened the the arm with a screw and applied som loctite to avoid it loosning. Using a Dremel I cut the excessive probing shaft of the screw and leveled it. Not so sure that the stand-off screws will hold, but they will do for now. I undid the the two middle screws and tightened the stand-off in their place.

I had to cut the corners of the locking mechanism to have the KK2 sit snug inside.

The battery can be mounted on the back or under the landing gear

The whole box is mounted with plastic stand-offs. The power distribution board is mounted at the bottom, it was locked in with a small stand-off, i measured and drilled four holes in the box, put the box on, tightened it with four low stand-offs. The KK2 was then mounted on these stand-offs and tightened down with plastic screws. 

hobbycnc motor alu motor mounts much more reliable and can take a relatively hard beating, they tend to just bent, a vice or a hammer can be used to level them out. I purchased mine some time in early 14, they are still going strong.

the wiring is done through the rubber pods keeping i neat and simple, i should have repainted the quad, but will get to that later.

lørdag den 16. maj 2015

Rctimer ATLAS Flight Controller

Just wanted to share some info on this newly released flight controller from Rctimer. It is actually a clone of DJI naza, it seems they reverse engineered the Naza, changed a few things to avoid lawsuits and named it Atlas, they weren´t even bothered to change the colour, I guess this is probably to let the consumers know that it is a clone of the popular Naza at the fraction of the price.

 Both controller share many of the same features, the atlas has IOC (intelligent orientation control or headless mode, RTL (return to launch mode), altitude hold mode, stabilize mode.

Installation of this flight controller took less than 15 minutes, the only soldering i had to do was to connect a XT60 connector for a lipo battery, the rest was very simple. The GPS and the LED fit into two connectors clearly marked, the one side of the board has 8 motor connectors and a Power input VIN that comes from the LED. The opposite side has connectors for your reciever. There are three extra channels, the first channel controls the stabilize, altitude and GPS mode. The second controls the RTL, IOC and Off. the third channel is not currently used.

The GPS can be angled at about 45 degrees

The LED displays which mode, you are currently flying in, by using a blue, green blinking sequence. It can also display how strong your GPS signal is using a red sequence. One of the cons in my opinion is the red sequence, the red is also used for battery voltage warning. When the battery is about 50 %, the battery warning is constantly blinking, thus suppressing the blue and green sequence. The battery LED blinked using the same sequence for the remainder of the flight, so is actually difficut to determine the amount of battery that remains.   

The controller can be configured using the ATLAS assistant and the provided USB cable. I could not change some of settings initially, until i upgraded the firmware from a version 1.1 to a version 1.7.
If you are using Windows 10, your com ports will not be available. Windows will detect and install the CP210x driver and it will show up under device manager.
 but the Atlas assistant will not detect or see the com port. To fix this right click on the ATLAS_Assistant file choose properties

go into the compatability section

 Tick the run as windows 8 box apply and save. and run the program.
After reading the forums, you can also just tick the Run as administrator box save and run.
Windows 10 blocks unistalled programs from accessing the com port. Seeing as this is downloaded, it has to be run as an administrator.
This also applies for the firmware update file.

The IMU calibration and the MAG calibration can be done on the fly when not connected to the assistant using the radio. There is a telemetry port provided on the board to connect to a ground station.

Flight characteristics: Altitude mode works pretty well even in windy conditions, very stable, the GPS mode seems to work ok but am experiencing a  few problems. When activated it initially works but a gust of wind makes the quad start toilet bowling and the circle radius increases for every circle.
Stabilize mode works like a charm and the IOC mode seems ok. The quad was very sluggish on the maiden flight, direction changes seemed very slow, the reaction time was often causing unwanted situations. I changed the Trim step on the Taranus Frsky to very fine and this made the big difference,  the quad felt more tuned in. Ascending is very slow, compared to the KK2. Full throttle on atlas is a controlled slow climb, whereas the KK2 really pulls some power and is more fun.

Verdict: Small and light, leaving you with a neat installation. Expensive compared to the KK2, the KK2 flies and feels more responsive when tuned in, but it does not provide the GPS, IOC and altitude-hold  mode the Atlas has. The KK2 is more fun to fly whilst the Atlas gives you the opportunity of more stable FPV control and installation is pretty slick on the Atlas. Never flown the DJI naza but if you are not willing to pay the steep price, well this is actually a good alternative.  

I have now been flying this bird for some time and i must say, it is kind of growing on me. One of the best things about this FC is its simplicity, i have had minimal break downs and maximum flight time. Even flying it in stabilize mode, it is easy to find and pinpoint the hover position without using the altitude hold function. Stabilize mode is much smoother than on my kk2 and direction change much slower. Makes this board much easier to control and gives you a better learning platform. I noticed a small bug, when i activate GPS mode after the first launch i have to keep my finger on the switch as the result is not always as wished. The quad instead of finding its position and hovering tends to rev up and turn away at a 45 degree angle and fly away. If i deactivate the GPS mode it goes back to its original hover. If i land the quad, disarm and rearm the GPS mode works properly. I don´t know if it has something to do with the GPS signal not been bound prior to takeoff. This is a pure FPV controller.