donderdag 16 juni 2011

Hide keyboard on input selection

When your activities first focus on opening is on an input field (like editText) you will get the android software onscreen keyboard popping up blocking half of the screen for your activity right away. To overcome this use this code:

getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

This will prevent the keyboard to popup until the user actually selects that input field. The way it should be!

woensdag 8 juni 2011

Laser Models Colibri .25 Trainer Review

This was my first kit I ever bought. I tried to fly it once it was finished years ago. Hand launched it, flying directly into a fence... Since then I didn't have the time (nor courage) to get back to this hobby.

Until recently when I started really learning to fly with cheap scratchbuilt foamies. So much more fun and no real issues when you dive into a fence for instance. In the beginning I even had several fuselages with me to the field in order to have at least some airtime :).

Now that I can fly and even have experience with ailerons and warbirds I got back to this balsa kit. It was built already, I only needed some minor repairs and redo the covering. It still had a glow motor installed so I ordered a 2217-06 brushless motor to get it up without the noise and grease of a glow engine.



I'm still no hero with oracover (well I don't have the right tools, just using a regular iron) so mine isn't looking as sweet as the one pictured on top here.

The Colibri is a 1400mm wingspan, +/- 1000 gram trainer model. It comes with or without ailerons. I have the 3 channel version (RET) which I regret right now. I should have gone for the aileron version directly.

It's known for it's easy built and nervous flying characteristics. Building was really easy with all the elements perfectly laser cut and numbered with clear instructions and full size plan. Landing gear (heavy one though), tank, control rods, servo tray and other hardware is included.

It should be a trainer I know. The trick is to keep it as light as possible. Going electric helps. Some other weak points are the wing connection (reinforce with glassfiber) and the non steerable tail wheel (really need to replace that!).

My plane/My experience


These are some pictures of my setup. With a 3s 2200mah lipo installed where the gas tank used to be and the ESC up front it balances well. Total flight weight is 1190 gram.

I could get it down a few grams replacing the heavy Graupner C508 standard servo's. Also the ESC I'm using is only rated for 25A which is just not enough. I have a watt meter installed in flight also as you can see in the pictures.

Here you can see how I used the mounting plate to secure the gas tank reversed in order to keep the battery in place. I also added a 3mm balsa sheet to support the battery.

The motor is installed using the holes I already made for the gas motor, adding some L brackets.

The ESC, only rated for 25A while full throttle with 9x5 prop is more towards 35 amps... I just don't throttle it all the way up.

Overall picture.

I went flying a few times now and indeed the take-off is a bit difficult due to the lack of a steerable tail wheel. When a bit more wind is available it takes of into the wind almost immediately. Without wind the runway is a bit harder due to the lack of a steering wheel. Also the control throws are quite heavy so some expo is desired.

Once up in the air it flies very well. I can fly it with very little power, almost gliding. If I cut power completely I get a very predictable stall and glide down. This sure is a good beginner airplane. Too bad I don't have the ailerons.

I had some hard failures during takeoff with the wing hitting the street. It was easily fixed and recovered. Still love the way you can repair balsa and cover up like you never crashed that plane :-).

2217-06 1500kv 250W brushless motor review

I ordered this brushless motor to convert my Laser Models Colibri 1400mm wingspan, +/- 1000 gram trainer. It was equipped with an OS MAX 25 (0.25 cid) before.


2217-6T (250W) 1500Kv SP Brushless Outrunner Motor

Specifications:
RPM/V:1500 KV
No load current / 10 V:1.6 A
No. Of cells: 3 Li-Poly/ 8-12 Ni-Mh/Ni-Cd
Max. efficiency:78%
Current capacity:28A/60 s
Dimensions:28x35 mm
Shaft diameter: 4 mm
Weight:70.8g / 2.49 oz
Recommended working current: 8 - 22A (efficient _ 70%)
Internal Resistance: 100 mΩ
Prop shaft adaptor output: 6mm
Recommended prop without gearbox: 8 x 4 to 9 x 5.

Again one I ordered from GiantCod instead of the chinese located HobbyKing: http://www.giantcod.co.uk/22176t-250w-1500kv-brushless-outrunner-motor-p-405612.html. I can buy these brushless motors from my local hobbyshop also.

Propeller:
Some websites list it as an 8x4 prop on 3s and 9x5 prop on 2s. I did some testing with my watt meter but this way you can't get it much above the recommended 22A on full throttle. I don't fly full throttle all the time anyway so I would suggest using the 9x5 prop on 3s. This way you can go over the recommended 22A without hitting the max of 28A and cruise around on a good efficiency.

Update:
When I received the motor it didn't look like the first picture that originally was displayed on the product page. Instead it looks like the motor on the new picture on the website:

My order must have been between transition. The yellow once I ordered and used before with great success. This black one I less satisfying... The backplate for mounting had some misaligned holes so it couldn't be used (yes I had it facing the right) and for some reason after some use the bell advanced forward on the shaft. Causing the bell to have way to much forward movement now (and a very short shaft :)). I tried fixing that removing the crub screw but it's just way to solid, can't loosen it.

No more of these motors for me for sure. I just noticed the NTM motors from hobbyking were in stock. Or at least some of them. I went ahead and ordered a 450 watt version, just to check it out. If that one runs wel those will be my next motor also.

Brushless motor shaft replace reverse instructions

This link has some good pictures on how to replace or reverse the shaft from a brushless (bell type) motor: http://www.maxxprod.com/mpi/tips1.html. Some motors use a c-clip to hold the back of the shaft but apart form that this tutorial can be used for any kind of motor.


Outrunner Shaft Replacement/Reversal
1.
Remove or loosen the setscrews at least two turns. Remove the collar
on the front of the motor.  Pull the rotating bell(rotor) from the rest of the
motor. There is a small wire washer behind the collar, don't lose it.
2.
If the rotor is tight in the motor, mount it to a plate and press it out.
It is best done on an arbor or drill press.


3.
The rotor will slide off the back of the motor.  The magnets
may pull the rotor back on the motor.  Hold the parts tightly
and pull them apart.
4.
Once apart be careful that the magnets in the rotor do not pick up
magnetic dirt.  Debris can get stuck and cause serious damage to
the motor.
5.
To remove the shaft use a plate or block with a hole to clear
the shaft.
6.
Lay the rotor as shown. Allow the shaft to hang though the block.
7.
Use a shaft or punch to push the shaft out. Be sure the parts are square
to prevent bending of the rotor.
8.
Push fit the new shaft in the rotor. If the shaft is not aligned properly
the bore can be damaged resulting in a wobbly rotor, which must
 be replaced. Use the press again if needed to install the shaft.
9.
If the motor is being used in the normal configuration, install the
shaft flush with the rotor face.
10.
Install the wire washer.
11.
Tighten the setscrew in the rotor. Slip on the collar and align the
set screw on the flat on the shaft. Use finger pressure as shown to
preload the bearings slightly by squeezing the rotor and collar toward
each other. Tighten the set screw in the collar while applying pressure.
1.
Loosen the setscrews and remove the collar as in step 1 above.
2.
Turn the motor onto the rotor as shown. The plate must have a
hole to clear the shaft. Use the collar as a gauge for the shaft.
3.
The shaft will slide through the motor until the press touches the collar.
4.
Tighten the setscrew in the rotor. Slip on the collar and align the
set screw on the flat on the shaft. Use finger pressure as shown to
preload the bearings slightly by squeezing the rotor and collar toward
each other. Tighten the set screw in the collar while applying pressure.
5.
Install the supplied mounting accessories as pictured.