Syma Forum

Raptor said
As i will be offline for the next few days, on a camping trip.

I have updated the RF Mod guide. (sorry its late)

It is missing a few of the last images, but hopefully it calcifies some aspects of the setup.

http://www.mediafire.com/view/.....1e086n3w44

 

Talk to you all again in 4 days. But for now, its time for sleep.

Hi Raptor, this is awesome!

I noticed that the url to the A33 Tx/Rx in your instruction document appears to be an invalid link

However, I can see the following A27 Tx/Rx on the RobotShop website:

link1

link2

Will this A27 Tx/Rx combo work as an alternative?

I should be getting a couple of 107s in the next week.
This is going to be my first mod when I can get around to it 

I know I'm not the first person to Mod a S107G , but I did and I like the outcome. I would not have thought of it had I not read in this forum about it. My S107g was in stock form until yesterday.

All I did was to remove the Main boom supports and the top horizontal wing the was attached to them. I left the tail fin next to the rear propeller as a safety device to protect the rear prop from damage.

Test flight proved to be a nice change. This little Heli really does fly faster and is waaaay more agile. I couldn't beleive the way this thing fly's now compared to stock.  The S107 fly's very nice out of the box, but I like this mod better.

Here's what I found out while doing this mod;

1.  I didn't have a phillps screwdriver small enough for the screws, so I used an inexpensive eyeglass repair kit screwdriver, and it worked great.

2. Most all of the screws required tightening up. I've probably flown this thing 70 times.

3. I lubed the plasctic gears with a dry teflon lubricant That I use to lube the actions of some of my guns. It goes on dry and does not pick up dirt, hair, etc. It's called Rem lube.

Now that I have done this Mod I have a few spare parts, so I found a small wooden candy box for storage. Now I keep all the spare screws, Heli parts, screwdriver, small pliers, charge cord, parts manual, and soon a complete blade rebuild kit which should be here soon. The little box is good as a Heli pad while charging.

Anyway I know I'm not the first to make this Mod, and would like to thank all that have done this and posted it, so a anoob like myself could try it out.

Chief T  >

i put the rf mod on the back burner for a little bit but in the mean time here's what i've been working on:

thanks for the help raptor

i think i messed this one up tho. i laid out the circuit you provided, but the LED didn't light. I'm still not sure where the problem is tho.

On the rx, i read a voltage between VCC and GND and even between VCC and DATA OUT but the best I could get between DATA OUT and GND was ~0.2v

On my tx, for some reason, there was a voltage between VCC and the RF SIGNAL wire as soon as I turned the controller on, and it would drop ~0.3v at full throttle, but I have a feeling that's wrong.  Did i damage the circuits by initially hooking up the transistors backwards? That's about the only thing I can think that I did wrong/deviated from your instructions.

I'll probably order another circuit and try this again soon after I figure out where I went wrong

as there seems to be some problems with the setup, as a last resort i think the modules need to be tested.

The way i did this on mine, was to connect  the transmitter module to a 5v battery, and and attach an antenna. with a on/off switch between the signal and Live connections.

On the receiver, i connected a lipo battery, an antenna, and a LED between the signal and ground.

when you switch on and off the transmitters signal, the LED should turn on and off, as you press the button. (if you don't press it/hold it down than it will start flickering after about 1second, but this is normal)

The circuit within the transmitter, decodes the the IR pules, and removes the 38khz modulation, into a frequency that the RF modules can handle. The transistor inverts the signal as the IR receiver is normally high (which the RF module doesn't like).

The transistor on the helicopter inverts the signal again so that the helicopter can recognize the signal.

before you go any further. On the first image that you sent me.there looks to be a bit too much of the antenna sticking through.

Try cutting off the excess antenna wire on the back of the receiver circuit. It may let it pick up a signal.

sorry, i meant to say its the receiver circuit attached to the helicopter that seems to be having the issue, not the S107 helicopter itself.

this issue could be caused by numerous different issues.

i.e antenna shorted to ground, no power going to the receiver circuit, resistors being damaged, transistor damaged by too much heat, etc.

I meant, using a spare LED, hold it onto the helicopters circuit to see if it was receiving a signal.

Hold the long leg (positive) on the "OUT" part of the circuit, and the short (negatve) leg to "GND"

it should light up in the same pattern as the one on the transmitter.

from what you have said so far, it sound like the issue is on the helicopter.

Sorry about the confusion over the capacitor. I made a silly mistake...

It should read 0.1uF (104 ceramic capacitor) however any electrolytic capacitor should work too, as long as the negative pin is pointing towards the bottom of the circuit.