[FaceDeAce]

Hi,
This is my first helicopter experience, so is a fun and new learning curve. Have flown this little thing a few times and so far have managed to keep it in one piece, except for a few blown blades of course.
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I have been tinkering and re-jigging the electronic setup. I am wondering if any of the experts out there see any issues with what I have done here. My concern is ensuring this stuff is well placed and protected for the inevitable catastrophic crash.

Here's what i have done, with pictures to show it.

- Reciever, I am using a Berg 7P. If fit very nicely on the bottom of the tail boom block. This position also makes it easy to get at plugs.

- GY240, I put this between the frames at the back. After reading some incidences of top of boom mounted gyros being whacked by the flybar, I thought this to be a much safer place.

- ESC, I have strapped to the side of the frame. I put it here as with the gyro in place there wasn't enough room between the the side frames and I wanted to put it where it would be getting tons of cooling air flow.


So, does this look good folks or do you see any potential problems with this setup?




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[BigBreeze]

I just got into 450-sized helis too. If you haven't already done so, I highly recommend you register at Helifreak.com, and a guy named Bob Finless has a series of videos specifically on the T-rex (and a number of other helis). One video is even about "Trex Electronics Placements and Overview"!!!!!

Here's the link to the entire build and setup video series for the Trex 450: TRex Electronics Placement

[Cougar429]

Pretty good setup, although I've found my ESC under the battery tray gets enough cooling. The secret is to get a large enough capacity ESC so that it does not work as hard and consequently produce a lot of heat. I'm running a 40A ESC in my 450 and it works fine for the type of flying I do. For my system requirements I've opted to eliminate the onboard BEC and go with a stand alone unit.

The other circuit that generates a lot of heat is the BEC portion that feeds your radio system and servos. Standard type drop the voltage as heat, where a "Switching Type" does the same by turning the power on and off very rapidly, so fast the end result is the voltage you want. Unfortunately there are some considerations in that, too. Switching types only like to be powered with a load connected, otherwise you could end up frying the circuitry. Another very important element is that it is very simple to design a switching type power supply. The difficulty comes in isolating the noise created in the process. That's why you can get serious interference issues with a lower priced or quality unit. For the same reason, isolating parts of your system from noise, you also want your power wiring as far away from any receiver/gyro/antenna leads to minimize interference.

Correct about the gyro. My only concern is you appear to have it locked down with a wire tie. This will only allow for vibrations to get into the gyro body, something you definitely don't want to happen. The sticky that comes with the Futaba gyro is designed to prevent this and should work fine on its own. Otherwise you can create problems, such as tail wag.

I've found when I have to replace it what has worked beautifully for me is some 3M "Scotch Brand" adhesive tape.

[cassat]

Claude,

Reverse your eceiver and gyro postion with each other.
Watch for the fish in Moberly!

[marcham]

Salut Claude.

Overall, it looks good. A few comments:

1) You cannot use a zip tie on the gyro. That would transfer airframe vibrations to the gyro and make the tail very unstable. Only use the provided double sided foam tape. Use rubbing alcohol to prep the service and remove any mold release agent that may be remaining from manufacturing

2) Generally, people place the gyro underneath the tailboom block. Is this a V1? Is so, you will need to shoe goo a small piece of plexiglass in place to have a flat surface to affix the gyro.

http://www.readyheli.com/RDLohr_s_T_...gyro_mount.htm

You can use velcro to affix the receiver in case you need to remove it for maintenance.

3) Most people place the receiver under the battery tray (velcro). This ensures the battery leads are kept as short as possible. You will also be able to connect the battery leads with the canopy installed by pulling them through the bottom hole in the canopy.

If you bring the heli to the island send me a PM!

[FaceDeAce]

Thanks for the great tips

I now know not to use a zip tie on the gyro. That certainly does explain some tail wagging. I kept reducing the gain on the gyro but it wasn't making any difference. Must be the zip tie. I will switch it to some foam tape, but I do like where it is currently located.

I considered putting the receiver under the battery. I will look at it again if folks think it better there than under the boom block as it is now. I chose the rear position, thinking that the nose is close to the motor and may be an RF noise problem, and that the nose is the most likely place to mash things to bits in a major crash.

This is a Trex450SA. Aluminum frame.

Thanks for the video link! I will certainly watch it when I get back to a high speed connection, next week.

[Cougar429]

I would leave the receiver where it is. You want it as far away from your power and ESC/motor wiring as possible anyway.

Don't use double sided tape unless it came with the gyro. Other than the 3M product I mentioned before, (which I double layer) most sticky tape does not have the proper consistency.

[FaceDeAce]

An update.
- I registered at helifreak and watched some of the videos. Good stuff over there, thanks for pointing me in that direction.

The only thing I changed on my setup was eliminating the zip tie and remounting the gyro using double sided tape. I couldn't find the 3M stuff locally so I went with a "LePage no more nails" mounting tape. Looks to be the same.
http://www.lepageproducts.com/produc...d=177&plid=686

The good news is that such a simple thing did make a difference. Tonight I did some hovering around. I had the gyro gain cranked back up and the tail wag was totally gone. Thanks for pointing out the mounting error on the gyro! I would not have know otherwise and may have ended up looking for a new servo or new gyro. It flies rock solid now, at least for my low skill level. Very happy heli nubee here.


My next question is around the antenna wire. Small heli, long wire. What do folks do about that? After running the wire through the straw, there is still two feet of loose wire left. And sorry, but no, I am not going spectrum just for a short antenna. I have too much invested in my 72 mhz gear. Check picture of what I have now.


PS: how do you like my $5 training gear? ping pong balls and 1/4" dowel.

[Cougar429]

I run Revolution Base-Loaded antennas on all my helis and since they stay relatively close I have not had any range issues.

Wish I had more and better pics of the rigs, but all have nearly identical mounting position and methods.

[benjhind]

Is there any reason not to mount your gyro as Cougar has done? Why would people bother modding their heli to put it under the tail block when you can just place it safely in the frame?

Ben