Renew Beginning

Just before I was a teen I used to build balsa gliders, and just started getting into RC gliders and order my (back then) first and expensive radio setup (transmitter, receiver and 3 servos) when teenagehood happened and my focus was pulled to other things. I always wanted to get back into this field, but never quite made it. Until now.

Among my RC interests (gliders, planes, jets, boats, cars) was always helicopters. I am very intrigued by the complex physics involved in those machines. A good book that I found at the library is "Radio Control Model Helicopter Handbook" by Don Lodge that really dwells down into the physics of the blades (higher speed and forces acting towards the further parts of the blade from the rotors creating variable forces along the blades for example). It may be a bit much for someone just wanting to fly a helicopter, but for those interested in the details I think it's a fantastic book (older book).

And so, I decided it's time I pushed myself back into the RC world and stopped just wishing I was in it. Being a hobby woodworker, and a hobby machinist I also have the tools and materials needed to build, mod,  upgrade, and later create anything I think or require.

I looked around available RC helis and decided that I wanted something bigger than the micro models available in toy stores, malls, etc, but still want to go with electric motor as it is quitter and can be used indoor. I have good faith in my abilities to pick up skills and will form a training plan and wanted a heli that I can grow with while at the same time keep the expense somewhat reasonable. All this lead me to decide to go with a 450 sized heli, and after finding and following MikeysRCs fantastic youtube videos showing how to build a 450 helicopter I was set to follow a similar build myself.

I ordered the EXI450 from xheli.com plus a 3500kV motor and the 2.4Ghz remote control and the rest of the electronics (servos, esc,gyro,batteries, charger) from hobbyking.com since they were much much cheaper per part then others. I must say, I was very pleased with xheli.com for their fast shipping and the parts look great. I am still awaiting the parts from hobbyking.com that for some reason took 4 days to process the order after it was paid for. also the shipping from hk was insane and after the fact that the order was shipped, I found out that if I order the same things from hobbypartz.com even though the parts themselves would cost a bit more, the free shipping from hobbypartz.com would end up saving me $20, and it's from the US so shipping would end up being faster as well. oh well, you live, and learn. tomorrow the rest of the parts will arrive, and I'm hoping all will be well.

I somewhat followed MikeysRCs recommendations for parts as I have no experience nor vast knowledge in the field and I tried to use the cheaper parts that had good reviews by other users which ended up being very similar to what is suggested in the above mentioned videos.

Here is what I got:
1 x EXI 450 Carbon Fiber kit (chassis, blades, canopy)
1 x exceed 3500kV motor ~19A
1 x FlySky 2.4Ghz radio system (transmitter,receiver) PC configurable via USB
1 x Turnigy 30A plush esc (Electronic Speed Controller)
1 x Turnigy Gyro
4 x HTX9000 9gr servos (0.12s speed)
2 x Blue Lipo batteries 11.1v 2200mAh 20C
1 x Turnigy Lipo charger

The way I see it, if the motor requires 19A current, the 30A esc can handle it, and as such the 2200mAh 20C battery should be able to handle that in turn (can handle a 44A load (2200/1000*20)) and should last ~6min flight time per battery, which is why I got 2 to start with.

If anyone is looking for the software for the transmitter hobbyking.com  has it for download on the transmitter part page at the time of this posting.

While waiting for the servos/gyro/esx/batteries I decided to do what I can in the mean time. First I took each screw on the chassis that screws into metal counterpart, and added blue locktite to keep it from coming loose in flight. I did the same for the screws in the main and tail rotor and I did encounter a couple of screws that I could not undo. I decided that if those screws are so tight that I cannot undo them, they will probably sustain the vibrations of the flights, and if not - I'll deal with them when they come loose as opposed to stripping their heads off now with excessive force.

I also mounted the landing gear, the boom supports, and the flybars and noticed that those were different than what MikeyRCs video shows. I guess I got a different EXI version than he was using in his videos.

The fist difference was the landing gear, in the videos the landing gears are made of multiple parts and screw to the chassis of the heli using 4 screws. my version uses a single molded landing gear part that mounts to the chassis using only 2 screws and some alignment bars.

2nd difference was with the boom support. I did not have an extra hole in the chassis to mount those to, and after checking xheli.com pages to verify I followed what I saw in their pictures and mounted it using an already existing screws that hold the chassis to the mounting bar that the landing gear mounts to:

The 3rd difference I noticed (so far) was with the flybars and the weights. the flybars that I have seem to have mounting holes that the weights fit into them as opposed to having the weights somewhere on the rod:

This does 2 things: 1 it keeps both weights at the same distance from the rotor, so as long as the rod is centered the weights should be level as well although there is no way of bringing the weights closer to the rotor and change their effect (ok I guess you COULD do that if you placed them out of the flybars). and #2 is that by locking the weights it also locks the flybars in place so they cannot rotate around the bar or come loose. I kinda like this, but then again - maybe I don't know enough to know better. time will tell.

So here is my work area while referencing MikeysRCs video to make sure I don't forget anything:

Oh, and I also installed the motor while at it... now just waiting for the rest of the electronics before I start configuring the transmitter accordingly.

I'm trying to see if it's worth writing an application for Mac to control/configure the RC transmitter, but more then likely I'll just laze out and fine a windows PC to run the provided windows app on.

Thanks for reading,
Peace!