Blimp Char-G, Boat Char-G

tinyrc · #1 07-20-2002, 04:18 PM

Has anyone tried transplanting the BC-G electronics to another vehicle type? It seems like a blimp would be very easy, you could just take a helium balloon, add the BC-G electronics and some balast to keep a costant height, and affix a prop directly to the motor to power it. You could then use the steering to either direct the motor in one direction or another, or to control a rudder behind the motor. Similarly you could add a prop to the motor and a rudder to the steering to create a Boat Char-G. Has anyone tried either of these?

schoon · #2 07-20-2002, 07:34 PM

Haven't tried - so no.

However, they do appear to be fairly trivial adaptions, particularly the boat. The blimp will need some sort of vertical control, as it's actually very difficult to get something perfectly neutral.

You could make it slightly negative and have the prop angled slightly down for up-force. Thus propulsion is also "up." As it should have a pretty sluggish terminal velocity, that should "fix" things.

Token User · #3 07-20-2002, 08:27 PM

How about the Bit Airplane.

OK, I only speak English, but a picture tells a thousand words. Love to see it fly

Token

tinyrc · #4 07-21-2002, 12:41 AM

Oh wow, cool, so many vehicle ideas, so few BC-Gs I'm willing to pull apart to make them!

TheFanMan · #5 07-21-2002, 02:54 AM

omg, that plane is awesome.... *GASP* I have an extra bc-g too! MWAHAHAHAHAHAHAHAAhahaa ha ha.... I believe I must try it..... it doesn't look.... too.... hard

TheFanMan · #6 07-21-2002, 06:22 PM

ok.... so it's pretty hard, but so far I've attatched a one of those motors from and old tape deck to a propeller that comes with one of those crappy balsa wood planes. I figure I should test and start out on one b4 I go onto a better plane

rabbitsperm · #7 12-09-2002, 08:55 AM

sweet

actofgod · #8 12-09-2002, 02:18 PM

blimp idea: I'm not sure how much voltage the left/right coils usually receive, but assuming it's equal to the voltage from the up/down -or- you could bridge any resistors on the pcb, a super-easy control scheme for a blimp would be to have two motors w/ props, one on each side. Wire the first to the up/down and the other to the left/right so that each can go forward or backwards independently. then turning is just like a tank tread; move one forwards and the other backwards and you'll rotate. Both together will thrust straight forwards or backwards. As mentioned, angle the props down slightly for up/down control and maintaining height. If you really were ambitious I suppose a third motor could turn the shaft that the other two are mounted on, letting you adjust in mid flight the props' angle of attack for steeper climbs/ decents/ straight flight.

Code:

rear view. x is propeller.
    ____
   /    \
   |    |
   |    |
 x-\____/-x

helicopter idea: I've been dreaming of making a bit helicopter ever since I saw king of japan's bit hovercraft prototype. Weight would be the main issue, as well as finding efficient engine/propellor combinations. Plus, you'd need 3-4 motors, one (possibly two) for vertical lift, one on back facing sideways for rotation (like a real helicopter), one on front for forwards/backwards movement (think single prop plane). The forward thrust would be controlled w/ up down controls, the rotation would be controlled with left/right controls normally used for coils (snipped off), and all I can think of for the top would be a potentiometer on the helicopter to adjust voltage until it will hover at a certain altitude. The PCB doesn't have enough channels for it to be adjustable from the controller, and you wouldn't want a simple on/off switch anyway or you'd drop like a rock.

All the NIMH cells needed to power that many motors at high enough RPM would probably weigh too much. you'd need something w/ high voltage and low weight, like the 3.6v rechargeable lithium-ion button cells found at this site

Code:

side view. props on front, top and side.
  ---------
    __|__      |
 | / /   \   -/+|-  
 ||--     ---- ||
 | \___________/
     /   /
    -------

#9 12-11-2002, 02:35 PM

Blimp idea :

Basically where the 2 propellers are located, use 1 bit on each side ( same frequency ) ? store the batteries and others in the middle , under the helium "blimp" and that oughta work no ?

-Lucas

dustn · #10 12-12-2002, 02:45 AM

Heres a heli to dream of... http://www.planetinternet.be/pixel/

dustn · #11 12-12-2002, 02:51 AM

Heres a heli to dream of... http://www.planetinternet.be/pixel/

epengr · #12 12-12-2002, 09:14 AM

Blimp:

To scale down bit (no pun intended) use the two motor idea for steering, one on forward and one on reverse channel (I think you could mod the remote with an extra button to fire both at once pretty easy) and the us the coils to control the pitch of an elevator maybe? Or better if you manage to get the steering channel to drive a motor, mount a third vertically for altitude control. Then you only need one bit, and two hands to fly?

I was working on the idea of scratch building a blimp a while back (before I met the bits) and while possible, there are a lot of little details to work out.

Oh and the helium is far from cheap!

Planes:

Some of us have been talking these over already:

http://tinyrc.com/forums/showthread....&threadid=4693

Copter:
I think I have seen a small RC that got away without a tail rotor by just using a large flat fine. The air resistance was enough to counter the reaction forces from the main rotor.
The Real problem with helicopters is how complicated it is to get them to move, There are a lot of forces and odd pyhsical laws involved when you get a big blade spinning fast enough to lift something....

slotsurfer · #13 12-13-2002, 09:31 PM

I built a BiT BLIMP it use one motor and a scratch built carbon fiber prop.You really dont need a second motor if position the tail fins in the correct circle you want to travel in front of you.The blimp it dimensions are 22" long 11" tall 11" wide at the center.I wanted a micro blimp for this project I already own a 36" Plantraco turbo twin saucer this is about as micro as you can go to lift the 8 gram gondola.The gondola is made out of piece of plastic of the front of a Tamiya parts package.I change the antenna to a small piece of coated wire they use to make motor windings. I used carbon rod to hang the motor from the gondola.Glued the prop to the pinon gear of the bit motor so it can slide on and off if I need to replace motors.It quite fun to cruise around my den that only 10' by 12'

slotsurfer · #14 12-13-2002, 09:33 PM

Gondola photo

tinyrc · #15 12-13-2002, 10:09 PM

Awesome!