Radio Control Hobbies

Radio Control Gear - I use a Futaba Magnum Sport 2-channel transmitter for all of my current RC models.
Transmitter - IMAGE
Receiver - IMAGE
Servo - IMAGE (Servo)
Speed Control - < IMAGE > - This is a Novak Rooster speed control which sends power to the 7.2 Volt Motor.
Turbo Optima Mid SE - This is my RC Car. IMAGE It is a four-wheel-drive (4WD) model created by Kyosho. The original 240 ST motor was replaced by a "Slot Machine" which provides about the same performance of the 240 ST (little did I know when I bought it!) It uses a Novak "rooster" electronic speed control (ESC) with reverse. I have actually run it through about three sets of street tires now, not to mention two sets of dirt spikes.

This is a very good 4WD car with all of the bearings that you could think of coming standard. These bearings are actually necessary to make the car the least bit competitive with the 2WD cars out there. It is really good at accelerating out of the turns, but the battery will dump before a comparable 2WD (although the handling is GREAT!!)

Anyway, it runs great and I run it all the time on the street, driveway, etc.
Stealth Hovercraft - IMAGE - This model was purchased from a small RC company called Kinetics. It has a single lift fan (slightly smaller than the usual RC Car motors) which allows it to float above the ground and dual thrust fans (same motor type as lift fan) which allow for the control of the vehicle.
I am 100% done constructing it, with only minor modifications from the included plans. I had fired it up without any control, and it was surprising how much weight it could support on our tile floor. I practically did a push-up off of it, and it stayed off the ground. I was initially worried about it not being able to create a sufficient cushion of air, but it seems to bee very powerful in this respect.
This strong cushion did persist when I took it outside on some rough concrete. I have ran it several times now, and though it takes a lot of getting used to how the vehicle reacts to control input, I am getting better as a hover pilot.
Occasionally it is hard to control because a slight wind will push it around (due to the frictionless cushion on which it rides.) And it also pointed out the flaws in our driveway - it reacts extremely to the slightest angle on the driveway, sometimes forcing the model dangerously into the street.
All in all, though, this is an excellent kit. All of the elements are made of light lexan or aluminum, and plenty of wire is included for the motors and the included lighting system. The three motors which are included seem to give a decent thrust (especially the lift fan) while giving a pretty reasonable running time before the battery runs out. I rearranged the wiring just a little bit to give the following benefits:
- Lighting (3 LED's) is hard-wired - This is a good indication that the battery is connected, and power is being supplied to the system. These lights can be seen to dim when the motors are revved - especially toward the end of the NiCad charge.
- Lift Fan is ON / OFF switchable - This is a convenient arrangement to have when small problems arise. The Lift Fan can be turned OFF, while leaving the Thrust Fans operational for checking of the Transmitter - Receiver link.
- Thrust Fans are ON / OFF switchable - This allows for the Lift Fan to be run with no other power drain (other than the Lighting LED's). When this switch is ON, the electronic speed control (ESC) allows for remote control of the Thrust Fans.
  
  Wiring Diagram
  
  This is the idea for my hovercraft (a simple picture)
  
  But I decided not to build my own until I at least found out if someone had tried it before - I found out I could buy a kit, so I did.
  I still may try my hand at a hand-made hovercraft, but not for a little while. I have been thinking about ways to improve on the design which I constructed from the kit. First of all, there should be some way (electronically speaking) to trim the two Th rust Motors to give the same thrust force (or closer to it). One thrust motor tends to overpower the other. This can be partly solved by trimming the rudder control, but the craft is working against itself.
  The use of a single, steer-able thrust fan (perhaps slightly more powerful) would simplify the design, while allowing for better control. One major problem with the design as given, is that when the Thrust Motors are reversed, there is very little steeri ng control. (This is when the uneven power of the thrust motors becomes a large problem.) When the model is reversed to decelerate, it tends to turn as well. This creates a challenge for attempting to stop the model, which begins spinning out of contro l. I would propose that instead of a fixed motor with a rudder which vectors the thrust, the motor itself should rotate left-to-right, allowing the full thrust to turn the model more effectively.
  A less drastic change to improve on the current design might employ rudders specifically included for reverse thrust steering. The would be placed in front of the thrust motors, allowing the vectoring of reverse thrust similar to the vectoring of forward thrust. This has the disadvantage that the vectored thrust comes from approximately the center of the craft, giving little of no steering effect. This may be solved by designing the Thrust Nacelles to run the length of the craft, instead of simply the rear. There could then be rudders on the front and the back. This heavy modification would create a very non-aerodynamic shape, however.
  Perhaps instead of trying to move or rotate the Thrust Motors, the power to each motor could be adjusted to give steering control (while employing dual thrust motors.) If a slight turn is desired, the left fan (for example) could be left at full throttle , while the right fan is decreased to half-power. If the most extreme turn is desired (interestingly with no net thrust) then the left fan could be full-power forward while the right fan is given full-power reverse. With the thrust fans positioned corre ctly (very far apart), this could give an extreme amount of torque, allowing for quick turning response not afforded by the currently designed model. Linear acceleration response should not be affected.
  I may start (CAD) designing my own (hovercraft model) version...
- Lego Radio Control System
- Take a look at my 1st Lego R C Model: Lego R C Car .
Send E-Mail to the Greek!!
( clampe@mednet.swmed.edu )

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by Craig A. Lampe