how would i directly wire 2 tank like drive motors to a transmitter?

using the controls as switches (no pcb).

ive tried, but i cant get it to reverse and turn.

I am not exactly sure what you mean. If you want steering like a tank, there are 3 ways of doing so.

suppose you have a transmitter with 4 channels on 2 sticks

code:

---

   1     3
  2+    4+

channel 1 left stick forward-reverse
channel 2 left stick lef-right
channel 3 right stick forward-reverse
channel 4 right stick left-right

---

Did you mean wiring the motors to a radio controller-s receiver or directly wiring the motors to a transmitter' s sticks for wire type control ???

most transmitters use variable pots inside them to send voltage signals to the radio cir cute they are not switches as such . They might work as switches in one direction ( for a short while until they burn out with the high current ) thats why you might have been able to make them go one direction if the pot was turned full on

if you are just trying to use an old burnt out radio for wire type control you might be able to fit micro switches inside it that the sticks can activate them then wire the micros up in cross over fashion to get forward and reverse .

lol might as well just jam some toggle switches on instead and save some $$
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Wow, thanks for the info leo-rcc.

I dont think ill use an esc or h-bridges just yet.

Yes Totally_Recycled. I wanted to wire the motor directly to the transmitter sticks.

I dont want to use toggle switches because i would get very low marks for it.

Heres my quick sketch of the motor pots.



I hope it explains it clearly.

Im not sure if it is DPDT.

BTW - Its my year 12 SAT.

Most transmitter sticks turn pots that have a resistance in the region of around 5K = 5000 Ohms.

Most Electric motors have winding resistances of less than 1 ohm

So your transmitter pots have about 5000 times as much resistance as your motors, meaning the motors are going to get about 1/5000th the power they require - you wont move far

Even if you could replace the pots with hypothetical 1ohm pots, you would still be using a resistor to control the power flow through the motors.

This means that any reduction in power/speed delivered to the motors is instead burned up inside your pots resistance.

Assuming your motors use somewhere between 10 and 100 amps at 12v, and you try to reduce the power to say half, then your pot needs to radiate somewhere between 60-600 watts worth of heat.
'Smokin (for a second or so, destruction immediately thereafter)

If there was an *easy* way to do speed control without spending hundreds of dollars on speed controllers, someone would have figured it out by now.

You should use (in order from cheapest to most expensive)

1. Servo driven Microswitches
2. Hacked Battery Drill Triggers (fiddly assembly required)
3. A Tank controller (George has posted links to some relatively cheap PicAxe powered ones before in the Tank threads)
4. a Picaxe relay controller (requires significant electronics skill to assemble)
5. a commercial ESC of some sort.
-- Electronizes are about the cheapest for the power rating.
-- Some RC Monster truck ones are ok if you dont have big motors and dont mind a small delay before reversing and run at low voltage.
-- a serious Robot Controller if you need serious power. (IBC, Sidewinder, etc)
_________________
Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Or you could just hack a toy car for the controll
_________________
A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking

True, although they usually run very small motors that are sufficient to hoot a 0.5kg plastic car around and run of AA batteries, so I dont know how much current/power they could handle for a bigger model without going boom.
_________________
Great minds discuss ideas. Average minds discuss events. Small minds discuss people

who said i was talking about those little 1's i was thinking about like about 1:10 size rc car which ussualy arn't very much if you look for cheap chinese ones.
most of them run on 12V have transmitter speed control and are aready working so its all good
_________________
A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking

Would you be happy to use two batteries?

If so ... Use the switch you've pictured first ( the left/right one ) on both sticks.

The following is the instructions for ONE motor and switch.....just do the same for the other stick /switch/motor.

Connect the batteries in series and use the center connection as the common to your motor.

The other motor connection will go to the bottom connection of your switch ( the long contact ) ... the other 2 switch connections go to either end of your series connected pair of batteries.

I'm fairly confident that this configuration will work....BUT ..don't blame me if you get smoke:)

Oh, I get it. you mean you are replacing the standard resistor-track pcb's in the pots with modified ones with sliding 0-ohm contacts to make them emulate switches. (duh to me)

Still, lots of current through sliding wiper arm contacts will likely cause some arcing and sparking, but it might work - for a while.

I cant quite follow your track pcb's though and dont have time to make a drawing right now.

You just want to simulate two SPDT switches per motor. The Center pole goes to the motor, the N/O and N/C contacts go to batt + and batt -. repeat for the other motor.

To do forward reverse, and side/side mixing instead of tank-steering (one motor per stick) would require some more thought, but since I assume this is a tank, why not use tank-steering ?
_________________
Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Buy two DPDT toggle switches and mount them into a piece of 3mm polycarb or MDF... Then wire it up so one toggle controls one motor, fwd/rev, and the other toggle does the same to the other motor... Lot easier then taking a transmitter pot, trying to hack it to work as a on-off-on switch...
_________________
https://www.halfdonethings.com/

I've uploaded a pic of my possible solution using your switch idea .......but with two batteries.

As suggested two stick tank style will be easiest ... but..if you are using a single stick .....just hold the transmitter box @ 45 degrees .... a corner facing towards you and a corner facing away.



http://www.robowars.org/forum/album_pic.php?pic_id=1438

You'll probably need to swap around the wires from the switches to the motors to get the correct directions.

I dont think i can use the 2 battery idea due to the time constraint.

Toggle switches are my last resort.

I dont think i'd do radio control again, due to extra functions I have.

I figured out that i'm royally screwed if i dont figure this out this weekend.

Ive also come to notice that my switch mechanism will never switch the polarities due to the nature of the switching. Ive tried swapping + with - when wiring to the switch and it made no difference.

I was thinking of using Picaxe, though i do not have an adaptor for my computer to program it.

Is it possible to build a H-Bridge using 4 transistors? I cant find any at DSE or Jaycar. I dont want to order online since i wont recieve it in time.

So basically ill explain my project so you get a slight idea of what ive built.
-Tank like robot
-Driven on 2 motors with tracks
-7.2v battery power (drive/cannon)
-Cannon extracted from tank (uses one motor direction to fire)
-12v seperate power (axe)
-Drill motor powering axe through sprocket and chain
-Tethered with 8 core wire
-Transmitter used at main controller

Main problems
-Getting steering to work (relates to axe control aswell)
-Getting axe motor to be powerfull (due to thin gauge wire in 8 core wire)
-Powering indication LEDs (dont have multimeter)
-Making everything look pretty
-Have until the 21st

Ill post pics tomorrow.

Hmm sounds like fun Wish you the best of luck sorry I cant be more usefull
_________________
A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking