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OHhh Yeahhh. Great Idea!You could use a board out of a bullet. Only cost $11
I think if I burn the transistor out from too much current I’ll replace the transistor with a bigger one. They’re only .99 cents for6 of them.
I’ve seen some pretty small helicopters.
http://www.hobby-lobby.com/piccolo.htm
I’d like to see you make a Bit Copter or Bit Plane
-Peter
JP does it say anything about results? Maybe my car is fast like his friends and that’s why my cap mods didn’t work. I have a theory that these cars are made in different plants or something because my friends RX-7 is alwyas slower then my WRX when races with the same motors.
-Peter
capacitors across motor terminalsactuall take electricity away from the motor (for a fraction of a second whenthat small)and store it to be used the next fraction of a second so the motor dosn’t take all the current at once.They call them startup capacitors. This way it evens the current flow out a little. Motors take double the current when starting thenwhile running which. And if a motor is held at a stop with electricy running throug it it will melt the windings. So the cap dosn’t allow it to do that on startup since the shaft is stoped for that short while. I tried a 100mf cap across my motor terminals of my 3.0 and it didn’t seem to make a difference so I thought exactly like b_drift and the car audio power Cap. Hooking it across the motor it won’t charge like a car one will. You’ll see the car ones are hooked right in parrellel with amps and are hooked up directly to battery at all times. The cap across the motor won’t do that since the motor is given power only when throttle is give. So I connected the top corner terminal on the PC Board abovewhere the motor wires go it. That’s also where the pos wire from the battery goes. Then I soldered the other wire to the emitter side of the transistor for the forward direction (third transistor down I think).I found the right transistor byjumping the transistor makes the wheels spin.Now the capacitor will charge at all times and dischargeto thetransistor when forward is pushed.This mod would help if themotor took more current then thecircutry could deliver on its own. (Just like the car where the amps take the current faster then it can get it from the batteryall the way back to the amp) But it didn’t make any difference. I have a feeling since the motor is so smallthat the circutry can deliver power just as fast as the motor can take it. You can’t make a motor take more current then it wants. You could hook up a hugebattery to the motor that was the same voltage and it wouldn’t spinn any faster and wouldn’t take any more current. A higher voltage would make it faster but then fry the motor.
Then I thought I’d hook the cap up to the terminals on the board where there’s already a cap thinking I’d add a little more capacity to that. But, again no difference.
Boy oh boy, I could ramble on about this stuff all day. I must be boring to listen to! Capacitor discharge, magnetic fields, motor current ratings … blahh blahh blahh. I sure hope someone is interested.
Anyway, I think I’ve hooked it up every which way I could think of and no change in performance.
Please tell me if any of you see different results.
-Peter
ok since i’m japanese, i’ll try and translate some main points. only thing is, i don’t know a lotta the fancy part terms so u’ll have to excuse me if the meaning is off. lol
anyways, he’s complaing cause his friend’s 3.0 motor is flying, while his is slow. so therefore, he’s come up with a way to add a “condensor” (spell)without the need for a soldering thing (lol forgot what they’re called st00pid me).
he went to his local hobby shop with 100 yen, and bought a 6.3V 100 ?F electric condensor. he saids that as long as it doesn’t hit hte ground, u canalso use a 10V or even a 16V.
on hte minus end of the wires, he put a cover on it, maybe around the same length as the antenna on the bit char-g. take off hte rear shaft, heat sink, and motor and face the front end to you. if u look at the area where hte motor used to be, there’s a small part of the gear shaftthat u can see from the side. using a small nail or something, push it 1mm~2mm to the side where hte gears are. that makes a small gap.
that’s it for the preparations. now he’ll put the condensor into the underside of hte chassis.
turn the car over (like in hte pic), behind hte rear shaft is a small square hole. put hte 2 wires into there and pull the covered minus wire up so it doesn’t hit hte shaft, then pull it onto the small gap that u made before (lengthwise, it should be just barely long enough). as for the plus wire, stick it into a hole where the stomach of the motor would be touching. it’s the gold colored piece that connects to the motor, any leftover lenghs of the wire, cut it. as for the small gap that u opened before, close it lightly with a small pench (dunno what it’s called in american…. lol forgot).
insert the motor and the shaft back in, and test it but be careful it doesn’t short circuit or something. as for the condensor itself, it will be hanging from the bottom of the rear, so tape it up to the chassis.
on a normal skyline body, the condensor is fine and won’t hit, but on the s2000 it may be a problem, so trim the body accordingly. sometimes it’ll look like a mega-huge muffler lol. and the clearance should be fine as long as it’s run on a relatively flat floor.
there you go. that took me over 20 minutes of my time. but it should be pretty much all correct. :smiley4:
a cap across the motor terminals usually cuts out interference. but in this case, i don’t know. b
This guy
http://www.makop.com/~silbee/hobby.htm
Also has a capcitor on his car. Look a the last picture of the Honda Integra. For some reson I could get this page to go through the translator
It is common to put a capcitor across motor terminals. Must admit I’m not sure why. I think the capcitor charges up when the motor brushes are shorted across two terminals. Anyone know for sure?
I assumed the bit had a capacitor on the circuit board. Perhaps it hasnt, or perhaps the 3.0 need a bigger one. Might have to dig through my boxe’s, see if I have a similar cap.
OMG. i just had a messed up idea. what about ripping out a circuit board from another car and adding it to the car, use only 1 battery, but as long as the board has the same freqs, you could use it to run the second motor. oooooooohhhhhh. helicopter!!!!!!!!!!!!!!!! airplane!!!!!!!!!!!!!!!! and i actually have extra parts!!!!!!!! ok bye. b
maybe it is simulating what a cap does for your subwoofers in the car. it keeps the bass from getting soggy, which could be the equivalent in bit char terms as keeping the torque up on the motor. on the 3.0 which is made for rpm, this might give it more low end to get it going. is the word i am looking for called voltage? b
Sorry, I was gong from memory, The spring coil goes around a black post which is part of the steering bar and the legs go on both sides of the T retainer (also part of the steering bar). The white trim shaft goed in between the legsof the spring when you put the steering bar in the car. Other than that everything else is correct.
-Peter
Not to be redundent but just in case someone’s looing here instead of “can’t go straight”
Centering the magnet won’t help it to go straight. That only helps if it’s steering sharper one way then the other. When everything’s clean, THE ONLY THINK KEEPING YOUR WHEELS STRAIGHT IS THE HIR SPRING!. How do I know, because the white adjustment on the bottom is connected to a shaft that goes between the legs of the spring that moves the spring left or right when adjusting the trim. Also, when going straight, the coils on either side of the magnet are off, therefore the magnet, being offset, wouldn’t matter since it’s not being pulled by either coil. (College physics finally paying off)
Anyway, ehough mumbo jumbo
The first thing to check is if there are any metal particles sticking to the plastic around the steering box (most likely problem). If so, the magnet is pulling itself toward those particles making it steer that way. Use a strong magnet to pull them off the body. Note: Usually the steering is not very responsive when this happens also.
Next make sure you lube all moving connections with dry graphite. Sometimes the steering just catches because its dry or has a grain in it (most likely not the problem)
If that’s not the problem take the steeringbox apart and see if there’s any particles in there and clean them (most likely not).When going straight neither coils is charges so the magnet is of no consiquence. The onlything keeping the wheels straight is the spring
Finally, if nothing is pulling the magnet either direction the only thing holding the wheels straight is the hair spring wrapped around the post on the steering arm with the legs to either side of the T retainer (I call it a T retainer because it looks like a “T” growin out of the steering bar). Sometimes the spring gets knocked off the white trim adjustment shaft making the wheels turnone way. That white center post is connected to your trim adjustment on the underside of your car. You’ll notice it makes the white shaft move from right to left when adjusted. This makes the spring legs move right or left making your steering go right or left. If the spring looks to be where it’s supposed to be then make sure the legs aren’t bent. They should be straight from the coil around the shaft to the end of the legs.
If the spring looks good let me know. I’ll tell you how to bend the spring so I goes straight. Trust me,I’ve done it to my own car. I had to have it all the way to the left before it would go straight. I didn’t have to bend my spring but I did anyway just because I didn’t like that adjustment all the way over.
-Peter
Now that’s a bit of usefull info.
Thanks PR!
-Floyd
Centering the magnet won’t help it to go straight. That only helps if it’s steering sharper one way then the other. When everything’s clean, the only thing keeping your wheels straight is the hairspring!. How do I know, because the white adjustment on the bottom is connected to a shaft that goes through the loop of the spring that moves the spring left or right when adjusting the spring. Also, when going straight, the coils on either side of the magnet are off, therefore the magnet, being offset, wouldn’t matter since it’s not being pulled by either coil. (College physics finally paying off)
Anyway, ehough mumbo jumbo
The first thing to check is if there are any metal particles sticking to the plastic around the steering box (most likely problem). If so, the magnet is pulling itself toward those particles making it steer that way. Use a strong magnet to pull them off the body. Note: Usually the steering is not very responsive when this happens also.
Next make sure you lube all moving connections with dry graphite. Sometimes the steering just catches because its dry or has a grain in it (most likely not the problem)
If that’s not the problem take the steeringbox apart and see if there’s any particles in there and clean them (most likely not).When going straight neither coils is charges so the magnet is of no consiquence. The onlything keeping the wheels straight is the spring
Finally, if nothing is pulling the magnet either direction the only thing holding the wheels straight is the hair spring wrapped around the center white adjustment post with the legs to either side of the T retainer. Sometimes the spring gets knocked off the T retainer making the wheels turnone way. That white center post is connected to your trim adjustment on the underside of your car. You’ll notice it makes the white shaft move from right to left when adjusted. This makes the spring legs move right or left making your steering go right or left. If the spring looks to be where it’s supposed to be then make sure the legs aren’t bent. They should be straight from the coil around the white shaft to the end of the legs.
If the spring looks good let me know. I’ll tell you how to bend the spring so I goes straight. Trust me,I’ve done it to my own car. I had to have it all the way to the left before it would go straight. I didn’t have to bend my spring but I did anyway just because I didn’t like that adjustment all the way over.
-Peter
Yes, that’s my only fear. Those transistors on the PC board look pretty small. I hope I don’t fry one using 2 motors. But like I said, there’s only one way to find out! Do the mod and cross my fingers.
-Peter
Or just copy and paste it. For some reason, direct links don’t work, but copy and paste does :smiley5:
Great first post fastburro! Possibly solving the problems of many more people is good. And it’s very good to have an EE around here. I’m an AE which isn’t very usefulformicro RC cars.
okay. that didn’t work. just go to the discussion section on bit char and then look for “alignment” derek’s post should help. b
here try this link
http://www.ausmicro.com/forum/display_topic_threads.asp?ForumID=3&TopicID=169
hope it helps. b
hey deejay. what size are the batteries for the epoch indoor racer? could you match it up with a bit char n50AAA battery to see if it is a match? thanks b
What do I do with the center magnet? If this has already been diagramed or expressed please leave thread.
Thanks
I have a 45MHz WRX, and took it apart to do the range mod. I found no capacitor on top, but being an EE and having a devious mind, I took out the PC board to look at the BACK of the board. Lo and behold, there is a 10pF cap soldered to the board in just the right place. Snip, snip; range now in the 7 meter class.
Moral; if you don’t find the cap on top of the board, look on the bottom!
Good luck!
Mark
the yokomo cars are supposed to be 1/60. they only come in the honda van form right now. the toyota (not sure which style) is the next one to come (waiting for that).
b
does anyone know what size the Epoch Indoor Racer batteries are? i saw a replacement battery set and it looked like 3 n50aaa cellsin shrink wrap. they were nickel metal. could be a winner since the cars are 1/43. b
take apart the front end and center the magnet. that should do it. b
yeah, shouldn’t be anything to worry about. just put harder tires on the front or softer tires on the rear to lessen your oversteer. if the car starts to barely turn, then you went too far. b
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