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View Full Version : Is it the transmitter or the receiver?


xenjoi85
2012.04.02, 08:56 PM
i bought a mini-z awd with a lot of up-grades on ebay. Extremely happy overall. however, for some reason, when i try to go forward, after going in reverse, it doesnt like to move. for some reason, if i stear left or right, it seems to start working again but not always. reverse works 24/7. but for some reason, the car doesnt like moving forward, AFTER reversing once. other then that, its flawless. is that the receiver, transmitter, or transmitter setting? i hope the later cause the other 2 are expensive


thank you very much

miniz racer
2012.04.03, 12:33 AM
try switching the motor wires on thr board

cowboysir
2012.04.03, 01:34 AM
lets get a bit more info:

1. Is it an ASF model or AM?
2. What kind of transmitter do you have?

It seems to me it could be as simple as the position of your fwd/rev throttle balance on your TX. With too much reverse setting you may not get forward as quick as you'd like....

herman
2012.04.03, 05:48 AM
if it's an asf awd... try doing a transmitter re-set and do a rebind...
hope this helps...

xenjoi85
2012.04.03, 07:28 AM
lets get a bit more info:

1. Is it an ASF model or AM?
2. What kind of transmitter do you have?

It seems to me it could be as simple as the position of your fwd/rev throttle balance on your TX. With too much reverse setting you may not get forward as quick as you'd like....


Firstly, thanks everyone for the responses and concern. I really appreciate it. Also for bearing with me because clearly, im pretty new to this.

Anyhow, its your standard fare KT-18 ASF 2.4 ghz transmitter setup. I'm not entirely sure its the throttle balance though because when i got the car and TX for the first time, it didnt want to go in reverse hardly at all. i found enough documentation online on the TX (It says its the manual but their isnt much info on programing it) to get the Throttle trim balanced a bit and actually have a reverse function but it never changed my inability to go forward, after, reversing.

i kinda figured maybe their is a trigger trick or something but that doesnt seem to be the case. i thought maybe whatever the throttle trigger engages inside the TX was dirty or something, but its so responsive when going forward i doubt that. =(

Thanks again

imxlr8ed
2012.04.03, 09:38 AM
You may be encountering the brake function when struggling to get it into reverse. With the first 2.4 boards, there is a 0.5 second delay from forward to reverse. This is so you can brake the car without going into reverse. When wanting to back up just wait a bit (0.5 sec), then push the trigger forward twice.

Now, if it's a KT18... I'm pretty sure you can flip the channels for throttle and steering, make sure your foward trigger pull is a pull towards the palm of your hand. If it's not, it should be. Sounds silly, but I've seen a few complete newbies pushing the trigger forward to go forward with other types of RC cars.

Throttle trim should be a few bumps above center, five beeps forward of center is where I'm usually at.

With that checked or adjusted, check your motor wires to the board, make sure the negative and positive are connected to the board correctly.

I only go to this detail because your initial post makes it sound like your brake function is reacting when you try to go forward, make sure the motor isn't wired backwards, and your controller channel is going the right direction.

Traveler
2012.04.03, 11:21 AM
I only go to this detail because your initial post makes it sound like your brake function is reacting when you try to go forward, make sure the motor isn't wired backwards, and your controller channel is going the right direction.

I was thinking the same thing, that the motor is wired backwards and the former owner flipped forward and reverse on the KT-18 instead of correcting the problem, thus resulting in reverse delay kicking in when trying to go forward right after reverse. Guess its true that two wrongs don't make a right :confused:

xenjoi85
2012.04.03, 12:44 PM
Thanks again guys for your input. Seriously appreciated. I will check the wire layout when i get home from work. i cant tell if i want that to be the case or not lol. Is that maybe why i am able to go from forwards into reverse INSATANTANIOUSLY? but cant do the same from reverse to forward?

i was wondering if thier was a double tap action to disengage reverse to go into forward whcih you kind of clearified for me. Thanks for that. Also, i am pulling thr trigger towards my palm for forward and pushing away for reverse so i am in the correct configuration in that reguard.

Is thier any way to completly reset the mini-z to start the calibrtation from square one? or to do the same with the transmitter? you were talking about how many clicks from center you are, and i think i can figure out whats "center" based on the beep patern, but id be easier to just hit a fat "reset" button.

Also, I ordered a MA-010 AE86 car that should arrive tomorrow. I suppose depending on how the car reacts, I should learn alot on my current situation. Thanks again!!

xenjoi85
2012.04.03, 06:05 PM
OK, Here is what i have learned. I am able to go from reverse to forward. If, while going in reverse, i pull the trigger toward me quickly and release, then pull toward me again, it goes forwards again. this seems like it supports the theory of reversed leads. i take it the idea is to be able to PUSH the throttle up as a break, and then up again for reverse. I have a picture as well to (hopefully) illustrate.

thanks again

Traveler
2012.04.03, 07:20 PM
OK, Here is what i have learned. I am able to go from reverse to forward. If, while going in reverse, i pull the trigger toward me quickly and release, then pull toward me again, it goes forwards again. this seems like it supports the theory of reversed leads.

Correct!

i take it the idea is to be able to PUSH the throttle up as a break, and then up again for reverse.

Yup!

I have a picture as well to (hopefully) illustrate.

Wires definitely reversed at the board (assuming the are on the motor correctly)!

thanks again

No problem.

Traveler
2012.04.03, 07:31 PM
Is thier any way to completly reset the mini-z to start the calibrtation from square one?

Not that I am aware of, unless is happens when you rebind to controller.

or to do the same with the transmitter?

On KT-18, press and hold down throttle trim button,
Turn on power while continuing to hold down throttle button,
When LED lights after about 3 seconds, release throttle trim button.
You are done reseting KT-18 but may have to rebind to car...

xenjoi85
2012.04.03, 08:07 PM
Fantastic! thanks a million Traveler. I think because we've gotten to the bottom of the issue and my soldering skills are...... sub par, i think i may leave it intact. it doesnt seem as if im hurting anything? the motor seems comfortable in any direction. for clarity though, which wires are reversed? i see that the 2 going into the body on the battery compartment have been replaced since the stock wire is white but im failing to see the correct setup (all the photos i see have the receiver cover in the way.) Again, thanks everyone for the feedback. i thought the US Mini-z Community was dead but im pleasantly mistaken

Traveler
2012.04.03, 08:27 PM
Motor wires are attached to the board with screws, so no soldering required. Just remove screws connecting motor leads to board (red and black wires with eyelets on left hand side in your picture), swap location of wires and reconnect with screws. Then reset KT-18 and you should be good to go!

xenjoi85
2012.04.03, 09:06 PM
Motor wires are attached to the board with screws, so no soldering required. Just remove screws connecting motor leads to board (red and black wires with eyelets on left hand side in your picture), swap location of wires and reconnect with screws. Then reset KT-18 and you should be good to go!

Woohoo! the red lead is exposed but i take it the negative is underneath the board correct? is their a trick to pulling the board out?

imxlr8ed
2012.04.04, 12:04 AM
Wait no!

The wires from the motor need to be switched! DO NOT SWITCH THE POWER LEADS FROM THE BATTERIES TO THE BOARD! YOU WILL FRY IT!

The screws on the left of your picture... the left!

Red wire (+) should be outboard, black wire (-) inboard.

xenjoi85
2012.04.04, 12:25 AM
Wait no!

The wires from the motor need to be switched! DO NOT SWITCH THE POWER LEADS FROM THE BATTERIES TO THE BOARD! YOU WILL FRY IT!

The screws on the left of your picture... the left!

Red wire (+) should be outboard, black wire (-) inboard.

ok. no worries mate, no changes made yet. thank you for saving me a lot of money

imxlr8ed
2012.04.04, 12:28 AM
Whew!!! ;)

The radio reset and the motor wire swap should get you back in correct running fashion, good luck!

xenjoi85
2012.04.04, 12:43 AM
Success! i flipped the wires as instructed. i had to reverse the steering setup on the transmitter but, i got it working!hitting up on the trigger only hits the brakes and i can immediately go back to the accelerator.

Many thanks again for all your help and taking me to class on all if this.

Traveler
2012.04.04, 04:29 AM
Souinds like the former owner really screwed up installing that boad, but glad you got it working correctly. :)