Jump to content
Sign in to follow this  
peta13

Tamiya Hilux High Lift / MFC-02 problem

Recommended Posts

Hi everyone, neubie here. Sorry for not making a post introducing me and my truck before even asking for your help, but before i could finish to build my truck i had some issues that i can find solution anywhere, and i was wondering if you guys could help me solve it.
My main problem is that whenever i trhottle foward or reverse a beep starts to sound, and if I dare to shift gears it all starts failing, steering and shifting go crazy, hazard lights start flashing and a beeping start and the only way of stoping this is turning off the truck/mfc and transmitter (Futaba Attack 4ywd). I've tried everything, changing cables plugins, trying to run the truck in rc mode, but every time i shift it all go crazy.
I've tried teaching the mfc as the manual suggest, but when i get to stage C, teaching shifting, the motor starts running and thats the sign the teaching fail.
Sorry for my bad english, i hope you can help me, i'm getting really frustrated here.
Thanks in advance.
Regards

Share this post


Link to post
Share on other sites

It does that sound when your batteries are almost dead

Share this post


Link to post
Share on other sites

Shodog thanks for your reply... i running brand new batteries in the radio, and a brand new, fully charged 7.2v Nimh 5300 mah. I even tried that battery with another car and works fine.

Share this post


Link to post
Share on other sites

Wow. Interesting.

Are you sure the shift servo is working properly?

It's like the moment the receiver asks the shifting servo to move, the feedback from the servo is causing havoc with the receiver.

It's in some sort of feedback loop and from that point forward the receiver ignores the transmitter.

If the MFC02 is removed from the equation, does everything work (FWD/REV/SHIFT/STEER)?

If you unplug the shift servo but leave MFC02 connected, does it still go crazy?

Share this post


Link to post
Share on other sites

Champ85 thanks for your reply...

I donĀ“t know how to get de MFC out of the equation, i donĀ“t have en extra ESC to test that. What iĀ“ve already checked was the second advise of yours, I unplugged the shift servo and the truck works almost fine... the beeping when throtteling is still there, but when I"shift" with my radio the truck doesnĀ“t go crazy any more. I guess that the servo is the problem, without the servo the truck doesnĀ“t go crazy, but why itĀ“s still beeping whenever I throttle?

Thinking of buying one or two good servos to replace these two, any suggestions?

Thanks again for all the help guys!!

Share this post


Link to post
Share on other sites

I forgot the MFC-02 has an ESC built into it, sorry.

During the teaching steps, are you supposed to have the motor hooked up? Most ESCs tell you not to, although I usually ignore that and it works fine anyway.

Defective MFC-02?

Are you using digital servos or analog servos? I don't see anything on TamiyaUSA about not using digital servos.

One final note: Generally (at least in the old days of 75MHz systems) it is a good idea to keep the transmitter a minimum of 1 meter away from the receiver during normal (non-bind) operation. Sometimes the receiver can get overloaded (signal strength) if the TX is too close. I doubt it is the cause of your troubles here, however.

I'm out of ideas, sorry.

Share this post


Link to post
Share on other sites

Champ85 thanks for your reply... These are digital servos, but just like you i couldnĀ“t find anything about not using digital.

I will try teaching the MFC with the motor (and servos) unhooked to see what happens.

I drove the truck several meters away and the problem was there too.

Thanks again

Share this post


Link to post
Share on other sites

Peta13..

I just watched your youtube movie, and the beeping sound that is coming from the car when you move the throttle stick forward and reverse just sounds to me like the transistors in the MFC-02 are switching, and it is normal to hear that sound on a brushed motor ESC.. (if you disconnect one of the motor wires and then move the throttle stick forward and reverse it shouldn't make the sound)..

OK, so when the shift servo is connected, it makes the MFC-02 do crazy things, and with the shift servo unplugged the MFC-02 is working fine..

What I would do next is unplug the steering servo from the MFC-02, and plug the steering servo into the MFC-02 where the shift servo was connected.. Then turn the car and controller back on and then test the MFC-02 again, and when you move the shift stick on your radio controller, (the steering should move) and check and see if the MFC-02 goes crazy again, or if everything still works fine..

If your MFC-02 works fine after this test, then I would say that you have a faulty servo..

You should be able to train the MFC-02 to your radio controller without the servos connected.. Also, take the wheels off when you are doing the teaching steps, that way if the motor does rev up, your truck wont run away from you.. ;-)

Share this post


Link to post
Share on other sites

Digital servos

- may draw a lot of amps, and cause a weak bec to sag (drop voltage)

- may generate electrical noise that interferes with analogue radios

I would start by making sure shift servo cable is nowhere near antenna cable or near mfu

Share this post


Link to post
Share on other sites

PETA 13

I read with interest your issue and watched your clip on YouTube....I assume/ hope that you have long since resolved this issue? If you have, what solved the problem?

I have a similar issue with a Tundra high lift. It is my second ever build and I class myself as a beginner and not at all clued up on the electronic side of things. I don't have the added complication of an MFC-02. My issue is with the gear change and the steering. I have a TEU-302 BK ESC as recommended for this kit. I have a Carson reflex stick 2.4 GHz RC with a 6 channel receiver. I was using Acoms AS-17 standard servo's - steering in ch1. ESC in ch2 and the gear change in Ch3. Steering is fine and the gear set up is good - mechanically, it works right. However, when I do change gears, the gear change servo locks up and then the steering turns one way and seizes up too. You then have to switch off and back on for it to reset but it does it straight away again. What makes me think it is similar to your issue is that the gear change also sometimes does what yours was doing in the YouTube video. Fully charged batteries...it does it from the start. I changed the servo's for tower pro mg995 metal gear digital servo's and it continues to do it. I also tried swapping the servo's into each other's channels so it changes gear on the throttle stick rather than the steering stick...no difference. They work individually if only one is plugged in but not together. So that leaves the ESC?? I wouldn't know where to start. Did you learn anything from your experience or does anybody else know what would be causing this?

Any help appreciated. I'm a new member on here and will upload some pics when I get done building...feel a bit cheeky signing up and straight into looking for help, but I'm stumped before I have barely started!

Share this post


Link to post
Share on other sites

Not all transmitters are compaterble with mfu's are you sure yours is compaterble with the mfu .

I was told this by my lhs when I brought my truck last year

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...