Mato Servo Nogo

Talk about all other types of electronics here, such as batteries!
User avatar
Herr Dr. Professor
Lieutenant
Posts: 3456
Joined: Mon Apr 22, 2019 10:48 pm
Location: Southern Wisconsin USA

Mato Servo Nogo

Post by Herr Dr. Professor »

I just got a Mato M10, a tank I have long wanted but hesitated to get because of its cost and reputation for problems. Sure enough, here is problem #1: the recoil does not seem to work at all. Here is problem #2, the gun elevation servo quit unexpectedly and inexplicably after functioning fine for a few test trials. Also, I have not seen the infrared flash (I don't really care), but the gun flash does work.

My inclination is to test the servos independent of the processor board to see if I can isolate the problems at the "end of the line" (so to speak). Then I can work back to try to test the processor.

1) Can I use a test 7.4 or 7.2 (Mato supplies a 7.4 LiPo) through the wires to see if the servos move?
2) If yes to 1, can anyone tell from the photos which is which for each servo? (These would be the wires to which I would attach my handy-dandy from the 7.2 or 7.4 battery test thingie made of pins.)

Remember, I am at a pretty basic level. In fact, this is my first tank with what I think are "assembled" (as opposed to in-house a la Taigen or HengLong) electronic guts and servos. I have tested wiring and motors before, although with hesitation and caution.

Here is the processor board (Clark?) intact as it came:
Receiver board intact.jpg
Here is the recoil servo:
recoil servot intact.jpg
Here is the turret with the elevation servo out of its mounting clamps:
Elevation Servo Out.jpg

Here is the turret wiring separated from the processor board:

Turret Wiring Out.jpg
Attachments
Turret Wiring Overview.jpg
User avatar
Rad_Schuhart
Warrant Officer 1st Class
Posts: 1979
Joined: Tue Jan 19, 2016 9:22 am
Location: Spanish living in Graz, Austria. Heart in UK.
Contact:

Re: Mato Servo Nogo

Post by Rad_Schuhart »

With such a power you will fry the servo immediatelly, besides the servos work different than the normal motors, hence have three wires.

If you have a normal hobby radio and receiver just plug it there and check if it moves.
My RC tanks website, loads of free info for everybody:
https://radindustries.wordpress.com/
User avatar
Herr Dr. Professor
Lieutenant
Posts: 3456
Joined: Mon Apr 22, 2019 10:48 pm
Location: Southern Wisconsin USA

Re: Mato Servo Nogo

Post by Herr Dr. Professor »

Thank you, Rad! Your answer also explains why I asked first, lest I make matters worse. I can test by re-assembling the board wiring.
User avatar
abramsky
Lance Corporal
Posts: 236
Joined: Thu Dec 03, 2020 12:55 am
Location: Poland

Re: Mato Servo Nogo

Post by abramsky »

Servo usually need a power supply with a voltage below 7V (or preferably it should be in the operating range of a typical receiver: 4-6.5V, although there are versions for higher voltage). However, a standard servo, if it gets more - you will fry its electroics.
If I were you I would use a Step-Down module to power the servo to lower the voltage taken directly from the battery (via the auxiliary power line) and from the MFU of the tank to the servo I would only take one Signal wire (S line). Btw. You write about 7.4V LiPo battery voltage:
Herr Dr. Professor wrote:1) Can I use a test 7.4 or 7.2 (Mato supplies a 7.4 LiPo) through the wires to see if the servos move?
2) If yes to 1, can anyone tell from the photos which is which for each servo? (These would be the wires to which I would attach my handy-dandy from the 7.2 or 7.4 battery test thingie made of pins.)
Which is a mistake because you are giving the voltage of an empty (dry battery) - a fully charged one gives 8.4V! And this will definitely fry the servo electronics (but the motor and potentiometer should be able to withstand it)

The servo cable has 3 lines;
S-signal (white or yellow)
VCC (POS + red)
GND (NEG - black or brown)

And this is how you connect the wires to it.
Below is a drawing showing what plugs and wire colors you can find:
SERVO CONNECTORS.gif
SERVO CONNECTORS.gif (21.03 KiB) Viewed 2414 times
http://domanrchobby.com/upLoad/image/20 ... 786543.gif

Update:
Your servo has a yellow, red and black wire which means:
Yellow - Signal - connect to MFU (Signal PIN)
Red - VCC (+ power supply) from the receiver or from the battery through step down - max voltage cannot be higher than 6-6.5V
Black - GND (ground / minus) just like red (+) you connect to
receiver or from battery by step down

You can also take up to 6V voltage from the MFU (if it is provided) but the easiest way is to take the power supply bypassing the MFU

P.s. And if this is Clark MFU and has dedicated outputs for servo - voltage servo probably should be reduced accordingly to their requirements? Am I right?
If I were you, I'd use a voltmeter, connect a servo extension cord, and measure the voltage between the BROWN and RED wires ...
User avatar
Herr Dr. Professor
Lieutenant
Posts: 3456
Joined: Mon Apr 22, 2019 10:48 pm
Location: Southern Wisconsin USA

Re: Mato Servo Nogo

Post by Herr Dr. Professor »

Thank you, abramsky, for all the information. I am keeping it and will read and re-read to learn. I believe the MFU in the Mato tanks is a Clark board, but I am not sure. Someone here on RCTW might know for sure. Again tonight, I will be trying the servos connected through the MFU supplied in the M10. Who knows, maybe a mysterious correction will occur.
User avatar
abramsky
Lance Corporal
Posts: 236
Joined: Thu Dec 03, 2020 12:55 am
Location: Poland

Re: Mato Servo Nogo

Post by abramsky »

You're welcome. You can also refer to this article:

https://www.makerguides.com/servo-arduino-tutorial/

Instead of Arduino boards - think that this is your MFU (the power scheme is identical).
Pay close attention to the drawing showing "Multiple servo motors connected to the Arduino Uno and an external power supply".

And as Rad_Schuhart mentioned before. To check if the servo is working properly you must have a hobby grade RC transmitter and receiver, or a sevo tester.
The voltage itself (POS and NEG) connected to the servo will do nothing if you do not give it a PWM signal.
Jofaur86
Warrant Officer 1st Class
Posts: 1663
Joined: Tue Dec 25, 2018 11:28 pm
Location: Centre France

Re: Mato Servo Nogo

Post by Jofaur86 »

User avatar
Herr Dr. Professor
Lieutenant
Posts: 3456
Joined: Mon Apr 22, 2019 10:48 pm
Location: Southern Wisconsin USA

Re: Mato Servo Nogo

Post by Herr Dr. Professor »

You gentlemen have been kind and remarkably fast in replying. I am using my iPhone now, but tonight I will have an internet connection on my PC and will check all three web sites you just recommended. Thank you.
User avatar
Herr Dr. Professor
Lieutenant
Posts: 3456
Joined: Mon Apr 22, 2019 10:48 pm
Location: Southern Wisconsin USA

Re: Mato Servo Nogo

Post by Herr Dr. Professor »

I just returned the wiring through the MFU as it was from the outset. I am now seeing that everything works, but for two new problems.
1) the recoil servo operates momentarily as it should; however, the barrel seems not to be connected to it. I will investigate this to see if a mechanical link has come loose.

2) the elevation servo is operating erratically:
...a) Sometimes it operates momentarily as I switch on the MFU power. I believe this is normal.
...b) Sometimes it operates in response to the transmitter control, but will not stop turning until and unless I switch off the MFU power.
...c) Sometimes it begins operating immediately as I switch on the MFU power, and it will not stop until and unless I switch off the MFU power.

(Phenomenon b initially led to panic as the arm of the servo wrapped up wires resolutely. :O I quickly realized it would be good to remove the servo arm not only from the gun, as I had already done, but also to remove the servo arm from the servo, too. :S )
User avatar
abramsky
Lance Corporal
Posts: 236
Joined: Thu Dec 03, 2020 12:55 am
Location: Poland

Re: Mato Servo Nogo

Post by abramsky »

a) This is normal servo behavior when you turn on the power.

b) the servo behaves in this way when the arm meets resistance (some obstacle in its path, e.g. cables or model element) before the arm reaches the deflection angle it received from the transmitter.

c) the same as in point b), or check if your transmitter (TX) works in a mode other than servo, eg PPM instead of PWM. I encountered such a problem with my FlySky i6x.
I also noticed a similar behavior ( like your C point ) when the servo gets too high supply voltage. I noticed this for the first time when I connected a servo to my new Chinese PWM converter with a supply voltage range from 3.3-24V. I turned out that it gives the voltage to the servo directly from LiPo 8.4V - despite the fact that it has a built-in Step-Down and the input was 5V ... I burned the test 9g servo in this way ...
Post Reply

Return to “Other electronics”