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Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Tue Dec 03, 2024 8:21 pm
by Thembi
General Jumbo01 wrote: Tue Dec 03, 2024 3:53 pm Hi again Thembi, l failed to spot you are running 13.5 motors. These are higher revving motors made for race cars so are less 'stable' than a 27t or more stock motor. You may find that simple replacing them with a well known brand 27t can, a low cost fix, may do the job.

Sent from my SM-A226B using Tapatalk
They seem to run quite slowly when testing (not moving the tank, just observing)

Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Tue Dec 03, 2024 8:22 pm
by Thembi
jhamm wrote: Tue Dec 03, 2024 1:03 pm Hi Thembi,
all brush motors are set to clockwise rotation in the timing by default.
If you run the motor anticlockwise, it runs slower.
The timing can be adjusted on the 540 13T motors seen on your picture.
This allows you to achieve the same speeds
Look at the video:
https://www.youtube.com/watch?v=UMN8a4N839Q
Really!? I'll check out the video, thanks!!

Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Tue Dec 03, 2024 8:32 pm
by tankme
jhamm wrote: Tue Dec 03, 2024 1:03 pm all brush motors are set to clockwise rotation in the timing by default.
If you run the motor anticlockwise, it runs slower.
The timing can be adjusted on the 540 13T motors seen on your picture.
This allows you to achieve the same speeds
Look at the video:
https://www.youtube.com/watch?v=UMN8a4N839Q
I'll have to disagree with this statement about the timing that ALL motors have positive timing. There are DC brushed motors that are neutrally timed from the factory, but I will agree that if you have a motor with some degree of forward timing it will run slower in reverse. And for those about to ask how can I tell what my motor timing is, only way I know of is to measure the RPMs of the motor in both directions. Driveline losses can also affect motor speed.

Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Wed Dec 04, 2024 5:47 am
by Pavel
Thembi wrote: Tue Dec 03, 2024 8:16 pm You mean a positive lead to its battery? Really?....why?

Sorry, what is "BEC"

Thanks!
Each speed controller is equipped with a device that supplies stabilized 6 Volts to power the receiver. BEС...
Inside the receiver there is its own BEС, but it is more for protection against voltage drops....
And in principle, it is unacceptable to use two such devices at the same time.
Some speed controllers do not specifically make BEС, they are called OPTO and then a UBEС is taken - a remote device, also receivers cannot switch currents greater than 1-2 Amperes, to power powerful servo drives, then remote devices are used.

Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Wed Dec 04, 2024 9:35 am
by jhamm
tankme wrote: Tue Dec 03, 2024 8:32 pm I'll have to disagree with this statement about the timing that ALL motors have positive timing. There are DC brushed motors that are neutrally timed from the factory, but I will agree that if you have a motor with some degree of forward timing it will run slower in reverse. And for those about to ask how can I tell what my motor timing is, only way I know of is to measure the RPMs of the motor in both directions. Driveline losses can also affect motor speed.
The most brushed motors have a forward brush-shift, when run in the reverse direction, will have, due to resultant lagging phase angle,
adverse effects resulting in poor commutation, undesirable electrical noise, and shorter life.
For this reason, the motors must be run in one direction only.
This is done simply to improve the degree of effectiveness.
Of course there are exceptions, and no one here disputes that.
As a rule, motors for left-hand rotation are marked separately, as are motors that do not have a preferred direction of rotation.
Of course, you won't find this information on cheap brush motors from China....
A look at the brush holder in the motor will show you whether this motor has a preferred running direction.
Just take a look at the Mabuchi website - one of the largest manufacturers of brush motors. ;-)

Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Wed Dec 04, 2024 12:39 pm
by Thembi
Pavel wrote: Wed Dec 04, 2024 5:47 am
Thembi wrote: Tue Dec 03, 2024 8:16 pm You mean a positive lead to its battery? Really?....why?

Sorry, what is "BEC"

Thanks!
Each speed controller is equipped with a device that supplies stabilized 6 Volts to power the receiver. BEС...
Inside the receiver there is its own BEС, but it is more for protection against voltage drops....
And in principle, it is unacceptable to use two such devices at the same time.
Some speed controllers do not specifically make BEС, they are called OPTO and then a UBEС is taken - a remote device, also receivers cannot switch currents greater than 1-2 Amperes, to power powerful servo drives, then remote devices are used.
Got it, thank you!

Re: Mixing Question, Spektrum, motors not starting simultaneously.

Posted: Wed Dec 04, 2024 2:29 pm
by Pavel
"""""A look at the brush holder in the motor will show you whether this motor has a preferred running direction.""""
Everything is simpler!
the manufacturer puts a red dot next to the motor terminal, on more expensive models the "+" sign is cast on the plastic of the holder near the terminal.
On others, on the back cover of the bearing there is an arrow indicating the direction of rotation, at which the motor produces maximum values.....