Prop question

[secrtwpn1]

While wiring up my motor on my 2.5" WTC, it appears to be faster in reverse. So, which direction does the shaft have to spin to go forward. Its for my Blueback....

Thanks
Farlan

[Ralph --- SSBN 598]

One of my boats does the same thing.
With Tx set at 100% forward and 100% reverse, the reverse is faster.
The motor was too fast so I reset the Tx output to 60% forward and to get the same RPM in reverse, I think the reverse is set at 25%.

As for which direction should the shaft turn to go forward, look at the propeller and see which way it needs to turn to push the boat forward.

If you push the Tx stick away from you, and the propeller goes the wrong direction, reset the Tx by reversing the channel signal.
Don't forget to reset the forward and reverse percentages as well.

[JWLaRue]

What brand/model of speed controller do you have? Some need to be set up with the transmitter to properly detect full forward and reverse. I'm not referring to which direction the motor turns for a given stick input, but whether to speed controller provides full power at either end of the stick throw.

-Jeff

[secrtwpn1]

Its an Mtronics speed controller.....I set it up per the instructions. Ralph, its not connected to a prop yet.....

[JWLaRue]

Okay...Mtronics ESC. What happens if you reverse the leads to the motor?

When looking at the stern (bow pointed away from you), the direction you want the prop shaft to turn for forward is clockwise.

-Jeff

[subdude]

Folks, please allow me to remind you that not all electric motors turn the same speed in both directions of rotation. If the commutator is "timed" to have a certain amount of advance when the brushes contact the commutator as compared to the moment when the armature windings are centered in the fields of the magnets, this results in a motor that is optimized for rotation in one direction. This is used primarily in motors designed for installation in R/C race cars, but can be found in other applications as well.

The easiest way to see if this is what you are dealing with is to hook the motor directly to a battery. Then reverse the polarity (wires) and see if the motor spins the same speed in both directions.

Mechanically, there is nothing you can do to change this short of rebuilding the armature. You can "compensate" for it by reducing the amount of radio input in the faster direction to make it seem more even.

Jim

[secrtwpn1]

Ok. Thanks for the info. The shaft spins clockwise...........

[cliffhanger67]

Folks, please allow me to remind you that not all electric motors turn the same speed in both directions of rotation. If the commutator is "timed" to have a certain amount of advance when the brushes contact the commutator as compared to the moment when the armature windings are centered in the fields of the magnets, this results in a motor that is optimized for rotation in one direction. This is used primarily in motors designed for installation in R/C race cars, but can be found in other applications as well.

The easiest way to see if this is what you are dealing with is to hook the motor directly to a battery. Then reverse the polarity (wires) and see if the motor spins the same speed in both directions.

Mechanically, there is nothing you can do to change this short of rebuilding the armature. You can "compensate" for it by reducing the amount of radio input in the faster direction to make it seem more even.

Jim

Would it then make sense to reverse the wires to put the faster rotation on forward if the propeller is so designed for that rotation? Thank you for this very valuable information as i have observed it on some of my motors and unhappily living with it.

[salmon]

I would add that most subs are overpowered and you will be dialing back the amount of juice getting to the motor anyways. So, the amount going one way or the other is not a issue and you might be overthinking this. There might be a slight AMP usage difference as well, but again not really an issue with the power supplies we are putting into the wtc.

[JWLaRue]

Would it then make sense to reverse the wires to put the faster rotation on forward if the propeller is so designed for that rotation?

You don't really have a choice here. The motor can only run in one direction to go forward for a given prop.

-Jeff