out the box timing?

[Dave Dodd]

brushless motor say 21.5t, what would the timing be out the box?
would it need to be turned down to make it 0 degrees?

+.....(|).....- is the middle zero or +.....|.....(-) is the minus zero

yes this is for the GT12 class

any help thanks

[imull]

The middle is normally 0, so you can advance and retard as required.

What make and model is it? Some are different, SP3 being one where there is only advance.

[SlowOne]

The markings on the can mean nothing in relation to absolute zero timing. To know exactly what timing a motor has you have to look inside it.

When the sensors are lined up with the gaps in the stacks, that is zero. Most motors will not run properly if you set them to that. Since they are all made differently, the manufacturer decide what is 'zero' on their markings. Most marked 'zeros' are between 10 and 20 degrees of actual timing relative to the stacks.

When a DC electric motor is under load, the interaction of the the permanent and electro magnet fields means they retard on timing. That's why every one of them comes with some advance. The manufacturer sets that depending on their motor design, and then marks the can accordingly.

The next thing that affects the timing is how close the rotor is to the sensors. The further away it is the later the sensor sees the rotor, effectively retarding the timing. So if you move a rotor closer to the sensors you change the timing. With all the tolerances on build, this can vary so the timing varies.

In operation, the sweet spot is a combination of timing and gearing. How you balance that off depends on your driving style and the weight of your car. The lower your corner speed, and the heavier your car, the more torque you need. Lower timing settings will give you more torque that you take advantage of by having a higher gear ratio. Factor in the weight and you'll find that it differs markedly between classes. For example, GT12 cars (950g) run their 13.5 motors around 65mm/rev to 70mm/rev depending on the motor, but the same motor in a 12th car (730g) would by up in the 80s.

So, in answer to your question is you cna have no idea what the timing is out of the box unless you look inside and measure the sensor's angle from 0 deg (sensor in the gap between the stacks) And if you did set them all to 0 deg, then they would be very different in performance.

The great thing about BL is that once you find the timing/gearing sweet spot, there is not much difference between the motors. However, if you locked them all at 0 deg actual, then there would be more difference.

- would turn timing down, + would turn it up. HTH

[Dave Dodd]

Thanks

slowone, i think it was you i spoke to at chesterfield. ?

[SlowOne]

Could be, I thought the question was familiar! As I said then, if the issue is one of equivalence (2S/21.5 v 1S/13.5) then it is a hiding to nothing. There is no equivalence between 2S and 1S whatever the motor because the voltage makes the physics very different.

Hope you sort it out with the guys at the Club and that you get the racing you want.