cyanyde

That statement is gonna make this thread famous...

Andrew S

iTrader: (3)

Is there a specific magnet you need to get? Or just the biggest one you can find?

calvin

Might want to check out this thread starting with post 146

http://www.rctech.net/forum/electric...uo-3-a-10.html

Mr RCTech

iTrader: (2)

Here is some FACTS about your rotors.

Neodymium (more precisely Neodymium-Iron-Boron) magnets are the strongest permanent magnets in the world.


What are neodymium magnets made from and how are they made?

Neodymium magnets are actually composed of neodymium, iron and boron (they are also referred to as NIB or NdFeB magnets). The powdered mixture is pressed under great pressure into molds. The material is then sintered (heated under a vacuum), cooled, and then ground or sliced into the desired shape. Coatings are then applied if required. Finally, the blank magnets are magnetized by exposing them to a very powerful magnetic field in excess of 30 KOe.

Can I make a magnet that I already have any stronger?
No, once a magnet is fully magnetized (saturated), it cannot be made any stronger. (New)
So, you can't make them stronger then they where new.

Does stacking magnets together make them stronger?
Yes, two or more magnets stacked together will behave exactly like a single magnet of the combined size.
This is what I use to recharge my rotors.
I combined 4 N42 Neo magnets (1''X3'') to form a block.

What does the "N rating", or grade, of the neodymium magnets mean?

The grade, or "N rating" of the magnet refers to the Maximum Energy Product of the material that the magnet is made from. It refers to the maximum strength that the material can be magnetized to. The grade of neodymium magnets is generally measured in units millions of Gauss Oersted (MGOe). A magnet of grade N42 has a Maximum Energy.

This info was cut a pasted from here:
http://www.kjmagnetics.com/FAQ.asp#strongesttype

Andrew S

iTrader: (3)

Thanks heaps for the info!

dvaid852456

I've just read through this thread and surely taking a 13.5T motor to full throttle with no load and maximum timing on the ESC will damage the motor or rotor?

I was always under the impression that you should never free rev a brushless motor as rotors can shatter?

dvaid852456

Also do you have any more information on recharging rotors?

Exactly what sort of magnets and in what configuration to you set them up in to recharge the rotor?

tc3team

I did it once and didn't even go full throttle...

The unloaded rpm on a brushless motor is immense.

Not something I care to try again.

13.5 Blinky, installed in the car however, is a very different story. It's obviously a lot smoother and possible, but I probably still wouldn't suggest doing it.

Save the mileage for the track!

dvaid852456

I have been doing some bench testing with my TCXX connected up to an Eagle Tree data logger and found the following results first with the SP Reventon Pro and secondly the Toro TS120:

Reventon Pro
Boost 80%
Turbo 140K
Motor Timing 20
Current 27.69A
RPM 32967

Toro TS120
Boost 24
Turbo 36
Motor Timing 20
Current 29.55A
RPM 32963

Both the settings above gave the maximum RPM for lowest current draw from a range I tested. Any further increase in timing did not increase the max RPM but only increased the current draw. Can I assume this is the peak setting for each ESC? From here is it a case of tuning for feel on the track?

niznai

To find the true zero timing of a motor you need to run it on the bench and turn the endbell until you find the lowest RPM for your selected voltage. The voltage doesn't count, the zero timing point does not depend on it (the RPM figure will, but what you're trying to find is the point where this is minimal by adjusting the timing on the endbell), so you can choose for safety something like 3V (or say a number of points on your throttle trim with zero timing on the ESC (blinky mode?)). More difficult to do with some motors than others, or impossible with some like the LRP where you have to physically change the inserts to alter timing, but you can still test and record RPM under same voltage and draw a graph.

Or you can try to find the manufacturer info on the web where available or the results of tests done by others (homologation bodies, perhaps?).

The maximum efficiency is indeed what you want to know (doesn't matter what the timing is). Serious manufacturers will have this info in the data sheet with their motors.

koz47

iTrader: (97)

I always recharge my rotors before the next race.
Its more consistent with no drop in lap times.[/QUOTE]



ALOL>>>>>> come on.. you were doing alright till that..

show me a pic of the 440 line you have from the pole