Some Technical Questions - Please help me.

[Roy Harris]

Please can anyone help me, on any/all of the following questions

Q.1 -- Will the Brushless Controller work with STATORS having more than 12 Poles ? If so, what is the Limit?

Q.2 What Governs the spacing between magnets around the can?

Q.3 What are the Reasons for using DELTA or 'Y' windings - If possible could someone send me a diagram of both to:- Roypaulineharris@aol.com

Q.4 Providing they don't get too hot, do you neodym magnets lose any appreciable amount of thier power over long periods of use?

Many Thanks in advance.

Roy Harris

[3DMomo]

Here are some links to help answer some of your questions.

Question 1.
http://www.powerditto.de/powerditto/Kombinationstabelle2.html
A list of some various other types that will work with a controller such as a CC.

Question 2.
Quote from Ron "Touching magnets will give lower flux, higher rpm, less torque.” So I believe the inverse is true for more distant magnets.

Question 3. Http://www.rcgroups.com/forums/showthread.php?s=&threadid=212576&perpage=15&pagenumber=1 There is a very straight forward discussion on the pros and cons of these two methods.

Question 4.
My personal opinion is that since these NeFeB Magnets are rare earth magnets they must have been around long. Sooooo I don't think anything demagnetizes them except for heat.


Hope that helps,

Mo

[swatson144]

Q.1 Stators need a multiple of 3 "poles" The size would limit our use. 9 or twelve seems to be the most bang for the buck size and compact wise. I Really haven't seen more. What did you have in mind?

Q.2 don't know how to say this without sounding smart grassed. The physical size of the magnets, spread evenly around the can. The rotor calc will let you imput your specs and give you the space between magnets.

http://www.gobrushless.com/testing/motor_rotor_calculator.php


Q.3 Pls see the appendix here.

http://www.gobrushless.com/GBL_single_troubleshooting.pdf

The description and pictures you seek can be found here, in part 4.

http://www.gobrushless.com/GBL_single_v2.pdf


Q.4 The magnets are permanet. Though no more so than most anything else in this world of entropy, and chaos. I suspect There'll be something new come along before I replace mine from degradeing. Like N100 or something. then my N50s will only be 1/2 as strong.


Cheers

[ron_van_sommeren]

...Q.1 -- Will the Brushless Controller work with STATORS having more than 12 Poles ? If so, what is the Limit?...
Yes. It depends on the number of magnets, not the number ot statorpoles. I controller has to work 6 times harder to drive a 12magnetpole motor, compared to a 2magnetpole motor. For 14magnetpoles that's 7 times more sweat, as far as computations are concerned (number of magnetpoles divided by 2). So if your controller can drive a 2-pole motor up to 150krpm, it can drive a 12pole motor up to 25krpm.[/quote]


...Q.2 What Governs the spacing between magnets ...Magnet circumference coverage of 70-85% is ok, give or take a few. Not very critical.

... Q.3 What are the Reasons for using DELTA or 'Y' windings - If possible could someone send me a diagram of both to:- Roypaulineharris@aol.comThe jury is still out on that one ;) You get the same motor character using x winds in Y and using 1.7x winds in Delta. Delta can have parasetic currents, not good for efficiency

CD-rom conversion homepages and manuals:
http://www.rc-unionen.dk/nytforum/topic.asp?TOPIC_ID=368&whichpage=1
http://www.rc-unionen.dk/nytforum/topic.asp?TOPIC_ID=368&whichpage=2

Mandatory reading :) cd-rom tips'n tricks:
http://www.rcgroups.com/forums/showthread.php?t=240993[/quote]

... Q.4 Providing they don't get too hot, do you neodym magnets lose any appreciable amount of thier power over long periods of use?...No :)