ES custom motor -- Vented or Enclosed ?

You can take part in determining the design of the "ES Custom" Transmagnetic BLDC motor -- I think this is a pretty rare opportunity for the ES community to reflect their needs directly back to the manufacturer (me). Depending on perceived interest from the community, and that I don't pull my hair out in the process, TM motors may be willing to make a low-volume run of consumer/retail motors to equip the ES community. The magnetic structure will be based on this diameter motor: http://endless-sphere.com/forums/viewtopic.php?f=31&t=44058 There will be a limited number of variables for which I will seek input from ES, to incorporate in the design (shaft, kv . . . . but most importantly, this one):

Assuming you must still accommodate for the differences (size, weight, cooling, complexity, hackability, etc), comparing motors of similar price and equivalent peak power you would more likely use : V, V+fan, E, E+fan

Vented (no fan) = short, probably the cheapest option (not significantly), but what's the point? put a fan in it for an extra inch.
Vented, shaft fan = highest continuous power option, longer (1" more than VnF)
Enclosed = external fins (bigger diameter), shortest -- could be potted or oil-cooled
Enclosed +ext fan = rear shaft, maybe shroud, if potted, comparable performance to V+fan, but heavier, larger dia

Persuasive arguments for your design of choice are welcome; because, as in the Scottish highlands, "There can be only one".

I always thought a little fan blowing all the heat out was a good idea. I mean my desktop, laptop, battery chargers, inverters, and certainly any electrical device that has a fair amount of current running through it does this. To me it seems funny not to have a fan.

Is it safe to assume that the ventilated will take on more power due to heat handling?

TransMagnetic motors are pretty incredible. Thanks for offering us this opportunity, Roller!

I voted for 'Vented, internal shaft fan'.

Now ..if 'Enclosed, oil filled, external fan' was one of the options..

A small wish list:

• You want vented to remove moisture. The holes – need at least one on each side – should be at the periphery of the cover to allow for weeping.
• The stator should be varnished to prevent rust.
• The phase wires should be upgraded to handle power; 12 AWG at a minimum.
• I dislike that the phase wires travel through the length of the axle because it can lead to premature wear and breaks; Crystalite in my mind got this part right.
• The motors should support disc brake by design – AND should easily accommodate mounting of European and American brake equipment without modification.
• Label the wires coming out of the motor so we know which one is A, B, & C.
• Use quality oversized precision bearings (or at least allow us to select that as an option) to improve freewheel.
• Should be able to handle 2kW all day long at STP. Additional ribbing (vanes) parallel to where the spokes mount is useful; some motorcycle motors are like this and serves to remove heat quite effectively without need for internal cooling or fans.
• Upgrade the magnets a notch to improve efficiency, or at least – give us the choice.

My ½ watt, KF

KF - thanks for the wishlist . . . if you can provide one for a "non" hub motor, as is being polled, that'd be groovy.

Knevil - Thanks man! whatever we come up with here, should fit better than an Etek in a pocket frame. Hey, I got into electrics to get away from oil.

cal3 - for this thought experiment, peak powers are equivalent; but yes, continuous running will be highest for Vent + fan. An identical enclosed motor (same speed, inductance, yaddah, yaddah) will achieve 70% continuous output of its vented equivalent. (restated, the V+f will have about 40% higher continuous running power than enclosed -- provided no special cooling measure are taken with the enclosed version)

various cooling efforts will bring an enclosed motor closer to parity with ventilated (potting, oil, external fan+shroud, etc); all will add weight or complexity.

I like sealed motors to keep out mud. Shoving it through a ventilated motor isn't fun.


For general mayhem a venting and fanning is best

I should mention, these are strictly BLDC motors.

They've run vented in thousands of lawnmowers, garden tools, rototillers, and similar heavy dirt/moisture ingress environments. Environmental contamination is a valid consideration for a vehicle app, but I think it is often overstated for a BLDC motor (NOT for a brushed motor -- the springs+comm surface get trashed pretty easily).

For real off-road nastiness, enclosed is likely the way to go . . . But I think we're looking in the 3kW max category for this motor design . . . real off-road stuff often needs more kW; I imagine these as mostly on-road sub 50mph, sub-freeway light vehicles.