> Hi Ed,It's impossible to make a drive that performs as well when the drive is
> <snip>
> DaveBranum
Howdy Dave....
I think we agree that a large motor will generally rotate at fewer rpm than a
small motor all else being equal. And the larger motor will have more torque
at slow speeds than a small motor. And that small motors are sort-of well
known for rocket ship rpm's at just a few volts with very poor speed regulation
over some range of input voltages. I do not disagree one whit with those
general characterizations of fractional horspower motors.
However, there is the point of 'good enough' vs. 'could be better'. If two
small motors, with all of their alleged faults, perform in a totally
satisfactory manner, what difference does it make if one larger motor performs
better? If two small motors start up very smoothly and slowly and can
tie-creep with the best, what difference does it make if a larger motor could
do it better?
I believe there is more of a difference between small crappy motors and small
good-quality motors than we commonly realize. Perhaps we should be giving the
'quality evaluation' more points than the 'size evaluation'? Excellent quality
motors are available in small sizes and they perform well. No doubt about that
-- just ask PBL or Jim Kindraka, both of whom advocate spending bucks on good
quality motors.
With regard to the Y-3 and the SD70, I can only report what I see. What I have
seen is that they perform very well and it is hard for me to ask for anything
more. The weight of the locos (both of them) is considerable, yet they pull up
grades with just a little current draw. High efficiency motors with new
supermagnets do have a place in model railroading.
Would one large motor be better? I suppose so, but I am not sure what I would
do with the 'better'? Would I pull a longer train? No, I can pull whatever I
want with the existing motors and heavy die cast frames or boilers. Would
slower speed performance be more satisfying? Not really. I would simply get
bored stiff watching it tie-creep for more than one foot no matter how slow it
went.
>From a practical perspective, I am not sure how 'better' due to a larger motor
>would increase my satisfaction with the product. I can think of several
>things to improve these engines that would make me happier, but increasing the
>size of the motors is not one of them.
> This is not a question of two motors or one motor but a question of where
> their design goals are aimed and what they choose to emphasize and to
> compromise to get there?
I think 'compromise' is an excellent choice of words. Lionel/AF has had to
make choices between internal electronics and mechanical drive train parts.
The competition for available space meant compromise somewhere along the way.
A larger speaker would improve the sound. Or adding another speaker would also
improve sound. Or a bigger smoke generator would make things even more
impressive. Or, an engineer that waves his hand. That would turn on the kid
in all of us. Or coal in the tender that gets 'used up' as the train runs
around the layout.
But a larger motor???? Not sure I see the added value of that at the moment.
Small motors pulsed with DCC seem to work just fine. Perhaps it is the DCC
that makes them run so well? Admittedly, I have not tried them with Legacy, AC
or DC. Are we looking for a solution to a problem that does not exist?
Just some thoughts. Worth what you paid for them.
Cheers.......Ed Loizeaux
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