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Re: [PSUBS-MAILIST] re-wiring trolling motors?
Ken,
I am not quite sure to understand what you mean by
"controller", because there is not much electronic inside the lower unit of a
MG. please elaborate.
MK lower unit has only red and black wires going
into the lower unit, an electronic board is in the top housing for speed
controls
MG lower unit has 5 leads going inside, there is an
electronic module for speed control in the top housing, like in MK, and a brush
card inside the lower unit on which are connected the wires and a Dura amp
module.
In my case since I do not use the electronic module
i use only the red and black wires. The other wires that I leave free are
normally used for speed control and sonar noise reduction.
I install my motor far enough from the sonar so are
not affected by magnetic noise.
I also prefer the 3 blade MG prop on the 2 blade
MK.
Herve Jaubert
----- Original Message -----
Sent: Sunday, November 26, 2000 2:01
PM
Subject: Re: [PSUBS-MAILIST] re-wiring
trolling motors?
This subject is a lot more interesting than Busby
as long as we don't get
into flame wars on whether MK or MG motors are
better.
I would prefer the MK motors without the motor controller
built into the
motor as the Motor Guide is reputed to do. I'm sure the
cost of the motor and
controller built as one unit is more expensive than
separate units from a
replacement viewpoint. Since I did my own
controller, this made the most
sense from a $ viewpoint. It would seem to
me that having the controller
built into the motor would offer much better
cooling for the electronics but
at the same time would expose the
controller electronics to motor flooding.
Better cooling of the
electronics should equate for improved reliability for
the MG electronics
but at increased replacement cost and potentially lower
reliability for
flooding problems, even if they pot the electronics. I only
paid $169 for
my 70# thrust MK motor. So the MK electronics have less cooling
but are
separate units. Replacement of only the motor or controller makes
sense to
me.
Problems due to flooding or high moisture usually takes a long
time to show
up.
I do think that except for the placement of the
controller and secondary
considerations the two vendors are nearly
equivalent. It's like discussing
which is better, a Chevy or a Ford
Pickup. They have to be able to do the
same things, reliably and at nearly
the same cost.
For reasons of stator demagnetization, most PM motors
operating from 24 volts
and up probably require controllers.
On
the increase in speed for a 107 pound thrust versus a 101 pound thrust.
Based on speed as a function of the cube root of horsepower (close enough
at
these speeds) the 107 pound thrust motor should give a higher speed by
about
1.9%. At a speed of about 5 knots this would increase the sub's
speed by less
than 0.09 knots, big difference.
Ken Martindale
In a message dated 11/26/00 10:08:45 AM Eastern Standard Time,
caribsub@coqui.net writes:
Other adavantage is the cost, less expensive since you don t
need the upper
unit, if you were interested I sale lower units MG 107
alone , forward and
reverse, 36 / 24 Volts, plus the stainless steel
shaft, plus the sacrificial
anode to be mounted on the shaft and the
prop kit for only $280, not
including shipping via UPS or check with
your motor dealer, but this
solution is the most cost efficient.