Model - PT Scotia - Shaft speed

[Derek Warner]

on Monday, April 15, 2002 7:38 PM - David Allinson wrote :

The motors were some surplus ones I found in an electronic magazine and were
made by ITT Automotive in Germany. They came with a small bevel gear on the
5mm output shaft which can be pulled off quite easily. They are rated for
use up to 16volts DC continuous, so hopefully I will get long and useful
life from them on 12 volts. The output speed at 12 volts is around 180 RPM.
I do not expect to run at that speed
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Thank's again David for the detail - from the posted snaps I could not see the actual
type of speed controller (for each engine)

Over the past year or so I have posted seven questions on the issue of actual shaft
speed (RPM) to model shaft (RPM) without any clear resolution - however from your
comments I suggest you will be glad of the 180 PRM available for Scotia

regards Derek

[Dallinson]

Derek.
The speed controllers are standard Electronize 43X. They are rather large,
but as I have space in the model they are no problem. I am more used the
ones they use on model cars which are very much smaller. Not sure why they
have to be quite so big and then not even waterproof!! They are fitted to a
removable wooden tray which slides out through the engine room space.
Normal paddle ships seem to run around 50 or 60 RPM but that is only the
speed you stir a cup of tea at. The paddle is 125 mm diameter. That is a
peripheral speed of some 70meters per minute at 180. Allowing for say 20%
slip, that should get me along at some 4.5 kms per hour. Seems about right
to me. I am just guessing the slip at this point. It may be more, in which
case it will go a little slower!!! Whatever, I think it will get around the
pond without too much damage to the banks from the wash!!!
Thanks for your interest.
All the best.
David