Hi Bob
I doubt whether the following will be of use to you – but I've had a rummage through my notes.
(Aghast at how long it's taking me to build my Northlight!)
The motor I used was salvaged from a piece of discarded equipment. It is a Mabuchi 385.
Nominal voltage 12V (6 – 18V) max. efficiency drawing 0.837 amps – c. 9000 rpm
(So I concur with Unbuiltnautilus!)
As I was planning to aim for “scale speed”, I used a 6V battery pack. (3700 mAH NiMH 5 cell).
If I were starting again, I would choose a SLA!
I did some testing on current draw:
7.5V 1.4A (stalled)
9.5V 1.8A “
Free running Stalled
5.29V 230mA 940mA
7.45V 250mA 1.3A
9.39V 270mA 1.7A
12.9V 310mA >2A
I have always been a bit mind-boggled at models needing a 20 or 30 A ESC! At the time, I wondered if the Puffer would move at all.
The video shows the result (taken at Wicksteed last May).
(The sound generator was not in my model!)
My initial guestimate for ballast was c. 1.5 Kg. I cut two pieces of lead 115mm long x 19mm wide x 22mm high to mount each side of the battery pack and two further pieces 50mm long. The total weight was 1452g.
The weight of the white metal fittings, batteries etc. was well over 800g and initial waterline testing resulted in the removal of one of the smaller pieces of lead (220g) Since then, I have always been trying to keep the weight of the fittings down (plastic oil-drum, wooden stern grating, copied crew in resin etc.).
These pics show the general arrangement:
http://s949.photobucket.com/user/photomultiplier/media/DSC01590.jpg.html][/URL]
http://s949.photobucket.com/user/photomultiplier/media/DSC01625.jpg.html][/URL]
http://s949.photobucket.com/user/photomultiplier/media/DSC02637_zpsqaegt9qg.jpg.html][/URL]
The total weight of my Northlight is just under 5 Kg, so I think John's estimate of 4.5 – 5 Kg is a bit on the generous side for 1:32 – but you don't say what you still have on board in the way of fittings.
Regards,
Mike