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Title: Great Brushed Motor for Large RC Boats Post by: VC on February 11, 2012, 11:04:27 PM This should be a very good motor for those who are planning on building a large boat ( 100 cm or near about) or need a lot of power for their smaller RC Boats. I have something similar and I am saving them for some BIG builds. At Rs. 700/- inclusive of postage, it is a very reasonable deal. (Though I am very confused about 16,500 rpm and 16,500 mA :giggle: - what is it???)
http://www.rchobbyproducts.com/productdetails.aspx?id=3049&colid=0&catid=639 Since it has a comparatively short drive shaft, coupling it with a prop shaft (direct drive) may be an issue, but the experienced modeller will circumvent that. Check with Roopesh for tips and tricks. DEFINITELY NOT FOR FIRST TIMERS. Cheers! Title: Re: Great Brushed Motor for Large RC Boats Post by: roopeshkrishna on February 12, 2012, 11:34:47 AM Good morning Sir..and this one is a Mabuchi, black can motors rated at the range of 20 Amps series, and with an RPM of 22,000 aprox. the denoted mA, is means all we know a 1000 mA means 1 ampere, so a 16500mA means 16.5 Amps..it was , mostly used on cars, for short bursting sprint runs.as it eats battery within a few minutes..as it drops about 20 Amps in a run..was using such motors in crafts, and it is far powerful..and the length of the shaft is not an issue, as we can make a coupling for it with bicycle spoke, or can add a brass drive gear to it..but need a powerful ESC with reverse..with a S A W supressor..mostly these motors use rare Earth, or strontium magnets..
Title: Re: Great Brushed Motor for Large RC Boats Post by: roopeshkrishna on February 22, 2012, 09:03:56 PM VC Sir..from your inspiration, i hold some research on same motor..but found desperating result..even with a heavy battery pack, it gave me a very short running time..and yes even at idling speed the motor was eating a lots of current from battery..(about 4 Amps)..so, i took little more efforts to find a good result to choose a motor selection..and at last found a good motor set up..usually, in ship or boat models, after a particular RPM, of the prop, the phenomena, Cavitation occurs..in this situation, the raw motor power is wasted almost fully..so, it is very nice to keep the power out within the cavitation limit. so, after some research works, i found even a 160 watt, 1000 RPM/Volt ECM is wasting much power as heat and free revs..so, i came to a position, with an ECM, after rewinding it..after rewinding the motor, it became more versatile, as the total amperage drops within 2.5 Amps at full load, with 2 inch hand made prop. this set up is now powering my new Pilot boat..will add all soon.. and with a 1200 mAh battery it runs for more than an hour..after the ESC stopped thrusting because of voltage limiting.so, its an interesting finding..and so, happy that my boats got a new innovative battery saving idea..and i will add all rewinding procedures, wire guage as SWG, type of copper wire, and DR..and also add a good alternative windings for the same MCM..after it is now running nicely..thanks for the inspiration.. :hatsoff:
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