Confused about motors? Thats me then.

Started by crowie100
4 replies 1 like 0 followers Last activity: 13 years ago
#5

Confused about motors? Thats me then.

Why not use the altogether more robust and cost effective Lithium/Iron Phosphate (LiFe) cells. They are the type of cells offered as an upgrade over NiMH by some power tool manufacturers, such as DeWalt. Theses packs often appear for sale new and secondhand on ebay. The method of harvesting them for our purposes is not difficult and can be found on a number of RC forums, or buy them new from HobbyKing and simply solder your own configuration, you will need to incorporate a balance plug in the same manner as a Lipo. Advantages include: a robust metal outer case similar to that of NiMH, they will not Ignite if punctured, they can withstand very high fast charge rates and even recover well from inadvertent over discharging, they have high thermal stability and are capable of sustained high current drain equaling that of Lipos and have a useful 3.3 volts per cell. Any sight increase in weight over Lithium Polymer in a boat is negligible and possibly at times desirable. You will find practically all modern chargers capable of charging Lipos will have a setting to accommodate Lithium Iron cells as well. The accompanying pic shows a pack I safely and simply re-constructed from a spare DeWalt power pack following the forum instructions. Fully charged the pack registers 20.3 volts and has maintained the same voltage after one year. A downside to some users could be that the max capacity of each cell is only 1.6Ahr however by doubling up the series pack and wiring in parallel a quite useful 3.2Ah will be attainted. Typical life expectancy of a new pack is in the region of 2000 cycles, I wonder how many Lipo owners could claim that.
Liked by Martin555
#4

Confused about motors? Thats me then.

And a bit more

Nicad /nimh batteries
older technology. they cannot supply the current that LIPO batteries can They are Heavy by todays standards

LIPO Batteries are becoming the new standard batteries and are used in many applications , and of course RC lighter weight and can deliver hugh amounts of power
WARNING They are not toy batteries and can become extremely volatile if they are subject to abuse eg not using the correct charger and discharging past their low voltage level , Probably the best battery us modellers have ever had BUT MUST BE TREATED WITH RESPECT
It can't rain all the time
#3

Confused about motors? Thats me then.

HI Crowie,

Welcome to the website 😊

There is a small section on the website that gives you the basics. You can find it here:

http://model-boats.com/rc/motors

In general:
- Power can be determined in two ways, speed and torque. Speed is simply the RPM (Rotations Per Minute) and torque is like the strength of those rotations. in boat terms, does it need to turn a big propellor or a small one.

- Watts is the amount of energy it requires. and is a calculation based on the voltage and the amps. Voltage and Amps I usually like to give my water tank example on: Voltage you can think of as being the height of the water in a tank, the higher the water the more pressure at the bottom. Amps is the width of the tank, so how long that pressure will last for before it runs out.

- Brushless & Brushed are types of motors explained in the example link above.

Any other specific questions and I'll do my best to answer! 😎

Stephen
We may not be able to control the wind 🍃 but we can always adjust our sails ⛵ - MBW Admin
#2

Confused about motors? Thats me then.

HI Crowie100

Its not rocket science
Power = watts = Volts x amps
Kv revs with 1 volt applied
brushless Basically a AC 3 phase motor with it own type of speed controller
Used a lot in RC aircraft Try Rcgroups for lots of info or Giantshark for competitive prices

Inrunner Looks like a conventional motor
Outrunner stationary windings with the stator plate /magnets revolving around the outside used mostly on RC planes

2812 motor 28 mm diameter and 12 mm wide ( general info but not always used in this configuration ( emax follow this rule )

And that is only for starters

emma
It can't rain all the time
#1

Confused about motors? Thats me then.

I am a total newbie to this electric motor stuff. Is there a book or list of some kind that will let me unravel the power, watts, amps, revs, brushless, Kv, and all the numbers that go with electric motors.
Please help - I have a headache. ❓

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