Build it YOURSELF!, a REAL ELECTRIC MOTOR

© Brooke Clarke 2007

Fig 1 approximately full size box top	Fig 2 Kit Contents sort of arranged

This electric motor kit was patented in 1932.  If you look closley at the box top in Fig 1 above you can see short cut marks that appear in pairs.  The kit is built on the box top.  The Box top and patent signature say G.W. Moore, but the patent printed name is G.A. Moore, typo?

Wire

In the kit is a piece of wire coiled a little over 1 ½" in diameter with a little over 11 turns.  The O.D. is a little over 0.026 so looks like AWG 22 which has 62 feet/Ohm.
This calculates as 0.07 Ohms and when measured using a Kelvin test lead set on the HP 34401 shows 0.084 Ohms.
The box says the finished motor will run from a No. 6 Dry Cell battery.  The instruction sheet also says to use a single No. 6 battery and that the motor will turn at over 6,000 RPM.

A No. 6 batery is 1.5 Volts when fresh so the current might be I = V/R = 1.5/0.085 = 17.6 Amps.  I don't know what the Internal resistance of a No. 6 battery is but doubt you can get anywhere near that current. 

as received (instructions not shown)	Working Universal Motor

Science First has been making this motor kit mainly for schools for many decades.  I'ts very similar to the above version, except there's now a seperate plastic base with provision for a single AA battery for power and an improved commutator.  The wire size has been reduced, maybe to allow for the smaller capacity battery.  The manual is on the Science First page for the Motor kit.

The furnished instructions leave something to be desired.  Maybe it's the intention of the sellers that the instructions are also a teaching tool to get the students to think ahead and not believe everything they read.  If that's the case they are OK, but if they are intended to allow you to make a working motor by following them, then they miss the mark.  With the exception of cutting a wire none of the assembly operations is permenant so the motor can be taken apart to fix a problem.

Sience First 10-100 Motor Generator

This Motor Generator is typically used in schools to demonstrate Faraday's and Lens's laws.  It's similar to the Saint Louis Motor, but a little more versatile.  The manual is on the Science First page for the Motor Generator.

In the left photo the permanent magnets for the filed are installed and the electromagnets are to the side.

The armature coil is 0.35 Ohms. The red and black wires are each about 0.01 Ohms and the two "D" cells and battery holder are about 0.25 Ohms.  Battery voltage is 2.956 Open circuit.  Don't know about the commutator resistance.  When the armature is held vertical, i.e. the brushes making contact the current is 3.2 Amps.

Video 10-100

 first run with Permenant Magnet field & problem with one of the brushes.
Watch on Google Video, or here.

---

---

1857209 Toy Electric Motor, G.A. Moore, May 10, 1932, 310/1 ; 310/40MM; 310/46; 434/380
2668924 Dynamo electric Machine, Frank Richard Merrlam (Redmond Co), Feb 9, 1954, 310/239 ; 310/216; 310/244; 310/258 -
2912604 Minature Electric Motor for Toys, Eurich (Mettoy, UK), Nov 10 1959, 310/1 ; 310/40MM; 310/40R; 310/46 - model train 3072812 Permanent Magnet Motor
3096452 Motor for Electric Clocks, A. W. HAYDON (Consoldated Electronics), Jul 2 1963, 310/46 ; 310/233; 310/36; 368/164; 968/494 -
3109946 Electromagnetic Motor
3305741 Minature Electric Motor, J. LINDNER, Feb 21 1967, 310/261 ; 310/1; 310/264; 310/270; 310/40MM; 310/46 - 6 pole 5621258 Toy Motor with Partial Coil Rotor
D237877 Motor and Generator Educational Board
D158705 see above

Electro-Magnetic Toy Engine - sounds like a gas or steam engine
Gilbert DC 3-pole Electro-magnetic Machine - used with early Erector Sets & a larger small appliance motor (maybe also Gilbert).
MESCO 1011 Toy Engine - works like a steam engine
Weeden D.C. Motor -a 2 pole D.C. motor
No. 6 Dry Cell - and  Flash Amps as measured with Pocket Ampmeters
Self Winding Clock Co. "Western Union" clocks - uses electromagnetic motor to wind spring page 1, page 2