Building and Improving a Simple Electric Motor

New Video 4-16-2020 – Simple DC Motors

Background

I found the contact area (brush) was too small with this design and the armature would often stop turning. Reliable operation should be the goal in all of your projects.		This kit version of the Beakman motor worked pretty well but has a long span between the armature supports and the contact area is too small. Battery contact was good because the battery was pressed firmly against the contacts which were also the armature supports.

This is the first version of a simple motor that I built. Fastening the supports for armature with masking tape is not a good idea. It did run for a time and then would require adjustments.		This motor was in a kit of more inventions. The battery connection method was not the best but the armature shaft did not span a long distance un-supported.

My Version of the Simple Electric Motor

First prototype of my version of the Beakman motor. The battery is clamped tight between the copper-coated clamp pieces and the armature supports are moved closer together.		Kevin Guy, the hobby guy gave me the idea to bend tabs over to give more area of contact, it works great!

I came up with the idea of gluing small beads on each end of the
coil so the armature would not move horizontally. The glue also firms up
the armature portion of the wire coming from the coil.

Materials

The following are pictures and descriptions of the materials I used
to complete this project. I made an effort to find materials that could
be found in almost any city at a reasonable price.

I found a real deal on ceramic magnets, 51 magnets for $6 at a store that
sells mainly tools. Northern Tool + Equipment http://www.northerntool.com

Radio Shack also sells ceramic magnets in smaller quantities.

This 100 count bag of sheet metal screws would supply enough screws for 25 motors. The large head on the screw holds the brackets down firmly and screws in easily to the pine wood once a starter hole is drilled.		I cut these copper plated tube straps in half to create the brackets used in the motor, two straps per motor needed. At lumber supply store I saw the straps in 10 or 100 count bags.

Pine board 3 ½” wide by ¾” thick makes a good base or the electric motor. The board will be displayed as 4”  by 1”, I found these boards 4 feet long for under $1.		I used hook-up wire to connect battery brackets and motor brackets. The red insulation is to indicate positive and the black to indicate negative. Color coding not needed for this project but I feel it is good to develop a habit of marking polarity.

Radio Shack sells 3-pack of enamel-coated magnet wire, I would suggest using the heaviest wire which is the 20 gauge.		I used craft beads to keep the armature (straight sections of the wire) from moving from side to side while running.

These “Mounting Squares” which are double-sided sticky tape provided and easy method to attach the magnet yet the magnet could be removed later with some effort. Magnets could be glued to wood base also but would be harder to remove later.

Tools

Wire Strippers can be found at Radio Shack or other stores that sell tools.		Low temp hot glue guns are normally found where craft supplies are sold.

______________________________________________________

Building the Motor

For each motor, cut two of the tube straps in half.		This will make four brackets.

The curved portion of the tube strap halves are easily straightened in a vise.

If you do not have access to a vise, the material could probably be straightened with a pliers or a hammer.

Side view of two brackets that have been straightened.		Back of two brackets that have been marked for two slits to be cut so tabs can be bent.

Cutting one of two slits, stop at horizontal line.		Bending the tab back the same direction as the bottom part of bracket.

Tab has been bent over, now make sure the other two strips of the bracket are vertical.		Trim off some of the material, only about 1/8” needs to stick up above the tab.

It is easier to strip the insulation off the wire when you have something to hold on the other end. I strip insulation off on one end, and then cut the wire. The wire should be around 3 inches long, ½ inch of insulation stripped off
on each end should be good.

Wrap the wire 15 times around 5/8” wood dowel, leave around 3” extra on each end of the wire. The number of loops is something that can be experimented with, try a few more or less, then observe change in speed.

In the middle of the loop one each side, wrap the ire around the bundle of wires a couple of times.		This is what the coil should look like now.

Mark the block 3” from one end.		Cut across the wood. Hand saw cut through the pine wood very quickly.

Mark where the bracket holes for the battery will go by using a D-cell battery as a guide. It will be a tight fit on the board. The holes in the bottom of the brackets are large enough that there is room to adjust the bracket some to get a tight fit to the ends of the battery.

Drill the starter holes for the screws a little smaller than the screw and not all the way through the board.		Use a large enough screwdriver to fit the slots in the screw head.

It is a good idea to file any sharp edges on the brackets.		Screw in brackets so that they are tight to the battery.

The straight section of wire on one side of the coil can be sanded completely around the wire.		On the other side only sand off the coating on half of the wire.

Looking at Cross Section of Wire for Half-Sanded Side

Glue the bead being careful not to get glue on the outside edge of the bead where it makes contact.		The completed assembly should look like this.

The brackets that support the armature need to be positioned so the armature fits between with a tiny gap on the outside of each bead. Screw in one bracket, and mark the hole for the opposite bracket.		The battery connection wires are bent in a half loop and put under the screw head as you tighten it down. Un-insulated portion of the wire is placed under the screw head so that the half-loop tends to curve with the direction the screw as tightened.

Place the sticky side of the double-sided tape on the wood base between brackets, then peel the backing off.		Place the magnet centered on the sticky tape.

Completed motor in action! You will probably need to give the coil a gentle shove with one finger to start it in motion.

Further Experimentation

You might consider:

•  Make a new armature/coil with more or fewer windings.
• Adjust the gap between the magnet and the edge of the coil to be less but not touch at anytime.
•  Try a stronger magnet such as a neodymium magnet.
  

  If Your Motor Doesn’t Run

  Don’t get upset, troubleshoot the problem. You will probably learn more if your project does not work perfectly from the start.

  Make sure:
  ♦ All the connections between the battery and the motor are solid.

   ♦ The armature wire is as straight as possible.

  ♦ The enamel has been sanded properly, half the diameter on one side and around the entire wire on the other side.

  My First 2-pole Electric Motor		Magnetic Switch Motor from Kit		Darcy Whyte Dinky Motor

  ScienceGuyOrg Blog Entries About Electric Motors
  2-Pole DC Motor Project – Some Ideas to Get You Started
  Getting the Gap Correct in Electric Motor Project
  Two Pole Example Electric Motor
  Magnetic Switch Motor Kit
  

 Darcy Whyte’s Dinky Motor Kit  – Order From This Link – Link updated 1/8/2016

Note: I received a request to include a link that might appear to be advertising but there is an animated video on DC motor operation that is well done on this webpage.

The Advantage of DC Motors Explained – Del Mar Fans & Lighting