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Insulators in the Slots
Jetijs,
Everything Lighty and Steven are saying is correct.
All motors that I know of are wound by hand. To prevent the damage at the edges, where the wire comes around the stator section, they insert a thin layer of material in a U shape to fill the slot. You can see these insulators in Steven's photograph. This is what Lighty was referring to as sheets of mylar. Even a thick paper is sufficient for this. Here in the USA, we use a thick paper material for file folders. It's about .010" thick (ten thousandths of an inch). If you have a similar material, just make your own slot insulators. Make them slightly longer than the slots, so the wire bends the paper around the edge as you wind the coil.
Another trick is to glue little pieces of wooden doweling cut in half to the ends of the stator pieces, to produce a semi-round end to the stator cores. This, along with the paper insulators makes winding the coils easy (ha ha ha) and prevents all possibility of breaking the insulation on the wires.
The "trick" to being able to wind a good coil is the ability to provide tension on the wire. If you mount your stator in a vise that is firmly mounted to your work bench, and then tie the beginning of the wire strand you are winding to some immovable object, then you will have BOTH HANDS free to manipulate the wire and keep tension on the turns as you make them, as well as on the turns you have already wound. It is a tiring and tedious operation. Your hands get very tired, but HEY, that's how it is done!
Wind one coil, leaving about a foot of extra wire at each end. Fill each slot to about half way. Then, unwind this coil and measure the length of the wire. This is the standard length all the coils will be. Cut 23 more lengths of wire at this length and wind each coil separately. Tie off the ends of each coil when it is done.
You only have 24 coils to wind, so by the time you wind the last ones, you'll be really good at it.
Remember, magnetic field strength is AMPERE-TURNS. You need to be able to get enough turns on the pole faces to create sufficient magnetism to attract the rotor. Since this is very similar to Steven's design, you may wish to take directions from him on what wire size to use and how to switch the currents.
This motor is a much more ambitious project than your first design, but if you stay focussed, you can do it.
I say, "GO FOR IT!
Peter
Originally posted by Jetijs
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Steven,
thanks for the explanation and the picture. But why is such a winding method not possible in our case? Why can't we just prewind each coil and then just put it in those slots? After all windings are done, we simply need to solder the needed coil ends together in series.
thanks for the explanation and the picture. But why is such a winding method not possible in our case? Why can't we just prewind each coil and then just put it in those slots? After all windings are done, we simply need to solder the needed coil ends together in series.
Everything Lighty and Steven are saying is correct.
All motors that I know of are wound by hand. To prevent the damage at the edges, where the wire comes around the stator section, they insert a thin layer of material in a U shape to fill the slot. You can see these insulators in Steven's photograph. This is what Lighty was referring to as sheets of mylar. Even a thick paper is sufficient for this. Here in the USA, we use a thick paper material for file folders. It's about .010" thick (ten thousandths of an inch). If you have a similar material, just make your own slot insulators. Make them slightly longer than the slots, so the wire bends the paper around the edge as you wind the coil.
Another trick is to glue little pieces of wooden doweling cut in half to the ends of the stator pieces, to produce a semi-round end to the stator cores. This, along with the paper insulators makes winding the coils easy (ha ha ha) and prevents all possibility of breaking the insulation on the wires.
The "trick" to being able to wind a good coil is the ability to provide tension on the wire. If you mount your stator in a vise that is firmly mounted to your work bench, and then tie the beginning of the wire strand you are winding to some immovable object, then you will have BOTH HANDS free to manipulate the wire and keep tension on the turns as you make them, as well as on the turns you have already wound. It is a tiring and tedious operation. Your hands get very tired, but HEY, that's how it is done!
Wind one coil, leaving about a foot of extra wire at each end. Fill each slot to about half way. Then, unwind this coil and measure the length of the wire. This is the standard length all the coils will be. Cut 23 more lengths of wire at this length and wind each coil separately. Tie off the ends of each coil when it is done.
You only have 24 coils to wind, so by the time you wind the last ones, you'll be really good at it.
Remember, magnetic field strength is AMPERE-TURNS. You need to be able to get enough turns on the pole faces to create sufficient magnetism to attract the rotor. Since this is very similar to Steven's design, you may wish to take directions from him on what wire size to use and how to switch the currents.
This motor is a much more ambitious project than your first design, but if you stay focussed, you can do it.
I say, "GO FOR IT!
Peter
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