| Author |
 Topic  |
|
fungus
Junior Member
249 Posts |
Posted - 23/11/2007 : 15:03:15
|
green_energy - the wooden alternator they made only had one set of magnets, they filled the centre of the coils with magnetite sand which provides a weak attraction.
I've stripped all the wire out now and on monday will bring the motor to get the laminations out in the lathe, then see what happens. What I'll probably do;
take the laminations off, then laminate some plywood together to make a former and mount it on the support block left over. Then I'll put it back in the metal lathe and clean it off/round it down.. I know its not too good practice to use wood in a metal lathe but it should work pretty good. Then I'll mark the slots and cut them out with a router. It originally had 15 turns/coil, if I kept the laminations it would be roughly 24 turns in the configuration I need, it'll likely be about 35 without the laminations. |
 |
|
|
green energy
Starting Member
United Kingdom
14 Posts |
 Posted - 23/11/2007 : 16:20:57
|
| Well I am going to very interested with the out come; I do not totally understand your calculations on the amount on turns of the new windings, but I guess more would be better. Was your 1000w model wired with 4 strands wound together? . I did do some very simple experiments of swiping a speaker magnet over a coil of wire sitting on the wooden bench with and without metal in the centre of the coil, without was not quite as good voltage but not that much in it. Good luck with it |
|
|
|
fungus
Junior Member
249 Posts |
Posted - 23/11/2007 : 19:14:04
|
| Woops- I meant 12 turns there.. On mine it was 2 strands together. |
|
|
|
green energy
Starting Member
United Kingdom
14 Posts |
Posted - 27/11/2007 : 07:40:44
|
| Hi fungus, wondered if you are able to reuse the copper wire removed from the metal |
|
|
|
fungus
Junior Member
249 Posts |
Posted - 17/12/2007 : 16:00:37
|
I've kept the copper wire so I'll be able to take it to the scrappy but not able to use it.
A bit of progress;
I've taken the steel core off of the shaft, I hacksawed through the support arms and turned off the rest on the lathe.
Today I recieved a 150mm block of nylon to replace it, I think it'll be better than wood and easy to machine etc, I'm going to get that turned down to shape I want tomorrow and cut out the slots for the coils. |
|
|
|
windymiller
New Member
United Kingdom
57 Posts |
Posted - 25/03/2008 : 23:47:10
|
Hi everyone who participated in the stepper motor mod
Can i first say it was probably the most frustrating ,time consuming problem ive ever had!!!.
Im sure every one else felt the same who had a go!!!.(hi fugus and weel done....i really mean it,you never gave in)
I did however have some good results in the mods i carried out to this motor,
The turning resistance (iron losses, eddy currents,coil losses)have been reduced by half(actually measured properly )
There is vertually no trace of cogging,and only a very slight drop in performance,in relation to rpm.
I did have the problem shelved for some time as i got fed up with it!!!
The way i did it was to grind off 1mm thickness across the full width of of the iron rotor(very acurately using a specially made jig )and then bond and wrap very thin plastic covered gardening wire around the full length of the rotor/coil very tightly along its length.
In effect giving the rotor a permanent shell of plastic covered steel wire.
I did think of using mig welding wire initially but i decided to have insulated metal wire instead ,hoping to eliminate some eddy currents,if there were any!!!.
I suppose you could class it as a slotless motor,as all the slots are now covered permanently with bonded wire.
I did cover the whole mod in varnish to add more containment of the bonded wire.
Overall the air gap was restored to normal by using the wire.....vertually no trace of cogging....its easier to tun than the unmodified one.
Unlikely to come apart as the iron core and windings remain stationary in operation......its the magnets that do all the moving.
Thanks for reading and cheers. |
|
|
|
Topic |
|
Interesting new source of possible wind generators
