Lockridge Device - Peter Lindemann

[Mark]

Turion

Peter recommends starting with 1 coil. It looks like the motor you have has 12 slots in it. If it does you want to wind a coil that goes thru slots 1 and 7 if you were to number all of them. Leave some extra wire on the start end because the commutator you'll be hooking it too wont be the closest one it will be one thats around 90 degrees over. While winding alternate which side you go around the shaft to keep things balanced. It wont reall matter which way you wind because you can always switch the wires on the commutator or switch the wires on the battery. Wind as much wire as you can fit and leave some extra for attaching to the commutator. I'd leave a few 4-5 inches on each end. After the coil is wound put the the rotor back into the stator. With the coil centered in between the gap of the 2 magnets you'll be able to tell which commutator section you want to attach the wire ends to because they'll be the ones the brushes are touching. You actually may want to attach the wires to the next commutator, a little after center, but Peter will need to comment on that.

[Matthew Jones]

@Turion...I think I was wrong the first description I gave.

Mark is right.

If you start on top. Wind a North coil by going clock wise, then go to the opposite side and go clockwise as well.

Take 12" piece of wire and a dowl rod and do 4 turns on top. Go down, do 4 turns on the bottom. That way you can see it. No matter what the NORTH side is on the HOT(+) input into the motor and the SOUTH is on COLD(-) input to the motor.

Brian,

Sorry I didn't comment on this earlier. If the stator magnets are really N-S-N-S, and not N-N-S-S as Matt said, then this really could be an excellent motor to work with. The one drawback is that it is designed to operate at 24 volts. The fact that it has 16 slots would let you wire it in a corresponding manner to Turion's motor, as I suggested in Post #230, above. I'm not sure it would work very well simply by snipping the connections as you have proposed in the linked image. One issue with this is that you are not going to have much "cool off time" for these windings if you run them at higher voltages, as I am recommending, to get ahead of the Back EMF. The other issue is that all of your turns produce a circular connection around the rotor, so it can partially discharge within itself, instead of discharging out the recovery brushes.
There are a lot of issues to balance off in these things to give you a motor with good torque, at good speed, with good recovery, that won't MELT!

Peter

Peter. The motor may be N-S-N-S south now that I look at the picture of the brush's.
Brush picture.
Sorry about that....

Matt

[Peter Lindemann]

Winding the Rotor

Turion,

YES, MARK IS RIGHT. The way you showed on your YouTube film won't work. The method is not to wind the wire AROUND the rotor section. You wind the wire AROUND the ROTOR!!! You have marked the rotor section, but it is actually the SLOT that is important.

Follow Mark's description. It's totally correct.

Peter

[Mark]

Hey Matt,

Do you have a small magnet handy that you could check to see what the arrangement of the magnets are on the 4 pole motor you have? If it is NSNS then motor wont work unless we change it to NNSS or knock 3 of the magnets out and make it a 2 pole with NS.

Mark

[Turion]

The Light Dawns!

OK, I think I understand how to wind this. I will try it tomorrow morning with a short piece of wire and post to YouTube and link it so you guys can see and tell me if it is right or, as usual, out in left field. Thanks for the help. This motor has sixteen sections, so Peter said #s 1 and 9 and then 5 and 13. That's my plan.

My second set of brushes won't be here until the end of next week, so I have lots of time to get this wound. But I have lots of other projects to work on too.

[Matthew Jones]

Souths are on top and bottom, North's are on each side. I checked them with a magnet.

You can also look at the wiring of the brush's. When you get your motor. The hot side of the battery will be in line with the with the brush's that fire the off of the sides.

Cheers
Matt

[Peter Lindemann]

Physical Balance

OK, I think I understand how to wind this. I will try it tomorrow morning with a short piece of wire and post to YouTube and link it so you guys can see and tell me if it is right or, as usual, out in left field. Thanks for the help. This motor has sixteen sections, so Peter said #s 1 and 9 and then 5 and 13. That's my plan.

My second set of brushes won't be here until the end of next week, so I have lots of time to get this wound. But I have lots of other projects to work on too.

Turion,

Sounds good. As you wind the wire and fill the slots, the first winding should go around the shaft on one side and the next winding should go around the shaft on the other side, etc... so the rotor retains physical balance as you fill the slots with wire.

Peter

[n84dafun]

Brian,

Sorry I didn't comment on this earlier. If the stator magnets are really N-S-N-S, and not N-N-S-S as Matt said, then this really could be an excellent motor to work with. The one drawback is that it is designed to operate at 24 volts. The fact that it has 16 slots would let you wire it in a corresponding manner to Turion's motor, as I suggested in Post #230, above. I'm not sure it would work very well simply by snipping the connections as you have proposed in the linked image. One issue with this is that you are not going to have much "cool off time" for these windings if you run them at higher voltages, as I am recommending, to get ahead of the Back EMF. The other issue is that all of your turns produce a circular connection around the rotor, so it can partially discharge within itself, instead of discharging out the recovery brushes.

There are a lot of issues to balance off in these things to give you a motor with good torque, at good speed, with good recovery, that won't MELT!

Peter

Peter,

Thanks for the feedback. As you may have already read, Matt confirmed that it was N-S-N-S, so that's a plus. If the turns produce a circular connection around the rotor, it would be true that the coils would discharge itself. However, since we're going to be cutting at the designated points near the commutators, there will be breaks in the turns and thus there would be no way that the coils would discharge itself except through the capture recovery brushes.

I am concerned about running the motor at high voltages because of the heating concerns that you mentioned. And you're right about the cooling effect problem. I'm still confused as to why we need to run it at higher than rated voltages. I'll read your earlier posts and think about it some more.

-Brian

[FRC]

Post # 170

Check out post # 170 Peter explains it in there. I think he has refered to that post many times before.

FRC

[Mark]

Peter,

Thanks for the feedback. As you may have already read, Matt confirmed that it was N-S-N-S, so that's a plus. If the turns produce a circular connection around the rotor, it would be true that the coils would discharge itself. However, since we're going to be cutting at the designated points near the commutators, there will be breaks in the turns and thus there would be no way that the coils would discharge itself except through the capture recovery brushes.

I am concerned about running the motor at high voltages because of the heating concerns that you mentioned. And you're right about the cooling effect problem. I'm still confused as to why we need to run it at higher than rated voltages. I'll read your earlier posts and think about it some more.

-Brian

Unfortunetly being NSNS is BAD! That will put the north facing magnets across from each other. If we wind a coil like Peter wants we will have repulsion on one side and attraction on the other. So the rotor will just lock up. This style of winding is what I will refer to as a window motor coil because of its similiarities.

Now I could still wind a coil like I proposed, which is similiar to how each coil is wound on the rotor now. But I would wind basically 2 of them that are across from each other and connected together in the middle to make one big coil. I will have to wind it a little different now though because the north magnets are across from each other. Instead of winding in one direction from the top crossing over the shaft and continuing in the same direction I will have to reverse the direction after crossing over the shaft. That way both outside ends of the coil facing the magnets will be emiting the same field.

I see one possible problem with this arrangement but may actually be a bennifit, I'm not sure. But lets say that both ends of the coil(s) are producing a north field and pushing against the north facing magnets. The ends of the coil(s) that are facing the rotor shaft are both producing a south field pushing against each other. This field will be like a supper pole and push outwards and could hinder or enhance the speed. And I also wonder what effect it will have on the shaft and bearings

Peter what are your thoughts on this.

[Mark]

n84dafun,

One of the reason we will be running at higher voltages is because we will be pulsing the motor and that will cause it to loose most of its speed. If we increase the voltage by 3 times hopefully we will be able to get 1/2 of its rated speed.

[Mark]

Hey Goreggie

I see your logged in, hows your build going?

[n84dafun]

n84dafun,

One of the reason we will be running at higher voltages is because we will be pulsing the motor and that will cause it to loose most of its speed. If we increase the voltage by 3 times hopefully we will be able to get 1/2 of its rated speed.

Mark,

That makes more sense now, thanks.

[Matthew Jones]

Unfortunetly being NSNS is BAD! That will put the north facing magnets across from each other. If we wind a coil like Peter wants we will have repulsion on one side and attraction on the other. So the rotor will just lock up. This style of winding is what I will refer to as a window motor coil because of its similiarities.

Now I could still wind a coil like I proposed, which is similiar to how each coil is wound on the rotor now. But I would wind basically 2 of them that are across from each other and connected together in the middle to make one big coil. I will have to wind it a little different now though because the north magnets are across from each other. Instead of winding in one direction from the top crossing over the shaft and continuing in the same direction I will have to reverse the direction after crossing over the shaft. That way both outside ends of the coil facing the magnets will be emiting the same field.

I see one possible problem with this arrangement but may actually be a bennifit, I'm not sure. But lets say that both ends of the coil(s) are producing a north field and pushing against the north facing magnets. The ends of the coil(s) that are facing the rotor shaft are both producing a south field pushing against each other. This field will be like a supper pole and push outwards and could hinder or enhance the speed. And I also wonder what effect it will have on the shaft and bearings

Peter what are your thoughts on this.

I don't think this is a problem. Your gonna get more speed out of it than you would under the other configuration, and you still only have to fire 2 times per rotation.
If you fire the coil just past the north magnet the field you produce will attract to the Souths on top and bottom.
The only delima is the core passing the south magnet might retain a north field. But the core shouldn't saturate that bad, after all your only using some small Ferrite magnets.

I guess I'll put my paper work off today and go cut one up and see what happens. I got everything I need to make this work.

Talk to ya soon.
Matt

[n84dafun]

Check out post # 170 Peter explains it in there. I think he has refered to that post many times before.

FRC

Peter's quote on poste #170:
"The final issue is to bias the Back EMF downward on the graph shown in the previous post. To do this, we have to run the motor on a higher voltage than it was or designed to do. So, for instance, if the motor was originally designed to run at 2000 rpm on 12 volts (as in the example above), then if we run it on 36 volts at 100 know it will produce 6 volts of Back EMF at that point. So, this is equivalent to running it in a position where 5/6ths of the voltage and current are getting through motor. This suggests that we should be able to recover up to 3/4ths of our applied electricity on our secondary brushes without interfering with our torque produ..."

So it looks like back EMF depends on RPM and the reason it only spins 1000 rpms at 36v is because we have less windings for torque and speed. The 36v compensates for the reduced windings as a result of the modification.

I think I'm starting to see the light on this one.

Brian