Oscillating Thunderbolt? (updated)

[JasonC]

Alright, I give up on trying to make a solenoid brush ring collector plate for the 1000-1003 conversion thunderbolt. I've been through and tried 3 or 4 different options and unfortunately, while its definitely possible to do, I just don't have the the tools nor experience to continue on trying to fabricate one from scratch.

So, I would like to give my t-bolt a Whelen characteristic, I wanna make it oscillate. Yea, thats right, spin one way 360 degrees, then reverse direction so I can hardwire it without brush ring collectors.

Now, I don't know to much about capacitor start motors like my rotator motor, but per Wikipedia: "The starting direction of rotation may be reversed simply by exchanging the connections of the startup winding relative to the running winding". So, with that in mind, I'm thinking about mounting a DPDT on-off-on switch that will be switched by the rotator pinion gear as it rotates to manually change the startup winding. Anybody have any thoughts/schematics/critiques at all on this? ANY thoughts or comments appreciated greatly!

[Daniel]

Perhaps you could take an old washing machine transmission and play with the gearing to get the desired range of motion.

[JasonC]

Perhaps you could take an old washing machine transmission and play with the gearing to get the desired range of motion.

Don't know much about that, but I want to keep it as simple and original as possible. I just need some sort of schematic or something to see how oscillation can work.

[Robert Gift]

...I'm thinking about mounting a DPDT on-off-on switch that will be switched by the rotator pinion gear as it rotates to manually change the startup winding. ...ANY thoughts or comments appreciated greatly!

That would work.
But if it fails to reverse, have a plug which will pull out before wires twist up and short.
What will the sudden change in direction do to the horn?
Will the moment arm on the neck be too great instantly changing from one direction to the other = twice the torque on the horn as from a dead start.
How about simply not turning it.

[JasonC]

That would work.
But if it fails to reverse, have a plug which will pull out before wires twist up and short.
What will the sudden change in direction do to the horn?
Will the moment arm on the neck be too great instantly changing from one direction to the other = twice the torque on the horn as from a dead start.
How about simply not turning it.

Yea, I'll definitely need a breakaway plug. And since it's going to be run off of the same contactor as the chopper, I'll need to run it at 8 rpm to eliminate to much down time in between oscillation, which will definitely add a lot of torque. I'm gonna have to research this some to see how Whelen does it, but I'm afraid they do it electronically, not really an option I want to pursue. We'll see I guess. like I said, ANY input on this would be much appreciated!

[Justin]

Some sort of home made slip rings?

[JasonC]

Some sort of home made slip rings?

What do you mean?

[SirenMadness]

I would go for some reciprocating switch, which reverses the polarity every stroke.

[Justin]

Some sort of home made slip rings?

What do you mean?

Like a solid metal core anode with a contact that simply remains touching the metal (like how electric trains touch the overhead wires), an insulating separator and an outer cathode, with the same contact.

[JasonC]

Some sort of home made slip rings?

What do you mean?

Like a solid metal core anode with a contact that simply remains touching the metal (like how electric trains touch the overhead wires), an insulating separator and an outer cathode, with the same contact.

From what your telling me that's pretty much the same thing as a brush ring collector. Here is the actual collector and brush assembly from Adam Pollak's 1003:







My idea was to lay a square sheet of coper over a thick piece of plastic, and then drill several circles down through the copper and into the plastic a little bit to make the brush ring. The brush holder assembly also didn't present a problem, except for where to find the actual brush holders! nobody has them as 99% of them are incorporated into actual motors themselves. Like I said, making one is possible but I just don't have the tools to do all of this like Federal did, and this thing may see real action again so if I have to question my own work, I'm not going to put it back into service. I want something failsafe.