Rotary Speed & Reverse Replacement

[Brad93]

This is broken.

Need to replace. Think all the contacts are for speed control. Seems to be three sets of contacts.

All controlled by this lovely old piece of electrical engineering that has been broken by my father. You could change direction on the fly.

can i replace this with some sort of modern electronics which will allow the instantaneous change of direction and speed?

I can think how to do it with three sets of reversing contactors, but that's getting a bit sharp.

 

[Gavlar]

What is it?
If it's for controlling a 3ph machine, you might well be able to simply use a 3ph - 3ph VFD.

Quick edit. I didn't notice the third picture!! An cheap AT3 inverter will do all you require.

 

[Brad93]

What is it?
If it's for controlling a 3ph machine, you might well be able to simply use a 3ph - 3ph VFD.

Quick edit. I didn't notice the third picture!! An cheap AT3 inverter will do all you require.

The motor seems to have brushes on a commutator so is either a slip ring motor or a repulsion induction motor.

 

[gaz1]

you can rebuild that by using the new tech whilst keeping it old

it all depends on what was used to make up what you have in that unit

 

[Erie Fred]

OOOOhhh...an old cam controller, still made (In Erie) for NYC transit cars....
Can't help you though, sorry.

Used to see them on large travelling cranes (up in the cab, one had at least 8 of them, operator used his knees on some of them) and pyramid rolls.

Maybe machinery surplus places, but usually they are "programmed" by setting of the cams.

 

[Brad93]

Some research and im now certain this is a slip ring motor, with speed control and more importantly high starting torque providing by altering the resistance of the rotor windings.

So a VFD is no go, really the only option is a rotary drum switch,

 

[Robotstar5]

Can the switch not be repaired?, those old units were built like a tank with lots of user serviceable parts inside.

 

[Kram]

How is it broken? The cam alignment looks a bit off with the fingers, but it looks fixable.

What you have is three leads coming out the motor, to the rotary switch, through a set of high power resistors that connect to a common point. varying the resistance, sets the speed.

Reversing will swap two of the other three wires going in to the motor, so likely 5 or, all 6 of the motor wires go to the rotart switch.

I may be wrong but believe you can short the 3 extra leads and run it from a vfd with the 3 extra connections connected together.

 

[Anguz]

That was built to be fixed

 

[gaz1]

How is it broken? The cam alignment looks a bit off with the fingers, but it looks fixable.

What you have is three leads coming out the motor, to the rotary switch, through a set of high power resistors that connect to a common point. varying the resistance, sets the speed.

Reversing will swap two of the other three wires going in to the motor, so likely 5 or, all 6 of the motor wires go to the rotart switch.

i would keep it as it is or make up a new one using delrin and delrin spacers

delrin for the screwed in power points and delrin to space between them

its really a switch i suspect the resistors/coils are elsewhere as all that piece is a cam switch with connectors