Swapping the rotor end to end just brings the shaft out on the other side of the motor. So looking at the motor from the side if the shaft originally came out from the right hand side and rotated clockwise when reversed end to end it now comes out of the left hand side so is rotating anti clockwise. The magnetic field is still rotating in the same direction and viewed from the right hand side it is still rotating clockwise. ( But now there is no shaft exiting from the right hand side.)

Les.

 

The basic shaded pole motor is uni-directional, hence it is used mainly for fan use.
And yes it is decided by the position of the shading ring. The only reason for swapping the rotor around is in order to use the output shaft of the motor which is rotating the same direction but the relative direction is reverse looking into each end.
Spin a rod in one continuous direction and look into each driving end of the shafts.
Max.

 

Guess my comment was not as clear as I thought. I was referring to the motor. Those are reversing relays, probably meant for reversing motors of various types. Since I'm not highly experienced with motors I just assume AC motors (single phase) are uni-directional (CW or CCW depending on field orientation). Three phase AC motors ARE reversible by simply swapping two of the phases. If you're running a 3Ø motor then those relays may be useful (as far as I know).

Universal motors can run on AC or DC. But they always run in one direction. If you know how to reverse a single phase AC motor - please share. It's my opportunity to learn something.

Check this out.

I'm still learning myself.

 

jtomich77,
I just realized you are dealing with a 3Hp motor. This will take some heavy duty switching. Can you get a photo of the motor's data plate and any photos of the control box(?)?
Ken

 

I would tend to use motor contactors, they have the required switching duty for motors and also the interlock, although made for 3 ph they also come with O/L if needed.
Max.

 

jtomich77,
I just realized you are dealing with a 3Hp motor. This will take some heavy duty switching. Can you get a photo of the motor's data plate and any photos of the control box(?)?
Ken

See attached. The control box is nothing special but a PWC switch, typical switch they use for boat lifts. As you can see the boat lift sticker. Appreciate you helping me on the matter. I'm such a novice when it comes to this.

 

Good! Now we have an idea of what you have. You say: "nothing special but a PWC switch, typical switch they use for boat lifts." With no model #, I pulled up a PWC lift manual for a BH-USA PWC LIFT. There are two wiring videos for a 110vac motor and a three position drum switch. Wiring

I may have missed it, but I got the impression that there is one control push button switch down stairs and one upstairs, not a single drum switch.
Ken

 

Have you thought of using a garage door opener. It already has adjustable limits and all of the logic built in.

 

The only problem with garage door opener is the limits are internal to the unit and have a range limited by the length of the adjustment screw.
So only OK as long as the overall operating distance is within this range.
Max.

 

Yes, @MaxHeadRoom I know this. The unit I speak of had a failed control board that Genie replaced the whole unit. The board has been scrapped for some components. Meanwhile I still have the DC motor. I'm still working out the gearing, whether I'm going to use it to drive a screw or pull a cable. Due to CV19 I've not put a lot of effort into that part. The part I am working out is the actual trolly and rail system. I plan on building a small wooden model and see what adjustments will need to be made. One big issue I have to solve is when the trolly arrives at the top - how do I tip it over so I can remove materials. Another big issue is going back down. If I have it in the shop - horizontal, loaded with a project, driving it out the door and down the rail I don't want it to tip over so fast that it throws the project off the trolly and crashing down.

But I don't want to hijack this thread. This has been more of a side discussion. The thread is to address setting up a dumb waiter with a call button and self actuation so that you don't have to hold a button or switch. My system is going to be manually controlled with a set of up-down switches both up at the shop and down at ground level so I can send or bring things up and down.

As I said, I only followed this thread because issues being faced with the dumb waiter. I really don't have anything of value to add; so I'm basically following it to see what others are suggesting. But as for my GDO, the motor is DC and can be controlled from two locations. As long as two switches (momentary ON-OFF-ON) are not operated both at the same time. That's highly unlikely. Another solution could be to have a single switch on a pendant that can be operated from ground level or from the shop floor. All minor problems to be addressed when it's time.

 

jtomich77,
Since you haven't answered my question about the switch(s), I went ahead and worked up a circuit diagram for a dumb waiter.
Limit switches on the first and and second floors
Momentary Call and Send push buttons on the first and second floors.
Fun project since I'm stuck (4-1/2 weeks) at home.
Ken

 

Maybe information details on the 20A 120vac motor for reversing is needed, not sure if you get DPDT contactors for 20a, may need two separate ones a double (reversing contactor)?
PWC switch doesn't really give info on the nature of motor switching.
Max.

 

Max,

Maybe not contactors, but control relays. More relays with DPDT configurations than contators.
Like this: 24vDC 40A DPDT Relay
The motor data plate in the photo jtomich77 sent in post #26 shows the wiring for CW and CCW rotation for 115VAC operation. That's where I got the terminal numbers.

Ken

 

With nothing but time on my hands, I modified my circuit. It adds a slight power-on-delay to allow the direction relay to switch first. These are C1, D2, and D4.

Ken

 

jtomich77 ,
Where you at in all this?
Ken

 

You need a limit switch at each floor for a start, The call PB (whatever floor) will latch in a relay to pick up the motor and unlatch when the dumb waiter hits the limit.
Also you need a dual contactor relay, for up/dwn.
Also do you need safety built in, such as a door or shutter to be closed before the D.W. moves?

Max.

Having the circuit latch is a sure way of having a disaster such as ripping a hand or arm off, because it is an open lift and not an elevator. A 20 amp hoist is fairly powerful, probably good for at least 500 pounds, able to do lots of damage.
The simple and safe way is to add a circuit with lights to indicate when it is at each position. Then whoever is operating it will know, not guess. Being able to stop it by releasing the button is the way to go.

 

Here is a bit more complicated version I designed with latches on the car and floor doors. But having an non-latching send configuration would also be good on a small dumb waiter.

 

There is a very good reason why there is no control box for sale or even published plans for one. A lift with no doors is a hazard to those folks who are not smart enough to avoid doing really dumb things.
And post #4 is clear that there are no doors or shutters on either opening. That means no latching controls at all. Certainly limit switches and lights would be very useful additions, and probably adding a light to indicate that it is in motion would also be good, and improve safety as well.