Reversing an rpc

[Ultradog MN]

A friend of mine has a lathe (and other machines) w/3 phase motor. The original motor control on the lathe has been changed/replaced so there is only forward. No reverse.
He runs it off a rotary phase converter which does not have any start capacitor/s on it
To start the rpc he hits the switch and kicks a T bar on the shaft with his foot to get it turning. Then all works good.
Somewhere I remember hearing that if he kicked the t bar the opposite way so the rpc was turning in reverse it would reverse the lathe motor as well.
Is this true?
Before I give him some quack advice I would like to verify that it is correct.
A guy doesn't need to reverse a lathe too often so this would give him that capability without any rewiring.
What do you electric gurus say?

 

[DDoug]

Before I give him some quack advice I would like to verify that it is correct.
A guy doesn't need to reverse a lathe too often so this would give him that capability without any rewiring.
What do you electric gurus say?

How cheap can you get ? Jeesh.

As Thermite detailed up above, "Plug reversing" can be done with an RPC, I have done it with my lathe.

 

[JST]

Agree, that would be the "around the barn the long way" approach.

Just flip the reversing switch on the lathe. That should work just as well as 3 phase. Mine does.

Yes, you probably do not want to have cheaped-out on converter capacity.

 

[Ultradog MN]

How cheap can you get ? Jeesh.

I asked an electrical question.
You have to give a smart ass answer.
Why?
Here is a smart ass reply.
My friend's lathe is a Monarch 12 CKK. It came from the factory in 1944 without reverse. Still doesn't have it.
Did you know there are are times a guy could use a lathe in reverse where you don't need it instant? Cutting internal threads is one example.
If he could have reversed the lathe simply by reversing the kick start RPC that might be handy to know.
Right?
By the way, it didn't work. He tried kick starting the the idler the opposite direction but it just kicked back and started in the usual way.

 

[JST]

........................
My friend's lathe is a Monarch 12 CKK. It came from the factory in 1944 without reverse. Still doesn't have it.
..........................
If he could have reversed the lathe simply by reversing the kick start RPC that might be handy to know.
...................................................

All it takes is an appropriately rated drum switch mounted in a convenient place and wired into the motor cable.. Presto.... reverse.

 

[Ultradog MN]

All it takes is an appropriately rated drum switch mounted in a convenient place and wired into the motor cable.. Presto.... reverse.

Yes.
Thanks.
Really just wanted to know about reversing the idler.

 

[JST]

Reversing the idler is the long way around the barn. YOU can DO it, but why?

 

[DDoug]

Reversing the idler is the long way around the barn. YOU can DO it, but why?

Uhm...because he's a "SmartAss" ?

 

[Ultradog MN]

Uhm...because he's a "SmartAss" ?

No.
It's more likely your lack of reading and comprehension skills.
I asked about reversing his idler - would it run backwards if he kicked the t bar the other way?
And I asked IF the idler would run backwards would that reverse his lathe?
Two simple questions that could have been answered with a yes or no.
But you especially couldn't just answer those questions. You had to call him cheap, talk about doing it right, instant reversing, drum switches, etc, etc.
None of which I asked about.
Perhaps in the future if a guy asks, "Is it raining?" you could say "Yes it is raining." or "No it is not raining." and refrain from condescending replies - or don't reply at all.
Read the questions more carefully and answer them succinctly.
That way you won't belittle yourself, as you have throughout this thread.

 

[scsmith42]

Reversing the RPC direction does not change the phase sequencing (as you discovered). A reversing drum switch is the proper option, or you can do the dual plug trick.

 

[dalmatiangirl61]

And no one has commented on the t-bar for kick starting the rpc, seems like a good pants leg or shoelace catcher to me. Hope he keeps the pets and children out of the shop.

 

[Ultradog MN]

And no one has commented on the t-bar for kick starting the rpc, seems like a good pants leg or shoelace catcher to me. Hope he keeps the pets and children out of the shop.

He doesn't wear his seat belts either.
The horror!

 

[dalmatiangirl61]

He doesn't wear his seat belts either.
The horror!

I fully support his rights to injure himself, my only concern is the innocents.

True story, knew a guy with a mining operation, inspectors kept telling him to put a guard over the crusher flywheel, he did not see the need. One day his daughter was there and needed to pee, she went behind the crusher, somehow she got caught in it and killed. I can't say for sure, but bet it still weighs on his mind.

Driving home a few weeks back I had a gang of motorcyclists in BDSM attire pass me, one column passed on right, other on left. One of the lead guys was swerving into oncoming traffic, including semi trucks, causing them to swerve onto the shoulder. I did think of calling the law, then reconsidered, natural selection will fix the problem sooner or later