Tree 2UV reversing switch rewire

[mdelke]

I acquired a Tree 2UV knee mill everything works fine except the switch to reverse direction on spindle motor. When I got it, it was wired for 440 3ph. replaced the magnetic controller with one with the correct heaters for 220 and rewired the motor for 220v 3ph according to the motor plate. The motor runs fine and is actually very quiet in forward. When I try to switch it to reverse it locks the motor solid. Only way to get the motor to move is disconnect the motor from the power feed. Once it is free I can start it in forward and it runs fine.

My thoughts are that the jumpers are incorrect because they were set up for the 440 wiring. ( in the drum switch)
I have tried to get a wiring diagram for it but no luck.
The attached photo shows the change in motor wiring.


Any thought would be appreciated.

 

[Flyinfool]

If it runs forward it should run in reverse. It uses the same 3 wires.
Double check your motor voltage connections.
Check for voltage on each of the 3 lines at the motor in both FWD and REV.

If all 3 wires have voltage at the motor in both directions then you may have a mechanical issue that is not allowing rotation.

If one wire has no power in one position then it is an electrical issue to chase.

 

[markba633csi]

I tend to agree with flyinfool, sounds more like a mechanical issue
The drum switch wires should be the same as for 440 Volt- It's still 3 phase
-Mark

 

[mdelke]

I double checked the wiring in the motor before I tried but, but you are correct I should check it again. The reason I think its an electrical problem is the motor hums bad when I out it in reverse mode. I am afraid if I have it that way to long I will blow a fuse or pop a heater before I can check all three lines in both positions. I will check in the morning again.

Thank You for the input
Mike

 

[Flyinfool]

Start by putting it in HI gear, and while running forward turn the speed up to at least 1300 RPM.
Turn the motor off and see if you can turn the spindle by hand in both directions with the same felt resistance in both directions. This is to check for mechanical issues.

You might be single phasing it when in reverse.
Try giving the spindle a spin and then while it is moving turn on reverse. A 3PH phase motor will sometimes run on single phase but will have very reduced power and RPM.

The only way to check for single phase is to check the motor wires for power.
If you are worried about popping something, Hook up the meter then turn it on just long enough to check it then move the meter to the next set and repeat.

If you have a clamp on meter it does not take long to clamp each of the 3 wires.

 

[markba633csi]

You can disconnect the motor while you measure the wires, if you are worried about burning something up
Probably the best way to do it anyhow. be careful

 

[Flyinfool]

Those motor wires are old and brittle, I hate moving them any more than necessary.

 

[mdelke]

I have been investigating the problem on and off for the last few days while getting ready for a procedure at the Veterans hospital.

When I check the voltage it shows 220 at all wires in the reversing switch, input side and output to motor side.
If I give the motor a spin then turn the switch the motor will run, in either direction.

This I am thinking points to a problem with the old brittle wires as you eluded to.

I have checked and there are no motor rebuilding shops near me at least in a reasonable driving distance, so I am guessing my pancake motor is toast and I will need to find a suitable motor to replace it.

Flyinfool you are very helpful and I did as you suggested connected the wires to my meter and turned on the switch read the meter and turned the switch off.

Anything else I can do here, you all have been very helpful as a newbie I am getting an education here.

Mike (The YOOPER)

 

[markba633csi]

You did change the transformer taps from 440 to 220 right?
-Mark

 

[mdelke]

This transformer you speak of should be where? The wires come from the phase converter to a fuse box switch on the machine, over to the magnetic starter which is new and from there up to the motor thru the reversing switch. I see no transformer in the line.
There is a transformer on the back of the machine. The tag on the transformer says 440 /110. I take it that it was for the light that used to be on the machine but was removed before I got it. I assume this because there is no output line from the transformer.

Any and all suggestions are appreciated.
This machine ran like a dream at the shop where I purchased it - I tested it - then they disconnected it and loaded it, but this was on 440.

Mike