Machine Repairs

[rake60]

This is a work related story but it always seem to happen the same with my hobby machines.

One of the production turret lathes at work broke down.
The turret would come forward to the collet but would not return.

One of the greatest mistakes in machine troubleshooting is overlooking the simple things.
I wasn't about to do that this time. Start at the beginning and go in sequence.

First I checked the microswitch that is supposed to stop the turrets forward motion. It's working fine.
Next, to the relays that microswitch is supposed to trigger. They are both tripping.
Now check the solenoid controlled pneumatic valve that controls the hydraulic directional valve. It works.
It has to be the hydraulic valve.

Get the maintenance manual out to locate the hydraulic valve.
The diagram shows Hydraulic Valve Q controls the turret forward and reverse.
So I go to a "retired" machine, steal that valve and swap it out on the broken machine.
It still won't cycle.

Look at that diagram again. Maybe there is another hydraulic valve in that circuit.

S#!t, the valve I changed was O not Q! Damn small print!

Change out the REAL Valve Q, the machine cycles perfectly and is back in operation.

Honestly, it always seems to go the same way for me at home! :wall:

Rick

 

[cfellows]

Yup, I routinely fix any number of things that weren't broke before I find the real problem!

Chuck

 

[kvom]

The first time I was ready to fire up my lathe after getting the rotary phase converter working and various parts replaced, I pushed the button and nothing happened. I figured it might be the fwd-rev switch, so pulled it out and checked the contacts, continuity, etc. All was good. I was then about to pull out the motor starter pushbutton switchs when I notice the writing engraved on the buttons.

Pushing the On button worked a lot better than the Off. :

 

[websterz]

The first time I was ready to fire up my lathe after getting the rotary phase converter working and various parts replaced, I pushed the button and nothing happened. I figured it might be the fwd-rev switch, so pulled it out and checked the contacts, continuity, etc. All was good. I was then about to pull out the motor starter pushbutton switchs when I notice the writing engraved on the buttons.

Pushing the On button worked a lot better than the Off. :

 

[Krutch]

It amazes me how the print keeps getting smaller and smaller. And double typed from time to time.
Don't even mention the chinese printed material!