Turning off equipment

[zeeprogrammer]

Just curious what others do...

I have a mini-lathe and mini-mill...I don't know how this applies to other equipment...

I sometimes find myself turning the speed knob to off and then switching out a drill bit or otherwise doing something with the chuck or spindle. This always bothers me as I've had experiences with other machines where a bit of static would cause things to jump or turn on. I've been trying to develop the habit to engage the emergency stop before I do anything with the chuck or spindle.

I've yet to have an issue with this...but it only takes one time.

I believe this is the safest thing to do...and part of my reason for the post is to remind others of that. But I'm curious if others think of this too.

I'm often reminded of this as I work on the mill...I can hear it humming when the emergency stop is not engaged. (On the plus side...I can it hear it.)

 

[Troutsqueezer]

Sometimes I like to live dangerously Zee, I keep the emergency switch on unless I'm not using the mill in the next half hour or so. Mine doesn't hum but I can hear the fan running.

The speed switch has a mechanical disconnect in it, you can hear and feel it as it opens and closes. Even if that failed, the speed switch would engage at minimum speed.

Same for the lathe.

-T

 

[Twmaster]

All of my equipment has a positively off power switch. The only time I removed the plug from the wall is if I am hand cranking or some such.

YMMV, may cause skin irritation. Processed in plant that handles nuts....

 

[bentprop]

If I'm changing a chuck,or something major like that,I'll switch the lathe off at the wall.
When I'm hand threading,i.e.,turning the chuck by hand,I will actually remove the plug from the wall socket.Why?I don't know,but i perhaps prefer the be rather safe than sorry.
When I'm finished for the day,I do the same thing.
This is especially important if you may have little ones coming to visit granpop's shop.They may inadvertently switch on a machine,which could have serious consequences.

 

[Deanofid]

I have switches on all my machines, Zee. My lathe has a variable speed motor and controller, and it
stops when the controller is turned to 'zero', but still, I turn off the power switch when I'm changing
work in the chuck and etc. Each machine has a switch wired into the power line, and mounted near the
machine where I can get to it without reaching over spinning parts.

Dean

 

[zeeprogrammer]

Thanks all.

I used to develop table-top robots and I still develop products with motors in them. I've had times where things would jerk or turn on with a sufficient ESD event. Maybe because the products were still in development...but I don't trust them anyway.

I notice my mini-mill speed knob doesn't have a positive off indent but my mini-mill does. There's been a couple of times where I thought I'd turned off the mini-mill only to find it suddenly start trying to turn (very low to zero speed). I think I turn the knob until I get some resistance but not enough to get to the indent. Maybe habit from mini-mill. If it's on, I figure it can run at any speed. A part can fail at any time.

Take care.

 

[dwentz]

My big lathe will not come on unless the chuck key is in the holder.

It only took one time to forget the key in the chuck for me to install that safety switch!

Dale

 

[ozzie46]

My big lathe will not come on unless the chuck key is in the holder.

It only took one time to forget the key in the chuck for me to install that safety switch!

Dale

I would be very interested in more info on how you did this.

Ron

 

[mklotz]

For the benefit of those new to the hobby...

Much home shop equipment (mine included) is not provided with magnetic start switches. [This is a switch that is held on by a relay. If power to the machine is lost, the switch returns to the OFF state and requires that the operator toggle the switch again to turn the machine back on. The machine will not restart when the lost power is restored.]

Lacking such switches, if you pop a breaker, your machines will restart when you cycle the breaker. In many cases the breaker is not physically located in the shop. This means the machines will be restarting when you're not there. Beyond potential damage to the machine and the job, this can be a real safety hazard to others, especially youngsters, who remain in the shop while you go to the breaker box.

Obviously, the best solution is to install magnetic switches. If you don't do that, try to train yourself such that your first thought when the power fails is to ensure that all the machines are turned off.

 

[davehall]

I'm also very interested in how you accomplished the chuck in the holder safety switch.

dave

 

[Tin Falcon]

I believe this is the type of switch marv is taking about
http://grizzly.com/products/Magnetic-Switch-Single-Phase-110V-Only-1-HP/G8290
The USAF shops had these on all the machines.
I like the I idea of the safety switch for the chuck key as well . An reduces time spent looking for the misplaced key.
Dave: I would think the cheapest way would be to wire a single pole momentary contact (aka pushbutton switch) in series with the normal power switch. when the key is in the holder the Button is depressed when it is not in the holder the switch and therefore the circuit is open and not run . An alternative method is use a micro switch and a relay . and if it is on a small cnc system it could be wired into homing /limit circuits some cnc systems have a cabinet switch that will not allow the system to stat unless the enclosure is closed.
Make sure all switches are properly rated.
Tin