Turning off spindle before changing bits?

[mmak2916]

For safety reasons, is it a good practice to turn off the spindle (by turning the key) before changing bits in between cuts? I'm paranoid that the spindle will accidentally start when I'm changing bits :eek:

[Brady Watson]

Yes. This is why the key is tethered to one of the wrenches.

-B

[mmak2916]

They forgot to include the spindle key with my Desktop so the key was shipped separately. Do you have a photo of how the key looks tethered to the wrench? Did it come this way with all the Desktop models? I suppose I'll tether it myself...

[scottp55]

Here you go M.
May have changed slightly as this is the first one Gordon Fabbed(Kirk got second and got a flat key like yours).

[mmak2916]

Ahhh, got it! Thanks Scott for the photo :)

[Ken Sully]

I have a PRS Alpha that did not come with a key. Is there an upgrade?
I would add it

[scottp55]

Ken, When I initially asked about it(and then they fabbed it FOR FREE-Way to go Shopbot:) ) ,it was because I'd seen that some of the bigger machines had it and I thought it was a great feature for what we thought at the time would be the work environment.
I thought all the newer ones came with it.
Rereading, i see that Russ and John mentioned it was on "Newer", so not sure when it became a"standard feature".
http://www.talkshopbot.com/forum/showthread.php?t=17702&highlight=spindle+interlock
Call Shopbot?
scott

[adrianm]

Mines a 2009 and it came with the key interlock.

[ssflyer]

Ordered my PRSAlpha in 12/08 - no key interlock, but also no problems.

[gc3]

Yes. This is why the key is tethered to one of the wrenches.

-B

curious to ask, why is there the need to cut power to spindle during a bit change? What would cause spindle to start alone other than a software glitch?

[Brady Watson]

curious to ask, why is there the need to cut power to spindle during a bit change? What would cause spindle to start alone other than a software glitch?

A number of things, including static electricity. I've never seen or heard of it happening, but since SB sells to educational institutions etc, an extra level of safety isn't a bad thing. It isn't hard for someone at a school let's say, to be changing the bit while someone else is fooling around at the keypad using the mouse. One click and you could turn on output 1 and start the spindle spinning...or already have Output 1 active and someone opens up the keypad and it starts spinning.

Personally - I'd jury rig it and not use it. I like compete control over the spindle starting and turning off + analog control of the speed. It would be nice to have it turn off automatically when a job was done, but it ain't broke & I ain't fixin it. The Desktop has it & I just leave it as-is...but the big tool rolls old school like it was when new. Less is more.

-B

[adrianm]

I cut the wrench off the key not long after getting mine. If some freak occurrence causes the spindle to start up and I get hurt then it's my own fault.

I had more problems from forgetting to turn it back on all the time...:o

[scottp55]

I like it as when I leave the spindle wrench on with the dustfoot magnet holding it while I blow out bit/collet that wrench is exactly my eyeball height:eek:
When keyboard was a few feet away I'd often ask someone to give me a touch more Z to get a long bit out, rather than unlock my wheels. Lot's of opportunities in a classroom setting or just teaching my friends kids or demoing for something to go wrong.
With Desktop placement of key is nice as the E-stop is just a toggle and can't tell you how many times someone(or the vac hose) has tapped the red plastic down and pressed the toggle ALMOST closed and if you looked at it crooked it would shut off. We have to manually set speed which means we have to go around the corner anyways so we have the key right in front of us.
Where's the key on big machine? On side of VFD?
Lot's more amateurs(including us which Gene hates:) ) with a Desktop in the house. Just feel safer leaving all the safety keys out and hanging and my blade down on my saw so the last thing my fingers hear isn't;
"What's THIS GREEN button Do?!" :)
I'm kind of attached to mine.
scott

[Simops]

I'm one of those bad boys that separated the key from the wrench:eek:
It just annoyed me enough to do it even though I knew it's there for a reason....
But I'm a one man band and know the state of my machine so feel the risk is low enough.....

Cheers

[Burkhardt]

curious to ask, why is there the need to cut power to spindle during a bit change? What would cause spindle to start alone other than a software glitch?
Well, theoretically a hardware failure or some bozo who turns on the machine while you are changing the bit. That said, it would be a HUGE problem if this is a router. For a spindle I would have much less concern because the starting torque is so low you could hold the wrench by hand and the VFD will go into stall fail. Well, at least with my 2.2kW spindle. But I doubt if that is still true with a fat 10hp spindle. Also, even the low starting torque may make the bit slice up your fingers.

That said, I don't turn off the vfd when changing bits. My personal choice and I still feel the CNC is by far my safest woodworking power tool.