Replies

1. 
   swenson | Feb 21, 2011 02:23am | #1

   I have done it but I'm not comfortable doing it. Not sure why, but a little voice in the back of my head tells me it isn't safe. Sometimes bad things happen when I ignore that voice. I know that this doesn't address the "harder on the tools" question, my gut feeling is that starting and stopping is a little harder on the tools but I have stopped doing this. With good ear protection you can't hear that the tool is running and I think that might be part of the little voice's problem with it.

2. 
   Frank Vucolo | Feb 21, 2011 10:29am | #2

   Unsafe

   Power tools require our undivided attention when running. 

   The benefit (if any) in terms of reducing wear and tear would be small in a non-production shop setting and simply not worth the risk. In fact, the cost in terms of longevity and wear and tear on the machine, even if significant, would not be worth the risk in my opinion.

   Frank

3. 
   Frank Vucolo | Feb 22, 2011 12:42am | #3

   You're right, Dusty...

   I was way out of line on that one. I don't know what I was thinking.

   Thanks for pointing it out and for reeling me in before this whole thread got way out of hand with people considering the whole safety issue.

   Frank

4. 
   Jfrostjr | Feb 22, 2011 10:09am | #4

   Start-Stop of machine tools

   Robert,

   I have  an Oneida DC. The instructions that came with the unit specified that it be started no more than "X" times in an hour or it would overheat and damage a motor component. (I forget the details as I last read them a few years ago.)

   As my concern is with frequent start/stops on the DC, my practice is to turn-off the saw and quickly turn-on the jointer leaving the DC running. I know this does not answer your question directly - but maybe the issue of motor damage is real considering Oneida's suggestion.

   Frosty

5. 
   DonStephan | Feb 22, 2011 07:30pm | #5

   My dust collector, using 6"

   My dust collector, using 6" pipe, is designed to collect from only one machine at a time, so I keep closed all but one gate.  But having no gates open could damage the dust collector.  I leave it run but turn off each machine in turn when going back and forth between jointer, planer, and tablesaw.

1. 
   robertmc | Feb 22, 2011 09:33pm | #6

   Dust Collector Running

   Good points on the tools running.  Regardless of whether or not I leave the jointer / tablesaw on for a few minutes when not in use, I also leave my DC running as it was my understanding it should not turn off and on frequently.  When going between tools, I open up the DC gate of the tool I am going to use before closing the gate of the one I just stopped using.  I understand shop safety is critical.  But if  the tablesaw is on for a couple of minutes while I turn around and use the jointer, the tablesaw blade guard is always fully operational (Powermatic bladeguard).  If I do not have the guard on, when using a dado blade for instance, i would absolutely not leave it running.  Anyway, I appreciate the feedback.  I guess I am trying to get a sense of how frequently turning a machine off and on creates a problem for the motor.  Are DC units unique? 

2. 
   woodhacker | Feb 28, 2011 10:01pm | #10

   leaving DC running

   Ialso have an Oneida DC. Dust collectors because of the weight of the fan start under a load which taxes the motor. Although my motor runs at less than 10 amps, the startup surge is in excess of 65-70 amps. This is why Oneida states that the collector should be left running rather than stopped and started frequently. Running with all of the blast gates closed does not in any way hurt the collector, in fact because it's not moving as much air the motor will run more freely and the amperage draw will decrease. Oneida also recommends that the blast gates be left closed when the motor is running in between tool usage.

6. 
   AutumnWoods | Feb 23, 2011 10:13pm | #7

   As long as it's safe

   I work at a home shop, which is somewhat of a production shop at times since I do this professionally.  I have from time to time left two machines running at once when I'm going back and forth between them.  If they share the same circuit, like many of my 220v machines do, just make sure their amp draw doesn't exceed what your fuse box can handle.  With 220v it's easy since the amperage is roughly halved.  But you have to be aware of who is or potentially could be in the shop.  Are there small children who could wander out to see mommy or daddy?  Are there people who have a tendency to stop by?  Or in a larger shop are there multiple coworkers who are using the same saw?  In a loud shop it's conceivable they might not hear it running.  I would say for most applications it is probably safe - I frequently leave the router table and table saw running when making small runs of moulding and don't see anything wrong with it.  And since the capacitors dump a bunch of amps into the motor every time it starts, my personal opinion is that it reduces wear and tear.

7. 
   AutumnWoods | Feb 23, 2011 10:13pm | #8

   As long as it's safe

   I work at a home shop, which is somewhat of a production shop at times since I do this professionally.  I have from time to time left two machines running at once when I'm going back and forth between them.  If they share the same circuit, like many of my 220v machines do, just make sure their amp draw doesn't exceed what your fuse box can handle.  With 220v it's easy since the amperage is roughly halved.  But you have to be aware of who is or potentially could be in the shop.  Are there small children who could wander out to see mommy or daddy?  Are there people who have a tendency to stop by?  Or in a larger shop are there multiple coworkers who are using the same saw?  In a loud shop it's conceivable they might not hear it running.  I would say for most applications it is probably safe - I frequently leave the router table and table saw running when making small runs of moulding and don't see anything wrong with it.  And since the capacitors dump a bunch of amps into the motor every time it starts, my personal opinion is that it reduces wear and tear.

1. 
   AutumnWoods | Feb 23, 2011 10:15pm | #9

   Sorry for the double post.

   My computer just freaked out.