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Power up speed
Posted: Thu Mar 07, 2013 4:15 pm
by wayne_eagle
Prior to buying my Shopsmith I had read a couple of reviews that admittedly were a bit critical. They didn't like the Shopsmith because, they said, the operating instructions said that the speed control must be turned to it's lowest setting before turning off the power and then brought back up to speed when it is turned on again. I tried that and it's a real pain in the posterior when I'm doing repetitive tasks.
I can't find those instructions in any of the manuals I have but it's a used machine and some of the instructions may be missing.
So my question is... does anyone actually do that?
I'm too impatient to do it all the time so will I be killing my machine by starting up at whatever speed I'm using?
I don't change speed without the motor running so I'm ok there.
I guess this may mean I'll be upgrading the power plant sooner than I thought.

Posted: Thu Mar 07, 2013 4:35 pm
by jbooher
If your breaker is 20 amps no problem starting the machine at higher speeds. On the other hand a 15 amp may flip the breaker at high speeds on startup.
Posted: Thu Mar 07, 2013 4:38 pm
by dusty
wayne_eagle wrote:Prior to buying my Shopsmith I had read a couple of reviews that admittedly were a bit critical. They didn't like the Shopsmith because, they said, the operating instructions said that the speed control must be turned to it's lowest setting before turning off the power and then brought back up to speed when it is turned on again. I tried that and it's a real pain in the posterior when I'm doing repetitive tasks.
I can't find those instructions in any of the manuals I have but it's a used machine and some of the instructions may be missing.
So my question is... does anyone actually do that?
I'm too impatient to do it all the time so will I be killing my machine by starting up at whatever speed I'm using?
I don't change speed without the motor running so I'm ok there.
I guess this may mean I'll be upgrading the power plant sooner than I thought.

Whether you find those instructions or not depends on what you are readings but YES those are the printed instructions from Shopsmith.
Does anyone actually do that? Yes, there are many who advocate that and are very disciplined at doing so.
The next question, logically, is does everyone do that? The answer there is an emphatic NO, Not Everyone. I will speak only for myself. I hardly ever do that and I have not now for about twenty five years.
The
one warning, however, is do not turn on the bandsaw or the disk sander, or the belt sander or the strip sander with the speed set up higher than the appropriate operating instructions say.
Can you do it and get away with it? I have already answered that question but the validity of that answer may depend on the wiring and breaker panels in your house/shop. The wiring should be no less than 14ga wire and the breaker should be no less than 15 amps. Depending on which circuit I am on, I have 14ga wire and either 15amp or 20 amp breakers. The best arrangement would involve 12ga wire and 20ga breakers.
I conclude from your questions that you are able to turn your Mark V on/off with the speed set at other than low speed (probably at saw speed). I seriously doubt that you have done any damage at all or you would not be asking.
It is my opinion that this "Safety Warning" was issued back in the days of fuse boxes, romex wire and wire stapled to open studs in the attic. If you still have a fuse box and old romex wire, you may want to disregard all of my positive comments.
Posted: Thu Mar 07, 2013 5:35 pm
by terrydowning
It is a good safety practice to turn down the speed before tool changes and at the end of your session.
If I'm using the band saw, table saw, or any other tool setup repeatedly in the same session I do not turn the speed down.
I try to turn it down at the end of the session and before tool changes.
Posted: Thu Mar 07, 2013 6:58 pm
by reible
terrydowning wrote:It is a good safety practice to turn down the speed before tool changes and at the end of your session.
If I'm using the band saw, table saw, or any other tool setup repeatedly in the same session I do not turn the speed down.
I try to turn it down at the end of the session and before tool changes.
This is pretty much how I do things. None of my machines seem to care much if they are set at low or at saw speed when starting. All of my machines were built after 1976 (well except my 10ER). I have 20A service and often use an extension cord of 12GA wire (25 foot) to operate in my driveway.
The biggest dangers would come when you might forget to lower the speed from a sawing operation and then attach say the bandsaw. If you think this might be a problem for you then hang a sign on the SPT shaft that reminds you to check the speed.
For even a better experience upgrade to the powerpro.
Ed
Posted: Thu Mar 07, 2013 7:35 pm
by terrydowning
reible wrote:. hang a sign on the SPT shaft that reminds you to check the speed.
For even a better experience upgrade to the powerpro.
Ed
What a great idea!!
Especially the PP upgrade (When I win the lottery) The sign is easily done and will happen sooner rather than later.
Posted: Thu Mar 07, 2013 9:55 pm
by BuckeyeDennis
I'm still pretty new at ShopSmith equipment and woodworking. But I do know a bit about electricity, and all the comments above make perfect electrisical sense (to steal a word that someone else coined). Yet I can still offer THREE additional benefits to turning the speed to low before powering off:
1) Improved fine-motor coordination skills. With all the extra practice, I can now usually crank the speed down WITHOUT painfully pinching a knuckle between the speed knob and the quill lock lever.
2) Mechanism maintenance. I diligently treated the variable-speed mechanisms with the prescribed oil and graphite lubricants after I got my SS, but the speed control still remained rather stiff. No longer -- gotta love that regular exercise!
3) Lastly, but by far the most importantly: if you don't turn down the speed, you don't get to enjoy that really cool windup noise when you fire it back up! No kidding, my 13 year old son told me, unsolicited, that was his favorite thing about the machine.

Posted: Thu Mar 07, 2013 10:25 pm
by JPG
That admonition was as Dusty has said a 'carry over' from the 3/4hp motors and typical residential wiring of a half century ago.
The 1 1/8 hp motor I believe has greater startup torque.
The indicator of whether you 'should' be adjusting to 'slow' when turning it off is the length of time it takes to 'wind up' to speed at startup.
The attached loads(SPT, sanding disk, saw blade) will affect that time.
If excessively long, and is repeated often short term, potential over heating of the motor can occur.
A not so obvious gremlin is when the speed is set to a high speed, and the SS is moved while NOT running, the belt can/may drop down too deeply in between the control sheave and the idler sheave. This creates the potential for the belt to jam at startup.
I would not be a fanatic re ALWAYS setting to slow at every power down sequence, but would recommend always setting it to slow at the end of a session, or when moving it.
However if slow startups are observed 'often' then cranking it down prior to power off is a prudent thing to do.
In addition to the mechanical loading, the power supply(wiring etc.) can also affect startup duration. The current surge at startup will create considerable voltage drop in the wiring and that in turn reduces the startup torque and therefore increases the time.
Setting it to slow at the end of a session will reduce the need for the 'sign'. If always at slow when 'beginning' a session, the mounting of a slow speed SPT will be 'uneventful'.
FWIW I rarely reduce speed when powering off, but then I have a 230V motor which draws half the startup current and the supply wiring is short.
My reflexes have been tested occasionally and they have proved fast enough(so far) for the occasional mental lapses!:D
Posted: Thu Mar 07, 2013 10:58 pm
by beeg
Now is this where I say. When ya turn it down to slow. Go slow down.
Posted: Thu Mar 07, 2013 11:06 pm
by JPG
beeg wrote:Now is this where I say. When ya turn it down to slow. Go slow down.
Yep! Go down to slow
slowly!