# Is a starter necessary?



## DavidR8 (Aug 20, 2020)

I have a Rockwell Unisaw with a 1.5 hp motor currently wired for 220v. It came with a Square D starter in a big metal box (10"T x  6"W x  4"D) with switches that are difficult to use when handling large sheets of plywood etc.
Is a starter strictly necessary or can I replace it with a paddle style on-off switch?
I know the saw had something much simpler when it came from the factory as there's a cutout in the cabinet for a simple switch about the size of light switch.


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## Larry$ (Aug 20, 2020)

If the starter is wired correctly it will have a motor overload circuit that is a good thing to have. You can add a paddle switch and locate it any place you'd like and leave the starter. Just wire the new switch to operate the magnetic pickup coil.


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## DavidR8 (Aug 20, 2020)

Larry$ said:


> If the starter is wired correctly it will have a motor overload circuit that is a good thing to have. You can add a paddle switch and locate it any place you'd like and leave the starter. Just wire the new switch to operate the magnetic pickup coil.


I'm definitely going to need some guidance on this!!!
I can shoot a picture of the wiring diagram and the actual layout.


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## Ulma Doctor (Aug 20, 2020)

you can wire this in easily









						ALLEN BRADLEY 140-MN-0240 MOTOR STARTER 1.5 HP  | eBay
					

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if i can be of service, don't hesitate to ask!


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## DavidR8 (Aug 20, 2020)

This is what I’m dealing with. 
The starter. 






The wiring diagrams. My apologies for the poor pics. Really hard to take shots of shiny paper glued into the corner of a box.


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## graham-xrf (Aug 20, 2020)

You get "starters" that amount to a latched relay switch, and you get "starters" that do lots more. Some modern starters have a bunch of electronics, but are small, and incorporated into the switch. The whole point is to have swiching that wont end up in a welded up mess!
*
So why do you need a fat double contacts, or even solid state switch?*
The reasoning goes like this..
You are (suddenly) connecting power to a motor which is standing still. It is a magnetic thing built of copper, and iron, and insulation, and like electric-magnetic things, only has any energy storage and exchange  properties when things are on the move. The fields have to be changing (AC) and the rotor has to be turning.

Stood still, at the instant you slam the switch, the motor looks like the nearest thing there is to a short-circuit! The copper wires are thick, and the very few ohms, or fractions of ohms, of DC resistance in them will allow a huge surge of current. It can be 10x or 20x, or even 50x the normal rated current. It can pop trips out unless they have arrangements to delay some milliseconds.That is why we have (in UK) Class C trips used for motor inductive loads.

 Once a motor is spinning, the iron has magnetic energy stored, and is generating back-emf. Without expanding on the detail about Lenz's law , the spinning rotor is also a _generator_, making a voltage that tries to send current in the opposite direction (i.e. "backwards"). This is called the "back-emf", which subtracts from the voltage you apply, and the motor is left to spin on the difference, the applied voltage being the winner. With a light or no load, the back emf can nearly equal the forward voltage. As you load the shaft, the back emf becomes less, so the current increases.

The problems come when you try to switch OFF. Taking away the forward voltage leaves the rotor spinning, with inertia, making a _very_ high voltage that can splat, burn and weld together switch contacts. Using a starter relay moves a short  copper bar with a contact at each end, and they let go together, minimizing or preventing altogether that mad splat.

Usually, a starter switch allows a "ON" momentary contact switch, which has a contact to keep the power on the relay after you let go the button "latched", and a "OFF" momentary normally closed switch in series with the relay coil to let it drop out, and this can be in series with a big red knob E-stop switch. E for "emergency". The whole thing can be quite small. This is a 260V rated 16A version I bought for a 1100W saw motor. It cheats on not having a separate the E-Stop by pressing onto the OFF button from outside the plastic lid.




*Going solid state*
Ahh - the SOFT start! Using a solid state switch, even with a latch relay, eliminates the contacts altogether. Solid state switches that have electronics to dial up the power stop that violent jerk on high power tools like saws, and eliminate the huge surge on the power.
*
Milliseconds timing helps*
There is one clever trick that can nearly eliminate the switch-on surge. The type of solid state relay used for ON-OFF switching (as opposed to power control) waits for the mains cycle to be at zero before turning on, so-called "zero crossing" switching. This is not the best for motor switching. If instead, the electronics waits until 12% or 15% _after_ the peak voltage in the mains cycle, the voltage driving the inrush current is headed toward zero. As it passes zero, and reverses, the magnetic field storage is established in the iron, the inductance becomes effective, with no drama. I used this trick to reduce a huge surge near 12x to a become a little 5% bump in the current.

Granted, the stuff we usually have in a typical HM shop is "small motor", though large enough to benefit from some care in starting and stopping. Hitting a 415V 3-phase with a direct line contactor start on a 110kW motor has it try to tear itself up out of the concrete mounts, but I saw it attempted. I spend a while, and a goodly chunk of client money installing decent motor control electronics for start-up, and a set of resistors that looked like room heaters, to brake it sweetly to a stop.


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## DavidR8 (Aug 20, 2020)

Thanks Graham!  I learn a ton of stuff here!


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## Janderso (Aug 20, 2020)

It seems the starter switch takes the insult away from the motor.
Is it safe to say it protects the motor?


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## graham-xrf (Aug 20, 2020)

David - that looks like exactly all the right kit, and (when I tilt the head thru 90°), I can see all the start/stop/ and E-stop circuits in the first picture. Also, it looks pretty much wired up already. Clearly it already works, but you need something somewhat more convenient. As @Larry$ suggest you can replace the function of the little push-button switches by taking wiring off to external switches with knobs as big as you like, located wherever you like within reach without groping around under a sheet of ply.
BUT..
For a thing like a saw, I suggest you stay with START, and two STOP push-buttons, one of them being a thing with a big red knob, as an E-Stop. Table saws are dangerous things, They need good attention to starting and stopping.

The circuit at top left (when I get the crick out of my neck) called REMOTE can be used, with the number of STOPS reduced to two (just leave out one of the three) and the number of STARTS reduced to one (unless you want the luxury of starting it by reaching here - there - everywhere).

Except for bigger fatter buttons located in more convenient places,you already have all the working stuff. All you really want is to dump the diddy little switches sharing the same box as the SSR, and put in something placed more conveniently. You will need some wires between the SSR (Solid State Relay) and your buttons. Have them in a single jacket. You're going to be OK on this one.


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## graham-xrf (Aug 20, 2020)

Janderso said:


> It seems the starter switch takes the insult away from the motor.
> Is it safe to say it protects the motor?


Not so much the motor, as the switch. Plain switches would have a very short life, and there is something quite alarming about a switch that welds itself into the ON state on a thing like a saw. I once tried to pull apart a burned up contact from a industrial relay that was operated with a load far exceeding what it was designed for. It was like it was spot-welded! I just love SSRs. No drama, nor bits to get splatted.


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## Bi11Hudson (Aug 20, 2020)

*graham-xrf *provides a very detailed and very good description on how a "small" motor does what it does. I would disagree with a few points but those would be technical and largely a difference in US vs UK electrical systems. Where I would comment here is more a matter of personal preference than an "approved" setup. A "Soft Start" is indeed a nice device, and if you wish to spend the money for one I hope you see the result in your power bill. I'm just not a fanatic of solid state devices when they aren't useful.

The answer you were looking for though can be expressed a little less technically for the (electrical) novice. Like many other small shop machines, the basic ON/OFF function is handled by a simple switch. Usually a "toggle" switch. Folks often use a light switch, though this is not the best idea. Light switches do not have the contacts to handle motor Start/Stop surges. What I describe below is the way my machines are set up. The arrangement is not universal, a "work in progress", as and when I feel like it.

First off, my compressor. 5 HP, single phase, huge inrush. Nominally, 5X run current. I installed a starter with the control circuit consisting of a simple toggle switch and the pressure switch. The concept being that the starter handles the motor current and the pressure switch has only control power. And the ON/OFF switch so I don't have to use the mechanical latch to turn off the compressor.

Next, the table saw, admittedly the most dangerous machine in my shop. I don't do "large" work, like a sheet of plywood. Mostly repetitive work where the fence is set up and I run a number of pieces. I do plywood with a "Skil saw" and "cut-offs" with either a Radial Saw or a Mitre Saw. The table saw NOW has a paddle switch, ON being a push button and off being the "paddle". I would like it to be on a starter, but not willing to spend the money. One day. . .

*Answer to your question*​What you have looks to be a magnetic(electrical) arrangement for Stop/Start. Definitely worth keeping, although it isn't absolutely necessary. *Ya got it, USE it.* The push buttons will be a "3 wire control" station. Simply stretching the wires to a practical location is all you need. A paddle arrangement can be finagled from a couple pieces of plywood and a hinge. The only advice I can offer is to use a piece of 3 wire cable and a box. Don't use "loose" wires. The push button looks like plastic (insulated), a "ground" wire isn't vital but a good practice. I often buy a heavy 3 wire extensiom some 25 feet long to make line cords. The short cut-offs are a handy source for this sort of work.

The point being is that it isn't necessary to remount the starter. Just punch out a KO(Knock Out) and use a Tommy connector to mount the cable. The push button station can mount wherever you want. I would suggest mounting it where you can "swat" the off paddle when you're running. Don't "look and resolve" in an emergency. Just swat it off as you go by.

Bill Hudson​


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## graham-xrf (Aug 21, 2020)

@Bi11Hudson : Agreed. A separate soft-start can run to three digit $$$, and what you get is the non-violent "safe" start without surges, with no savings on power nor anything else to soften the blow to the wallet.

They are now becoming more standard in mass produced kit. I purchased a 10" sliding compound mitre saw "Evolution" brand from a UK store for £150. I was in a hurry at the time, with a lot else on my mind. It looked like it would cut 2 x 4s and did not make the eyes water when paying up like would be for the DeWalt, which looked much the same.

When I tried it *WoW!*
Soft start, and built in electronic braking to come to a stop. I had bought the whole saw for less than a unmounted soft-start gadget from RS Components.

I noticed it cuts the wood just fine, though seems to run "slower" than expected, and it has a weird trick blade tooth getup. Then I start paying attention. "Multi-material" ! This one cuts straight through 1/4 inch steel, somehow without making it incredibly hot.
*--> Soft-start saw*
My point is - if soft-starts can be built into kit at that price, it should be more affordable to get the electronics for external use.

*Other motor start switching.*
Centrifugal switches built into the back of some 3-phase motors to change the wiring from STAR during run-up to DELTA when at speed. Some motors have the smaller built centrifugal switches intended to be taken out to the external contactors where the wiring change-over happens.

For motors with wiring to reverse direction, both 3-phase and single phase sorts, they have arrangements to sense when it has come to a stop before getting going in reverse. Some have ON-Delay relays with time-outs. With  simple direct wired switching, say to a lathe, I don't know in detail what happens if you take the lever knob straight across from *FWD* to *REV* while running, but I am pretty sure it cannot be anything good!

Sure - you can make most stuff start and stop with ghetto switching, but expect that the (many) starter switching gadgets available were not invented for nothing! The yellow/red/green goodie in post#6 cost me £14.95.

[Edit: @DavidR8   - I should mention that if you do have a E-Stop switch in series with OFF, while being  NC (normally closed) with momentary open operation, proper E-stops have a mechanical click-latch to keep them open after being pushed, usually released by giving the knob a little twist]


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## projectnut (Aug 21, 2020)

As mentioned I would leave the starter in place and wire in a remote start/stop switch in a convenient location.  Here are a pictures of a couple of my machines that have starters and remote start stop switches.




Note the start stop switch just behind the table on the right side of the picture.  It's attached to the box with the starter and overloads.




This lathe has a complete remote control station  The box with the starters is on the left side of the base  The  forward, and reverse buttons  start the motor in the proper direction.  There is also a speed increase and decrease button as well as a shutoff easily within the operators reach.  Since a saw only runs in 1 direction at 1 speed you would only need a start and stop switch.


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## machPete99 (Aug 21, 2020)

I have a similar Unisaw, but with 3HP motor, and a low voltage controlled starter system, and "remote" low voltage switch located under the fence rail (operator side). On mine there is only a remote control, it does not have any switch located at the starter.

Looking at your wiring diagram it appears that you should be able to install a separate "remote" switch. If the switch buttons on your starter are momentary contact you should be able to setup a remote. Usually the start switch is normally open with momentary close, and the stop switch is normally closed with momentarty open. You could get the appropriate separate pushbutton switches or get one combination switch of the appropriate type.


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## graham-xrf (Aug 21, 2020)

@Bi11Hudson . Bill - If the motor current is going through the pressure switch, and it sticks on start-up, would the kit keep going until the pressure safety valve lets go, and even then, keep going? Of course,it may be that the pressure switch kit has thru-line contacts rated for the motor, or operates some other internal stuff - I don't know.

I only mention it because a pressure switch I have here does not have the kind of contacts common for a motor relay, small little contacts, and is wired in a 24V circuit in series with the starter coil.

This also brings about the point that in big machinery, it is common to have a little 24V power supply transformer, and 24V relay coils, so that all the push-buttons, starts, stops, E-stops, whatever anyone might touch, and mounted externally, are operated with only fused a low voltage 24V on them.

Maybe this is more of an issue in UK, where the ring main is 240V 32A, so maybe not what one wants on and around over a machine. I always specified low voltage external kit for starting and stopping the big stuff. We exclude here the exotic stuff, like "intrinsically safe", for hazard area mining kit, which gets rather special.


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## 7milesup (Aug 21, 2020)

Dave... I have a similar saw. Jet cabinet saw. 3hp 220v.
I made up this hokey paddle switch thingy that I have been using since 2007. A simple tap of the knee as I finish the cut shuts the saw off.


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## DavidR8 (Aug 21, 2020)

7milesup said:


> Dave... I have a similar saw. Jet cabinet saw. 3hp 220v.
> I made up this hokey paddle switch thingy that I have been using since 2007. A simple tap of the knee as I finish the cut shuts the saw off.  You could glue some velvet around the "On" button hole if the edge is too sharp.


Thanks, I might do a bit of engineering to see if I can do something similar.


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## Larry$ (Aug 21, 2020)

DavidR8 said:


> This is what I’m dealing with.
> The starter.
> 
> 
> ...


You've got all you need in the wiring diagram. On the page: Control wiring, combined remote & cover, the two dashed lines indicate new wires leading to you new paddle switch location. Circles at the end of wire indicate a connection of the same # on the next diagram. As you can tell by looking at the diagram. any # of start stop locations can be added. Supply power comes in @ connection 2 . and flows thru all the normally closed stop switches that are series connected. The start switches get their power from the same point. They are parallel connected & normally open so any one of them can start the motor via the pickup coil. Once the pickup coil has pulled in it is maintained by the auxiliary contact block on the side of the main block. The aux contact is also wired in series with the normally closed stop switches & the overload contacts.

When you have a dust collector in you shop and want to have start/stop stations at each tool, you can take advantage of this same wiring scheme. I've always just added a 24V transformer, with a built in fuse holder, as the power supply so I could use exposed light gage wiring, & cheap switches. The voltage of the pickup coil or solid state device needs to match the power supply. There is a catch in using really cheap switches, they are easily kept from making contact by dust between the points.  Makes it hard to find the fault.


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## WCraig (Aug 21, 2020)

DavidR8 said:


> I have a Rockwell Unisaw with a 1.5 hp motor currently wired for 220v. It came with a Square D starter in a big metal box (10"T x  6"W x  4"D) with switches that are difficult to use when handling large sheets of plywood etc.
> Is a starter strictly necessary or can I replace it with a paddle style on-off switch?
> I know the saw had something much simpler when it came from the factory as there's a cutout in the cabinet for a simple switch about the size of light switch.


I know you've had a lot of information thrown at you but this diagram from the Vintage Machinery site shows pretty clearly how to wire in a secondary control station for a magnetic starter:






Either Green button momentarily energizes the contactor and starts the motor.  Either Red button breaks the circuit that keeps the contactor closed and therefore stops the motor.

There is a couple of good pages of info under Section 4.2 at:





__





						Main Page - VintageMachinery.org Knowledge Base (Wiki)
					






					wiki.vintagemachinery.org
				




BTW, it is also possible to buy other control station buttons that would fit in place of the ones currently in your SquareD starter.  IE one with a Red mushroom top for Stop.  May take quite a bit of searching on eBay to find exactly what you want.

Craig
(I have a mag starter on my 1.5 HP Unisaw.  I really don't want it to restart after a brief power outage.)


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## Janderso (Aug 21, 2020)

I like your Sheldon lathe Projectnut!!
How come the chip pan is so clean?


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## Bi11Hudson (Aug 21, 2020)

graham-xrf said:


> @Bi11Hudson . Bill - If the motor current is going through the pressure switch, and it sticks on start-up, would the kit keep going until the pressure safety valve lets go, and even then, keep going? Of course,it may be that the pressure switch kit has thru-line contacts rated for the motor, or operates some other internal stuff - I don't know.
> 
> I only mention it because a pressure switch I have here does not have the kind of contacts common for a motor relay, small little contacts, and is wired in a 24V circuit in series with the starter coil.
> 
> ...



That's *affirmative*, my compressor originally came from Sear's. Both the compressor and the (ASME) tank are "DeVilbis", the rest of the stuff is Craftsman.(Sear's) The contacts in the pressure switch are *much* too small to handle a 5HP startup, especially under load such as the compressor. Even with an unloader. . . That was my primary reasoning for adding the magnetic controller in the first place.

I had acquired it as junk and thought to myself "Now where would it be most useful?" I didn't have a table saw at the time or it might have ended up there. But in the long haul, the compressor would be the best place to use it. I installed it the first time the contacts failed. And converted the motor to 240 volts at the same time. Looking to reduce the line current.

And, to your question, the answer is *YES*, if the contacts welded I would be in deep do-do. The only "safety" on such machines is the pressure relief valve. I've never had the dubious experience of a duplex failure but thinking about it is frightening. And that on a good day. It could very well have happened. There is no indicator to note failure of the (purely mechanical) valve. It could fail and not be noticed for months.

You mentioned a low voltage magnetic controller for some of your equipment. Such is not the norm in the States with 120 volt supply. Most of our equipment, at the hobbyist level, is direct powered. The only machine I have that came with a magnetic controller is a (commercial??) planer. And the controls may well have been installed by the previous owner.

Outside of "industrial" installations and air conditioners, I haven't seen magnetic/low voltage controllers in "consumer" related products. It may well be the use of 240 volts supply(mains?) VS 120 volts supply. I'm not impressed with it, but that's the way it is. Most likely because it's cheaper and most manufacturers are looking at the "least cost" way of doing things.

Sorry, I could preach for hours on the safety VS cost of devices. There's no challenging the "Follow The Money" mind-set.

.


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## Ulma Doctor (Aug 21, 2020)

i always liked footswitches
lift your foot to stop, push the pedal to start


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## projectnut (Aug 21, 2020)

Janderso said:


> I like your Sheldon lathe Projectnut!!
> How come the chip pan is so clean?



I haven't been able to spend much time this summer working in the shop.  I generally clean the floor and the machines when I'm through for the day so the dogs don't track around swarf or get some stuck in their paws.  They've been clean and waiting to be used for quite a while now.  The wood working machines on the other hand are being well used.  I'm not sure if I'm making any progress, but I've had to empty the dust collector twice this summer.  The 10 gallon shop vacuum also gets emptied on a weekly basis.

To tell the truth I haven't used hardly any of the metal working machines in about 6 weeks.  I started pressure washing the house and deck which has lead to repairs on the decking and benches.  It's a bit frustrating trying to piece in new parts when the originals are over 30 years old and there isn't a straight board in the bunch.  I was originally going to replace all the decking and the benches, but treated deck boards are all but impossible to find, and dimensional lumber isn't much easier.  For this year the repairs will have to do.  

Yard cleanup may be another daunting task this year that keeps me out of the shop.  Late next month I'm supposed to get some more replacement parts.  I'm not sure how mobile I'll be when the leaves start flying.  They tell me "you'll be as good as the 6 million dollar man when we're finished".  I certainly hope so.  Looking at today's prices I think Lee Majors got a hell of a deal.  I'm looking forward to being faster and stronger, but I'm not holding my breath.  For being "retired" I certainly am not bored for lack of things to do.  I start my day between 5:00 AM and 6:00AM and don't get back to bed until 10:00 PM or 11:00 PM.  I keep telling myself "it's because I have so many things to do".  In reality it might be because I don't move as fast as I did 20 years ago.


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## Bi11Hudson (Aug 21, 2020)

Ulma Doctor said:


> i always liked footswitches
> lift your foot to stop, push the pedal to start



A foot switch would be a very nice addition, *within limits*. I have a few "industrial" switches, but I personally wouldn't want one on any of my machines. The only place I have one is on the "variac" used with a resistance soldering stand. If you do opt to use one, be sure to use a guarded version. A dropped scrap could cause a serious problem.

.


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## 7milesup (Aug 21, 2020)

A foot switch on a tablesaw  would be a no go in my opinion.  Balance is critical and one is working with pieces of different sizes of stock.  When you run a sheet through you are moving at least 4 feet, usually closer to 8 feet to get the stock through.  I don't see a foot switch working at all.


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## DavidR8 (Aug 21, 2020)

I have a foot switch on my drill press but I would not want one for my saw. 
I can see where the idea has merit, in practice I think it would be a bit sketchy. 


Sent from my iPhone using Tapatalk


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## Ulma Doctor (Aug 21, 2020)

Bi11Hudson said:


> A foot switch would be a very nice addition, *within limits*. I have a few "industrial" switches, but I personally wouldn't want one on any of my machines. The only place I have one is on the "variac" used with a resistance soldering stand. If you do opt to use one, be sure to use a guarded version. A dropped scrap could cause a serious problem.
> 
> .


i use these kind


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## graham-xrf (Aug 22, 2020)

@projectnut : Oh yeah - I get so distracted just looking the stuff in your lovely shop!  
Thanks for the pics.


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## hman (Aug 24, 2020)

DavidR8 said:


> Thanks, I might do a bit of engineering to see if I can do something similar.


Here's a possibility for you.  It's a design I came up with in 2009.  Rick Sparber (an HM member and good friend) was kind enough to add to his website.  Hope it's of some help to you!


			https://rick.sparber.org/ssw.pdf


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## Bi11Hudson (Aug 24, 2020)

A beautiful design. I have seen several Rick Sparber spots, nice work all. 

What I would comment on here is the particular switch used and its' limitations. First of all, that design switch is available in two pole for use on 240 Volts. In the UK and other 240 volt line countries however, a two pole switch isn't usually necessary. A phase to neutral connection is the norm.

Now, the down side to my remarks. The contacts in any "light" switch are not rated for motor use any larger than a pedestal fan. A "Dremel" is fine, a drill press isn't. A lathe or table saw is out of the question, don't even consider it.

.


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## graham-xrf (Aug 24, 2020)

Bi11Hudson said:


> A beautiful design. I have seen several Rick Sparber spots, nice work all.
> 
> What I would comment on here is the particular switch used and its' limitations. First of all, that design switch is available in two pole for use on 240 Volts. In the UK and other 240 volt line countries however, a two pole switch isn't usually necessary. A phase to neutral connection is the norm.
> 
> Now, the down side to my remarks. The contacts in any "light" switch are not rated for motor use any larger than a pedestal fan. A "Dremel" is fine, a drill press isn't. A lathe or table saw is out of the question, don't even consider it.


Absolutely! About using domestic lighting switches, you said it all.

There is a reason why there are switches specifically intended for motors. Particularly, there are design features in contactors to make them suitable for switching inductive loads. A machine motor is an inductive load. In concept a contactor is just a "relay", but a special one. When the armature of the contactor pulls in it in effect makes  short bars contact on both ends. Also, you are switching both the line, and the neutral return.

There is a whole class of contactor we hobby machinists don't need, known as "safety relays" where internally, all connections circuits go through _two_ breaks in series, just in case one welds closed, and all normally open switches are internally _two_ switches in parallel, just in case one stays open.  All they do is switch other contactors or SSRs. Safety relay systems just for policing E-stops can get complicated, and very, very costly!

Like I said - we don't need them, but we do need to be realistic about how motor starting and stopping works, and use something up to the job. They need not be expensive. Most of us manage with motors less than 2HP.

I guess I have a bit of a bias, now that I no longer tangle with 150HP motors pumping jet fuel. Even for the "very small" motors that drive my lathes, I would never consider a domestic resistive load lighting switch. White things with rockers? No thanks!


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## hman (Aug 24, 2020)

OK, you both make a good point.  Back when I wrote the article in 2009, a Dremel was pretty much all I'd used the switch design for, so there wasn't a big issue.  

It's also been pointed out to me that if the switch is left on and power fails, whatever is connected will start up by itself when power returns.  Of course, that's also the case with any equipment (like a small lathe) that has a "sustained" power switch.

That said, I  do have this switch on several of my motorized tools.  I'm pretty sure I made it a point to buy 20 amp rated Decora switches, just because I was concerned about motor inrush loads.  If needed, I could wire the switch to a suitable motor contactor for higher current or 230 volt loads.  

Anyway, the following tools make use of the safety switch.  Note the installation dates and motor horsepower info.  None of the switches have given me ANY trouble since being installed.

Craftsnman-Parks 18" vertical wood bandsaw, horsepower unknown, installed 2013, used 1-2 times per week.
Harbor freight 14" wood bandsaw, 1 "Chinese" horsepower, installation date unknown, used 1-2 times per month.
Delta 1x42 belt/disk sander, ⅓ HP, installed 2013, used several times per day.
Grizzly G4000 9x20 lathe, ¾ "Chinese" horsepower, installed 2013, sold 2019, used 2-3 times per week when I owned it.


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## projectnut (Aug 25, 2020)

Janderso said:


> I like your Sheldon lathe Projectnut!!
> How come the chip pan is so clean?



Just to prove the machine does get used here are a couple pictures of it with the adaptor for putting marine antifreeze in the new pressure washer.  Note there are a few chips in the pan.  As for the adaptor it's another one of those protracted projects.  What was supposed to take an hour is still sitting in the chuck a day later.  With all my recent rearranging of the shop I put my short internal threading tools in a "special place".  Now I have to find the special place to do some internal, and external threading.  If this turns out like most "little projects" it'll take longer to find the tooling than it will to cut the threads.


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