Help with Replacement KO Lee T&C Grinder Motor Switch

J

jbaccell

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Hi All,

I posted the below at the other forum, I'm tapping into the collective wisdom here as well.

Thanks, much.

Joe

Good Evening,

Still working on my recent acquisition of a KO Lee model B960 T&C Grinder. The toggle switch for the work head needs to be replaced and I'm not sure of a source for it hence my inquiry here. The switch mounts (photos below) to the housing using two small screws and after quite a bit of searching, I can't seem to find a drop in replacement. I'm hoping someone can point me in the right direction.

If I may, the wiring to the motor and switch is crumbling so replacement is in order. I'm not sure what kind of strain relieve is used where the wires enter/exit the motor housing. I attached a photo of that too in the hopes someone can guide me with that as well.

Many thanks and much appreciation.

Joe
 

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Thanks so much for your help. The issue seems to be the way the switch mounts. The grinder uses two screws to affix the the switch, not the center stem and nut as most toggle switches mount. And yes, it's a reversible motor so double throw switch is needed.

Thanks again for your help, I do appreciate it.

Joe
 
You are right about the state of the wire insulation, but not to worry. No matter how bad, you can carefully undo the plastic tape, and work back to the where they connect the coils. If you don't want to get up to joins, then you can carefully cut away, or slide off the old insulation, and slide on some quality heat-shrink. The copper is elemental, it will always work.

The crimp terminations, and the tool that one uses are widely known, and pretty much universal. Red. blue, yellow, depending of the the size of wires that must be crimped. There seems enough slack there to simply cut them off and start over, but if you don't want to, another plan is to use heat-shrink that will just about get over them, and shrink onto the wires. If the insulation is still flexible, and not "crumbly" further back, you can opt to let the heat-shink overlap them a little, but leave them in service. You can get terminals from eBay or Amazon, or a hardware store. If changing terminals, yes do get the red ones, but also make sure you have the correct eyelet size for the terminal screw.

The toggle switch can also be replaced. From your pictures, it seems to be a centre-off type. Is this a reversible motor? In 3-phase motors, reverse is achieved by swapping over any two of the three terminals. In single phase motors, identified by the presence of the capacitor, reverse is achieved by single pole change-over as to which winding is fed via capacitor. I can't tell from the pictures which it might be.

Is the view of the red terminals actually a view of the back of the switch? If so, it looks like DPDT (double pole, double throw) changeover. You do not have to use screw-on terminals. You can, if you like, get one with push-on spade terminals, and the appropriate connects to crimp onto the wires.

@Be_Zero_Be posted while I was typing, and he has found a switch with screw-on threaded terminals.
 
graham-xrf said:
You are right about the state of the wire insulation, but not to worry. No matter how bad, you can carefully undo the plastic tape, and work back to the where they connect the coils. If you don't want to get up to joins, then you can carefully cut away, or slide off the old insulation, and slide on some quality heat-shrink. The copper is elemental, it will always work.

The crimp terminations, and the tool that one uses are widely known, and pretty much universal. Red. blue, yellow, depending of the the size of wires that must be crimped. There seems enough slack there to simply cut them off and start over, but if you don't want to, another plan is to use heat-shrink that will just about get over them, and shrink onto the wires. If the insulation is still flexible, and not "crumbly" further back, you can opt to let the heat-shink overlap them a little, but leave them in service. You can get terminals from eBay or Amazon, or a hardware store. If changing terminals, yes do get the red ones, but also make sure you have the correct eyelet size for the terminal screw.

The toggle switch can also be replaced. From your pictures, it seems to be a centre-off type. Is this a reversible motor? In 3-phase motors, reverse is achieved by swapping over any two of the three terminals. In single phase motors, identified by the presence of the capacitor, reverse is achieved by single pole change-over as to which winding is fed via capacitor. I can't tell from the pictures which it might be.

Is the view of the red terminals actually a view of the back of the switch? If so, it looks like DPDT (double pole, double throw) changeover. You do not have to use screw-on terminals. You can, if you like, get one with push-on spade terminals, and the appropriate connects to crimp onto the wires.

@Be_Zero_Be posted while I was typing, and he has found a switch with screw-on threaded terminals.
Click to expand...
Hi Graham,

I appreciate you taking the time to help guide me, much appreciated, it's very helpful. The issue with the replacement switches I have found is they do not have the two threaded screw holes to mount the switch like the original. Any idea where I might find a replacement or could it have been a proprietary switch made for KO Lee? The grinder is quite old and the wiring crumbling but not the wires going to the motor, the wire from the line to the switch. I plan on replacing that but I'm not sure about the strain relief where it enters the motor housing..

Thanks again,

Joe
 
graham-xrf is mostly on point with restoration of the wiring. Strain reliefs have several solutions, depending on the exact situation. First and simplist is a knot as the wires come out of the enclosure. Beyond that, a cable clamp if there is a proper sized hole to mount it. I salvage old power tools, including the strain relief device on the line cord. In any application, primary concern should be protecting the wires, usually with shrinkable sleeving. For portable cable, rubber jacketed SO or the like, a short piece of heavy wire wrapped around the jacket was used for years by OEMs.

The switch mounting is an indication of age rather than a proprietary device. If a 12mm hole is there, the suggested can be used. Lacking that, a sub-plate can be "finagled" to hold the switch. A 12mm (15/32 inch) hole in a piece of sheet metal is all that is required. The screw mount switches can still be found, but a used or "new old stock" switch really wouldn't be any gain. A new switch can be had but may be rather costly. One point of interest is a "pause toggle" mechanism that requires a pause between directions. I haven't seen one for many years, today's use is usually a "Fwd-Stop-Rev" pushbutton with relays. Any mechanism that requires that pause between directions will suffice.

.
 
Bi11Hudson said:
graham-xrf is mostly on point with restoration of the wiring. Strain reliefs have several solutions, depending on the exact situation. First and simplist is a knot as the wires come out of the enclosure. Beyond that, a cable clamp if there is a proper sized hole to mount it. I salvage old power tools, including the strain relief device on the line cord. In any application, primary concern should be protecting the wires, usually with shrinkable sleeving. For portable cable, rubber jacketed SO or the like, a short piece of heavy wire wrapped around the jacket was used for years by OEMs.

The switch mounting is an indication of age rather than a proprietary device. If a 12mm hole is there, the suggested can be used. Lacking that, a sub-plate can be "finagled" to hold the switch. A 12mm (15/32 inch) hole in a piece of sheet metal is all that is required. The screw mount switches can still be found, but a used or "new old stock" switch really wouldn't be any gain. A new switch can be had but may be rather costly. One point of interest is a "pause toggle" mechanism that requires a pause between directions. I haven't seen one for many years, today's use is usually a "Fwd-Stop-Rev" pushbutton with relays. Any mechanism that requires that pause between directions will suffice.

.
Click to expand...
Bill,

I thank you, Graham and Be_Zero_Be for taking the time to help, I appreciate it more than I can express in words. I just ordered the switch that Be_Zero_Be linked to and I will either just mount it as most toggle switches mount or make a plate as you suggested. Thanks for your advice with regards to the wiring and strain relief...

Thanks again to you all.

Joe
 
Last edited:
jbaccell said:
Hi Graham,

I appreciate you taking the time to help guide me, much appreciated, it's very helpful. The issue with the replacement switches I have found is they do not have the two threaded screw holes to mount the switch like the original. Any idea where I might find a replacement or could it have been a proprietary switch made for KO Lee? The grinder is quite old and the wiring crumbling but not the wires going to the motor, the wire from the line to the switch. I plan on replacing that but I'm not sure about the strain relief where it enters the motor housing..

Thanks again,

Joe
Click to expand...
Hi Joe
You don't have to get stuck just because you can't find an exact switch that can mount onto original screw holes. It's only a switch, and you can go ahead and work up your own replacement little project. A bit of a bracket with a hole in it can mount any number of toggle switch bodies. Try for quality. Pick a switch with a way higher over-rated current. The surge current on start-up is several times the motor normal current, and the generated voltage splat when switching OFF can mess up contacts until they weld together, or burn up.

If you can, check for a switch with an AC motor rating for inductive loads, but don't go mad trying for it. I have found that using a (say) 20A switch for a 5A expected motor current is the kind of approach that works.
 
Installed the new switch today, works perfect. Thank you all for the help, much appreciated. Now I need to figure out what type of lube the KO Lee B943 power work head uses in the worm drive. I can't find any mention of it in any of the literature I looked at.

Joe
 
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