Vintage pedestal grinder find

[RobsForge]

Found in the same garage I bought that rolling toolbox table. Very upset because I don't have 220 in my garage so I can't even plug her in

I can't wait to clean it up and make it look new again. The pedestal is an old Black & Decker. I really can't find any information on the grinder or base but I'm sure it works just fine.

$100 find, I figured why not since I spent $100 taking my girlfriend to dinner last night, so this is my treat. That being said....I find $100 to be a fair price.

 

[nine4gmc]

$100, that's waaay too much, send it to me for proper disposal.

Great score man, I'd go so far as to say you ****.

 

[meatsis]

Yeah you ****!

I would have bought that too for $100

 

[txvwnut]

Since you don't have 220 in your garage just send it over here and I'll hook it up and give it a test run(s) for you.

No no no it's no trouble at all I'm happy to do it.

 

[larryq]

Well done sir, $100 is a giveaway for that

 

[6PTsocket]

I think you may be in luck. It is rare that small 1/2 hp Baldor 230 volt motors are not dual voltage. If you look at the current rating on the name plate, it says *2/4 Amps. With two different currents listed, this strongly suggests that it is. The normal dual voltage arrangement is to have two 115 windings wired in series for 230 volt opperation and wired in parallel for 115. It made little sense to manufacture two different motors when just splitting one 230 volt winding into two and attaching two more wires would allow it to work on either voltage. Call Baldor, they are very helpful. If you want to take a look, pull it off the base, remove the battom cover. The wires should be tagged T1, T2, etc. If you have T1, T2, T3 and T4. And T1 and T4 go to the switch and T2 and T3 are tied together, you are in luck. For 115 volt operation,T1 and T3 go to one side of the switch and T2 and T4 go to the other side. Of course you have to change the plug.

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[exmaxima1]

I think you may be in luck. It is rare that small 1/2 hp Baldor 230 volt motors are not dual voltage. If you look at the current rating on the name plate, it says *2/4 Amps. With two different currents listed, this strongly suggests that it is. The normal dual voltage arrangement is to have two 115 windings wired in series for 230 volt opperation and wired in parallel for 115.

You may be right, but I'm not seeing "2/4". It looks like 2.4 to me. The angle of the slash does not match the slash in the 1/2 hp spec.

In any case, the pedestal was worth $100....

 

[6PTsocket]

You may be right, but I'm not seeing "2/4". It looks like 2.4 to me. The angle of the slash does not match the slash in the 1/2 hp spec.

In any case, the pedestal was worth $100....

I was just going from the picture. It is hard to tell from that. You have the actual grinder to look at. It sure looked like a * to the right and something diagnal to the decimal point that looked like part of a slash. Fooled me.

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[AnEv942]

Nice!
Just curious- could be because the grinder is so BIG.. throwing off the visual scale...
but what plug is that on the power cord?

 

[EOC_Jason]

When you zoom in I thin it does say 2.4 and the / mark is just a scrape. Still it wouldn't hurt to remove the plate on bottom and look, there might be a wiring diagram stuck on there. Likewise you can try calling Baldor and see if it can be rewired...

Nice find though, looks solid.

 

[ndnchf]

You can run it off a VFD. I have a drill press with 3 phase, 220v motor. It runs off 120v single phase via a TECO FM50 VFD. Works like a champ.

 

[454ragtop]

You can run it off a VFD. I have a drill press with 3 phase, 220v motor. It runs off 120v single phase via a TECO FM50 VFD. Works like a champ.

The grinder is single phase. While rare and expensive single phase VFD's do exist, could probably buy a new Baldor grinder for what one costs.

 

[Shootinok]

Great find.
I recently scored a similar base, though yours looks older with the B&D in a hexagon.
Mine just says B&D on it below the top plate. I was willing to pay $70 just for the base.

 

[exmaxima1]

The grinder is single phase. While rare and expensive single phase VFD's do exist, could probably buy a new Baldor grinder for what one costs.

I've seen you say that a number of times, but still can't figure out how they could work. If you drop the speed of a single phase motor you run the risk of activating the start winding. It will not handle that very long and will burn up.

Can you provide a link to a VFD that operates on single phase motors?

 

[454ragtop]

I've seen you say that a number of times, but still can't figure out how they could work. If you drop the speed of a single phase motor you run the risk of activating the start winding. It will not handle that very long and will burn up.

Can you provide a link to a VFD that operates on single phase motors?

Take a look here http://www.invertekdrives.com/variable-speed-drives/optidrive-e2-single-phase/
I used to always say there were no single phase output VFD's, then someone on here corrected me. So I stand corrected, but I don't think they are a viable option for a home shop, most of the time be better off swapping in a 3 phase motor to be able to use a VFD.

 

[exmaxima1]

Take a look here http://www.invertekdrives.com/variable-speed-drives/optidrive-e2-single-phase/
I used to always say there were no single phase output VFD's, then someone on here corrected me. So I stand corrected, but I don't think they are a viable option for a home shop, most of the time be better off swapping in a 3 phase motor to be able to use a VFD.

The caveat is that the single phase motor cannot have a start winding: it must be split phase or permanent split capacitor type. Many vintage Baldors are indeed permanent split cap and this VFD would work. Most grinders, as well as nearly every machine motor (drill press, mill, saw, etc), have a start winding and they would not be eligible for this VFD.

 

[454ragtop]

The caveat is that the single phase motor cannot have a start winding: it must be split phase or permanent split capacitor type. Many vintage Baldors are indeed permanent split cap and this VFD would work. Most grinders, as well as nearly every machine motor (drill press, mill, saw, etc), have a start winding and they would not be eligible for this VFD.

Like I said, I don't think they're a viable option, and would never recommend one. But when I said in the past there are no VFD's for single phase motors, I was corrected.

 

[EOC_Jason]

Running a 220v 20A circuit is pretty easy just get you some 12-2 romex, a double-pole breaker, 20A 220v plug, etc, etc... Would also be useful for a small air compressor, heater, little welder, and more!

 

[6PTsocket]

Nice!
Just curious- could be because the grinder is so BIG.. throwing off the visual scale...
but what plug is that on the power cord?

It is wired for 220 with a 220 plug but many Baldors are dual voltage and can be switched by moving a few wires and changing the plug. This does not appear to be one of them. It is only 1/2 hp. so it could easily run on 120 of it had the flexibility to do so.

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[6PTsocket]

When you zoom in I thin it does say 2.4 and the / mark is just a scrape. Still it wouldn't hurt to remove the plate on bottom and look, there might be a wiring diagram stuck on there. Likewise you can try calling Baldor and see if it can be rewired...

Nice find though, looks solid.

It was wishful thinking. It is just a slash. I just worked with somebody that has a dual voltage one and the conversion instructions were only in the owners manual, unlike bare motors that have info. on the plate. But it never hurts to look.

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[6PTsocket]

I've seen you say that a number of times, but still can't figure out how they could work. If you drop the speed of a single phase motor you run the risk of activating the start winding. It will not handle that very long and will burn up.

Can you provide a link to a VFD that operates on single phase motors?

There is no start winding. There is a run winding and a phase winding working with a run capacitor to control direction. No centrifugal switch, either. Grinders are not built to start under load so have no need for high starting torque. In the last week I have looked at a lot of Baldor grinder schematics.

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[6PTsocket]

The caveat is that the single phase motor cannot have a start winding: it must be split phase or permanent split capacitor type. Many vintage Baldors are indeed permanent split cap and this VFD would work. Most grinders, as well as nearly every machine motor (drill press, mill, saw, etc), have a start winding and they would not be eligible for this VFD.

I have worked on any number of single phase motors with a start winding, start capacitor and cenrifugal switch. If they are made for high torque start application, like an air compressor, that is what is used. Google "single phase, capacitor start motor diagram" and you will get countless hits.

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[6PTsocket]

Has anybody consudered the simple solution of a step up transformer? 220 V x 2.4 A = 528 Watts,
Allowing for for motor starting current a1Kw step up transformer is under 50 bucks. Just plug it in and go.

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[exmaxima1]

There is no start winding. There is a run winding and a phase winding working with a run capacitor to control direction. No centrifugal switch, either. Grinders are not built to start under load so have no need for high starting torque. In the last week I have looked at a lot of Baldor grinder schematics.

Not sure if this is correct. I've seen many grinders with start windings: my vintage Atlas is cap start; my CM "block" grinders all have start windings but most use a current relay in lieu of a centrifugal switch; my 1/3 hp Baldor used a start winding and relay; my 10" Dayton and 10" Milwaukee both are cap start; I believe my Delta 7" is split phase w/switch. In fact, the ONLY grinder I own that is cap-run is my 1/2hp Baldor from the 70's.

But all of this is kinda moot. None of those single-phase-output VFD's increase the line voltage from 120 to 240 volts. You would still need a transformer anyway.

 

[exmaxima1]

Has anybody consudered the simple solution of a step up transformer? 220 V x 2.4 A = 528 Watts,
Allowing for for motor starting current a1Kw step up transformer is under 50 bucks. Just plug it in and go.

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[bczygan]

Run 240!!!

 

[6PTsocket]

Run 240!!!

For under 50 bucks and ready to go in 5 minutes? If he has no other use for 240 it is a waste of time and money. If he doesn't do his own work it can cost big bucks.

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[6PTsocket]

Not sure if this is correct. I've seen many grinders with start windings: my vintage Atlas is cap start; my CM "block" grinders all have start windings but most use a current relay in lieu of a centrifugal switch; my 1/3 hp Baldor used a start winding and relay; my 10" Dayton and 10" Milwaukee both are cap start; I believe my Delta 7" is split phase w/switch. In fact, the ONLY grinder I own that is cap-run is my 1/2hp Baldor from the 70's.

But all of this is kinda moot. None of those single-phase-output VFD's increase the line voltage from 120 to 240 volts. You would still need a transformer anyway.

I just went back to make sure I read correctly. The only thing I questioned is when you said that single phase motors can't be cap start. Maybe I am missing your point. Single phase, cap start motors are very common. I have seen the Baldor relay start and I was probably wrong to assume nobody uses cap start with a switch in a grinder In fact I think my old Craftsman is one. I remember the distinctive click. On a related note we had a Leeson motor that had a solid state switch for the start circuit. The company that makes them can size them to replace any centrifugal switch that needs replacement. Two leads go in series with the motor to measure start current and the other two replace the old mechanical switch. To size it you only need the current rating off the motor plate. The wires in series with the motor are the primary of a current transformer, just a couple of turns that will have no effect on motor performance. Neat, nothing to wear out.

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[pstemari]

. The only thing I questioned is when you said that single phase motors can't be cap start. Maybe I am missing your point. Single phase, cap start motors are very common...

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And three phase cap start motors don't exist. Three phase windings don't have a dead spot like a single phase does. The cap is effectively faking a second phase for the start winding.

 

[6PTsocket]

And three phase cap start motors don't exist. Three phase windings don't have a dead spot like a single phase does. The cap is effectively faking a second phase for the start winding.

Very true. They are so much more efficient and cheaper. But no 3 phase at my house. I used to live in an old apartment with a fuse box. I found two legs coming in. I had a solid 120 from each to neutral but only 208 across the hots. Could I have had 2 legs of a 3 phase in a residentisl building?

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[EOC_Jason]

Very true. They are so much more efficient and cheaper. But no 3 phase at my house. I used to live in an old apartment with a fuse box. I found two legs coming in. I had a solid 120 from each to neutral but only 208 across the hots. Could I have had 2 legs of a 3 phase in a residentisl building?

Quite possible if it was an older area or next to some industrial. Or maybe that is the only transformer they had available when the previous blew.

 

[exmaxima1]

I just went back to make sure I read correctly. The only thing I questioned is when you said that single phase motors can't be cap start. Maybe I am missing your point.

Yes, I believe there is confusion. What I tried to convey is that the ONLY single phase motors that will work with a VFD are those motors that DO NOT HAVE A START WINDING. The only common types that would work would be shaded pole (like in a record player or small appliance), or cap-run/permanent split (like in fans or low power machines that don't require much start up torque), or brushed ac/dc motors (like power drills, saws, routers, etc). Those types do not have a separate start winding.

ANY motor with a start winding would be at risk with a VFD if the speed was allowed to fall to the point where the start winding would re-activate and stay engaged---where it ultimately would burn out. This precludes the use of a VFD on most higher power single-phase motors: cap start, split-phase, cap-start cap-run, etc.

And in regard to the current sensing relay you described, they have been around for almost 50 years and are commonly found in both cap-start and split-phase motors. Replaces the centrifugal switch as you noted.

 

[RobsForge]

I'm going to call Baldor and see if I can rewire but if not I think I'm just going to rig up and extension cord out of 12-2 from my laundry dryer which is next to my garage. When I have my own shop/garage I will spend the time and money to do it right because as of right now its an unnecessary expense. You guys are great, thanks for the responses and info, glad I finally joined the forum.