Bench grinder problems

[bbcmudtruck]

I just picked up a Dayton 1hp 110/220 bench grinder for cheap. Heres the problem, when I turn it on, it turns very slowly and the motor heats up. The safety shields have a built in shut off it appears. Could I dike those wires and wire them directly to themselves to bypass the safety's? The guy that I bought it from said that he was having trouble with one of the safety switches the last time he used it. Which to his recollection has been more than 5 years ago. He said it ran great the last time he used it, but he did have to fiddle with the safety switch a little. I'm as green as they come to messing with wiring, so I'll see if I can figure out how to post up some pictures to help.

 

[bbcmudtruck]

Photo

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[bbcmudtruck]

The black thing in the eye shield is the safety I think? There is one in each of the shields. When you rotate the shields down, it is supposed to let it run properly. The wires are old and chewed up with several bare spots as well. Can anyone point me in the correct direction to start getting this thing up and running? Or is it even worth messing with? Thank you!

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[btdobie]

I wouldn't rule out the possibility that the power switch is bad as well. If you want to bypass the safety switches, my guess is that you just need to wire the power switch straight to the motor. The safety switches are most likely installed in series with the power switch on a unit of that age.

 

[The Cobbler]

does the motor spin freely & easily by hand ? if not you likely have bearing issues
does it have a start capacitor? that could be bad .
I suspect the safety's are a bulb switch so they cut the current if the shields are not down but thats a guess on my end .

 

[bbcmudtruck]

Thank you for the help! Is this old bench grinder worth fixing up in the first place?

 

[bbcmudtruck]

does the motor spin freely & easily by hand ? if not you likely have bearing issues
I suspect the safety's are a bulb switch so they cut the current if the shields are not down but thats a guess on my end .

Yes the motor spins freely and easily. I can give the wheel a spin and it will spin over several times on its own before stopping. The wheels appear to spin true and there isn't any noise coming from the bearings when I spin it by hand. Not to say they don't need to be replaced, just trying to give you guys as much information as possible. I believe you are correct about the safety's as well.

* I don't know what a start capacitor is or what it would look like. I can easily get more photos if you let me know where to look!

 

[The Cobbler]

if it is a small easy fix yes it is worth it IMO
if the armature or field is bad , I don't think it would be worth the repair

 

[The Cobbler]

I edited my original post after you quoted it, read about the start capacitor

 

[bbcmudtruck]

I'm not sure what the start capacitor would look like or where it would be located. I can get you more photos, I just don't know where to look.

 

[The Cobbler]

it would be under the motor base with the switch & wiring

 

[bbcmudtruck]

It also says that its 110/220 on the badge. Could it be that its wired for 220? I'm just plugging it into a 110 outlet.

 

[btdobie]

it would be under the motor base with the switch & wiring

I will have to look up that specific motor but my guess is it is a split phase motor not a capacitor start. Capacitor star motors are only used where high starting torque is needed. Split phase Motors have a starting coil that is disconnected by a centrifugal switch once the motor picks up speed.

Update:. Looks like that is a capacitor run induction motor. So there is a run capacitor.

 

[bbcmudtruck]

Here's a photo of under the base.

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[btdobie]

It also says that its 110/220 on the badge. Could it be that its wired for 220? I'm just plugging it into a 110 outlet.

If it has a 110 plug it was probably wired for 110, but that's no garuntee.

 

[American Locomotive]

I see a capacitor, it is likely failed and should be replaced. You should get heat shrink and covet up all the bare spots on the wires.

 

[bbcmudtruck]

I see a capacitor, it is likely failed and should be replaced. You should get heat shrink and covet up all the bare spots on the wires.

Thanks for the help guys! I'll try to track down some parts and report back.

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[The Cobbler]

you need to match the values of the capacitor if you do replace it.
there is a number something like 280 MFD 110-125 VAC the MFD number needs to be matched . the voltage can be equal or higher , in other words the VAC could be 220 or 440 etc in this case. do not go lower on the voltage

 

[bbcmudtruck]

you need to match the values of the capacitor if you do replace it.
there is a number something like 280 MFD 110-125 VAC the MFD number needs to be matched . the voltage can be equal or higher , in other words the VAC could be 220 or 440 etc in this case. do not go lower on the voltage

OK I'll take capacitor out tomorrow and clean it up some more. Where's a good place to look for parts?

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[American Locomotive]

Another possibility is that the centrifugal start-switch (if it has one) is dirty. They can be difficult to get to in a grinder.

Try wrapped a string around the a stone, giving it a good hard pull and then turning the grinder on. See if it gets up to speed on its own.

 

[Michael_in_DE]

Personally, yes, I do think it's worth messing with. Dayton makes great stuff, and your alternative solutions or replacement are buying something new/plastic ew, or buying another used one and then you could be exactly where you are now.

if you can fix it, it will be a cheap fix. I would just cut those safety switches out and tie those wires together. And if that didn't work I would trace those safety wires back to the base with a multimeter and cut and them and tie them off together there.

 

[exmaxima1]

...if you can fix it, it will be a cheap fix. I would just cut those safety switches out and tie those wires together....

Agreed. I suspect those eyeshields were aftermarket since that grinder looks like a Doerr and I've never seen shields like that on a Doerr. And certainly not wired with BX-style electrical conduits. I'd assume all the wiring needs to be redone.

 

[bbcmudtruck]

Agreed. I suspect those eyeshields were aftermarket since that grinder looks like a Doerr and I've never seen shields like that on a Doerr. And certainly not wired with BX-style electrical conduits. I'd assume all the wiring needs to be redone.

You would be correct in the sense that all of the wiring needs to be redone! Most, if not all of the wiring has bare spots from old age. What gauge of wire should I use?

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[American Locomotive]

Whatever gauge wire it has. Probably 12 gauge minimum since its 1HP

 

[pcmeiners]

Agree with Btdobie, likely a split phase. I have a 3/4hp Dayton and it has centrifugal start switch, open up the motor and check it. I would replace the capacitor due to it's age, but that does not account for the motor heating up.

 

[exmaxima1]

You would be correct in the sense that all of the wiring needs to be redone! Most, if not all of the wiring has bare spots from old age. What gauge of wire should I use?

The motor coils will be configured in multiple pairs, so you will have lots of wires sharing the current path. I would use 16awg minimum for your motor (2 conductors of 16awg equals 13awg if there was such a thing). Or you could simply match whatever the present wire gauge is.

 

[bbcmudtruck]

I appreciate all of the help fellas!

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[stonesfan68]

That model number looks like a Grainger part number...And when I put it in the Grainger website it comes up as obsolete. Contact Grainger and see if they have any parts available for it. At the very least they'll have the start capacitor- usually for pretty cheap.


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[bpjr]

I've purchased start capacitors for 1 hp motors locally and on ebay. Locally is about 4x the price.

 

[DadsTools]

I'm in awe of folks that want to tackle this kind of old electrical item. They scare the bejeepers out of me! Gosh, this one is pre-zip code! (((((shuttering))))) But I accept that some have more energy, ambition & spare time than I.

The heating up is not good--it may either mean the motor is not drawing power as it should, the excess power being expressed as heat, or it's encountering undue resistance either electrical or mechanical. If the bearings are still correct, it should spin more than just a few times after you give it a good spin by hand--should turn quite a few revolutions, in fact.

Bet the insulation on the coil wire wraps are bleeding electricity. Heat breaks it down even more. This could cause it to run slow or erratically, and the extra electricity not being allowed to travel the total distance of every single wire path will express as heat. You always hear the saying, "They don't make 'em like they used to." When it comes to modern insulating materials, that's actually a very good thing they don't! Imagine the hours of fun re-wrapping that armature--can't think of anything better I'd rather do with my spare time.

Run away! Run away!

 

[bbcmudtruck]

I'm in awe of folks that want to tackle this kind of old electrical item. They scare the bejeepers out of me! Gosh, this one is pre-zip code! (((((shuttering))))) But I accept that some have more energy, ambition & spare time than I.

The heating up is not good--it may either mean the motor is not drawing power as it should, the excess power being expressed as heat, or it's encountering undue resistance either electrical or mechanical. If the bearings are still correct, it should spin more than just a few times after you give it a good spin by hand--should turn quite a few revolutions, in fact.

Bet the insulation on the coil wire wraps are bleeding electricity. Heat breaks it down even more. This could cause it to run slow or erratically, and the extra electricity not being allowed to travel the total distance of every single wire path will express as heat. You always hear the saying, "They don't make 'em like they used to." When it comes to modern insulating materials, that's actually a very good thing they don't! Imagine the hours of fun re-wrapping that armature--can't think of anything better I'd rather do with my spare time.

Run away! Run away!

So in your opinion, I dont have anything worth fixing? Serious question as I dont have any experience with electricity on this scale. I picked it up along with a pile of shovels, spades, scoops etc for 20 bucks. I feel as though I got my moneys worth just from the shovels. So if its junk and not worth fixing, I'd be bummed out but not financially hurt.

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[DadsTools]

So in your opinion, I dont have anything worth fixing? Serious question as I dont have any experience with electricity on this scale. I picked it up along with a pile of shovels, spades, scoops etc for 20 bucks. I feel as though I got my moneys worth just from the shovels. So if its junk and not worth fixing, I'd be bummed out but not financially hurt.

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In my opinion, no. ESPECIALLY if you have no experience messing with an 'ancient' electrical device like this. Doesn't mean it's 'junk'. Just means it's like any project: how much time are you willing to invest in it compared to the return on that investment? How much of your life-substance are you willing to devote to it? It's like buying a fixer-upper house, then finding all the hidden nightmares once you start opening up the walls. You could wind up buying all the parts, re-wiring it, and still have issues. Perhaps the bearings need replacing (if it only turns a few times after you spin it by hand, they do, guaranteed). Perhaps the brushes. Perhaps the armature needs re-wrapping. Then when it's done, what do you have? And old piece of electrical shop equipment that still has a zillion miles on it and has really no collector's value to speak of and no unique feature/capability that you can't get with a modern grinder. It's not like an old art deco bakelite collectible radio or something like that, or a pre-war Bailey wood plane that cuts better than anything made today. Or an antique coffee grinder or pedal-driven drill press that would be a delight to vintage-style woodworkers. Even with these, none has the safety risks associated with this kind of equipment. It's just an old bench grinder. Life's too short. Now, if it were your Dad's and you just want to put it back into service for sentimental reasons, that's a different story. But then it would be far more than just an old bench grinder to you.

 

[bbcmudtruck]

In my opinion, no. ESPECIALLY if you have no experience messing with an 'ancient' electrical device like this. Doesn't mean it's 'junk'. Just means it's like any project: how much time are you willing to invest in it compared to the return on that investment? How much of your life-substance are you willing to devote to it? It's like buying a fixer-upper house, then finding all the hidden nightmares once you start opening up the walls. You could wind up buying all the parts, re-wiring it, and still have issues. Perhaps the bearings need replacing (if it only turns a few times after you spin it by hand, they do, guaranteed). Perhaps the brushes. Perhaps the armature needs re-wrapping. Then when it's done, what do you have? And old piece of electrical shop equipment that still has a zillion miles on it and has really no collector's value to speak of and no unique feature/capability that you can't get with a modern grinder. It's not like an old art deco bakelite collectible radio or something like that, or a pre-war Bailey wood plane that cuts better than anything made today. Or an antique coffee grinder or pedal-driven drill press that would be a delight to vintage-style woodworkers. Even with these, none has the safety risks associated with this kind of equipment. It's just an old bench grinder. Life's too short. Now, if it were your Dad's and you just want to put it back into service for sentimental reasons, that's a different story. But then it would be far more than just an old bench grinder to you.

Thank you for the honest opinion! While I have your attention, what brand would you keep an eye out for? I've read a bunch of reviews on the newer box store grinders and they all seem to have their problems. Not being true to being under powered.

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[American Locomotive]

Oh give me a freaking break @DadsTools. It's a bench grinder with like 6 wires total in it. Even a complete novice could re-wire it in an hour or two.

Furthermore, it's an american-made 1HP bench grinder. Have you priced out a 1HP bench grinder recently? You're looking at $250 minimum for a cheap import unit. To get a heavy-duty U.S made equivalent to that, you'd be shelling out closer to $800-$1000. Buy a $10 capacitor, heatshrink, wire nuts, a 3-prong plug end and 10 feet of 12-3 SJ cord from Home Depot. It'd probably be about $40 all together.

Thank you for the honest opinion! While I have your attention, what brand would you keep an eye out for? I've read a bunch of reviews on the newer box store grinders and they all seem to have their problems. Not being true to being under powered.

I would honestly disregard his advice. As I mentioned above, you'd have to spend close to $1000 to get a grinder truly equivalent to that Dayton.

 

[bbcmudtruck]

Oh give me a freaking break @DadsTools. It's a bench grinder with like 6 wires total in it. Even a complete novice could re-wire it in an hour or two.

Furthermore, it's an american-made 1HP bench grinder. Have you priced out a 1HP bench grinder recently? You're looking at $250 minimum for a cheap import unit. To get a heavy-duty U.S made equivalent to that, you'd be shelling out closer to $800-$1000. Buy a $10 capacitor, heatshrink, wire nuts, a 3-prong plug end and 10 feet of 12-3 SJ cord from Home Depot. It'd probably be about $40 all together.

I would honestly disregard his advice. As I mentioned above, you'd have to spend close to $1000 to get a grinder truly equivalent to that Dayton.

Lol OK. I welcome all advice from people who have knowledge on this thing. I'm willing to spend some money on it, hell I was certain I'd have too when I bought it. How hard is it to change the bearings and where would I get them from?

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[American Locomotive]

Before condemning the bearings or anything like that, you need to get it running.

 

[DadsTools]

Oh give me a freaking break @DadsTools. It's a bench grinder with like 6 wires total in it. Even a complete novice could re-wire it in an hour or two.

Furthermore, it's an american-made 1HP bench grinder. Have you priced out a 1HP bench grinder recently? You're looking at $250 minimum for a cheap import unit. To get a heavy-duty U.S made equivalent to that, you'd be shelling out closer to $800-$1000. Buy a $10 capacitor, heatshrink, wire nuts, a 3-prong plug end and 10 feet of 12-3 SJ cord from Home Depot. It'd probably be about $40 all together.

I would honestly disregard his advice. As I mentioned above, you'd have to spend close to $1000 to get a grinder truly equivalent to that Dayton.

It's wonderful that you can diagnose every problem this grinder may have without ever having inspected it in person. You don't even know if the casting inside is still good--with something running at that kind of rpms, it better be. And yes, while you can re-wire it easily, this will not solve the bearing issue it obviously has, nor will that fix the kind of overheating problems he's reporting. You should know that. Maybe you missed that part of it--the devil's in the details, and not everyone has the inclination for them. It's easy to pontificate then sit back and watch the other guy deal with the doing--kind of sadistic in a way, or like rubber-necking an accident.

As far as it being USA, you're right....but it's an OLD USA that doesn't work right anymore with serious as-yet-to-be-determined problems. All kinds of old USA stuff out there that's too far gone to play with. Just because it's USA doesn't mean you should fix it no matter what the time or cost. If one is hot for an old USA grinder at a bargain, find one that's working right already--still will be at a price advantage you speak of. And remember, bbcmudtruck is telling us he has no experience tackling this kind of project. I'm trying to have mercy on the fellow.

There's a lot of stuff out there that is fine for the occasional user without having to spend $800-1000. Please.

 

[454ragtop]

"the bearing issue it obviously has" ?? How can you tell that without it running? OP needs to first check to see if it's wired for 115 or 230 volt and go from there. How's a person supposed to learn if they don't try? It's not rocket science, or anything to be afraid of, just use care and common sense and ask questions as needed.

 

[American Locomotive]

And yes, while you can re-wire it easily, this will not solve the bearing issue it obviously has

What "obvious bearing problem"? He said it turns freely. A grinder with a centrifugal start switch (like this one has) will not turn as freely as a PSC grinder.

nor will that fix the kind of overheating problems he's reporting. You should know that.

The motor has a starting problem. An electric motor that isn't turning will turn all of the electricity it consumes directly into heat. If a bad capacitor, faulty start switch, or faulty wiring is preventing the start windings from working, the motor will get extremely hot rapidly.

You should know that.

You're jumping to all sorts of conclusions, when the reality is that the grinder probably just needs a re-wire and a cleaning. It's worth throwing $40 in parts and time at. Worst comes to worse, you have a bunch of wire and cord for something else.

 

[DadsTools]

Lol OK. I welcome all advice from people who have knowledge on this thing. I'm willing to spend some money on it, hell I was certain I'd have too when I bought it. How hard is it to change the bearings and where would I get them from?

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Depends on whether they're pressed on the arbor--considering the age and brand, they might be. You'll have to find the exact correct size replacements, and you won't know that until you tear it apart. Unless some expert in here can tell you precisely what size they are and where to order them without having inspected them first. Then let's hope the channels for them in the casting and the arbor are are still fine--if there's corrosion on the arbor under the bearings, once you remove them and clean the arbor it will no longer be the same diameter because of the metal loss due to the oxidation. Very critical for something turning heavy wheels at those kinds of rpms.

Hey, but have at it. No sweat off anyone else's back here. We're just talking--you're the guy who has to do the work.

As for buying a new one, it just depends on how heavy you're going to use it and what you can spend. Think about it--if everything made today is no good, almost no one would own a working bench grinder! Doesn't sound like you're going to do machine shop production work. Mechanics just need them sometimes to remove rust or grind a screwdriver or tool, sharpening, or modify'fabricate a part. Read online forums that are more machine-shop oriented and see what they like.

Good luck!