let's see your craftsman block grinders

[JCMTools]

I'm in that camp. Long spin time = dry bearings. BUT long spin down also means the machine is in good working order, just needs new bearings. imho

That all makes total sense.

Anyone have thoughts on re-using the felt washer when switching to sealed bearings? The seals do the same job as the felt washer but I'm currently going with the idea that 1) it could protect the spring washer a bit and 2) it can't hurt.

 

[torqueman2002]

That all makes total sense.

Anyone have thoughts on re-using the felt washer when switching to sealed bearings? The seals do the same job as the felt washer but I'm currently going with the idea that 1) it could protect the spring washer a bit and 2) it can't hurt.

I've refitted the felt & spring washers, I think the 'end play' would be impacted without them. Just my opinion, YMMV.

 

[nine4gmc]

I reused them as well.

 

[jakemac]

Flip 'em over and carry on.

 

[JCMTools]

I could use some advice and help.

I've been working on restoring my 3/4hp 397.19670 with the burnt starter winding.

I sprayed the windings with urethane seal coat and I got the castings painted and the main housing assembled and wired. So far so good. But then I turned it on and after running for 15 seconds, smoke starts coming out of the winding. I tried running it a few times and it starts up just fine but soon starts smoking.

Now I'm trying to figure out what I should do.
Is it the relay that's sticking? If so, can I get a new one?
Should I look for a matching unit and swap out the relay and stator?
Should I look for a similar unit and re-use the painted castings, then sell off the remaining parts?
Should I just part the thing out and start looking for a better solution?



Thanks.

 

[Outlawmws]

Is the seal coating made specifically for motor windings? (they do get hot)

Does it require a curing process? (baking, heat lamps etc...)

Did is run cleanly before the seal coat?

Have you tried measuring resistance for each of the windings to see if they are equal? (Or close to it)

 

[torqueman2002]

JCMTools - have you seen the related links on relays? Also, see the link in my sig. line for more resources.

Cleaning a relay. Post 62
http://www.thegaragegazette.com/index.php?topic=18119.msg235337#msg235337

http://www.garagejournal.com/forum/showthread.php?t=179799

Klixon Relays
http://www.sensata.com/klixon/motor-protector-4cr.htm

http://www.garagejournal.com/forum/showthread.php?t=115423

 

[JCMTools]

Answers inline:

Is the seal coating made specifically for motor windings? (they do get hot)
Yes. It's CRC Urethane Seal Coat.

The label doesn't say "Motor and Generator Winding Coating Insulator" like the image Davefr linked to, but I figured it was just a newer label design. Did I get the wrong stuff? (The red urethane seal coat on Amazon has the same label as the clear).

Does it require a curing process? (baking, heat lamps etc...)
No.

Did is run cleanly before the seal coat?
Yes, but I didn't run it for more than a minute and the starter winding may have been overheating but had already cooked off anything that could smoke.

Have you tried measuring resistance for each of the windings to see if they are equal? (Or close to it)
Yes, and I had the stator tested with a megger

 

[Leadberry]

I've got a 397.19590 60's 1/2 HP, and I'm trying to wrap my head around it because it has a start relay AND a capacitor. There is no centrifugal switch. It definitely looks like a start cap, but I had accidentally rewired the motor without the cap and it started and ran just fine. Can anyone confirm what the purpose of the cap is?

 

[scooternut]

Picked up my first block grinder today, a 1/2 hp commercial ... because you guys talked me into it with your enthusiasm. I'm certain it'll be better than my 15 year old china B & D.

Been watching craigslist for a complete one, preferably 1/2 with dust chutes and an original stand. This one showed up yesterday for $75, I didn't even try to haggle as he was a nice guy, it was exactly what I wanted, condition seemed right, and it was complete.

Story was that it was from his father in laws basement and he already had a grinder that he liked, which I did see in his nice clean shop.

Ill have to read up some more to see what I need to do to it. The wheels show little use, the left is more course than the right, and each stone carries the same label so I'm hoping they are original, meaning little use.

View media item 44549
View media item 44548

 

[drivesitfar]

Scooternut: happy to see you got a Craftsman block now. also nice to hear you didn't try to negotiate with the seller because that original Craftsman stand is worth what you paid for it and the 1/2 HP commercial block is one of the best 1/2 HP grinders they or almost anybody sold when it was made.

 

[jakemac]

Woo Hoo ! Another vict......... err, member of the club.

 

[torqueman2002]

I've got a 397.19590 60's 1/2 HP, and I'm trying to wrap my head around it because it has a start relay AND a capacitor. There is no centrifugal switch. It definitely looks like a start cap, but I had accidentally rewired the motor without the cap and it started and ran just fine. Can anyone confirm what the purpose of the cap is?

"As I understand it about reluctance motors, once the main coil is synced up the secondary coil is not really important to the running of the motor. But if the phase shift is too much it will fight the main coil and have torque/speed maintenance/power consumption problems."

http://owwm.org/viewtopic.php?f=1&t=77190&start=15#p544004

 

[JCMTools]

JCMTools - have you seen the related links on relays? Also, see the link in my sig. line for more resources.

Cleaning a relay. Post 62
http://www.thegaragegazette.com/index.php?topic=18119.msg235337#msg235337

http://www.garagejournal.com/forum/showthread.php?t=179799

Klixon Relays
http://www.sensata.com/klixon/motor-protector-4cr.htm

http://www.garagejournal.com/forum/showthread.php?t=115423

I'm not really excited about the thought of taking apart the relay since it looks to be welded together.

What if I wired a light switch into the starter winding circuit between terminals 2 and 21 in the diagram below and then manually opened the circuit after the motor starts? That way, I can be sure that the starter winding is off and not causing the smoke.

 

[torqueman2002]

scooternut - Nice grinder, good start on your Block collection. Not many can stop at only 1!

Check into dressing the wheels. It looks like the RH one has non-ferrous material (aluminum) deposited on it. People do use the same wheels for ferrous and non-ferrous metal, but it is not a recommended practice.

http://tinyurl.com/Norton-Grndng-Dos-and-Donts

 

[torqueman2002]

JCMTools - I think wiring a switch in, can be better answered over on OWWM.com, than me guessing.

There are a lot of people there with motor experience.

 

[McBrownie]

Been watching craigslist for a complete one, preferably 1/2 with dust chutes and an original stand. This one showed up yesterday for $75, I didn't even try to haggle as he was a nice guy, it was exactly what I wanted, condition seemed right, and it was complete.

With an original stand AND the quench tray for $75!?!?!!?! Very nice find and a great grinder! I have one just like it and it is a smooth running machine.

 

[JCMTools]

OK, thanks Tman

 

[McBrownie]

JCMTools - have you seen the related links on relays? Also, see the link in my sig. line for more resources.

Cleaning a relay. Post 62
http://www.thegaragegazette.com/index.php?topic=18119.msg235337#msg235337

http://www.garagejournal.com/forum/showthread.php?t=179799

Klixon Relays
http://www.sensata.com/klixon/motor-protector-4cr.htm

http://www.garagejournal.com/forum/showthread.php?t=115423

TM,

JCM's smoking windings are making me think more than twice about putting in a fuse like you did in the above links. I have a question, though. You ended up having to put in a 15 Amp fuse to keep the grinder running. What is the difference between running with a 15 Amp fuse or running on an outlet with a 15 Amp circuit breaker? Wouldn't the circuit breaker flip just like the fuse would blow?

 

[torqueman2002]

McBrownie - I don't see why it wouldn't.

I have the garage/shop wired for 20A, and Go Blue! is 1 HP, which draws a lot of current on start.

I was hoping it would start and run on a smaller slo-blow fuse. The fuse needs to be sized to the lowest rating that will allow it to start/run safely.

 

[JCMTools]

Here's an update on the smoking gun-metal blue grinder.

I wired in a 7 amp slo-blo fuse and it doesn't blow. I also wired in a switch to manually cut out the starting winding after startup. It still smokes. This makes me think that it's the urethane spray. I don't know that there's anything I can do to get the urethane out of the windings, so I might have to let it smoke some and see if it just burns off. I'm going to go on the OWWM board and seek some advice on what to do.

 

[McBrownie]

Here's an update on the smoking gun-metal blue grinder.

I wired in a 7 amp slo-blo fuse and it doesn't blow. I also wired in a switch to manually cut out the starting winding after startup. It still smokes. This makes me think that it's the urethane spray. I don't know that there's anything I can do to get the urethane out of the windings, so I might have to let it smoke some and see if it just burns off. I'm going to go on the OWWM board and seek some advice on what to do.

TM and JCM,

This is what I'm going to do, start small and work my way up to a fuse that just makes it. Thanks for the advice and testing. And, good luck with "Gunsmoke".

 

[nine4gmc]

JCM, did you clean the inside of the stator of urethane? Wish I could help but I really don't know much about the insides of electric things.

 

[JCMTools]

JCM, did you clean the inside of the stator of urethane? Wish I could help but I really don't know much about the insides of electric things.

Not sure what you mean. I masked off the inside surface of the stator (the stacked iron that looks like inside barrel staves, if you will) when I sprayed the windings. I did wipe a light coat of oil on the inside surface to discourage rust before assembly.

 

[nine4gmc]

That may be the oil burning off. Like I said, I don't know much but I think that metal should be clean and bare? Maybe someone with actual knowledge will chime in.

 

[Leadberry]

"As I understand it about reluctance motors, once the main coil is synced up the secondary coil is not really important to the running of the motor. But if the phase shift is too much it will fight the main coil and have torque/speed maintenance/power consumption problems."

http://owwm.org/viewtopic.php?f=1&t=77190&start=15#p544004

Thanks torqueman. I actually did some research and was able to find the answers I needed. The relay is either a starter current or potential relay, and takes the place of a mechanical centrifugal switch in controlling the start cap.

Edit: Also, I'm assuming that guy meant to say induction motor.

 

[JCMTools]

That may be the oil burning off. Like I said, I don't know much but I think that metal should be clean and bare? Maybe someone with actual knowledge will chime in.

That's entirely possible, and if true, great.

 

[exmaxima1]

That's entirely possible, and if true, great.

An unloaded grinder should barely get warm. I suspect you have some shorted windings.

 

[McBrownie]

I was snooping around in Torqueman's backyard on CL tonight and saw this grinder. It has a 397 prefix and kind of looks like a block grinder, but I've never seen one like this. Has anyone else?

http://detroit.craigslist.org/mcb/tls/4746997575.html

 

[Leadberry]

I was snooping around in Torqueman's backyard on CL tonight and saw this grinder. It has a 397 prefix and kind of looks like a block grinder, but I've never seen one like this. Has anyone else?

http://detroit.craigslist.org/mcb/tls/4746997575.html

5.5 amps is creeping up on 3/4 HP territory. That thing definitely looks stout.

Edit: It looks like someone just relocated the nameplate to make room for the switch.

 

[drivesitfar]

McB: i'm wondering if you should have PM'd TM before you posted this because i think that is a modified block and he's on the hunt again. heck that stand with those tool rests is something i could use on any grinder or buffer i own.

JCM: has the smoking stopped? hard to say what caused it so let's hope it's the little bit of oil or some overspray burning and not your grinder's parts.

 

[jakemac]

I was snooping around in Torqueman's backyard on CL tonight and saw this grinder. It has a 397 prefix and kind of looks like a block grinder, but I've never seen one like this. Has anyone else?

http://detroit.craigslist.org/mcb/tls/4746997575.html

McB: i'm wondering if you should have PM'd TM before you posted this because i think that is a modified block and he's on the hunt again. heck that stand with those tool rests is something i could use on any grinder or buffer i own.

Yup, modified. I googled the model number and it came up with a bunch of regular block grinders (most of the pictures were from this thread). Somebody went to town on that grinder to make it work for their shop. I wonder if OSHA was involved. Fortunately they kept the label to keep the confusion (and panic) to a minimum.
Nothing to see here folks, move along.

 

[JCMTools]

JCM: has the smoking stopped? hard to say what caused it so let's hope it's the little bit of oil or some overspray burning and not your grinder's parts.

I just checked in answer to a question on the OWWM board about the smell of the smoke. I haven't had the nerve to start it up and let it run, so it's still in the same state that it was when it first started smoking.

 

[McBrownie]

McB: i'm wondering if you should have PM'd TM before you posted this because i think that is a modified block and he's on the hunt again.

Oh no! TM, my apologies if I have caused any trouble. The "coolness" factor is definitely high on that one.

 

[torqueman2002]

drivesit & McB - I have been holding out on you.
I spotted it <1 hour within seller's posting. I talked to him before he left his house to go to the shop.

I almost went to meet him because it was so 'industrial' looking with the tool rests I need for Go Blue. I even got an eMail from a friend alerting me to the grinder.

Anyway, it was a nice day to work outside and I backed away after thinking about what he told me.

The grinder was re-wired some years ago when his employee did not shut it down in time when it stalled (I think he said it was at start-up), the base is filled with shot and weighs 300 - 400#s (he'll load it in the truck).

Now, all that is fine, but I just have no way of getting it out of the truck, once home AND now hold on ---- I, I, ... have, ... I have (oh **** this is hard) I have enough grinders and no room.

There, I said it. Why don't I feel better!?

 

[torqueman2002]

McB - No problem here. I have, after all, publicly sworn off purchasing (for my own consumption) any more Block grinders.

So, here's the link to the grinder.
http://detroit.craigslist.org/mcb/tls/4746997575.html

I too think the label was re-located, maybe at the time of a re-wind? There is a SS hood. It is in a sheet metal shop.

I could be convinced to bring this home for some one (minus the CM cast iron base with toll rest assemblies).

 

[McBrownie]

I just checked in answer to a question on the OWWM board about the smell of the smoke. I haven't had the nerve to start it up and let it run, so it's still in the same state that it was when it first started smoking.

That is a tough spot to be in.

Here is a link to Baldor motor specs that talks about temperature rise in "open air drip-proof motors along with other things:

http://www.baldor.com/pdf/specguide.pdf

They mention an ambient operating temperature of 40C (104F) for Design C motors with an allowable operating rise of 80C (176F). So, I assume that the motor can reach a temperature of 120C (280F) without damage? I also assume that is under load. It does not mention what is normal for no load conditions.

Do you have a way to measure temperature?

 

[McBrownie]

drivesit & McB - I have been holding out on you.
I spotted it <1 hour within seller's posting. I talked to him before he left his house to go to the shop.

I almost went to meet him because it was so 'industrial' looking with the tool rests I need for Go Blue. I even got an eMail from a friend alerting me to the grinder.

Anyway, it was a nice day to work outside and I backed away after thinking about what he told me.

The grinder was re-wired some years ago when his employee did not shut it down in time when it stalled (I think he said it was at start-up), the base is filled with shot and weighs 300 - 400#s (he'll load it in the truck).

Now, all that is fine, but I just have no way of getting it out of the truck, once home AND now hold on ---- I, I, ... have, ... I have (oh **** this is hard) I have enough grinders and no room.

There, I said it. Why don't I feel better!?

That's certainly a unique grinder and that base is really nice. Too much of a tool for my small area. I'm really liking my workmate dolly. It seems just right for a garage and is multi-purpose. I'm in the same spot with grinders. In fact, once I get my 3/4hp industrial sorted out and make sure it runs well, I may part with one or both of my 1/2hp's. Yep, I said it and I don't feel any better either.

 

[drivesitfar]

TM: here's what you need if you want to keep the back in shape and still be able to buy those COOL and HEAVY items. Bishamon Mobi-lift table is the one I'm posting a picture of that is a bit spendy because it has the push button power option. or there are some for about $100-300 that are rated for up to 600 pounds that are manual.

you should be able to get that stand on your truck with the seller's help and maybe get it off when you son is around to help. it would look very cool under BIG BLUE.

i bought this Jet lift that i'm hoping will work great for my little shop and really wanted a REAL fork lift, but not enough room for one (yet).

McB: Whew that was close.

Also good to hear the workmate makeover stand is working out.

JCM: good luck

 

[nine4gmc]

What a bunch of Wuss', I though this thread was all about MORE, MORE, MORE!!!