let's see your craftsman block grinders

[McBrownie]

Yup, ended at $305 plus the ride.

44 Bids. I guess there are more than a few fans of the big boys.

 

[bagged89s10]

Yup, ended at $305 plus the ride.

Happy seller and will be a happy buyer. I'll tell you what, I won't be selling mine unless I find another one, maybe if I find more than just 1 more. Lol

 

[jransom]

Some of you may remember this post above from a few days go... I had big plans to set up my old 1/3hp roundtop grinder for polishing and that new-to-me 1/2hp for grinding and wire wheeling. Well, today, as luck would have it... I went and picked up another 1/2hp from the 70's (I think) but the industrial version with 8' wheels and longer quench tray. It's pretty clean minus a very subtle splatter paint job. I guess now they'll each have an individual purpose. Doesn't show it but it came with both plastic shields and a small box of wheels. $50 seemed more than fair. The actual picture here is from the seller. It cleaned up nicely with some Simple Green when I got it home. I'll post a picture soon. It's just missing one spark arrester. Also, it has a washer I can't seem to get off on the right side. Any ideas?

I got that washer off tonight thankfully. Guessing it either A. has an inner diameter bur that ate into the spindle (the spindle groove is tiny, maybe a 32nd of an inch wide) or B. It is warped in a manner that has caused the inner diameter of the flange to be smaller than it should. Once I got it off I tried to slide it back on and it seemed to be too small. The other ones All fit fine. Wierd. Anyone want to sell me a flange? Thanks!

 

[Outlawmws]

do you have a reamer? just clean it up slightly

 

[jransom]

I don't have a reamer but I guess I can go pick up a round file and file it real quick. I bet that will do it. Thanks!

 

[dngrmse]

Or use a dremel with one of those little drum sander attachments, if you have one.

 

[jransom]

Yeah, you just jogged my memory. I have a little sanding stone that mounts in my drill. That will do it. Thanks!

 

[bagged89s10]

Yeah, you just jogged my memory. I have a little sanding stone that mounts in my drill. That will do it. Thanks!

Or just grab something round, wrap it in sandpaper, and sand it by hand. Many ways to fix the burred up washer.

 

[808state]

Well I started my restore. Got everything dismantled and discovers the right bearing must've been spinning in the race.

 

[torqueman2002]

Well I started my restore. Got everything dismantled and discovers the right bearing must've been spinning in the race.

I don't see anything obviously different from the one's I've replaced the bearings on.

The bearing to housing is an interference-fit. The bearings sometimes stay on the arbor when removed from the housings. The outer race should not spin in the housing, however.

LOCTITE 38652 620 Bearing Mount can be used on reassembly if needed.

However, it will require heat for removal; but that should be many years in the future.

IIRC - the LH side of the rotor has the cooling fins.

 

[808state]

The last pic shows some deep gouge marks in the LH housing. I thought it may have been from the bearing spinning, is it from the casting? If it is spinning, is Loctite 609 too weak to use when I replace the bearings?

I don't see anything obviously different from the one's I've replaced the bearings on.

The bearing to housing is an interference-fit. The bearings sometimes stay on the arbor when removed from the housings. The outer race should not spin in the housing, however.

LOCTITE 38652 620 Bearing Mount can be used on reassembly if needed.

However, it will require heat for removal; but that should be many years in the future.

IIRC - the LH side of the rotor has the cooling fins.

 

[nine4gmc]

Was the bearing locked up? If not, I do not think that it would spin in the housing. It would take a lot of force to spin a locked bearing in that housing and I don't think the motor has that much torque.

 

[torqueman2002]

The last pic shows some deep gouge marks in the LH housing. I thought it may have been from the bearing spinning, is it from the casting? If it is spinning, is Loctite 609 too weak to use when I replace the bearings?

I believe the groves are a design feature, I have seen them on several Blocks.

"Loctite ® 609™ is a low viscosity, rapid-curing anaerobic adhesive that augments the strength of press fit assemblies or slip fit assemblies up to 0.005"in diameter. Adds up to 3,000 psi holding power. Recommended for parts that will need subsequent dismantling, i.e., retention of bearings onto shafts and into housings."

http://www.loctite.com.au/3320_AUE_HTML.htm?nodeid=8802648195073

 

[nine4gmc]

I was under the impression they were marks from assembly. The bearing scuffing the housing when being put together.


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[Outlawmws]

I was under the impression they were marks from assembly. The bearing scuffing the housing when being put together.


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Those are probably from the cutter after boring the bearing cup, and when its withdrawn it scores the bore coming out.

 

[alpinewhite]

Me thinks that if it were spinning on the housing, the evidence would be a lot smoother and brighter than this.

 

[808state]

Sounds like nothing to worry about then. Thanks fellas!

 

[torqueman2002]

Sounds like nothing to worry about then. Thanks fellas!

You betcha.

 

[MPOWERD]

I am still disassembling my 1/2 HP Blockhead to solve the rough start...

Got this one rucker from ArnFest in the mean time...

1 HP Blockhead. Its huge compared to the 1/2 HP and 1/3 HP!!

Works perfectly and is complete, even with the cooling tray!

 

[bagged89s10]

I am still disassembling my 1/2 HP Blockhead to solve the rough start...

Got this one rucker from ArnFest in the mean time...

1 HP Blockhead. Its huge compared to the 1/2 HP and 1/3 HP!!

Works perfectly and is complete, even with the cooling tray!

Sounds awesome but your pictures aren't showing.

 

[jransom]

I ran my 1/2hp 397.19441 with a 1" x 6" Scotch Bright "Fine" wheel on it for about 20 minutes straight tonight and it got almost hot to the touch. Is this normal? By the way, that wheel is amazing for shining things up.

 

[Toolguybak]

I ran my 1/2hp 397.19441 with a 1" x 6" Scotch Bright "Fine" wheel on it for about 20 minutes straight tonight and it got almost hot to the touch. Is this normal?...

No this is not normal.
Possibly the bearings need to be changed.
Or someone installed sealed bearings, which should be switched back to shielded bearings.

 

[Toolguybak]

?...
Got this one rucker from ArnFest in the mean time...

1 HP Blockhead. Its huge compared to the 1/2 HP and 1/3 HP!!

Works perfectly and is complete, even with the cooling tray!

I'm glad it went to a good home.

 

[exmaxima1]

No this is not normal.
Possibly the bearings need to be changed.
Or someone installed sealed bearings, which should be switched back to shielded bearings.

Sealed bearings work fine. They are routinely used on motors of the same rpm, and rated for >2x that rpm. Their modest drag will not overheat a grinder.

 

[Bobioz1]

Sounds normal. If you worked it for 20 minutes straight and it was almost cold to the touch, that would be abnormal.

 

[jransom]

Alright, thanks guys. Do I need to worry about this heat damaging the capacitor or anything?

 

[torqueman2002]

I ran my 1/2hp 397.19441 with a 1" x 6" Scotch Bright "Fine" wheel on it for about 20 minutes straight tonight and it got almost hot to the touch. Is this normal? By the way, that wheel is amazing for shining things up.

I'd say, after using a Block, if you cannot keep your hand on it for 60 sec, look for reasons why it is too hot to the touch.

That's assuming, the ambient is ~75F.

I work my grinders for rust removal, shaping, and the like, for <20 min.

Buffing and polishing, I expect will put a greater load on the motor.

1/2-HP may be on the limit for what you are doing.

Just a guess, perhaps those with more buffing/polishing experience can speak to this point.

 

[nine4gmc]

My 1/2 hp gets HOT after a good wire wheel session. It still has the factory bearings and takes a while to spin down so I know there's no drag, just hot from use.


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[alpinewhite]

Motors get hot. That's normal. In electronics, the rule-of-thumb is that nothing should get too hot to the touch. I'm not sure if the same rule applies to bench grinders.

 

[jransom]

Alright, I ran it straight tonight for 25 minutes. Only at the very end did it get hot enough to not keep my hand on for long. I only had one wheel on it and it ran great. I think it's fine. I decided to disassemble it and give it a once over before it goes into action. Need to figure out the trick for pulling all the leads of the switches and such.

 

[torqueman2002]

Alright, I ran it straight tonight for 25 minutes. Only at the very end did it get hot enough to not keep my hand on for long. I only had one wheel on it and it ran great. I think it's fine. I decided to disassemble it and give it a once over before it goes into action. Need to figure out the trick for pulling all the leads of the switches and such.

The Blocks are designed for home and not commercial-continuous use, possible exceptions being "Industrial" and "Commercial" Blocks.

I think your grinder is OK if not worked too hard for too long. Most of these Blocks have been around since the early 80's and longer, they are well built but aging.

I picked up a 3/4-HP Baldor recently, and it is easily 3x the weight of my 3/4-HP commercial Block. The Baldor is designed for continuous-commercial use, however.
http://www.garagejournal.com/forum/showthread.php?t=304967

I use needle nose pliers to remove the slide terminals inside the Blocks.

With the component secured, I use the needle-nose pliers to grab the female terminal between the wire-crimp and the folded-over portion of the terminal. Then I pull the terminal straight off the component's male-terminal.

Edit - (based on jransom post below).
Keep the component's male-terminal secure with a 2nd pair of needle nose pliers.

I hope that's what you were asking.

 

[bagged89s10]

Boston guys, go save this grinder!



1/2 hp Sears Bench Grinder $30
http://boston.craigslist.org/sob/tls/5243880121.html

 

[Tradersalt]

When these sold originally was the base always optional ?

 

[nine4gmc]

Yes, base was optional, light was optional too I believe.


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[Bobioz1]

Adding to what Torqueman said about removing the terminals. When pulling terminals off the Capacitor, hold the top with your finger or the lid will come off and your Cap guts will fall out.

 

[Bobioz1]

Water tray was optional also. Have 39719580s that came with and without.

 

[McBrownie]

Adding to what Torqueman said about removing the terminals. When pulling terminals off the Capacitor, hold the top with your finger or the lid will come off and your Cap guts will fall out.

Only AFTER you discharge the capacitor.

 

[Bobioz1]

Optional...... But a good idea!

 

[exmaxima1]

Optional...... But a good idea!

I wouldn't worry about it too much. In an AC motor circuit the capacitor is constantly being "charged" and discharged 60 times per second as the AC current changes direction. The cap's sole purpose is to induce a phase shift in the start winding, not to provide a surge of power as many believe. Only a DC voltage can truly charge a capacitor (and store energy) and there are no rectifiers in a cap-start motor to produce DC.

There are lots of myths about people getting electrocuted from caps, but almost without exception they were in a DC circuit. Plus the total energy in a small device such as a start capacitor could not maintain adequate current to kill a human, though it might bite pretty bad in a DC circuit.

BTW, to give you an idea of the size of start capacitors consider that even a large one is on the order of 100-200 microfarads, or MILLIONTHS of a Farad. In contrast, a large one like Alumapro's The C.A.P., which I engineered years ago, is 15 Farads or 15,000,000 microfarads. That is a huge amount of capacitance, yet it's only enough energy to light a 12v headlight for a few seconds, or a large power amplifier for a few milliseconds.

 

[Bobioz1]

I had my 1 horse running right before I tore it down. I wasn't sure about the cap, so I shorted it with a screwdriver. It threw off a huge snapping spark and a little smoke. I thought I ruined it. The others I've torn down were not operated for a few days and the caps did nothing when shorted.