Craftsman 1/3-HP Round-top Block Grinder m-397.19580, restore

torqueman2002 · May 16, 2016

Here is my latest effort at bringing the much liked CM Block grinders more years of service.

I apologize, I have no Before pictures to share. I've contacted the previous owner and will post them here, if he has any to send along.

So, the restore will start with the Block already apart.

The LH felt washer, spring finger-washer, and bearing on the arbor/shaft, before bearing removal.

RH

Close up, the fingers of the spring-washer point towards the bearing.

For details of the bearing removal and installation, see: the "Fire & Ice" thread: CM Block Grinder bearing replacement - 3 methods.
http://www.garagejournal.com/forum/showthread.php?t=328228

The above original bearings were:
NDH 77503 | ID=17mm | OD=40mm | W=12mm
Replacement bearings NTN 6203ZZC3.
http://bearingfinder.ntnamericas.co...ow-radial-ball-bearings?itemids=130253+130486

RH housing, showing field coils & their 3-wires (Red, Black, White-which appears almost Tan), power switch, power cord & its 3-wires (Green, Black, White; Ground, Hot, Neutral), and relay.

The terminals on the power switch and the relay, which have no wires connected, are for the Hot and Neutral wires of an optional lamp. *See diagram below, for more details.

*Wiring diagram.

115V%20Block%20Wiring%20rev01%20P1110134.jpg

Fi%20Field%20Coil%20Winding%20Resistance%200.33-HP%20m-397.19580.jpg

The Power Cord and grommet are removed from the outside. Squeeze* the grommet, easing the wire and grommet into the housing. Note: a small amount of lube can help the grommet and cord through the hole in the housing.

Remove the grommet and feed the Power Cord back through the hole.

I used a small metal die grinder bit -- to remove the back of the Label's rivets, and a punch -- to remove them from the center band.

The stones removed, the RH stone had both flanges mounted inboard of the stone and the arbor nut run-up against the stone. This is dangerous, because it unevenly distributes the clamping force on the stone and can cause failure and great bodily injury.

LH stone, showing evidence of grinding on the side. This is dangerous. The stone is not engineered for side loading and can cause failure and great bodily injury.

I destroy and discard the used stones on the Block grinders I restore.

Please see the link in my signature line for more on Grinder Safety and grinding stone selection.

NOTES
* Strain relief pliers are available from Amazon and make strain relief removal/installation easier. Link --> http://www.garagejournal.com/forum/showpost.php?p=6354558&postcount=269

Continued on Page 2.

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Parts 'n pieces, after media blasting, sanding, 'masking', 3 coats of Rust-Oleum primer, with sanding in between coats.

I use small orange 'carrot' stoppers to plug threaded holes, and larger stoppers to plug the bearing seats.

I waited 48 hours and placed the painted parts in the oven at 225F for 30 mins.

Note: Baking the paint helped the paint to harden faster than air curing, but the parts still need care in handling to avoid scratches.

All electrical connectors were cleaned with Caig Laboratories, Inc. DeoxIT.
http://www.markertek.com/brand/Caig-Laboratories-Inc?Category=ContactCleaners-Degreasers&Display=25

The terminals were tightened up.

Knipex flat-billed pliers a very handy.

Note: This time, I did not mask the 4-posts on each housing that holds/aligns the field/coil assembly.
Consequently, re-assembly of the field/coil was problematic.
I resolved the alignment problem by removing the paint on the inner surfaces of the 4-posts on each of the housings.

The Block is re-assembled and test run, before proceeding.

Woops! Can you spot the dumb mistake?

LH flanges, tool rest, and hardware - after blasting and wire wheeling. A bright/polished finish.

RH flanges, tool rest, and hardware - after blasting and no wire wheeling. A softer/satin finish.

For disassembly of metal framed eye shields, see the following link to: "Craftsman Block Grinder metal eye shields."
http://www.garagejournal.com/forum/showthread.php?t=329103

Reassembly of small metal framed eye shields. Amazingly, the 8-tabs survived.
3M Super Strength Molding Tape 03609 1/2" (12.7mm)

Knipex flat-billed pliers used again, with Gorilla tape 'covers'.

I think I can re-create these transparent labels, with AVERY templates.

Rust-Oleum Hammered - Copper (210849) and Dark Bronze (7218)
Yup, the LH tool rest is mounted backwards!

A Big Thank You to Pupuhd, for the excellent badge!
:thumbup:

Thanks for looking.

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Page 3. Updated - Oct 23, 2016

I decided to change the badge rivets to solid copper, and add a RED accent stripe.

Try as I might, these are the only 1/8" copper rivets I could source.

1/8" x 3/8" Round Solid Copper Rivet | Part#: CB000NB9FXO

I had a brain storm/fart. I thought speed nuts might hold the rivets.

Home Depot - SPEED NUTS | #8 FLAT TYPE | EVERBILT
Part#: 8 8748000108 2

That proved to be too unreliable, so I practiced using a rivet gun and bucking bar.

Several tries with the air hammer using different size cupped head bits: 3/32, 1/8, & 5/32 and a flush bit with 1" diameter face.

My testing showed the #2 bit produced results closest to original, more practice on my part will improve the results.

I may drill out the center of the rivet shaft, to lessen the number of strikes needed to set the rivets. This may lessen the stress/distortion on the badge.

I put a fine wire wheel on the left, and a fine stone on the right. This 1/3-HP Block will be used for light duty wheeling - cleaning of threads and such.

The next shot is without flash.

Now, I should really get the red Baldor off the bench!

Thanks for looking.

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Page 4.

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Page 5.

Cruzan80 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

So how did you get the glass out while still having the tabs survive? Slowly bending the minimum amount necessary? Does the tape mean there is a gap between the inside front edge of the shield and the glass for "grit" to get inside?

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Cruzan80 said:
So how did you get the glass out while still having the tabs survive? Slowly bending the minimum amount necessary? Does the tape mean there is a gap between the inside front edge of the shield and the glass for "grit" to get inside?

Funny you should ask.

I began an 'experiment' with these tabs, but on the large metal frames, for the topic of a Metal Frame Eye Shield thread. I still plan to post it, BTW.

During the experiment, I started the Bearing Replacement and this 1/3-HP restore threads.

Anyway, the eye shield tabs on this grinder turned out much better than the large size.

Not to steal away from the next thread, I'll just say I was lucky and these tabs survived with, as you put it "Slowly bending the minimum amount necessary".

There is a gap between the glass and frames at the top and bottom; just like CM had them built.

More in the upcoming thread.

Thanks for looking.

Zeeman · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Right on Doc! Excellent job as usual.

Zeeman · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Hey, when you get a chance, please look at the insides of my grinder and tell me if I need an extra connector on the switch, or if I can just hook up my lamp with what I have. I believe it is just like this one that you are working on. I believe my picture is in your thread What's all the fuss on page 5. Thanks.

mbsinmich · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Fantastic! Looks better than new!!

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Zeeman;

From this picture, I'd say yes. That is, if you want to turn the lamp ON/OFF even when the Block is OFF.

Put this style of terminal adapter (1->2) on the HOT (Black wire) side of the switch and connect the lamp's smooth wire to it.

You'll need a lamp socket with a switch, like the following.

Then connect the lamp's ribbed/striped wire to the relay's empty terminal with the White wire.

Zeeman · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

And if I just wanted to be able to run the lamp when the grinder is going, could I use just the connections I have now (the ones on the relay and switch that are not being used)? Sorry for so many q's.

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Zeeman said:
And if I just wanted to be able to run the lamp when the grinder is going, could I use just the connections I have now (the ones on the relay and switch that are not being used)? Sorry for so many q's.

NP - yes, the empty terminals will power the lamp only when the Block is running.

No need for a lamp socket with a switch then.

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

mbsinmich said:
Fantastic! Looks better than new!!

Thanks!

Zeeman · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

torqueman2002 said:
NP - yes, the empty terminals will power the lamp only when the Block is running.

No need for a lamp socket with a switch then.

Thanks. Smooth to the switch, and ribbed to the relay then?

torqueman2002 · May 16, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Zeeman said:
Thanks. Smooth to the switch, and ribbed to the relay then?

Yes, sir.

Zeeman · May 17, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Thumbs up to you.

exmaxima1 · May 17, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

mbsinmich said:
Fantastic! Looks better than new!!

+1, definitely better than new.

drivesitfar · May 17, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Doc: amazing rebuild as per the usual. :thumbup:

were you just seeing if you could do another total block restoration like you've done several times in the past or did PUP'S new label give you the inspiration to make the old block look new too? :dunno:

WELL DONE SIR!! nice thread, pictures, comments and results

EX: i'm guessing Doc meant to put round top in the title and maybe a Senior Moment sort of like the tool rest. or if it is a flat top i'd like to know why too because looks like the round tops I like a lot better.

torqueman2002 · May 17, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

exmaxima1 said:
+1, definitely better than new. Anyone know why that's called a "flat top"? Looks very rounded to me

Oh ****!

torqueman2002 · May 17, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

drivesitfar said:
Doc: amazing rebuild as per the usual.

were you just seeing if you could do another total block restoration like you've done several times in the past or did PUP'S new label give you the inspiration to make the old block look new too?

WELL DONE SIR!! nice thread, pictures, comments and results

EX: i'm guessing Doc meant to put round top in the title and maybe a Senior Moment sort of like the tool rest. or if it is a flat top i'd like to know why too because looks like the round tops I like a lot better.

Drives - I suppose it was the Perfect Block Storm in some ways.

I got a really nice 1/3-HP ROUND-TOP from a GJer (mbsinmich) who is almost a neighbor and he had PUP's label, so we made a deal.

I also wanted to start a thread for bearing removal/installation and another thread to try heating the tabs on the metal framed eye shields. Also, it gave me a chance to play with baking the paint, which helped the paint to harden faster than air cure, but it still needs care in handling.

Now, of course comes the hard part. Keep or sell? :dunno:

Oh, about the title. All I can say is thanks to you and to exmaxima1. I completely missed that.

However, it has given me an idea for my next thread(s) - What did Torqueman Mess-Up? :lol:

Sort of like Where's Waldo.

drivesitfar · May 17, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Doc: I bet you could hear me chuckling clear in Detroit from Seattle. I knew the label was the key, and again well done with all the work you did. i'm guessing maybe a little longer in the oven for the paint or maybe just leaving it alone for a few days is the answer?

Ex caught your title and the SENIOR MOMENT and I just agreed. I really like the round tops better so maybe a couple scotch brites or specialty wheels on it and you can put it in line with the BIG UNS?

cheers and always nice watching you work and instruct us on how to do any job you do the right way. :thumbup:

also nice safety tips about the wheels. i'm still amazed I was injured or blinded from one of the old grinders I've used in my lifetime. I never knew to stand to the side of a grinder when turning it on and I can't tell you how many old grinders on benches piled high with junk that I've just turned on without any safety gear just to see if they run. 3600 RPM and having a stone come apart is maybe close to bullets flying around.

CAN THERE REALLY BE ENOUGH SAID ABOUT SAFETY?? for those of you that don't believe a grinder can KILL you just google it. also there is a grinder safety 101 thread I started in general tools section that has some graphic pictures and videos and not just DARWIN AWARD winners. some of the injuries are some of our GJ members who forgot safety first.

http://www.garagejournal.com/forum/showthread.php?p=5745414#post5745414

torqueman2002 · May 18, 2016

HOTFR8 - Fixed it for me. "It should show up as you ask but all replies to the original post will still show flat top."

:bowdown:

torqueman2002 · Oct 23, 2016

Updated Page 3, above.

Youngfd · Oct 24, 2016

I would have used epoxy glue on the brass rivets and been done. Great looking grinder!!! J

pendragon1998 · Oct 24, 2016

Great restoration! I am starting on a similar vintage Craftsman 115.6962 motor from 1953. Where did you source those plugs?

Re:safety. I recently read a thread, maybe at owwm, where they were talking about wire wheels trapping fingers down between the wheel and the rest. One guy nearly lost a finger and another guy knew several guys who had. Gave me pause, and I will be looking for opportunities to blast instead of wheel, where appropriate, to minimize the wheeling I have to do.

exmaxima1 · Oct 24, 2016

pendragon1998 said:
Re:safety. I recently read a thread, maybe at owwm, where they were talking about wire wheels trapping fingers down between the wheel and the rest. One guy nearly lost a finger and another guy knew several guys who had. Gave me pause, and I will be looking for opportunities to blast instead of wheel, where appropriate, to minimize the wheeling I have to do.

That is certainly something to be concerned with. I have a wire wheel on my 10-inch grinder with the guard, and there have been times when the part I was working on got grabbed into the guard and if it was my finger it would have been torn off. I now mainly use wire wheels without guards--I use a 1/2hp block with no guards, and 2 grades of wire wheels. Works great, and I only use the big 10" when I'm cleaning something big like a vise body or sander platen (something that won't get sucked into the guard). And really big stuff is much better suited to an angle grinder.

Rileysan · Oct 24, 2016

pendragon1998 said:
Great restoration! I am starting on a similar vintage Craftsman 115.6962 motor from 1953. Where did you source those plugs?

Re:safety. I recently read a thread, maybe at owwm, where they were talking about wire wheels trapping fingers down between the wheel and the rest. One guy nearly lost a finger and another guy knew several guys who had. Gave me pause, and I will be looking for opportunities to blast instead of wheel, where appropriate, to minimize the wheeling I have to do.

The opportunity for fingers to get caught in the guards is minimal, imo. However, wearing gloves while using a bench grinder will make this hazard greater. I've worn out a dozen wire wheels and a grinder over the past 25 years and have never had more than a little scratch on my fingers. I wouldn't worry too much about it ...

Brian

Rileysan · Oct 24, 2016

Regarding this model of grinder. Is this considered a proper Craftsman "block" grinder or not? I have this exact model. It runs great and really doesn't need restoration but you inspire me!

Brian

torqueman2002 · Oct 24, 2016

Youngfd said:
I would have used epoxy glue on the brass rivets and been done. Great looking grinder!!! J

That is a good suggestion, thanks.

I did consider that, but have had inconsistent results with epoxy and I wondered about the vibrations.

I will most likely try it on another rebuild/restore.
:thumbup:

torqueman2002 · Oct 24, 2016

Thanks for the compliment. I'll reply below in Red, so our members using their mobile devices can better see.

pendragon1998 said:
Great restoration! I am starting on a similar vintage Craftsman 115.6962 motor from 1953. Where did you source those plugs?
I am thinking you are asking about the plugs that hold the badge/label on to the center band.
If you search Amazon for "1/8" Solid Copper Rivet" you'll see a number of choices.
Re:safety. I recently read a thread, maybe at owwm, where they were talking about wire wheels trapping fingers down between the wheel and the rest. One guy nearly lost a finger and another guy knew several guys who had. Gave me pause, and I will be looking for opportunities to blast instead of wheel, where appropriate, to minimize the wheeling I have to do.
That is a good point and 1 reason why I restored this little guy.
I have both a 3/4 and 1-HP Blocks fitted with wire wheels. I find parts need to be held securely and the small parts like bolts and screws that need threads cleaned up are especially problematic on these Big Boys.
I hold small items with a variety of pliers, Vice Grips, and even a small hand-held vise.

I plan to move the tool rest out of harms way, just like I've done on his Big Brothers.
Also, remember to wear both safety glasses and a full face shield when wheeling and grinding.

torqueman2002 · Oct 24, 2016

I want to thank everyone for their comments, suggestions, and personal experiences.

Grinders are so common, there's a real risk of taking them for granted and thereby overlooking the potential danger involved using them.

Rileysan - the 1/3-HP model 397.19580 grinder is a round top Block.

It seems to have been Sears best selling grinder back in it's day. At least judging from the vast number I see in SE Michigan's CL and estate sales.

For more information on which of the Craftsman grinders are considered Blocks, please see: "Craftsman Block motor Bench Grinders - What's the Fuss (with resource information)". Here's the link (it is also linked in my signature line).
http://www.garagejournal.com/forum/showthread.php?t=249539

Thanks for looking.
:thumbup:

Rileysan said:
Regarding this model of grinder. Is this considered a proper Craftsman "block" grinder or not? I have this exact model. It runs great and really doesn't need restoration but you inspire me!

Brian

torqueman2002 · Oct 24, 2016

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

mbsinmich said:
Fantastic! Looks better than new!!

I know this is an older reply/post, but I believe you know the original owner of this Block.
:thumbup:

M_George · Apr 1, 2017

Torqueman, Just wondering, what media do you like for blasting the block grinder housings?
I have an HF spot blaster, but it gets the job done with a little patience.

torqueman2002 · Apr 3, 2017

I use Black Diamond medium, from TSC. $7.99/50 lbs.
http://www.tractorsupply.com/tsc/product/black-diamond-medium-blasting-abrasives

Beater5liter · Apr 5, 2017

Torqueman, you mentioned you "throw away the original grinding wheels" . Is that because someone was "side grinding" or are they just likely to fail from old age?

torqueman2002 · Apr 5, 2017

5liter - I replace the stones on used grinders because their history is questionable.

A vitrified stone, that most all home grinders use, can be damaged by moisture/dampness. The bonding material/glue can weaken and the stone can break apart at speed.

I see about 50% of the used grinders with some form of stone damage: wet/damp - rusty flanges/parts, side-grinding, non-ferrous grinding, even wood grinding. The last on probably not fatal, but what else might the PO ground on the stones?

Stones are a reasonably priced consumable.

Side grinding and grinding of non-ferrous metals, can also dangerously compromise a grinding stone.

On the other hand, I am using stones that are over 5 years old, and in 1 case a seldom used grinder has 30 year old stones.

Age may be a factor. I am waiting for a reply from Norton on that question.

UPDATE - April 6, 2017
I contacted Norton (Saint-Gobian) customer service today, Tel: 254-918-2313.

The representative, confirmed that a properly store/used vitrified grinding stone does not have a shelf life.

The key is the stones must have been in a cool & dry environment and pass a ring test.

This is not the same for rosin based grinding stones; they do have a shelf-life. I do not have/use rosin base stones. I do not have any information about them to share.

beltdrive · Apr 6, 2017

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Hansen Rivet may have those rivets. Maybe I missed it but how did you restore the metal front tag? I must have about ten of these grinders in my basement and garage that I have picked up at flea markets....waiting on me to clean up. Two of them are the more rare 1/2 horse power.

One I use daily...I took off the metal wheel guards and have a different wire brush on each side. I find that putting a wire wheel inside a guard not only scuffs up the unit, but doesn't allow for full use of the brush.

The guy who restored that one with the red trim...I saw it on ebay today....for the amount of work that is, it's a bargain price.

beltdrive · Apr 6, 2017

I agree...I like to use the wire wheels with no guards....but I wear goggles and , depending on what I am handling, leather gloves.

torqueman2002 · Apr 6, 2017

Re: Craftsman 1/3-HP flat-top Block Grinder m-397.19580, restore

Please see my comments in RED.

beltdrive said:
Hansen Rivet may have those rivets.
They will have aluminum rivets, but not the copper.
Maybe I missed it but how did you restore the metal front tag?
I got it from a GJ member that is no longer active, as I understand. But, there is another member, Mattblast, that is helping others with their labels. 'Vintage Grinder Sticker Reproduction' --> http://www.garagejournal.com/forum/showthread.php?t=356439
...

The guy who restored that one with the red trim...I saw it on ebay today....for the amount of work that is, it's a bargain price.
Thank you.

Craftsman 1/3-HP Round-top Block Grinder m-397.19580, restore

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