How do I get this Craftsman block grinder apart?

larryq · Mar 9, 2014

Bought a vintage CM block grinder the other day. The wiring needs some work, in fact I probably need to replace one of the wires (the white one in the pics) coming off the block. This thing is approx from 1960 and the pvc or whatever coating they used in the day is cracking and I can see a green patina on the copper wiring.

I've got all the bolts and screws out but I'm having trouble separating the halves. They seem to be press fit together. Any advice on how to do this (and put it back together?)

rickhigginshtbr · Mar 10, 2014

bump, out of curiosity for myself. Haven't taken one of my blocks apart yet, but on the old B+D one I did, the bearings had to come out, then it separated with ease.

Bigplum · Mar 10, 2014

not familar with that one but at a guess its the bearings stuck in the housings ,
maybe a bit of heat on the outer and a tap with a soft mallet ?

torqueman2002 · Mar 10, 2014

There are many CM 'Block' motor style grinders. More pictures would be good for us to help you get this apart.

By the look of your's, it might actually be a pre-Block grinder.

If it is, there will be a start-capacitor start-up switch in the RH housing.

First, I would soak with penetrating oil of choice (Kroil, PB Blaster; not WD-40 not worth your trouble). If you do try heat, be careful, p oils are flamable.

Remove the LH side, remove the field windings, disconnecting/cutting any wires necessary.

Then work on RH side. You want to remove the rotor from the RH housing, leaving the bearing in the housing; or unscrew the start-capacitor start-up switch from the housing and remove the rotor and bearing from the housing.

Here's a link with more information on a similar re-build.
http://tinyurl.com/CM-1-3HP-Li-l-Brownie-115-7566

Link to: "Vintage Craftsman "Block Motor" bench grinder info -" Thread.
http://tinyurl.com/CM-Block-motor-style-grinders

Also, see: "let's see your craftsman block grinders" Thread.
http://www.garagejournal.com/forum/showthread.php?t=157794

Good luck, and don't forget to let us know how you are making out; with pictures!

larryq · Mar 10, 2014

Thanks BigPlum and Torqueman. Sorry for the blurry pics, I will post more (and better) when I get home tonight.

Outlawmws · Mar 10, 2014

Larry,

This is without actually being able to see much of what's going on; If you have the screws holding the shells together off, then the only thing that should still be connecting them is the bearings, which should be a slip fit into the housings, and a light press fin on the armature shaft.

I see some sort of cover on the ends: Any screws on these? I'd take them off before exerting any pressure.

larryq · Mar 10, 2014

Outlawmws said:
Larry,

This is without actually being able to see much of what's going on; If you have the screws holding the shells together off, then the only thing that should still be connecting them is the bearings, which should be a slip fit into the housings, and a light press fin on the armature shaft.

I see some sort of cover on the ends: Any screws on these? I'd take them off before exerting any pressure.

Thanks as always Outlaw. I believe I got all the screws out, as well as the thru bolts that go from one side all the way to the other, but will triple-check tonight. So far the only force I've exerted is a little hand pulling, so no damage done.

Torqueman, your excellent grinder restore thread looks exactly like the one I'm working on, including the lack of wheel guards, by design from what I can see. Given a recent thread discussing the risk of a wheel exploding if mistreated, I have to wonder why that design ever existed at all?

Outlawmws · Mar 10, 2014

Larry, when you can post pics of the label, and we can see what era it is, but you go back far enough and NOTHING had guards! Pedestal grinder stands are often sans guards or even rests, as they were probably intended for buffing and polishing, but you give a mechanic an arbor, he's going to stick a stone on it...

I can remember being in our one car garage as a toddler and turing on my dad's grinder and my mom coming out and scooping me up and punishing me for it.

The "grinder" was two open ball bearings (think bicycle bearings) supporting an arbor, bolted to a 4x4 with a chunk carved out to clear the middle pulley, exposed belt to the (antique even then) open frame motor, that drove the whole mess. That POS followed us through 5 moves before finally being abandoned by me.

That thing made the most horrendous noises you can imagine, due to the sloppy ball bearings! (Yet my dad managed to detail out a 1920 savage 250-3000 action on it, down to polishing the thing prior to having it blued to about the deepest blueing you can get on a gun...)

All that noise (along with all the junk on the workbench vibrating in simpatico with the "grinder") was what brought my mom running...

larryq · Mar 10, 2014

Some more pics. As you can see in the third pic, I *think* I've got all the bolts and screws out. I can spray some kroil near the bearings and see if the halves come out that way? :dunno:

larryq · Mar 10, 2014

Let's try those pics again:

Outlawmws · Mar 11, 2014

Larry, I think I found your grinder in the 1959 Craftsman catalog.

Was there a date on the bottom cover plate? (Was there a bottom cover plate? :evil:

)

If I'm right, it should have come with open side guards, rests and eye guards.

larryq · Mar 11, 2014

Outlawmws said:
Larry, I think I found your grinder in the 1959 Craftsman catalog.

Was there a date on the bottom cover plate? (Was there a bottom cover plate? )

If I'm right, it should have come with open side guards, rests and eye guards.

Thanks for the sleuthing Outlaw :thumbup:

Yes, remarkably enough there is a bottom cover plate but I didn't see a date stamp on it, will look again.

I did get the unit apart with a little Kroil and some gentle taps with a hammer. My big issue now is replacing that patina-ed white wire. It goes into the armature so I have no way (that I can see) of getting at it from its base.

Problem is, that wire is greened up and sketchy from top to bottom so just splicing it at a location won't do a whole lot of good. I can post more pics tonight to show what I mean.

jakemac · Mar 11, 2014

Slip a white shrink tube over the wire. It will look like new. If it looks new, it must be ok. Right ? :lol_hitti

torqueman2002 · Mar 11, 2014

First, take a trip over to http://vintagemachinery.org and their sister site http://owwm.org/. There's a lot of information on these vintage tools, including manufacture dates and ranges.

There's a post of another grinder like your 0.25 HP model 397.19501. http://vintagemachinery.org/photoindex/detail.aspx?id=15121

I searched my library of CM grinder manuals/part diagrams with out luck. But, the above VM site has a library of manuals in pdf, free for downloading - your's may be available.

Second. You have a split phase/induction-repulsion motor. It has a rotor, not an armature. I think what you are refering to is the white wire from the field winding(s). I agree it needs to be replaced, and I'd do the others as well.

Third. Your model, as you no doubt have discovered, has a start relay - not a capacitor with start-switch assembly as I originally thought. The relay can be dis-assembled, cleaned, and put back into service; if you think it warrants. The one I opened (1 HP CM Block motor), didn't show too much contact pitting. So, unless you measure an out of range voltage-drop, I wouldn't open it up.

For more info. see: "Topic: Block Grinder rescue - UPDATE: Go-Blue! 1 H.P. Model 257.191600" http://tinyurl.com/Go-Blue-Block-Grinder
Posts #2 & 3 « Message by torqueman2002 on August 19, 2013, 06:57:20 AM » & « Message by torqueman2002 on August 11, 2013, 08:15:26 PM »

:thumbup:

larryq · Mar 11, 2014

torqueman2002 said:
Second. You have a split phase/induction-repulsion motor. It has a rotor, not an armature. I think what you are refering to is the white wire from the field winding(s). I agree it needs to be replaced, and I'd do the others as well.

Thanks for the info and links...yes, you're right I misspoke and meant the white wire of the field winding. Even with a manual I'm still not sure how I can 'get down the rabbit hole' and redo the white wire from where it starts, however deep it goes.

Tempted to solder a few strands of new copper wire to this one for a stronger connection...not the same as replacing the whole wire but I don't know how I can do that.

Outlawmws · Mar 11, 2014

Lets get pics. Usually the wires CAN be replaced where they connect to the winding wire.

torqueman2002 · Mar 11, 2014

Well, parts for these guys are hard to find, and I would think a field winding especially.

I am lucky to live in an area with an abundance of production shops of all sorts. When I wanted to have the 1HP 257.191600 Block grinder rotor and windings tested (they had water/rust marks), I took them to an electric motor rebuild shop.

They had motors 1/2 the size of my truck, waiting to be rebuilt; but, they checked out my parts for $20 & within a day.

So, if I had what you're describing, I'd see if an electric motor shop could offer some help/suggestions.

Best of luck.

tedsters · Mar 11, 2014

larryq said:
Let's try those pics again:

Larry

I think your grinder is a 1961 yours is coded J61 not sure if the j is for January or June but pretty sure its a 61 heres a pic of mine and its date coded on the front

tedsters · Mar 11, 2014

ok now that looking at larrys and mine if his is a 1961 with the crown top logo and mine is a 1958 without the crown logo what year did the crown logo arrive, kind of curious know i know if i dig deep enough i could find out but someone on here has to know a few of you guys are pretty knowledgable in this craftsman stuff

tedsters · Mar 11, 2014

Outlawmws said:
Larry, I think I found your grinder in the 1959 Craftsman catalog.

Was there a date on the bottom cover plate? (Was there a bottom cover plate? )

If I'm right, it should have come with open side guards, rests and eye guards.

Outlaw

looks like mine in post #18 wish i could find that pedestal for mine

torqueman2002 · Mar 11, 2014

tedsters said:
ok now that looking at larrys and mine if his is a 1961 with the crown top logo and mine is a 1958 without the crown logo what year did the crown logo arrive, kind of curious know i know if i dig deep enough i could find out but someone on here has to know a few of you guys are pretty knowledgable in this craftsman stuff

You are right! Make your way over to nine4gmc's: "Show your Crown Top Love"

http://www.garagejournal.com/forum/showthread.php?t=199000

tedsters · Mar 11, 2014

Thanks torqueman

torqueman2002 · Mar 11, 2014

You bet. It's amazing the knowledge to be had on this site. Good, helpful guys/gals, too.

Outlawmws · Mar 11, 2014

Tedster, IIR (Based on the catalog listings) the Crown logo (Generally, not necessarily for grinders) started in a small way in 58 or so, solid from 60 to 69 for sure, and tapering off but still in use on some tools as late as 73.

Generally the logos tended to run within a decade: 35-45 Long C Craftsman, 50's Oval, 60's Crown, 70's the newer logos... but with plenty of overlap, probably to ease re-tooling costs for suppliers.

larryq · Mar 12, 2014

Here are the promised wiring pics. I'm using the red wire as the example here because of the better contrast but the black and white ones do the same.

Note the "rabbit hole" it goes down. Not sure how to get at the bottom of the wire, if at all possible, or if I should put a drop or two of solder down there to solidify things? :dunno:

Definitely open to suggestions. Thanks for everyone's advice thus far.

Bigplum · Mar 12, 2014

I'd sleeve / heat shrink the wire then put some silicon RTV around the rabbit hole,
No point in trying to get down there if the wire is still connected well.

tedsters · Mar 12, 2014

torqueman2002 said:
You bet. It's amazing the knowledge to be had on this site. Good, helpful guys/gals, too.

Outlawmws said:
Tedster, IIR (Based on the catalog listings) the Crown logo (Generally, not necessarily for grinders) started in a small way in 58 or so, solid from 60 to 69 for sure, and tapering off but still in use on some tools as late as 73.

Generally the logos tended to run within a decade: 35-45 Long C Craftsman, 50's Oval, 60's Crown, 70's the newer logos... but with plenty of overlap, probably to ease re-tooling costs for suppliers.

I am Amazed all the time when i come on this site the knowledge and helpful information that is shared, this forum has really helped me learn a lot about tools and its all good :thumbup:

DanDio · Apr 25, 2014

larryq said:
Bought a vintage CM block grinder the other day. The wiring needs some work, in fact I probably need to replace one of the wires (the white one in the pics) coming off the block. This thing is approx from 1960 and the pvc or whatever coating they used in the day is cracking and I can see a green patina on the copper wiring.

I've got all the bolts and screws out but I'm having trouble separating the halves. They seem to be press fit together. Any advice on how to do this (and put it back together?)

Hey Guys glad to be here, found this thread doing a google search because I just bought one of these today myself. Got it for $25 off CL. Here's the listing.

CM 115 7566

Beautiful piece of vintage machinery, it's going to look quite nice in my garage shop. Funny, my white wire is crapping out too and it broke off at the capacitor. The other wires are in better shape, same as yours. I'm just going to solder it back. Why are you opening yours up? I saw this one on eB for $400 and it's 1/4 HP split phase.

eB listed

I think I did pretty good today.

Bmozer · Jul 12, 2018

I understand that this thread is 4 years old, but I'm in need of some help. I've got this same grinder, putting it back together after a restoration and can't find my wiring picture I took before disassembly! If someone could post a picture or draw a picture of the wiring from the cord, start relay, and switch I would be so amazed! I've tried many combinations but it just hums, and yes, it worked before I tore it down.

torqueman2002 · Jul 12, 2018

By 'the same grinder' what model number and HP are you referring to?

I skimmed the 2 dozen or so posts, but didn't spot that information.

Bmozer · Jul 12, 2018

Model 397.19501 1/4 hp. J-61

torqueman2002 · Jul 12, 2018

Bmozer said:
Model 397.19501 1/4 hp. J-61

I don't have any information on that model, but member firemansdt posted one some time ago.

I do have pictures of a 1/4-HP m-397.19400 round top. See below.

Best of luck.

Please let us know how you make out.
:thumbup:

Bmozer · Jul 12, 2018

I don't mean to hijack this thread, but here are some pictures of what my grinder wiring looks like. I've got the tan from the windings going to the switch, just not sure where the red and black winding wires go on the starter relay.

Outlawmws · Jul 12, 2018

better pic of the relay and its post markings?

Bmozer · Jul 12, 2018

Outlawmws said:
better pic of the relay and its post markings?

Here ya go

torqueman2002 · Jul 13, 2018

Bmozer said:
Here ya go

I'm always surprised at the variations in these simple machines.

That is a Klixon relay (if I'm not mistaken), a configuration I haven't seen before.

This relay information may help, sorry I don't have the exact model you are looking for.

Demarrage => Start-up | sont => are

The following, while it does not cover your exact relay application, it is a good description of how the Block current based relays operate.
NOTE: Automotive relays are voltage based relays and operate differently.

I hope this helps.
:thumbup:

6PTsocket · Jul 13, 2018

torqueman2002 said:
I'm always surprised at the variations in these simple machines.

That is a Klixon relay (if I'm not mistaken), a configuration I haven't seen before.

This relay information may help, sorry I don't have the exact model you are looking for.

Demarrage => Start-up | sont => are

The following, while it does not cover your exact relay application, it is a good description of how the Block current based relays operate.
NOTE: Automotive relays are voltage based relays and operate differently.

I hope this helps.
[emoji106]

They do electrically what a centrifugal switch does mechanically, connect and disconnect the start winding. Sears shows them as no longer available but Klixon makes them in a few variants and with different current ratings. If buying one generically, the object is to have it disconnect when the motor is at 80% of full speed. As the motor speeds up the inrush current drops until it reaches the value on the motor plate. You want one that opens a little above the motor plate current. Too high and it disconnects too soon and start torque is poor. Too low and the start winding may never disconnect. They are also made in solid state instead of a magnetic relay. We had a solid state one come with a Leeson motor, at work. They were easy to select. Supply the motor plate current and you got the right relay. They will also replace a bad centrifugal switch, which can come in handy with an old or obscure motor.

Sent from my SM-G900V using Tapatalk

How do I get this Craftsman block grinder apart?

Well-known member

Attachments

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Attachments

Well-known member

Attachments

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Attachments

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Attachments

Well-known member

Well-known member

New member

Member

Well-known member

Member

Well-known member

Attachments

Member

Attachments

Well-known member

Member

Attachments

Well-known member

Attachments

Well-known member