let's see your craftsman block grinders

[MercLSU]

vertguy you ****!

I picked this commercial block up for $5, it spins ok without any drag but when you hit the switch to on it runs extremely slow and is noisy. Don't know if it's a 1/2 HP or 3/4 HP block with the missing label. The base plate is not correct and has no holes for the hold down bolts or grommet cushions.

Bluebolt,

I picked up this grinder along with another, mostly for the stand they were on a while back. I hadn't done anything with the grinder as I couldn't source end caps and have a dedicated grinder with wire wheels, a buffer, etc. Assuming you weren't going to refurbish that one and the bolt patterns were the same between the flat and round top end caps, next time you're down this way you're welcome to it. It ran fine when I plugged it in last.

http://www.garagejournal.com/forum/showpost.php?p=5393922&postcount=7526

 

[torqueman2002]

vertguy you ****!

I picked this commercial block up for $5, it spins ok without any drag but when you hit the switch to on it runs extremely slow and is noisy. Don't know if it's a 1/2 HP or 3/4 HP block with the missing label. The base plate is not correct and has no holes for the hold down bolts or grommet cushions.

That IS a you **** price!

If the arbor shaft is 5/8", it is probably a 3/4 or 1-HP Block; if it has a 1/2" arbor shaft, it is probably a 1/2-HP.

Another way to possibly cross-check what model/HP the grinder is, check the relay number and search on:
SearsPartsDirect website link - --> http://www.searspartsdirect.com/
eReplacementParts website link - --> http://www.ereplacementparts.com/craftsman-grinder-parts-c-158286_159871.html

Or, maybe it is listed below.

I see mounting 'holes' on the side covers. Is there another base plate not shown?

Try giving the stone/wheel a spin by hand at start up. If that brings it up to speed, check the start-up circuit, including the capacitor for loose/bad connections.

Also, the power switch does not look OEM, it could be wired wrong.

Once you can narrow down what arbor size, wheel dia., relay p/n, cap p/n; I may have a wiring diagram that will work, or you can look through this slide show.
http://s786.photobucket.com/user/torqueman2002/slideshow/CM 009 Wiring Schematics

Good luck, be sure to let us know how you are making out. Feel free to PM me, also.

Mike

 

[torqueman2002]

Hi fellow Blockheads, I'll make my comments in RED.

While not technically a Cfman Block, still cool. Anyone have any info on this guy? Ive never seen one like it before..
I recall seeing one on OWWM website.

Illuminated shields. Only 1/3 hp but the grinder is HUGE. Plastic water tray that is definitely original....
These are pre-pre-Blocks and are very robust! They weigh a 'ton' and must be made of CI.

The red cooling tray is a huge bonus, they go missing most of the time. Another big plus is the great condition of the center band.

Here's a slideshow of 1, waiting it's turn for a restore.
http://s786.photobucket.com/user/torqueman2002/slideshow/CM%2033%20HP%20115_7397%20115V%20Romeo

From sears-craftsman-1953-power catalog, downloaded from OWWM website.

Great find!

They show up occasionally. IIRC, they were a post-war item, before the round-tops came out. Found it on pg 23 of the 1948 catalog, illustrated with a C Underline logo.

Did some more digging, and they are between 48-53, before the round blocks came into being.

Very good research and information.

Look at what followed me home from the flea market this morning. I almost walked away and decided it was worth a price check... and when the seller mentioned $35, I had no choice and could not get my money out fast enough. Especially after countering with $30 that he gladly accepted

He even guaranteed it worked and gave his number in case I had issues.

Thought an updated block stand family photo was in order (have another 1/3 under the bench as well). Not sure if this one is staying, but a quick power up confirmed it ran smooth as butter.

It sure looks right at home!

 

[Rileysan]

Part it out. I have dibs on the end covers.....

Add me to the list of buyers interested in parting it out. I need the end covers as well!

Brian

 

[bluebolt]

Woohoo this might be a 1 HP block!

8" wheels and 5/8" shaft

Relay is 03V9V 4CR-20-713

I don't see any markings on the capacitor.

I think it is wired wrong, will post pictures later.

No "burnt" smell or any obvious sign of damage to the windings.

The base plate I was talking about was the tin cover for the bottom, this one is homemade and does not have the cutouts for the mounting bolts.

I am pretty sure the band is home made too, I can see the Sharpie marks for the bends!

 

[bluebolt]

Bluebolt,

I picked up this grinder along with another, mostly for the stand they were on a while back. I hadn't done anything with the grinder as I couldn't source end caps and have a dedicated grinder with wire wheels, a buffer, etc. Assuming you weren't going to refurbish that one and the bolt patterns were the same between the flat and round top end caps, next time you're down this way you're welcome to it. It ran fine when I plugged it in last.

http://www.garagejournal.com/forum/showpost.php?p=5393922&postcount=7526

Thanks for the offer MercLSU looks like I will try to fix this 1 HP block!

 

[torqueman2002]

Woohoo this might be a 1 HP block!

8" wheels and 5/8" shaft

Relay is 03V9V 4CR-20-713

I don't see any markings on the capacitor.

I think it is wired wrong, will post pictures later.

No "burnt" smell or any obvious sign of damage to the windings.

The base plate I was talking about was the tin cover for the bottom, this one is homemade and does not have the cutouts for the mounting bolts.

I am pretty sure the band is home made too, I can see the Sharpie marks for the bends!

If that Block were mine, I'd verify the non-OEM power switch is able to handle the amp-volts a 1-HP motor will draw on start-up.

Should you decide to replace the start cap, the exact MFD value is not critical, just stay within about +/-10%.

The following caps. were on the 1 HP Blocks I've seen/worked on.
Mallory
210-260MFD 110VAC
15539080
235-817X-02

Go-Blue!
243-292 MFD
BC-243
replacement:
Dayton
233-280 MFD, 110-125V
2MDR9
UNSPSC # 39121521
Dia. 1 7/16"
Hgt. 3 3/8"
Grainger
Amazon /Zoro Tools $6.24 & ~$5.00 S&H

Link to Go-Blue! rebuild.
http://tinyurl.com/Go-Blue-Block-Grinder

Links to DPST toggle switches.
http://www.mcmelectronics.com/product/26-5125
$15.06
https://www.zoro.com/carling-techno...quikconnct-2gk91-78/i/G3912763/?category=4800
$7.90
Amazon - Gardner Bender GSW-14 Heavy Duty Toggle Switch, 20A 125VAC, Double Pole Single Throw, ON-OFF, Screw Terminal
$6.29/Prime

 

[bluebolt]

The capacitor has this on it under the tape Torqueman2002

MALLORY
Made in USA
210-260MFD 110VAC
15539080
235-8117K-02

I will post pictures later tonight

 

[torqueman2002]

The capacitor has this on it under the tape Torqueman2002

MALLORY
Made in USA
210-260MFD 110VAC
15539080
235-8117K-02

I will post pictures later tonight

1-HP!

Replacements at Amazon for $8.00
216-259 MFD

Wiring diagram from Go Blue!
Note: Circuit numbers are for my reference, they do not appear on the wires.

Coil resistance.

From inside bottom cover, dual voltage wiring diagrm.

 

[bluebolt]

Thanks Torqueman!

I am going to start by getting a new switch and doing the wiring like your diagram above, it's not even close to that right now!

 

[torqueman2002]

Thanks Torqueman!

I am going to start by getting a new switch and doing the wiring like your diagram above, it's not even close to that right now!

The Go Blue! restore thread should also show how the wires are routed.

Let us know if you have questions. Feel free to PM me also.

 

[Outlawmws]

BB, I wonder if yours was wired up for 220 use? That would mess it up for 120!

 

[davethorik]

Finally picked up one of the big guys.
397.19450 Craftsman Commercial 3/4 hp w/ stand
Works, everything is there, but the right side tool rest is broken (see pic)
Overall, grinder is rusty and dirty, but i dont think i did too bad.

$60

 

[bluebolt]

Here's pictures of the inside of the 1 HP block.

I can put my 75 cent water tray to good use now!

I have a 1/2 HP block for parts that I will get the band off of.

 

[JZiggy]

Bluebolt -- I'll see if I have a proper bottom cover for you, if you want it.

 

[bluebolt]

Bluebolt -- I'll see if I have a proper bottom cover for you, if you want it.

Thanks but my parts block should have a cover.

 

[exmaxima1]

Here's pictures of the inside of the 1 HP block.

I can put my 75 cent water tray to good use now!

I have a 1/2 HP block for parts that I will get the band off of.

It might say 1hp on the nameplate, but I don't see much difference from a 3/4hp or even a 1/2hp commercial. Where's the mass?

 

[torqueman2002]

Here's pictures of the inside of the 1 HP block.

I can put my 75 cent water tray to good use now!

I have a 1/2 HP block for parts that I will get the band off of.

It looks like the replacement power sw is a SPST and the person in there before you got really creative on wiring the relay, etc ...

BTW - I was able to get a replacement center band 534434219 1-HP, Price: $16.23/ea. (March 2015) from eReplacementPart.

It does however have the rectangular power sw cutout.

 

[torqueman2002]

Finally picked up one of the big guys.
397.19450 Craftsman Commercial 3/4 hp w/ stand
Works, everything is there, but the right side tool rest is broken (see pic)
Overall, grinder is rusty and dirty, but i dont think i did too bad.

$60

I doubt you will find a replacement tool rest.

I wonder if that could be welded/brazed.

 

[torqueman2002]

It might say 1hp on the nameplate, but I don't see much difference from a 3/4hp or even a 1/2hp commercial. Where's the mass?

My guess is the field coil windings are different as I think the 5/8" rotors are the same.

Well, now I'm not sure.

I just did a quick check of p/ns of:
1.0-HP 257.192190
1.0-HP 397.19360
0.75-HP 397.19670
0.75-HP 397.19470
0.75-HP 397.19350

No common p/ns for rotors or stator/coils.

 

[Bobioz1]

Finally picked up one of the big guys.
397.19450 Craftsman Commercial 3/4 hp w/ stand
Works, everything is there, but the right side tool rest is broken (see pic)
Overall, grinder is rusty and dirty, but i dont think i did too bad.

$60

Bummer about the tool rest. But since your into the grinder and stand so cheap, consider a belt grinder attachment.

 

[JZiggy]

My guess is the field coil windings are different as I think the 5/8" rotors are the same.

Well, now I'm not sure.

I just did a quick check of p/ns of:
1.0-HP 257.192190
1.0-HP 397.19360
0.75-HP 397.19670
0.75-HP 397.19470
0.75-HP 397.19350

No common p/ns for rotors or stator/coils.

Compare to the thickness of the armature on my "known 1HP" block:

 

[MercLSU]

Probably a long shot, but anybody near Staples, MN and willing to pick up / ship a block grinder if I pay them (reasonably) for their time?

 

[bluebolt]

I just pulled the band and sheet metal bottom cover off of my parts 1/2 HP split phase grinder and was shocked at how clean it was inside! If one of my 1/3 HP grinders has an internal problem it may get a 1/6 HP upgrade LOL.

Also comparing the rotor, windings and armature of it to the 1 HP block is a BIG difference.

 

[exmaxima1]

Also comparing the rotor, windings and armature of it to the 1 HP block is a BIG difference.

I guess what I was alluding to was the total weight of the machine to handle the extra power. CM block grinders use common die-cast enclosures for nearly all the sizes, and simply install longer motor guts into them for the various hp ratings. While I am ok with the modest sized 1/4-1/2hp models, when you get into the 8-inch sizes the wheels dominate the weight of the grinder. I've owned several of the 3/4hp blocks and rarely used them due to the vibration if one of the wheels was even slightly out of balance. In contrast, my current 1hp grinders are massive: my Dayton 10-inch has 1-inch arbors and weighs about 90 lbs or more; my Milwaukee (Wissota) 10-inch with 3/4" arbors is close to 75 lbs, I'd guess. I'm curious how others are enjoying their 8-inch CM blocks with 5/8" arbors and less than 40 lbs.

 

[mattblast]

I'm always on the lookout for good grinder (though I do have 4 or 5 of them already depending on how you count). Saw this 3 day old listing on Craigslist Tuesday night. Figure it was worth a try to see it it was still available.



It's a good deal on the stand and was about 70 miles away. My in-laws live about 30 mins away and are retired and offered to pick it up for me. The seller was great - he disassembled it and lifted it into their trunk last night. I didn't want to post anything until I had it in my possession in case anyone saw this posting and tried to offer him more for it.

Ok, maybe it doesn't look like that great of a deal but the second photo on the listing is what really got me interested.



It's my first 1 HP block. My biggest was 3/4 HP until now. It is a bit dirty but works perfectly. Only issue is no eyeshields and one rubber foot is missing. Here it is after a few minutes cleaning it up. (Still spinning a minute after I turned it off when I took this photo)



And the badge


My plan is to sell off the stand which will more than pay for the grinder plus the cost to replace the eyeshields. It does need some new stones which I already picked up.

I'll probably leave it as-is other than some cleanup. It's tempting to tear it open and restore it but that's going to have to wait until I have more time.

 

[JZiggy]

Good find Matt!

 

[torqueman2002]

Yes, that's the real deal!

The big boys, 3/4 & 1-HP, get beat like a rented mule!

It should clean up nicely. I'd want to check the insides for questionable electricals (ie: missing ground, ...), and of course the power cord.

Well done!

 

[mattblast]

I couldn't resist taking the grinder apart. There are many projects I'm currently working on including the kids bathroom but I was up early this morning and needed a project. It was just too tempting to resist.

Here it is after initial disassembly and cleaning.

(Wife's away for the day so I can get away with using the counter top)

Wasn't planning on changing bearings but since its apart I will. They show 77503 which appears to be a 6203zz. Pair of good quality ones is less than $10.

Any suggestions on repainting? I can glass bead or aluminum oxide blast but probably the glass bead will be better for aluminum. Or maybe just lightly sand and then a repaint.



Other project taking up workbench so I did this on garage floor. Really have to stop taking on new projects.

 

[JZiggy]

Light sand and repaint works fine for these in my opinion.

 

[exmaxima1]

Labor Day Findre-Block w/Stand

Seller had a CM grinder with stand. Claimed it didn't run so willing to sell for $20. Figured worst-case I could part it out, so I made the hr trip. Turned out to be a 7" Cap-Start pre-block but still a good deal. Got home, plugged it in and it runs fine

Never had a pre-block, so kinda excited to look inside. Weighs twice what most blocks weigh, and 5.5 amps for a 1/3hp grinder is no toy.

 

[Outlawmws]

Stands seem to go for 5X what you paid, so yesyousuck

 

[torqueman2002]

What he ^^ said!

 

[Kaervak]

Here's a 3/4 HP block somewhat nearby me for $70. It's complete too, even has the heavy duty base. If I don't pick it up for myself, I can snag it for someone here.

http://cleveland.craigslist.org/tls/5764003597.html

 

[exmaxima1]

Here's a 3/4 HP block somewhat nearby me for $70. It's complete too, even has the heavy duty base. If I don't pick it up for myself, I can snag it for someone here.

http://cleveland.craigslist.org/tls/5764003597.html

Funny how "Sears Best" was a split phase 3/4hp with lower amperage than the 1/2hp cap-start model.....

That said, I'd grab it in a heartbeat for $70!

 

[davethorik]

Funny how "Sears Best" was a split phase 3/4hp with lower amperage than the 1/2hp cap-start model.....

That said, I'd grab it in a heartbeat for $70!

Yeah, I scratched my head when I read the plates on my C'man Commercial 1/2 vs 3/4, the 1/2 draws 6.2 amps vs 6 for the 3/4

 

[larryq]

Hoping the experts could help with something. I'm trying to strip down and restore a 1970s block grinder and am having a hard time figuring out how to split the two halves apart to get at the rotor and bearings?

Are there screws going through the magnet that I have to remove to do it, that hold the halves together? (Click the image to see it properly.)

 

[mattblast]

The bearings are holding it together. It's a press fit and can be snug. Just have to work the two halves apart to pull bearing out of position. Some light taps with a piece of wood may help (I used wood dowel and tapped it with a hammer to split halves)


Screw you show is used to secure stator to left side housing. You will eventually remove it.

 

[JZiggy]

I like to put the exposed rotor end into a soft-jaw'ed vise, using the side that the armature is screwed into (RH side of your picture, larry). Then you can tap on the other housing side until it slides off.

That fact that you have a bit of a gap between those two sets of cast fingers means you're already making progress.

 

[torqueman2002]

Good suggestions from JZ and Matt ^^.

Here's a thread if you'd like to see some more ideas.
http://www.garagejournal.com/forum/showthread.php?t=328228

Let us know how you make out, or if you have any questions.