Actually, that means the bearings are dried out and SHOT. Fresh shielded bearings rarely roll more than a minute, and sealed bearings stop much faster yet. Of course, those heavy 8-inch wheels add a lot of mass, but 3 minutes is still way too long for good bearings.
let's see your craftsman block grinders
- Thread starter emeraldcoupe
- Start date
Actually, that means the bearings are dried out and SHOT. Fresh shielded bearings rarely roll more than a minute, and sealed bearings stop much faster yet. Of course, those heavy 8-inch wheels add a lot of mass, but 3 minutes is still way too long for good bearings.
Yep
I put sealed bearings in all of my overhauls and they bring the stones to a stop in more like 30 seconds at most. There should be a bit of drag from the grease and the seals.
Hiatt1991
Well-known member
Darn. Oh well, at least replacing the bearings isn't too hard. Hopefully I'll get some time to do that down the road.
MissileBear
Well-known member
Badge pic attached - it's a Delco. Aren't pre-blocks all Packard units?
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drivesitfar
Well-known member
MB: I can't recall exactly what you grinder looked like, but your badge is a PRE BLOCK sort of badge and with the January 1961 date i'm guessing it is. it's not common so you might have a somewhat rare one or maybe those just didn't get posted on this thread. in any case maybe Doc or another member can say for sure.
looked like a nice grinder when i first saw it and i personally like the block round top and the pre blocks better than the flat topped ones.
thanks for posting the close up of the badge and i hope some of what i said helped you.
looked like a nice grinder when i first saw it and i personally like the block round top and the pre blocks better than the flat topped ones.
thanks for posting the close up of the badge and i hope some of what i said helped you.
AdrianBoomer
Well-known member
MissileBear
Well-known member
Is there a specific feature that defines a block vs. a pre-block? I suppose I could look at the windings and compare... Aside from the cast iron body and different on/off switch, it's identical to the other early blocks I've seen.
drivesitfar
Well-known member
MB: i only buy them and use them the other guys here will answer your questions cause they know these old blocks better than maybe their SS#.
cheers
cheers
MissileBear
Well-known member
It's an early block for sure - first picture on first post:
https://www.garagejournal.com/forum/showthread.php?p=4000528#post4000528
As far as I can tell, these were the absolute first of the series.
https://www.garagejournal.com/forum/showthread.php?p=4000528#post4000528
As far as I can tell, these were the absolute first of the series.
drivesitfar
Well-known member
MB: i'm just used to the badges with the date stamp on the front like yours and some pre crowntop logo is what we call a PRE BLOCK. i'm here to learn otherwise if you think it's a BLOCK.
Adrian: best of luck on the stand finding its way to you, but nice find and restoration of your $20 block.
Adrian: best of luck on the stand finding its way to you, but nice find and restoration of your $20 block.
If it's cast iron, it's a Pre-Block. More info on this thread:
https://www.garagejournal.com/forum/showthread.php?t=339921&highlight=pre+block+love
MissileBear
Well-known member
I was under the impression that Delco (vendor code 397) never made a pre-block....pre-blocks were made exclusively by Packard (vendor code 115).
Torqueman has this same grinder listed as picture #1 on his FAQ - maybe he can chime in?
torqueman2002
Well-known member
To my eye, and based on the model number prefix of 397, it is a very early cast iron, round top, Block.
"What is a Block grinder?
"... the classic Craftsman bench grinders that were manufactured for Sears by Paramount/Allegretti & Co. from the early 1960's to early 1980's. Affectionately known as "Block Motor" grinders because of their unique shape, these power tools have developed a large following among shop enthusiasts because of their legendary reliability, accuracy, and power.
The "Block Motor" grinder can be readily identified by the Sears manufacturer prefix of 397 or 257 (as in 397.XXXXX); which is stamped on the front label. Popular models include 1/4-HP, 1/3-HP, 1/2-HP, 3/4-HP, and 1-HP Industrial units."
Link to: "Vintage Craftsman "Block Motor" bench grinder info -" (source)
http://tinyurl.com/CM-Block-motor-style-grinders
"People always want to know what makes these things {CM Block grinders} so special; here's the reason. Look at those field windings. That is some VERY thick copper wire. When compared to a modern Chinese winding, these look GIGANTIC. The imports use very thin field wire. This is what makes these "block motors" so darn powerful and long lasting." Source - http://tinyurl.com/0-5-HP-CM-Block-Motor-FINISHED"
https://www.garagejournal.com/forum/showpost.php?p=4000526&postcount=1
If the early cast iron "blocks" (397 mfr) share the same stator lamination dimensions as the later aluminum alloy blocks I would agree with you. And I don't really know for sure if they do. But I do know that the Pre-Block that I own has a MUCH larger stator lamination assembly than the alloy blocks, and the weight of its rotor/shaft assembly alone is nearly the full weight of a lower hp alloy block grinder.
Can you confirm that all Blocks (early cast iron and later alloy) share the same stator laminations and rotor diameters? If so, I absolutely agree with you. Otherwise I maintain that the differences between the cast iron Pre-Blocks and alloy Blocks is too great to segregate by manufacturer code.
torqueman2002
Well-known member
I'm sorry, but I can't answer that very good question.
I have to defer to the OP in this thread. --> http://tinyurl.com/CM-Block-motor-style-grinders
From what I can glean from that thread, the term "Block" grinder was in regards to the shape and the manufacturer was mainly noted as a frame in time. I don't get the impression that the prior manufacturer was even considered (or known), or it would surely have been included since the block shape is essentially the same.
Since there are so many similarities in the tool rests, eyeshields, end bells, etc, it looks like Sears handed the tooling over to Paramount/Allegretti & Co and they commenced with the same cast iron designs for several years before re-tooling to the alloy versions in the early 60's. I would not be surprised if the early cast iron "blocks" shared the same motor structure as the prior Packard-made grinders. It would interesting if someone could take some pics and dimensions of their cast iron block components during a rebuild.
If it is confirmed that all cast iron versions have the same motor components, and different from later alloy versions, the decision should be made to either: a) include ALL the block-shaped grinders as "Block" grinders, or b) define all the cast-iron models of both manufacturers as "Pre-Block".
My vote will be for the latter if all the cast iron internals are the same (and different from alloy versions).
michaelwolson
Well-known member
Very excited. Picked up my first true "block" grinder this past weekend. Paid $25 for it at an estate sale. My Dad said I should've counter offered $20 but I was just glad to find one in the Bay Area. Once restored it'll replace my newer craftsman grinder.
I am confused though. Here's the one I've had for a while (took the image from ebay):
That is not a "block grinder" right?
Here's my new acquisition waiting in a long line to be restored:
I am confused though. Here's the one I've had for a while (took the image from ebay):
That is not a "block grinder" right?
Here's my new acquisition waiting in a long line to be restored:
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franksinatra
Well-known member
Guys, I have a quick question on grinding stones and wire wheels. What size wheels are you using? I have a 6" wheel on now and it seems too small, granted it's lightly used. I have measured and a 7" wheel seems like it would easily fit but they don't have much for grit options. Anyone use the 7" wheels? Thanks for your help.
torqueman2002
Well-known member
I agree, I think Sears had the design, specs, and probably tooling. They could have looked for low-cost supplier - like auto manufactures are doing.
It would be great if there was someone who knew (ie: worked on the design, etc ...), but it's likely there are few, if any, of those people still around.
It sure would be easier if we could just go by the model number, but as the little example michaelwolson posted of m-397.19330, there are obvious exceptions. And probable more 'skin-deep' ones as well.
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EOC_Jason
Well-known member
What is your HP? I believe 1/4HP & 1/3HP is 6", while 1/2HP & 3/4HP are 7"... 1HP might be 8"?
I bought some 7" wheels off eBay. I made the mistake of buying a 3-pk of various grits that were pretty cheap compared to buying nicer brands... The plastic bushings were junk and wouldn't stay in place, took forever to align & balance the wheels... I will never make that mistake again.
Buy Norton wheels, forget the other cheap ones. If you can't find a 7" just use a 6" as they are much more common and probably cheaper.
Outlawmws
Well-known member
At least some 1/2 HP used 7" wheels. Mine, designated "Commercial", gold crown label, has 7"wheels and guards to suit/
Outlawmws
Well-known member
I don't believe Sears ever was an actual manufacturer, despite many implied advertising statements that they were. They contracted the products and sold under their name or their many trademarks (Craftsman, Dunlap, Etc...)
The Packard/Delco/Sunlight/ acquisitions/mergers, were long and convoluted,
Allegretti & Co & Paramount; Paramount (now Poulan), who continued the Delco model Block Grinders also had acquisitions going on.
The mergers, acquisitions, and possible tooling sales between companies, were between the manufacturers, and Sears simply made new contracts with new suppliers as needed.
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Understood, but that doesn't preclude Sears from owning the tooling. Many companies (including mine) source various products from other manufacturers but buy the tooling to ensure exclusivity. When/if I move to a new vendor, it is not unusual to move the tooling to the new vendor. And in the case of castings, that is typically sourced independently and shipped to my vendor to utilize in my products. That way I own the tooling (or molds) and am free to shop various vendors for manufacturing.
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drivesitfar
Well-known member
Ex, Doc, Outlaw & ALL: I think MB's block looks exactly like my round tops except for the badge which made me think about it being a PRE BLOCK.
personally i like the PRE BLOCKS maybe a bit better than the round tops cause i think they are both great grinders and i like the badge on the PRE BLOCKS better.
JasonEOC: thanks for the tips on buying smaller grinder wheels and QUALITY NORTON brand ones instead of what is on sale or the exact size wheels sent out of the factories.
personally i like the PRE BLOCKS maybe a bit better than the round tops cause i think they are both great grinders and i like the badge on the PRE BLOCKS better.
JasonEOC: thanks for the tips on buying smaller grinder wheels and QUALITY NORTON brand ones instead of what is on sale or the exact size wheels sent out of the factories.
Outlawmws
Well-known member
Exmax. That is a possibility; I've just never heard/seen any verified cases of that with Sears. I know of few products that Sears carried you could not buy elsewhere under another name. Those that I have noted, when they ended production with Sears, it just ended. Something the producer didn't want to carry...
I have countless tools from Sears that I also have with another branding, if not more than one. Not saying it's not possible, but if it was done, it wasn't common.
I have countless tools from Sears that I also have with another branding, if not more than one. Not saying it's not possible, but if it was done, it wasn't common.
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maxwage
Well-known member
I know both are 1/3hp, but I'll bet the Wissota runs smoother. I have a Wissota E-6 (E-33) as well that I bought to use as a small buffer, and they are outstanding little machines.
maxwage
Well-known member
I know both are 1/3hp, but I'll bet the Wissota runs smoother. I have a Wissota E-6 (E-33) as well that I bought to use as a small buffer, and they are outstanding little machines.
The Wissota runs much smoother so it's my primary grinder
Sent from my iPhone using Tapatalk
BRWEIDEM
Well-known member
Joined the club today. Found this 7", 3/4 HP, 397.19350 nearby. Didn't steal it but paid what I thought was a fair price. This is my first craftsman grinder, not sure if it is block, pre-block, or not even a block? Can anyone take a look and comment? Ive seen some pretty good looking resto's on this forum but this one is in great condition so I was considering just leaving it the way it is. Any way to date these grinders? Briefly took it apart but didn't see anything that resembles a date or date code. Thanks for your feedback.
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EOC_Jason
Well-known member
The bottom cover *sometimes* will have a date stamp on the inside.
BRWEIDEM
Well-known member
Glad you mentioned the bottom cover. While looking it over at home i noticed there is just a galvanized plate screwed into the bottom side. It struck me as weird and I wondered whether or not these grinders came with just a plate on the bottom or if there is supposed to be an actual cover. Based on the bends and cutouts it doesn't look homemade. Does anyone have a picture of the underside of one of these or a description of what is supposed to be there?
Outlawmws
Well-known member
What you describe sounds pretty normal. its a very basic cover, only for handling until installed.
torqueman2002
Well-known member
BRWEIDEM
Well-known member
Jason, Outlaw, Torque, thanks for the help. Pulled the bottom cover off again- no date stamp. You mention flat top block, where do these fit in the realm of block grinders? Is there any previous info posted on different styles of blocks and when they were produced?
Meantime, on the hunt for a second unit. I'm already addicted.
Meantime, on the hunt for a second unit. I'm already addicted.
MissileBear
Well-known member
I might dig into this over the next few days - unfortunately I only have a true 1/3 HP and a 1/2 HP block to compare to (sold the 1/4 HP flat top a while ago).
No need to check any block grinder (round or flat-top types) with an alloy chassis, as they definitely use a smaller motor structure than the older cast iron versions. What I wanted to know was if the early "397" cast iron grinders versions utilized the same guts as the prior "115" designs.
What I now see as a possibility was that early "397" was Delco, and they may have taken over the tooling and molds from Packard ("115") in the late 50's. And then Paramount/Allegretti & Co bought Delco---and retained their "397" code---but redesigned the model line to all new alloy versions with smaller guts. If this is the case, the term BLOCK grinder should not be based strictly on the mfr code (since 2 companies used the 397), but instead to differentiate BLOCK and PRE-BLOCK based on whether it is cast iron or alloy framed.
Outlawmws
Well-known member
AFAIK, 397 was always Delco. 
AFAIK, 397 was always Delco.
I found 2 names for "397" on the vintage machinery site:
http://vintagemachinery.org/Craftsman/manufacturers.aspx
I assumed it was right, but who really knows.....
alpinewhite
Well-known member
Guys, I have had the addiction for several years now. I'm at 4 block grinders and I'm only using one. How do you guys set up multiple grinders? I'd love to see some pics to get ideas.