let's see your craftsman block grinders

[Shiftless]

There must have been some additional circuitry in the form of a DC-DC converter to pump up the voltage to some value far above 9 volts. You can put you arms across a 12 volt car battery and not get a shock--you need more like 75-90 volts to even feel it. So summing the resistance of 100 persons in series like that will need more like 75-90 volts PER person (7500-9000 volts total) to get a "jolt" as you say.

You raised some excellent points. The event I mentioned happened more than 20 years ago and the place where I was standing was at least 50 feet from the lecturer. Who knows what the guy had besides the little 9 volt battery he waved around. Good thing nobody in the group relied on a pacemaker to keep his heart going.

 

[mroneeyedboh]

So Ive been looking for an old Block grinder for a few months now and honestly, Im tired to searching DAILY. What does come up is either too much money or isnt the size I want ( Id like to be around 3/4-1hp, Granted it may be a bit much but Id rather have one grinder that I can make work than have multiple like some of ya lol. I dont honestly have the room for more than one.

There is a member on here that offered me a 3/4 HP and an older metal 80's 1hp, the shipping makes the deal not super good but the prices aside from shipping ( Im not upset about the shipping at all ) are good. ID rather give a GJ member my money than someone thats looking for pure profit off of FleaBay.

The 3/4 model is 397.19470 and the 1HP model is: 257.192190. So the 1HP is at the end of the era of the good blocks, and it has the extended spindle, or longer spindle, whatever ya would call it.

I guess what Im wondering is, is the 1hp too much for grinder and wire wheeling? I may start to do some polishing here and there but would be more geared towards wire wheeling and grinding. Is it better to get it bigger ( i.e. the 1HP vs the 3/4HP ). And is that model of the 1HP still made by the coveted manufacture as the older Blocks?

 

[drivesitfar]

Mr: Great post and questions. I'll let others address which 3/4 or 1 hp blocks are the great ones and which might only be good if that's the case. Not trying to prevent you from buying a nice block but you might expand your search to other grinders and buffers. I do love the old block grinders and the round tops especially. Check the vintage grinder thread for maybe some other brands to look for.

I have a baldor 3/4 hp buffer that can throw things across my shop if I'm not paying attention so any 1/2 hp and bigger Baldor should do most anything you ask it too. Dayton, black and Decker older USA made ones are great too.

You might find that an eBay seller is also a member here and I'm sure they didn't get them for free so keep checking if one of us doesn't have one to sell you.

 

[Bobioz1]

That 1 horse is as good or better than the older models. As far as is it better to get it bigger, if they made a 1.5 horse I would be looking for one.

 

[Outlawmws]

You also need to consider what speed the 3/4 and 1HP are. the 1/2 and 1/3 are 3450 IIR.

At 6" wheels vs. 7 or 8 on the big boys, if they are at 1750 the SFPM comes down, which in IMHO the 6" 3450's are a bit on the high side... Pretty easy to burn stuff up.

 

[exmaxima1]

You also need to consider what speed the 3/4 and 1HP are. the 1/2 and 1/3 are 3450 IIR.

At 6" wheels vs. 7 or 8 on the big boys, if they are at 1750 the SFPM comes down, which in IMHO the 6" 3450's are a bit on the high side... Pretty easy to burn stuff up.

I've never seen a CM block grinder at anything BUT 3450 rpm. I have a Rockwell 7-inch that runs at 1750 (and so does Torqueman), but those are fairly rare. I sold off my 8-inch blocks as they, as you say, were too fast and things could go bad in a heartbeat.

 

[mroneeyedboh]

3580 rpm is what that 1 Hp runs at

 

[mroneeyedboh]

So I'm now confused... What RPM do I want to be looking for? It seems they are all around 3500-3800...

 

[drivesitfar]

MR: since i don't own a 3/4 or 1 HP block i still can't say if they are all 3450 (or maybe it says 3600 on the label), but some bigger grinders like Baldors have 1700 RPM versions.

 

[Outlawmws]

I just stated my preferences. That size wheel will cut fast at those speeds, but fast cutting generates heat. Lots of it. There is a reason they have a cooling tray...

 

[mroneeyedboh]

Ha-ha. True.. But great another thing to figure out... First its HP and now its RPMs...

 

[exmaxima1]

So I'm now confused... What RPM do I want to be looking for? It seems they are all around 3500-3800...

The actual rpm depends on load and slip, but in theory you would have 3600 rpm (no load or slippage) based on a 2 pole motor running at 60 hz. But average slip is about 4%, so you get 3450 rpm. You can scale from there: 4 pole = 1800 rpm, 6 pole = 1200 rpm, 8 pole= 900 rpm, etc. Subtract 4% under load and you get a pretty good idea.

 

[exmaxima1]

MR: since i don't own a 3/4 or 1 HP block i still can't say if they are all 3450 (or maybe it says 3600 on the label), but some bigger grinders like Baldors have 1700 RPM versions.

Most bench grinders are all 3450 rpm up to about an 8-inch wheel. At 10-inch, it is nearly mandatory to reduce speed since most wheels can't safely go faster than that. My Dayton 10-inch is 1750 rpm, and actually grinds slower than a 6-inch grinder running at 3450 rpm. But you can really lay into a bigger grinder and work a coarse wheel.
The handful of small slower speed grinders are geared towards tool makers and machinists that are dealing more with tool steels than the typical fabricator's mild steel applications. Less chance of taking the temper out of a tool.

 

[mroneeyedboh]

Thats what I was wondering. I have been using a baldor at work that is around 3600 and I never noticed anything. If it were to get hot, Id cool it or just not really allow it to get hot to begin with.

 

[RHJO51]

Hello, I purchased a old Cman block grinder recently for $60. These are pretty hard to find in my area and this 1/3 HP grinder was what I was looking for. It's a 397.19511 . Can anyone tell me what year it is? I think it's a oldie but not sure - no date stamp on the bottom. Also, what is that color - it's gold and redish brown? Thanks for you help. - Jim

 

[McBrownie]

Hello, I purchased a old Cman block grinder recently for $60. These are pretty hard to find in my area and this 1/3 HP grinder was what I was looking for. It's a 397.19511 . Can anyone tell me what year it is? I think it's a oldie but not sure - no date stamp on the bottom. Also, what is that color - it's gold and redish brown? Thanks for you help. - Jim

Congratulations! That is what called a "pre-block". A predecessor to the block grinder, but still a great grinder. Stamped "62" on the label, so a 1962 model. I don't think I have ever seen exhaust ports and side covers on that style. Really nice.

 

[JZiggy]

Formula to get surface feet per minute on a grinding wheel:

- Rotational speed in rpm
- Wheel diameter in inches
- Output speed in feet per minute

FPM = 0.2618*RPM*Diameter

(Someone check my math!)

 

[McBrownie]

Formula to get surface feet per minute on a grinding wheel:

- Rotational speed in rpm
- Wheel diameter in inches
- Output speed in feet per minute

FPM = 0.2618*RPM*Diameter

(Someone check my math!)

I do FPM = RPM*Pi*Diameter and then divide by 12 to convert from inches to feet.

Pi D being the circumference of the wheel in inches.

So, FPM = (3450*3.14*8)/12

View media item 58241
Check my math too!

 

[torqueman2002]

Hello, I purchased a old Cman block grinder recently for $60. These are pretty hard to find in my area and this 1/3 HP grinder was what I was looking for. It's a 397.19511 . Can anyone tell me what year it is? I think it's a oldie but not sure - no date stamp on the bottom. Also, what is that color - it's gold and redish brown? Thanks for you help. - Jim

Jim, nice find on the pre-Block.

I restored one like it. If you want to see what I did, follow this link.
Note: There is a fragile internal switch mounted on the RH housing.
http://www.garagejournal.com/forum/showthread.php?t=107194

Also, there are a lot of links and resources in the 1st link of my signature.

This link will take you to the page with colors.
http://www.garagejournal.com/forum/showthread.php?p=4000528#post4000528

 

[s14brent]

just came home with this 1/2 hp 397.19340 (could barely get the # off the label!). I got an extra lamp shade from the guy so I replaced the cracked one on my other 1/2 hp commercial grinder immediately!! He even threw in some other model cm eye shields that need some dire clean up. super nice older guy with an amazing garage. wish I could have taken some photos there.

 

[JZiggy]

Great find! It looks to be in very nice shape. I love that style of eye shield as well.

Looks like all it needs are some bumper feet

 

[Reversepolarity]

Nice

 

[Outlawmws]

Hello, I purchased a old Cman block grinder recently for $60. These are pretty hard to find in my area and this 1/3 HP grinder was what I was looking for. It's a 397.19511 . Can anyone tell me what year it is? I think it's a oldie but not sure - no date stamp on the bottom. Also, what is that color - it's gold and redish brown? Thanks for you help. - Jim

Jim, roughly 60's with the crown emblem.

 

[Outlawmws]

Formula to get surface feet per minute on a grinding wheel:

- Rotational speed in rpm
- Wheel diameter in inches
- Output speed in feet per minute

FPM = 0.2618*RPM*Diameter

(Someone check my math!)

I do FPM = RPM*Pi*Diameter and then divide by 12 to convert from inches to feet.

Pi D being the circumference of the wheel in inches.

So, FPM = (3450*3.14*8)/12

View media item 58241
Check my math too!

Both formulas are correct.

 

[RHJO51]

Jim, nice find on the pre-Block.

I restored one like it. If you want to see what I did, follow this link.
Note: There is a fragile internal switch mounted on the RH housing.
http://www.garagejournal.com/forum/showthread.php?t=107194

Also, there are a lot of links and resources in the 1st link of my signature.

This link will take you to the page with colors.
http://www.garagejournal.com/forum/showthread.php?p=4000528#post4000528

Very helpful, thank you!

 

[RHJO51]

Jim, roughly 60's with the crown emblem.

Good to know. - Thanks!

 

[torqueman2002]

Very helpful, thank you!

That's good to hear.

You are most welcome.

 

[bagged89s10]

I just want to thank JZiggy for helping me with editing a label file for my 1HP block. Hopefully I will have it restored this spring.

 

[Ridjobradi]

I found a 1/2 hp block for $50, while traveling to Portland. I am at the UPS store now, having the grinder and the now separate stand boxed to take home as checked luggage.

I will be ordering new shields and looking for a new sticker.

 

[torqueman2002]

I found a 1/2 hp block for $50, while traveling to Portland. I am at the UPS store now, having the grinder and the now separate stand boxed to take home as checked luggage.

I will be ordering new shields and looking for a new sticker.

Welcome to GJ and to the Block thread.

Good find!

Check the link in my signature line for more resources, including a non-OEM replacement for the power switch.

 

[Ridjobradi]

Thank you for the welcome. I look forward to using the resources you and others have posted.

 

[McBrownie]

I found a 1/2 hp block for $50, while traveling to Portland. I am at the UPS store now, having the grinder and the now separate stand boxed to take home as checked luggage.

I will be ordering new shields and looking for a new sticker.

Nice grinder and stand. $50, even with packaging, is a good deal. Congratulations and welcome to the block grinder community.

 

[Ridjobradi]

It was a close call for the checked baggage. It was almost too big, 58 pounds with the stand. I fly often, so I can check up to 75 with no fee.

 

[CalsXS2]

So has anyone gotten anywhere on the modified lamp shade.

I grabbed an old drop light at the fle market today for $1.

It's pretty close to the one on amazon.

This one measures roughly 3-1/2'' x 6-1/2''. With a grip range of roughly 1-1/4'' - 1-1/2''.

Think I'm in the ball park. Anyone care to measure their plastic cover.

What's the diameter of the socket where the clamp goes.

Sure wished I had my grinder. Only one month to go,,,lol.

 

[drivesitfar]

CAL: while the other members are out i can say there are many examples of members using desk lamps to either replace or add a lamp to their block in this thread. i know it's a long read and i wouldn't want to have to re read it again to find something, but you might learn more about these amazing little grinders.

i think DaveF made a lamp shade with a metal worklight, but i can't recall if he bought a plastic cover for it.

hope your 3/4 block runs smooth and doesn't take too much work, but it is 50 years old so will probably need something i'm guessing.


RB: what part of the US do you live at? if you are in Seattle i live 5 minutes from Seatac and have been known to drop off some cool things to guys waiting for a plane there.

i remember when 75 pounds used to be the limit and even before that when they really didn't weigh them much. if they could lift it then it flew. i'd have an issue traveling now trying to get my set of golf clubs and full bag on the plane with a 50 pound limit so i guess the new ship stix might be the answer.

congrats on your purchase and post up some pictures if you have any. also in case you didn't know there are a few members on this thread that might be able to change bearings and restore a block in their sleep. so ask if you might have a question, but the thread is a good read and has a TON of information not only about grinders, but a lot of other things sort of related like safety and buffers and such.

 

[Ridjobradi]

I live in Houston, but I was in Redmond for 2 days, San Francisco for 1, then Portland for 2 days. I was searching craigslist in each location.

I have been through the entire thread at least once. I found the thread because I wanted a vintage grinder to go with my other tools. Most of my equipment is pretty WWII and wanted a made in USA grinder.

I would prefer a pretty block, but I am happy with my find, especially since I found it with the lamp, quench tray and stand.

 

[jakemac]

Getting one step closer.
So here's the progression. A few years ago I picked up my first block grinder. An 8" 1hp with issues, but still usable if pampered (the same model as JZiggy's). A month ago I finally got around to opening up the bottom to look inside. Today, I was able to get the start capacitor out so I could get the numbers off it. Of course, it's discontinued due to gov't regulations, but with a little homework on Searspartsdirect, ereplacementparts, Google, and Zoro.com I was able to come up with the authorized substitution. I ordered a new one through Zoro and with shipping and tax the damage was $12.45. It will take about a week to get here. Who knows, in another year I may get around to stripping the nasty paint off and repainting.

Well, that was a waste of time.
I finally got to replace the start cap tonight and the grinder is still having the same start up issues. Makes lots of buzz/grind noise when you turn it on, but is fine when it gets up to running speed. If I don't give the wheels a spin to get it going, it will pop the breaker before it gets rolling on its own.

Guess I'm back to scratching my head.

 

[exmaxima1]

Well, that was a waste of time.
I finally got to replace the start cap tonight and the grinder is still having the same start up issues. Makes lots of buzz/grind noise when you turn it on, but is fine when it gets up to running speed. If I don't give the wheels a spin to get it going, it will pop the breaker before it gets rolling on its own.

Guess I'm back to scratching my head.

Try checking the start winding for continuity. It is very common for a stray lead to break from vibration, and I've soldered a number of them. If the winding is good, you can try checking the voltage across it when you turn it on---simply flip the grinder on its side, open the bottom plate and attach your meter leads to the windings right at the relay. At startup, you should have voltage and current going to both the start and run windings.

 

[G20-Budo]

Well this isn't a block grinder, but it looks like an OLD Craftsman.

http://stlouis.craigslist.org/tls/5438969581.html

 

[exmaxima1]

Well this isn't a block grinder, but it looks like an OLD Craftsman.

http://stlouis.craigslist.org/tls/5438969581.html

Sounds like it needs a new start capacitor, but I'd absolutely take it for $10