Tool Talk

Classic Power Tools => Classic Power Tools => Topic started by: OilyRascal on January 01, 2013, 04:42:41 PM

Title: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: OilyRascal on January 01, 2013, 04:42:41 PM
I've been looking for a good deal on an older pedestal grinder.  I ran across this advert. today on Craigs.  New one on me, and thought I'd share for discussion.

"1/2 hp 4 amps 3450 rpm
Shows wear grandfather owned it came to me I guarantee they
don't make them like this anymore.
These are not easy to come by.
Price is firm and worth every penny."

http://columbus.craigslist.org/tls/3511486996.html
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: rusty on January 01, 2013, 05:07:54 PM
I have one exactly like it, except it says Sears on it....

The tool rests are missing...

Good solid machine :)

Edit: I lied, the sears one is under the bench, See below...
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: skipskip on January 01, 2013, 07:18:42 PM
I think this is Chinese from the wagon peddler, but I'm not certain.

Skip
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: OilyRascal on January 01, 2013, 08:21:59 PM
I think this is Chinese from the wagon peddler, but I'm not certain.

Skip

I didn't follow you.
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: scottg on January 02, 2013, 11:23:41 AM
6" grinders are mostly for homeowner sharpening shears and other very light duty.
There are some heavy 6's out there, but this isn't one. 
I want an 8" minimum and 10 is better.

 I too think this is a recent Chinese grinder. I have an 8" that looks just like it. Different name, but the construction is identical.
 Lately the Cummins name has been drug though the worst kind of mud. Peddlers selling considerably lower quality goods than Harbor Freight, are seen traveling the backroads of America setting up for a day at every crossroad.  Usually they pre advance their coming with sales fliers in every mailbox in town. Cummins is one of the favored brand names they use.

The classic Craigslist story isn't always total bullshit. Often they can say it with a straight face.
 Sometimes grandpa lived a --very-- long time and bough some piece of crap just before he died,......... last week! 
   yours Scott
 PS Shopping for a grinder? The distance between the wheels sets the price,......... every, single, time!  Close set wheels like this? ICK
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: rusty on January 02, 2013, 04:52:57 PM
The original design.....
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: OilyRascal on January 03, 2013, 07:16:10 AM
I appreciate the information & perspective.  I wasn't seriously considering this one rather interested in the discussion, but appreciate the background information nonetheless.

Had always gauged the durability/stoutness/desirableness of one by it's a) HP and b) duty rating.  I'm curious how the wheel size comes into the quality equation.

I'm also now very curious about distance between the wheels.  What is the significance here, motor size/rating?
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: Ietech on January 03, 2013, 11:30:59 AM
I appreciate the information & perspective.  I wasn't seriously considering this one rather interested in the discussion, but appreciate the background information nonetheless.

Had always gauged the durability/stoutness/desirableness of one by it's a) HP and b) duty rating.  I'm curious how the wheel size comes into the quality equation.

I'm also now very curious about distance between the wheels.  What is the significance here, motor size/rating?

The big difference in the wheel diameter is SFM (surface feet per minute).  The larger wheels at the same RPM have much more SFM. As the wheel wears down the SFM is reduced but the RPM will be exactly the same.

 I might also mention that on the larger grinders the wheels are generally wider. Wheel Spacing (as was mentioned before) is a very important aspect. Wider spacing gives distance from the motor on each side which allows you to grind or brush large or odd shaped items. Close wheels are generally a PITA.

Above all "Don't Forget Grinder SAFETY and proper use" a bad wheel will eat your lunch. The bigger the wheel the more lunch it will have.
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: keykeeper on January 03, 2013, 03:47:09 PM
Not knowing much about grinders, I found one at a pawn shop a couple years back that intrigued me. A Baldor which is nice and wide, ran good, tool rests intact. They had $54.95 on it. I figured for a used tool that was a little steep, knowing they probably only gave some poor schmuck $10 for it on pawn. I knew Baldor was a good brand, but I passed....

As soon as I got home, I looked it up on the 'net. Same grinder retailed over $300!!!

I rushed back and got it for $50 tax included.

Glad I did. ;)
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: rusty on January 03, 2013, 06:39:00 PM
>"Don't Forget Grinder SAFETY and proper use

**Cough**...uh..yea, don't look too closely at mine -P
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: scottg on January 03, 2013, 07:53:18 PM
A Baldor which is nice and wide,  $50 tax included.

Baldor is the gold standard, especially in the smaller grinders. As good as it gets, generally. Its the grinder we all wish we had. 
 Sears Roebuck also sold a heavy duty grinders in the smaller sizes. Even these were too expensive for me through the years. They are commonly called block grinders since the center motor cover looks like a block. Usually cheaper on the second hand market than Baldor.

   I currently have 3 grinders, and I hate them all!
  I have 3 polishing heads in service and I marginally like these better.
 I do have 2 ball bearing polishing heads in reserve though, and I have hope for those, someday.
  I also have a good sized lap (9") I want to turn into a horizontal disk grinder one day. 
 I am currently short of motors and space. I have belts and pulleys and one motor ready to go, but the bench I use for the polishing heads is already crowded. 

 Oily
 Easy things to look at when grinder shopping.  The distance between the wheels. (Its really about armature strength and bearings, but the distance is the exterior tipoff.)
 Eye guards? A pitiful piece of wimpy plastic barely hanging on? Is not a good sign. 
 Tool rests? paper thin stamped steel strapping is not what you want to see.  Heavy cast iron and sturdy linkage,......... is.
 
  yours Scott
   

 
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: dimwittedmoose51 on January 20, 2013, 06:42:25 AM
All: I got suckered into a Cummins grinder on ebay for like $35 for shipping and all.  The seller swore it was US made.  Poor packaging ended up destroying the on off switch, I whined, and the guy refunded my money(he didn't want it back either....lol).  So, for a 10 dollar switch from the electronics store, I had a grinder that had no US or China marking s  on it.

Within the last month,  it was making some real noise and it was time to take it apart and see what the problem was.  Getting it apart was a trip, having to fabricate a plate with the pattern of the 3 screw holes for the guard so I could use a jaw puller to get each housing off.  Much to my surprise the right side had #10 machine screws holding the guard on while the left side only had #8's.  I repacked the ball bearings with some of the red Mobil 1 synthetic grease and put it all back together.. it's quiet now.  Nothing inside had COO info on it.

I'm still kicking myself for not buying the Baldor(was a new name to me at the time) 6" grinder that was just down the street from us at a yard sale.  The guy wouldn't go down to $30 and I was trying to show my better half that i was using "restraint".  It had a HD frestaning stand too   and was vibration free and quiet as a mouse.....AND really old. 

I saw a fancy Dayton for sale complete with the dust exhaust ports at a farm sale.  The guy wanted $50 for it.....but I looked closely and it was made in Asia as well.   Pass.

A few years ago I bought a Craftsman 8" "Professional" Grinder for like $160.   POC, made in China, and doesn't have any more torque than the Cummins.

So goes my grinder history.......

DM&FS
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: pritch on February 09, 2013, 10:33:38 AM


A few years ago I bought a Craftsman 8" "Professional" Grinder for like $160.   POC, made in China, and doesn't have any more torque than the Cummins.


I probably have that same one. I'm not real happy with it. It is better than the one I got off the cummins truck. That one smoked 10 minutes after I plugged it in.
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: packardv8 on February 10, 2013, 01:26:45 PM
Quote
The classic Craigslist story isn't always total bullshit.

Craigslist is always "buyer beware" because there's no guarantee, no warranty, no returns.   Doesn't matter whether the incorrect description is from an innocent idiot or a guilty crook, result is the same.  It's up to us as buyers to make an informed purchase.  I no longer invest $4-a-gallon diesel fuel unless the photos back up the BS.

 jack vines
Title: Re: Cummins Mack 6 in. Heavy Duty Electric Bench Grinder
Post by: johnsironsanctuary on February 11, 2013, 09:51:39 AM
I have been using a little 1940's 1/4 HP Sears Companion grinder for about 30 years now. I have sharpened mower blades and have ground some fairly big stuff. I am careful not to bog it down. I agree that Baldor is the good stuff in spite of SNL claiming he was from France.