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Big dumb pedestal grinder

Andrew S

Member
Joined
Jun 11, 2020
Member Number
1963
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16
Ok, new guy here, and I tried to find the "big dumb pedestal grinder" thread that was hyped last week on IG. By the time I got here, the site was down, and seems to have lost a few days worth of entries.
Anyway... I also have one of those big dumb Cincinnati pedestal grinders in the project queue. So I'd love to see the thread resurrected, and figure out what the best plan moving forward with this thing will be.

Andrew
 
Thank you Gots_a_sol - twas me!

The thread was lost in the site crash and I just haven't gotten around to starting it back. Sucks too because vetteboy79 had dumped some serious tech in there about wiring as delta vs wye and ending up at 215V 50hz, then running a VFD. Would lose some RPM but with fresh big wheels, it may not matter that much on these big beasts.

@[486] mentioned to use a transformer to step up from 220V 1φ to 440 1φ and then wire up a capacitor with the start button to make the motor run as its own version of a Rotary Phase Converter

My alternate plan, if this motor core can't be made to work, would be to pick up an Inverter rated 3φ motor and then make new shaft support plates that also adapt the current shaft arbor assemblies and connect to the motor shaft ends where they are supported in the housing. Theres even a chance that the support couplers are also carriers for the motor shaft in the end cap housings. Would certainly be some machine work but it would salvage a very cool old grinder that has some family history in my case.

Here is a more recent picture I took while I was tearing down my Cinci mill the other day. The Bridgeport mill and GPW grill behind it for scale.

20221218_174803.jpg
 
that's the largest grinder I've ever seen. :eek:

what the hell you putting in there. god damn
 
Andrew S said:
Sure looks familiar:


Mine is 220 3-phase, I had planned to hide a VFD inside the column.
Click to expand...
They are pretty much identical, and I am jealous that you have the tool plate and cooling cup for yours still! I was wondering what the tabs on the sides of the column were for and also thought maybe the two holes at the bottom were done after the fact but yours has the same ones.

I mean, they are damn identical otherwise, so makes me wonder if mine might have leads inside I can get to and it is actually a dual wound motor.. maybe? These things are so big and dumb, that its just awesome.

Here is the tag on mine. Yours is straight up branded as a Cincinnati, and strange enough, I never really noticed before that mine is "Div. Cincinnati Elec Tool Co." This is gonna lead to some digging. If the SNs are related, yours is notably older.


0929181811.jpg


woods said:
that's the largest grinder I've ever seen. :eek:

what the hell you putting in there. god damn
Click to expand...

A bucket of impatience because a whole lot of metal is gonna move really damn quick. Honestly though, anything big that needs a good re-grind. I have a lot of big ass Morse taper drills (talking 1-1/2" to 2-1/2") that are beat to shit and need some good reashaping before they go into the Sterling drill grinder for final sharpening work, so I figure I can use this to get things close and then go from there on the Sterling.

I picked up a vintage Calder brand dresser for this thing a while back too, brand new in the box and it is also to scale of the machine. I'll snap a picture of that.
 
Mine came from the scrap pile at work. Way too cool to get turned into a Kia, so I drug it home. Also way too big to be practical, but I don't think I need any justification around here!
I test ran it before loading it up, and there are three leads that exit down into the column. Bearings sounded fine, hopefully they won't need replacement. I also assumed the two-hole pattern was a later modification until I saw yours.
Vintagemachinery.org has some Cincinnati Electric sales catalogs, based on the photos I figure mine was built in early 1950s.
I'd be happy to trace/dimension the tool plate and cup if you want to recreate something similar.
 
woods said:
that's the largest grinder I've ever seen. :eek:

what the hell you putting in there. god damn
Click to expand...
You need to get out more.

I thought Jason @ Fireball had a video specifically about this one, but I can only find it in a shop tour vid. Cool thing here too is that one off to the left was made by Black & Decker back when they actually made real tools.
1671569358899.png




Or this big bitch
1671569502643.png
 
AlxJ64 said:
The thread was lost in the site crash and I just haven't gotten around to starting it back. Sucks too because @vetteboy79 had dumped some serious tech in there about wiring as delta vs wye and ending up at 215V 50hz, then running a VFD. Would lose some RPM but with fresh big wheels, it may not matter that much on these big beasts.
Click to expand...

Did you understand enough of that to get the basics of it? Really would rather not type all that again :laughing: I figured that'd potentially be a way you could experiment using stuff you've already got laying around to see if it'd be worth repowering or not.
 
I didn't know these things existed. Seriously cool stuff
 
Still think a VFD through a transformer would be fine.
 
D Nelly said:
I didn't know these things existed. Seriously cool stuff
Click to expand...
I've seen them out there for sale through the years, a buddy of mine owns a big 220V one that's old school. Me personally, I just don't see the need for something like that in my shop. Takes up waaaaay too much room to just grind on a piece of metal other smaller tools will do imo.

They are cool tho and while I have the urge to pick one up, I know it's just not practical, but a badass tool to own tho.

I have something in my shop now that big and dumb like those grinders but mine is a huge ass 2HP 3 phase belt grinder. Now that mofo is badass and if given the chance, would grind a finger to the bone in less than a nano second too. I just power it up on my rotary phase convertor when I use it
 
D Nelly said:
I didn't know these things existed. Seriously cool stuff
Click to expand...
they're generally billed as "snagging grinders"

snags were the hard disposable guys doing the initial grinding on castings

Big 'kill you quick' type of machines:
machinehub.com

SETCO 925-525 - Grinders, Snagging

Used machine for sale - SETCO - Grinders, Snagging - SETCO 925-525 MODEL 300 SINGLE END LEFT HAND SNAG GRINDER WITH 25 HP MOTOR, STARTER AND DOUBLE PALM BUTTONS
machinehub.com machinehub.com
 
I'll throw in my Cincinatti Pedestal Buffer in this thread since I only posted it at the old place.

Only a 1/2 horse motor but it doesn't stall with 8"x1" cotton buffs on it. Which is all I need. I run it at half speed (1750) and it chugs along just fine. Converted from 3 phase with a VFD.
The really wide throat is nice for the work I do on repro 16th century armour.

1671991496344.jpeg
 
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