View Full Version : Tool Grinder

10-28-2012, 08:50 PM
Got this recently in exchange for some machine repair work.
Did'nt realize it would turn out to be as much of a project as it is.
As I got it, there was no water trays & no water cup, and the wheels are toast
but the rest of it seemed to be there.

Cant find a name or label anywhere on it.
I searched all over to compare to look of the motor housing and other
details to try to figure out the make to no avail.

See the cast iron ends & how they terminate to large raised areas
towards the center where the 1/4"-20 bolts connect the 3 piece
motor housing together.

Does anyone recognize that construction detail as a clue
to the maker?

This machine has NO aluminum, and NO metric fasteners, it has cast
iron tables, trunions,and wheel back plate although the plate
may be steel I'm not sure.

10-28-2012, 09:11 PM
Since there is no name plate or specs on it I have no way to know
the motor RPM among other things.

The bearings squeel so they need to be replaced.
The bearing # is 99504 but again no makers
mark on the bearings.

Not quite sure how to remove the bearings as they sit deep
in a recess.
This stack of parts gets removed to be able to see the bearing
on the left end.
The right end is a little different, fewer parts and a sort of split
spring washer/spacer.
Someone obviously painted the machine even in places where
they should'nt have, which I removed with a wire wheel.
This is the casting that forms the wheel guard/trunion mount etc...
you can see the two small wide stubby pins that the trunion rides
in that were fully painted as were the surrounding flat surfaces.

10-28-2012, 09:15 PM
Your grinder has a lot of similarity to the HF grinder I have. You might take a look at these 5 videos of a rebuild of the HF grinder to see if yours can be further disassembled the same way:


10-28-2012, 09:26 PM
Hi Gary,
I've seen the videos and while they shed some light on HF machine,
mine is a completely different beast, much heavier built.
Thanks for the response though.

10-28-2012, 09:58 PM
It is a good chance that it is a Baldor as they are a major manufacturer of grinders and have been for years. Here is one of their pedestal grinders from the 40's with the same construction, which is typical for the period;


It is probably 3600RPM, any good bearing house can match up the bearings for you.

10-28-2012, 10:09 PM
Thanks Jim,
I think you've got it pegged!

Dr Stan
10-28-2012, 10:11 PM
It is a good chance that it is a Baldor as they are a major manufacturer of grinders and have been for years. Here is one of their pedestal grinders from the 40's with the same construction, which is typical for the period

Baldor is also my call. Excellent grinders.

10-28-2012, 10:13 PM
Possible match for your bearing here:


Look about a third of the way down the page, in the "ND" column. It cross references to 6204-2RS, a pretty garden variety motor bearing. That page gives dimensions, see how they match up with what you have.
Looks like a fun project.

10-28-2012, 10:37 PM
Hi Alan,
Thanks for the link.

I see your in Dracut, I'm in Lowell which as you know is just one
town away.
I was born in Dracut in 1960 and lived there for my first nine years and
then the family moved to Lowell. I've been stuck here ever since.

Perhaps we could get together sometime for a shop visit.

12-02-2012, 08:21 PM
Was busy with other things, but now back to this project.
Got the bearings at the local eastern bearing in Billerica Ma.

Made 4 shouldered bushings with counter sunk holes in the large end
to receive the rounded off ends of threaded rod to act as pushers
so I could push off an end bell.

12-02-2012, 08:58 PM
The bushings and threaded rods worked nice and the end bell came off easy.
A cheapo 3 jaw puller and a little light tapping with a hammer persuaded
the bearing & spacer to come off next.

The shot above shows the opposite end of the motor shaft.
Notice just past the inside of the bearing you can see a felt washer
and then the inner steel plate with 4 theaded holes.

The next shot shows a stack of 7 parts.
right to left...inner steel plate W/threaded holes....felt washer.....
....bearing....spring washer(large end against bearing outer race so that it wont spin).....
....thin( 0.031")spacer washer with depressed center section to house felt washer.......
....felt washer....and outer steel plate w/through holes for the round head machine screws.

Now notice that there is NO thin inner spacer w/depressed center to house
the inner felt.
It seems as though upon assembly, that the felt would just squish as the screws are drawn
up tight pulling the inner steel plate against it.

This shot shows the mock up of the stack next to its relative position
along the shaft.

12-02-2012, 09:00 PM
oops forgot the pic of the 7 parts.

12-02-2012, 09:18 PM
It just seems like there should be one of those depressed washers
at the inner end.
Anyone agree or disagree??

I would like to get this figured out before I press the bearings on!

Also after having removed the bearings and the spacer/sleeves, I decided
to mount the shaft between centers to check runout at the shoulder
face where the inner bearing race /face seats against.

I found about 0.001" axial runout using a 0.0005" indicator on one end and
somewhat less on the other end.
I thought that this would multiply alot by the time it got out to
the 6" steel plates.
So I honed a HSS tool and turned just a smidge off the shoulders
and got the runout to a couple tenths.

12-10-2012, 08:23 PM
I called Baldor. I introduced myself, and began to explain that I have one of their
old 6" tool grinders and I am looking for.....woman interupts...
...where are you calling from sir?...says the woman on the other end of the phone.
Lowell Ma. I responded.......silence.......then I get transfered to someone in
my state.....another woman says hello...

So I start all over again and explain that I'm lookin for info on the grinder
as the name plate is not on the motor...
....Baldor...part number please...
uhm...you dont seem to understand...I dont have the name plate or model
number, so I am trying to get that info from you...
Baldor...model mumber please....

Do you have a parts dept that I could talk to?
Maybe some old timer that would be familiar with baldor tool grinders?
I was hoping that a major long standing AMERICAN company like baldor
would be able to help me out.
You know good old customer service.

I'm looking for a parts manual and possibly parts for my machine.
....Baldor.... spec number please....we handle everything from
here...model or spec number please...........................

So as you can see Baldor was no help at all, didn't even want to try.
What a drag.
So down cellar to the home shop I go.

I decide to see if I could make one of those depressed cup washers.
Measured the thickness of the original at 0.032"
Scrounging around, I found a piece of 0.032" stainless that I canabalized
from a junk wood planer platen.

Used a pair of aviation snips to hack off a chunk larger than needed,
and hammered flat.
Then cut close to a traced O.D. layout line using my die filer with a hack saw
blade mounted to get a workable blank disk.

Loaded the blank in the 4 jaw in the lathe to drill & bore to 1.120"
lop off a 1 5/8" length of 3" solid round 6061 alum at the horizontal band saw
Load the 6061 in the 4 jaw & turn these features
To match the original part shape so I can use it as a male press die,..which by the way is something that Iv'e never done before...use or make press dies that is....

More next post

12-10-2012, 08:35 PM
Then of coarse I need to make the female die

The two dies and the bored blank ready to press

I used my cheap cummmins hydraulic 10 ton press to press the part between the two dies
& forgot to take a pic of that sorry.

Here is what I ended up with.

Not too bad I think.
Now just need to drill the 4 screw holes.

12-10-2012, 08:38 PM
Still, the funny thing is....after having made that part.....I still can't confirm
if the part should go in the machine or not.

12-10-2012, 08:40 PM
Nice work. Thanks for posting such clear steps

12-25-2012, 09:14 AM
I had to do a little digging, but here's the name plate on mine:

http://bp1.blogger.com/_PMdIQ1bpCSc/RjntdWj59-I/AAAAAAAAAUI/YgbhKAtEccw/s400/i.jpgRestoration Pics (http://prowave.blogspot.com/2007/05/baldor-500-grinder.html)

12-25-2012, 10:54 AM
Great Job! Just an FYI I have an older grinder that needed bearings and I tapped the end of one of the shafts to get the motor housing apart. It came apart easily after the "seal" of 50 years of whatever was broken. The spring washer is in there to take endplay out and on mine I had to cut a pvc bushing to get it just right. I beleive the new bearings were a bit smaller......in the end it worked out wonderfully as the grinder runs so much smoother than anything you get today. I really enjoy reading the threads on old machine tools getting rebuilt and brought up to spec, in the end you have something really worth owning as the machines were built to incredibly high standards :)