DIYbanter - View Single Post - FA: Dumore Tool Post Grinder Inserts, K.O. Lee Index Disc and other metalworking items on Ebay

In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:

According to Joseph Gwinn :

Series 11? I inherited a Series 11 from my maternal grandfather, long
before I had any idea what a toolpost grinder was. I pulled it out of
dusty neglect and ran it, but the spindle bearings don't feel right,
and
heat up if the unit is run. The motor is in perfect condition.

Interesting -- one of the bearings in my *motor* feels lumpy,
but the spindle bearings are in great shape.

I bet replacing a motor bearing is easier than a spindle bearing.

Yep! As long as I can find the proper replacement. These are
wider than I would have expected for the diameter. I'll have to dig out
the number from one and see what I can find to match.

I doubt that Dumore makes their own bearings. Actually, theyt may still
use the same bearings, or will know where they got them.

I'd like to take the spindle apart and see if I
can fix it. If spare parts are available.

Not from Dumore, at least. Same for the manuals.

I'm hoping that they used standard bearings.

Perhaps -- but no bets there. Especially in the spindle.

If it's a ball/needle bearing, they probably buy them from one of the
usual suspects. Ball/needle bearing manufacture is very specialized.

Are the screw threads normal (right-handed) or reverse (left-handed)?

I don't know. I never have felt the need to pull those caps
off, since my spindle runs smoothly at present.

OK. I'll have to fiddle a bit, will assume right-hand at first.

I bet that this has not changed, so these spindle caps will work the
same way on current models.

Do you have the wrench for holding the pulleys still while you
undo the nuts securing them? I'm going to have to make one. I just
made a wheel guard for mine for the larger wheels (if I can ever get the
nut off the smaller pulley on the spindle to swap them for slower speeds
for the larger wheels).

I don't think so; I'll have to look again. The belts are flat and the
pulleys are smooth and crowned, and a steel-jawed wrench would chew the
pulleys up I would think. Unless there are holes in the pulley disks to
admit the pins of a spanner.

I expect the wrench to be something like the one for zeroing a
micrometer -- a quarter circle or so, with a spur to go into the slot in
the hub which engages the flat on the spindle.

I just looked at the unit. I think it would be hard to keep a
quarter-circle spanner on that. I would guess that a piece of thick
sheet metal with two teeth coming in 180 degrees apart would work better.

I bet people just grabbed the bigger pulleys by hand, or used a strap
wrench on the crown.

The larger pulley came off nicely with just that -- a hand grip.

The smaller one (on the spindle) is too tight.

I was able to get both pulleys off without difficulty, although the
smaller didn't want to slide on the shaft after the nut was removed.
What worked was a set of Jacobs JT1 wedges applied by hand. This
started the pulley sliding, breaking the gummed oil bond loose. Solvent
would also help.

I think that I'll have to make a collet style clamp for the OD
to hold it unless I can make a working hook wrench as above.

Or, bore a hole the same size as the pulley in a piece of hardwood, saw
into two halves, and use the pieces in a vice to firmly grip the pulley,
and have at the nut with a socket wrench.

I've used this trick to disassemble an old B&S micrometer, using two
oaken clamps on the knurls.

Are the pulley nuts right-hand, or left-hand?

The one on the motor is for sure right-handed. The spindle
*looks* right-handed from what I can see of the threads, but until I get
it off, I can't be sure. If you can get the nut off your spindle end
pulley, you could tell *me* which hand it is. (Which side has your
smaller pulley -- the spindle or the motor?)

It turns out that they are both right hand.

My unit is set up the same way, with big pulley on motor and small
pulley on spindle. If the motor turns at 5000 RPM, the spindle will
turn (2.165/0.906)= 2.39 times faster, or 11,948 rpm.

I also need to make the adaptors for mounted stones for inside
grinding. I *think* that the thread on the business end of the spindle
is 1/4-32, and have just ordered some taps and a die for making things
to fit -- and for cleaning up the threads on my spindle.

There appear to be three lube points for the spindle -- one with
the flip-top lid near the center, and two with felt plugs under hollow
screws near the ends -- probably for small needle roller bearing cages.

I found three as well, and filled them all with oil.

Good -- a light spindle oil, I hope.

Well, ordinary motor oil. 10W-30? What grade is light spindle oil?

The bearings in the motor are sealed, and I think that I'll need
to replace one -- the one at the pulley end.

On mine, the bearings are not equally toasted, but I'll replace both if
I can.

The one on the free end of the motor is in very good condition,
absolutely free motion. But, I'll probably [buy] at least buy two bearings so
I have the option of replacing it at need.

Good idea.

Joe Gwinn

Good Luck,
DoN.

I wish luck were not required, but Thanks.

And the same to you.

Enjoy,
DoN.