1966 Brown & Sharpe 618 Micromaster spindle repair (pic heavy)

[Janderso]

If you are interested in this project, I will post pics along the way. What a beautifully made machine!
I noticed a bearing noise the other day, I assumed it was the drive motor bearings. I removed the motor, spun the spindle, yikes. It’s the spindle bearings. I measured .0002” at the taper when I spun it by hand. When I lifted up on the taper it read .003”=too much!! It has to be repaired or scrapped. I can’t do it.
I’m tearing into it. I’ve pretty much decided to send in the spindle unit to have it rebuilt. They guarantee it to be, “as new” when I get it back.
The price is over $3,000. I think this machine is worth it.
Stay tuned.
Jeff

 

[benmychree]

Good move to send it away for rebuilding, trying to DIY could result in damage and inaccuracy. I would never attempt it, and how many of us have the necessary clean room, nor access to the proper lubricants, and necessary special tools.

 

[Richard King 2]

I have and would do it. But I'm special. LOL Does your head have those spring loaded adjustment under that are under the plugs on the head-stock hold downs? Be sure you get a written Guarantee from the rebuilder.

 

[Janderso]

I have and would do it. But I'm special. LOL Does your head have those spring loaded adjustment under that are under the plugs on the head-stock hold downs? Be sure you get a written Guarantee from the rebuilder.

Spring loaded plugs on the hold downs, hmm, not sure what you mean.
Today I’ll pull the pulley off the back of the spindle, from there I think there are just the four bolts and the unit comes forward.
And yes, Richard, if I were you I would rebuild it myself

 

[Janderso]

Good move to send it away for rebuilding, trying to DIY could result in damage and inaccuracy. I would never attempt it, and how many of us have the necessary clean room, nor access to the proper lubricants, and necessary special tools.

Not only a clean room but handling the bearings and getting the proper orientation, the right amount of grease, the run in, it has to be done right.
I don’t have any experience with spindles.

 

[Richard King 2]

Spring loaded plugs on the hold downs, hmm, not sure what you mean.
Today I’ll pull the pulley off the back of the spindle, from there I think there are just the four bolts and the unit comes forward.
And yes, Richard, if I were you I would rebuild it myself nylong plugs on the hear

On the 3rd picture... the plugs or covers on the inside edge of the hold downs. You leave them off and move the head until the nylon plug (can't remember if it has springs), but there is some sort of adjustment.

 

[Janderso]

On the 3rd picture... the plugs or covers on the inside edge of the hold downs. You leave them off and move the head until the nylon plug (can't remember if it has springs), but there is some sort of adjustment.

I'll check it out. I'm going to clean up the headstock I can take a better look.
Thanks,

 

[Janderso]

On the 3rd picture... the plugs or covers on the inside edge of the hold downs. You leave them off and move the head until the nylon plug (can't remember if it has springs), but there is some sort of adjustment.

I see the plugs, there is nothing in the holes they plug? I didn’t see anything drop when I pulled the side ways off. (See pics of side bracing)
The pulley came off nice and clean.
There are no Bubba marks anywhere. I wonder if this is the first time the spindle and motor have been out of this headstock.

 

[akjeff]

If you'd like a competing bid to compare to, I highly recommend these folks. https://www.cm-spindle.com
They rebuilt the spindle of my Lagun mill, and reground the R8 taper( with the spindle in my quill, not a fixture ), and it turned out perfect. Turn around time was amazing. Really good people.

 

[Janderso]

Talking with Richard King and one of his associates gave me the confidence to do this myself.
It’s really simple.
I have it apart, I’ll clean it up, source the bearings and go from there.

Speaking of bearings.
Made in USA
Size, ID 35mm, OD 62mm, 14mm wide.
ABEC7. MRC107KR-db, LV 93