120 Inch Niles Boring Machine Finally Arrives

Hey, that is great...You are having waaay too much fun there!
Mind it looks a bit cold and wet in one of the pics.
Thanks for posting, great pics.
Real big boys (& girls) toys.
I only get to play with little kitty toys... _{(now where did I put my string and feather?)}
Del

Great stuff! Can I come?

Good inspiration at the time of recession

Nice pics.

Your work schedule is diffidently laid out for you

p911

What a lot of great toys to play with. I wish I could be there. It's great that you have rescued all those wonderful machines. Where did the Niles come from? shipyard, railroad facility?

Now I know where my magnetic drill went. I may just have to come up there for a couple of weeks to negotiate it's safe return.

Note worn, circular way that the table rotates on. It has worn two concentric ridges. We are contemplating installing 980 1/2 inch by two inch long hardened dowl pins in this depression in order to rebuild the way.

Hi,

great work! Magnificent post.

I would suggest to not use pins as the available area is small and to position to exact depth is nearly impossible. So extra grinding and some polishing will be necessary.

First of actions: rework by turning, milling or grinding the worn surface to sufficient flatness and squareness (wanted axis location with respect to perpendicularity to other slides).

To achieve this, fix a hand grinder (good quality preferred) to the inner bearing (where the pneumatic tool is shown in the pic), turn by hand and grind the surface to a good level.

Then decide to use either bronze pads or phenolic pads or turcite or Moglice.

Bronze pads to be screwed in place phenolic or Turcite to be glued, Moglice to be cast.

All these are much better than hardened pins on cast iron.

The problem with hardened pins - if all in one plane and slightly polished - will be that the lubricant will be quickly driven out of the contact-zone.

Any more questions and comments on "how to" appreciated.

RHABE

Do you believe the rim was designed as a load bearing surface?

Or is it wear of or lack of proper adjustment of the shaft bearings which has allowed the rim to be scored?

Hi,

I am sure that the rim supported the axial load,

this is necessary at a large diameter as the workpieces on the big horizontal table are often put down with excentricity or unbalance, and static weight is large with these workpieces.

I assisted once repair of a similar machine.

The shaft-bearing is only to support against radial load from the driving gear and from radial cutting-forces. (Else a long and thick shaft with 2 bearings would be necessary).

RHABE

Else a long and thick shaft with 2 bearings would be necessary

am I not seeing that which you have described? Being as this is proportionately a 120" swing the shaft is of considerable girth. These machines did have a very slow rotation and though the pieces machined upon them were of great weight and often seemingly off balance this is overcome axially.

In operation it was deemed beneficial when possible to add counter weight.

There is not provision for lubrication of this surface, there should be a wiper to prevent debris from gathering under the table though.

"m I not seeing that which you have described?"

You are right, I overlooked the lower radial bearing - maybe not expecting there another bearing as this is not a good solution.

"There is not provision for lubrication of this surface, there should be a wiper to prevent debris from gathering under the table though."

Maybe the company was not aiming at long life, maybe somebody removed the wiper or seal. The wear of the axial bearing is really heavy, this is not by usual usage.

Counter weight: naturally, everybody will try, but only coarse balance will be achieved, not necessary to do better.

The size of the shaft is ok, but the lower radial bearing is spoiling the quality as with 3 bearings these should be oriented to each other with ultraprecision.

(only Moore was able to do this, look at their still existing measurement machines or jig-grinders - beautiful work but replaced by cheaper constructions with airbearings or fluid-bearings). Look at the book "Foundations of mechanical accuracy" - fantastic to know and choose what to do.

So with the direction of the two radial bearings not matching the vertical to the axial bearing there will be huge internal forces by misalignment and early failure or unacceptable distortion of machine and early wear of bearings and gear.

The 8 slots in the shaft maybe intended to make the shaft flexible so that the lower radial bearing is tolerated up to some radial position error. But I assume that this flexibilisation is not at all enough.

Without knowledge about the parts attached to the lower end I cannot decide if to remove the lower bearing or make the shaft more compliant or adjust the location of the lower bearing or the tilt of the axial bearing.

RHABE

The rim doesn't support anything

Where is in your thoughts the axial bearing located?

You have to support tons of weight plus considerable cutting forces.

I would bet it is the rim that was used as axial bearing. Else it would not bben worn out in this severe manner.

RHABE

There is a bearing of sorts however it is of the nature of a steady rest rather than what you're considering.

Understand there is a thrust adjustment in the pit at the low end of the spindle shaft to manipulate the clearance at the rim.

Quote from 1891 manual:

Table Bearing. - An annular bearing under the outer edge of the table is provided, and when heavy pieces are to be worked the spindle step in relieved and the table allowed to rest lightly on this outer bearing. Thus adjusted the machine works with all the steadiness of a heavy planer and all the precision of the most accurate lathe

to wit this annular bear was used only for heavy or off balance pieces, otherwise the spindle step thrust mechanism would lift the table off the annular bearing. This annular bearing is of a pad type as in a steady rest which is all this feature is intended to be.

It is what Niles calls a step actually we know as a thrust bearing. So we have (1) a thrust bearing at the bottom of the pit with a mechanism enabling a table adjustment on the fly from outside the pit, (2) lower and upper bronze spindle bearings. All these components need work together as one or we will have accomplished nil.

A suitable replacement bearing pad material may be Turcite

It is a fine example of a cast shaft eh?

Hello,

This is really cool stuff. You are blessed to be able to follow your dream. Do it as long as you can afford it. I love seeing guys and girls working together on old machinery. It is really, really awesome.

Keep up the good work, it is inspiring. Newer is not always better and neither is older, older is normally a little cheaper up front, making it possible to do cool stuff but newer machines are normally more efficient----and green. I bought an old T-Lathe at auction it was huge and very useful for skiving material for a job I had to do.

A Berkely CA company bought up, every old T-lathe and O.D. Grinder in the area and added cnc controls. They used them to turn lasts for sneaker manufacturers. Imagine a post stuck to the toe and heel of your shoe. Now take that and mount it between centers on a lathe or I.D. Grinder. That would be the finished product from the lathe or grinder controlled by the cnc. It is amazing to see what innovative - smart people can do with scrapped machinery. By the way the cost of the refurbished machines was in the $250K realm.

Bye for now.