B.F. Barnes 11” thread cutting lathe spindle bearing question

[ArtTech]

Hello all. I have a few questions related to A Barnes Lathe.
The subject has on right side leg casting:
11”
B.F. Barnes CO.
Rockford ILL U.S.A.

I have disassembled the head to repair a worn low gear engagement key.
I am now in process of re shimming bronze bearings (bushing)
I am wondering if someone can give me guidance or a link to the correct procedure to headstock shimming for this lathe. Also any help identifying repair procedures links or info on this particular lathe would be helpful.
From what I gather, the front spindle bearing is done first. Does one shim both sides of the cap equally, or one side only? What are the proper clearances? Radial and axial values for the front bearing at this point are .002” in both directions. Seems free running.
I am now working on the rear bearing (if in fact I have the front bearing correctly set). Is the cap to be shimmed on one side or both sides, or is this a matter of trial and error, to produce free running?
What are the correct clearance values (radial and axial) for the front and rear bearings?
The rear bearing set up on my lathe is:
Towards the front of rear bronze bearing (bushing), there is a hardened steel washer, in front of this a bronze washer, and then the gear which runs the lead screw. Is this the correct orientation for these components? Any help or direction would be appreciated. Alex.

 

[wdTom]

Usually one keeps the shims equal so the cap isn't being bent when shimming bearings. I would guess .001 to .002" bearing clearance to be good. I use a dial indicator and pry bar to check clearance. Keep a check on bearing temperatures when you start it up. At up to 4 or 500 rpm which is about max. for old lathes you should be able to put your hand on the bearings and they shouldn't be more than slightly warm maybe. Make sure of a good oil supply. While maybe not necessary I like drip oilers for plain bearings so they have a steady supply of oil.

 

[Mike C.]

Whatever you do, don't remove the oilers and put grease fittings on the bearings! Have seen many a machine ruined that way.

 

[michiganbuck]

Think if it seems too loose I would 2 x 2 the front and the back to see the move. Reduce shims to shoot for .0035. fire it up and run for 1/2 hour at 300RPM feeling for heat. When warm 2 x 2 lift and indicate again then reduce to make .002
Would take care to tighten the same amount with using a toque wrench.
You might shoot for .0015 both ends and end play warm IMHO.

 

[ArtTech]

Thanks for all the reply's. The B.F. Barnes lathe spindle is back to life, and tighter than ever!! As a follow up question with regards to the oilers, which are a drip type on this lathe, what is the purpose of the felt at the bottom of the oiler holes? Is the felt a filter for oil, or is it a "wick" to control oil supply, or is its purpose entirely different? TIA Alex.

 

[Daniel Silverman]

Hi ArtTech,

I also have an 11" BF Barnes just like yours, but branded as Rockford Economy. I like the look of your safety guards, but I could never drill and tap a new hole in an antique machine.

In answer to your question, the felts are primarily wicks and possibly also wipers to catch contaminants that might be in the spindle bearing.

I have two questions for you, too, or for whoever can answer them- my apologies if this is a thread hijack, but I think it is relevant.

First, neither of our lathes appears to have provisions for adjusting axial spindle play. How were you able to do this? If you shimmed it, where did the shims go?

Second, does your lathe completely lack graduated dials as mine does? How do you get by without them?

Thanks,
Daniel

 

[ArtTech]

Daniel, glad to hear of another similar lathe. I know there were a few variations of the Barnes lathes made in Rockford ILL. On my lathe, to adjust the axial clearance of the spindle, there are two adjustment screws at the split bearing on the rear of the spindle. There is a screw on both the top and lower half of the bushing. If you look at the pics, you can somewhat make out the screws. What I did to adjust the axial clearance was to lightly assemble (after shimming for proper radial clearance) the rear bearing caps. I carefully tensioned the adjustment screws until I could feel minimal resistance (by finger turning) in the thrust washer forward of the bearing. It was a trial and error setting, and once comfortable that all had been adjusted, I tightened the screws holding the caps and ran the spindle for about fifteen minutes, checking for heat buildup or excessive play. After the shimming process, the lathe spindle works great.
As far as a graduated dial, my Barnes has one stationary graduated dial for the cross feed. It is an odd machine as each graduation moves the cross slide .004” on radius (.008” diameter). While using the machine I use a sharpie marker to give a reference for multiple parts. The carriage, compound and tailstock hand wheels have no dials. My work around to the carriage not having a method of measurement was to make a stop using the parts from a extra micrometer I had around. You can see the stop in one of the pics at the beginning of this thread, it was a simple component to make, but using it and gauge blocks has made repeat parts much easier to make.
If your machine has no dials, you may be able to adapt some type of existing dial to your cross feed screw (think creatively) so you can use the cross feed to measure. The other method to measure using the cross feed or carriage is with a dial indicator (btdt). The indicator measurement method can also be used for a higher level of precision.
I outfitted my lathe with a (I think) AXA quick change tool post. This and a few indexable turning and parting tools. I would say having a QC tool system has made this antique a very useful utility.
How many of the change gears do you have with yours? I have yet to acquire the complete set, but continue to look on ebay from time to time.
I am amazed and can appreciate the degree of precision of this “farmers” lathe, built one hundred years age. Arttech

 

[IrbyJones]

Hi ArtTech,

I also have an 11" BF Barnes just like yours, but branded as Rockford Economy. I like the look of your safety guards, but I could never drill and tap a new hole in an antique machine.
<snip>
First, neither of our lathes appears to have provisions for adjusting axial spindle play. How were you able to do this? If you shimmed it, where did the shims go?
<snip>
Thanks,
Daniel

Daniel,

I think the 11" headstock is similar to the 13" headstock that I have. The rear brass (or bronze) bearing is threaded into the rear of the headstock. It has a big nut on the outer end of it that locks it into the headstock. The spindle axial play is adjusted by loosening the big nut, and turning the bearing by the hex portion that sticks out the back to move the bearing in/out to set the axial play. Then without turning the bearing, tighten the big nut to lock the adjustment.

The headstock on ArtTech's lathe has been heavily modified, so it has a different axial play adjustment.

Irby

 

[Daniel Silverman]

Dear Irby and Alex,

Thank you both very much for your input. I greatly appreciate the information and help you've given.

Irby, my headstock is more like Alex's than what you've described. I think you might have a WF and John Barnes, whereas we have BF Barnes lathes. I'm not aware that BF Barnes ever made a 13" lathe.

Alex, with your instructions I was able to disassemble my headstock and adjust the radial clearance using shims (none were present when I acquired the lathe). My rear bearing is only cut on one side instead of split completely in two as yours is. I assume it flexes when compressed by the bearing cap.

I am still working on making the axial adjustment. Since my rear bearing box is one piece, I have one screw instead of two on the back of it. This screw has run out of adjustment so I will need to add some kind of a shim washer anyway in order to make the axial adjustment. Your thrust bearing appears to be made of bronze, but I have a few red plastic washers instead. I am considering replacing them with a needle thrust bearing of the correct size.

If I have measured correctly, the gears are 12DP, .500" wide, and .625" bore with a .125" keyway. I do not know how to measure the pressure angle but maybe I can find some kind of gauge for it.

I have what I believe to be a complete set of change gears: 15, 16, 24, 30, 32, 34, 36, 40, 44, 46, 48, 52, 56, 64. They are enough to do all of the combinations on the threading chart, which I will attach for reference.

I think I will make no attempt to attach graduated dials, but your suggestion to use a hard stop or dial indicator is a good one, so I will order one of those.

Thanks again for your help and I wish you both good health and good luck with your lathes.

Sincerely,
Daniel Silverman

PS. I take back what I said about the felts in the headstock- I think it makes no sense for them to catch and hold grit when the grit should be flushed out and away by spindle oil.