Logan 400. Headstock. (Total Logan 400 Rebuild)

[mjhenks]

Had this Logan for 10 years and my Grandfather 50 years prior. Has served me well cutting soft stuff but recently noticed movement in the chuck and took it apart to investigate. I have a few questions i hope i can get answers to.

1. Are the spindle bearings pre-loaded or are they clearance and get their pre-load strickly from the take-up nut on the gear drive side? I found my take-up nut rather loose found but there is play in the main spidle bearing when it is not mounted. Mainly axial.

2. What torque should the take-up nut be set to?

3. I figure new spindle bearings are smooth as silk. Mine are not super rough but not super smooth either. When do you decide to spend the $100 for a new one?

4. I put the spindle back into the bearings and housing without the drive pulleys and gears. I tightened the lock-nut moderatly and measured the run-out. It measured .0006". I deflected the nose in all four directions getting ~.001" deflection but always returning to within .0001" If i spin the spindle at that point (with a chuck on it) it will spin free for about 45 seconds. Does that all sound right?

(Edit July 2020) You can also see my install of a QCGB here. here

 

[mjhenks]

More pictures. ID plate and S/N.

Bearing in housing is the gear side smaller bearing. New Departure 773L07

The bearing on the spindle is the main. I have not found the part # yet but it is New Departure and ends in L08 (Not sure what that means) May be 4473L08 but need to confirm.

 

[Chuck K]

The bearing is loaded by the take up nut. Tighten it as tight as you can get it (within reason). When you had the bearings out you should have cleaned and regreased them. The rear bearing could probably be found cheap enough but the front bearing is rather pricey. It may sound strange, but soaking the bearing in Pine Sol will soften the hard grease so you can rinse it out with hot water. You will have to pry the shields off to clean and regrease them. Fill them about 1/3 to 1/2 full of quality grease and they will probably be good as new.....or tighten the nut and run them the way they are.)

Chuck

 

[Redlineman]

Hey;

My experience is with 200s. I don't know if I can assume commonality to the 400 or not, but it would not surprise me that the bearings were the same. It is my understanding that the CORRECT main spindle bearing was/is preloaded from the manufacturer (that is why they are pricey), and can only be sourced now through Logan, who had a bunch made especially for them with the proper preload. The bearing number is the same as the generic version, I believe, but a generic bearing WILL NOT work, having far too much play to cut without chattering. The drive end bearing is generic. Tightening the take up nut on the drive side of the shaft only draws the components on the spindle together tighter. It does not load the main bearing. There is a slick fix for this that adds another bearing that bears against the back of the headstock and allows you to preload a generic main bearing, but it takes a bit of doing.

You can leave the bearing shields in place and service the bearings. Picking them out will almost always destroy them, and they are not very successfully reinstalled after removal. Go ahead... ask me!
:whiteflag:

Wash them out by whatever means works for you and let them dry. When your solvent of choice runs clear, they are clean. Some people have had luck using a generic bearing cone type packing tool for this. Others have very successfully used a pressure pot of some sort like is used for spraying paint. This has been a topic of discussion recently on Practical Machinist Antique forum.

 

[ricsmall]

If you have a vacuum sealer in the kitchen, put a good amount of grease in the bottom of bag,drop in bearing, then vacuum seal it. It works like a charm.

Richard

 

[mjhenks]

Got the main bearing off today and cleaned up the spindle. Made a press collar to get it off by pressing on the slinger. Worked well.

Can confirm now that the main bearing is: New Departure 4773L08

Now to clean them up. I do not think i will try and get the shield off. Looks like a loosing battle. I think the bearings are going to fine once i clean them.

Next item to ponder is how far to go in fixing the housing up knowing that will spill over into the rest. Painting is easy but my background there is prepping and painting cars. I do not want to go that far but i think she needs new paint.....

If i take it off the bed how hard is it to realign?

Anyone have a source for a reversing gear bracket? I need a new handle. One on Ebay but i do not need the gears.....

 

[Redlineman]

Hmmm...

Very different spindle from the 200. Does that snap ring looking item - which I assume is supposed to be the "spring washer" - go under the front bearing cap? These are shown in the parts book (LA-247), but there is no mention of them on the Logan site. Neither my lathe nor the complete original headstock I bought for parts had one. Hmmm....

 

[mjhenks]

The snap ring goes around the main spindle bearing.

I figure it is pulled against the housing when the end nut is tightened allowing the spindle to pull on the inner race of the main spindle bearing. The nut load against the inner race of the smaller rear bearing is transferred to the smaller snap ring in the rear of the housing setting the axial preload

Being Conrad ( deep groove or regular ball bearings) sort of creates a "X" in bearing terms to provide a little more stiffness. ( meaning it forces the ball bearings slightly to the side of the bearing race simulating what an angular contact bearing does)

Anyways... Off to soak bearings

 

[Redlineman]

Hey;

I should reiterate that all my comments are based on the 200 I'm familiar with, and there may be slight to significant differences in other models. I need to investigate that spring washer a bit more, since the bearing cap is the only thing that holds the spindle in place, other than main bearing to headstock friction.

FWIW, my 200 had layers of gack paint all over it. It needed so much mechanical work that doing a complete refresh including stripping and repainting seemed the best course. I'm a recovering auto refinnisher myself, and doing paint projects is about the last thing I want to do. Mechanical is so much easier!

 

[mjhenks]

Thanks

As you are I am learning that the 400 is different from others although the principle seems similar to the other 9" models out there

I have the headstock all apart now. I have cleaned all of the parts and stripped the gear cover of a few layers of paint. The headstock body is next.

Question. How do you remove the Logan name plate?? Grind off the rivet heads and drill out??

Also it looks like new bearings are in store. Old ones are actually pretty rough...

More pictures later...