Crossfeed more difficult after new (correct) oil and taper cleaning?

I apologize for the somewhat confusing title, let me set the scene and maybe it will make more sense. (For the record SB 10L from the mid 40s)

So yesterday I thought I'd try my hand cutting a taper. Set everything up, only to find that I could barely move anything laterally once I had everything tightened down. Did some research online and a lot of posts indicated that it may be as simple as years of dirt and dried oil gumming things up. I pulled the taper attachment off and gave it a good cleaning, and sure enough, it all moved together as I thought it should. While I had everything apart (and since I had recently received the proper a/b/c and way oils), I also decided to put the correct oil in the reservoirs/oil holes etc.

Anyway, so I put everything back together, and tried it out. Everything moved laterally as it should but the cross feed knob simply didn't feel the same anymore. It felt like the entire unit was dragging when I moved it in and out. I played with it for a bit, looking for some obvious reason, and ended up removing the taper attachment (in case there was friction and it was somehow affecting it) so that the screw was basically free. This provided *some* relief, it still felt as if something was too tight(?) or had no lubrication. I noticed that the machined surfaces (even with fresh oil) had sort of a black discoloration to them. In fact,running my fingers down them, the oil that was left on the machined surface almost felt gritty.

The only thing I can really think of is that my introduction of new oil has somehow knocked loose 70 years of built up grime and swarf that had been stuck in the oil passages? Since I'm this far along I thought I might was well pull the cross feed off and give it a good cleaning anyway, but was looking for other input since it's sort of a PITA.

I'm not sure what else I could have done that would have affected the cross feed this way. Can you guys think of anything I missed?

Does the machine have the telescoping crossfeed leadscrew?
It sounds like the leadscrew nut is binding.

a couple of pictures will make it a lot easier to help

janvanruth said:

Does the machine have the telescoping crossfeed leadscrew?
It sounds like the leadscrew nut is binding.

a couple of pictures will make it a lot easier to help

Click to expand...

It does have the telescoping crossfeed lead screw.
Pictures of what exactly?

My first though was some sort of friction between the lead screw and thrust bearing(?), but the behavior remains even after I remove that portion of the assembly (albeit lessened). Basically by disconnecting the taper attachment points, I took it out of the equation as the sole cause of the binding. From looking at the diagram that really only leaves two main contact points: the machined surface of the crossfeed where it rides back and forth, and the brass nut that actually moves it back and forth.
I was trying to disassemble the crossfeed mechanism to get a good look at it, but got stuck trying to remove the nut/guide at the front.

So further update, finally got everything taken apart and cleaned and lubricated. When I got it reassembled I was pretty sad because I had an even weirder issue. Post assembly the handle would turn butter smooth for 5 revolutions....and then catch on something. You could easily power through it, but it was wierd to have smooth-smooth-smooth-smooth-smooth-catch-smooth-
smooth-smooth-smooth-smooth etc.

Then just to check I loosened the screw that hold the crossfeed/saddle to the apron. As i loosened those up.... bam, everything was smooth as butter again. Tightened back up, and the problem reappeared.

So I'm confused, I can accept that tightening those two screws up adjusts the position of the two pieces relative to each other, and I'm guessing somehow affects the drive gear/crossfeed screw geometry.... but surely there must be a better way to align those than randomly choosing a screw tightness?

jholder said:

So further update, finally got everything taken apart and cleaned and lubricated. When I got it reassembled I was pretty sad because I had an even weirder issue. Post assembly the handle would turn butter smooth for 5 revolutions....and then catch on something. You could easily power through it, but it was wierd to have smooth-smooth-smooth-smooth-smooth-catch-smooth-
smooth-smooth-smooth-smooth etc.

Then just to check I loosened the screw that hold the crossfeed/saddle to the apron. As i loosened those up.... bam, everything was smooth as butter again. Tightened back up, and the problem reappeared.

So I'm confused, I can accept that tightening those two screws up adjusts the position of the two pieces relative to each other, and I'm guessing somehow affects the drive gear/crossfeed screw geometry.... but surely there must be a better way to align those lthan randomly choosing a screw tightness?

Click to expand...

You probably have an upset or chip in one of the teeth of the Crossfeed gear in the apron.
Ted

These machines have been working in various environments for 3/4 of a century, in various states of upkeep. Dirt and grime move around sometimes, and sometime go away on their own.

Sometimes doing a light cleaning loosens more grime and you get what you got both times. Usually cleaning a certain assembly at all requires fully cleaning it. Try to enjoy it- have a bunch or brushes, cleaners, rags around and spread it out. Then you won't dread it so much.

Make sure the oil hole for the cross feed screw in that neck that threads into the apron MATCHES the hole IN the apron. This may sound confusing- but in my later model 10L, when I threaded that neck into the apron, those holes did NOT line up, effectively not allowing ANY oil in! Hah hah!

Just a piece of shim in between allowed that neck to thread in tightly and still line those holes up.

Probably not your problem, but worth mentioning here.

Bernie

warning- nit picky trivia time..

The oil hole in the saddle and cross feed bushing do not have to line up, and actually if they do that is really not optimal.
Reason- when the bushing is threaded into the saddle the two parts mate up in a way that creates an oil reservoir, debris will drop to the bottom of the reservoir leaving clean oil to feed into the hole.
If the holes line up not only does it create a direct line for junk to get in you also lose the effect of the reservoir.

for my SBs on the bushings assemblies I made for them I went for around 4 or 8 o'clock, so gravity would wash the debris past the hole but leave the reservoir effect intact.

Very interesting! I was wondering how such a blatant issue would make it to my machine, or I thought someone removed the shims before. Very interesting...


Bernie

jholder said:

It does have the telescoping crossfeed lead screw.
Pictures of what exactly?

My first though was some sort of friction between the lead screw and thrust bearing(?), but the behavior remains even after I remove that portion of the assembly (albeit lessened). Basically by disconnecting the taper attachment points, I took it out of the equation as the sole cause of the binding. From looking at the diagram that really only leaves two main contact points: the machined surface of the crossfeed where it rides back and forth, and the brass nut that actually moves it back and forth.
I was trying to disassemble the crossfeed mechanism to get a good look at it, but got stuck trying to remove the nut/guide at the front.

Click to expand...

my guess is that your telescoping leadscrew doesnt actually telescope
if you disconnect the taper attachment points and turn the handle the leadscrew should slide out of the assembly
if it doesnt, it would mean that if you connect the taper attachment it would take a lot of force turn the handle.

you have swarf between the pinion gear in the apron and the cross feed screw as Ted states, pull the apron and the cross feed screw assembly, clean them, inspect the teeth for damage, file them if needed. We recommend cleaning at least every 50 years...lol you're over scheduled maintenance at 70...

Steve