Seneca Falls Star Lathe 11”

[ejwan]

Got some more time in tinkering with the lathe. My lathe left end looks exactly like Jim’s headstock.

Is the blue circle the ball thrust adjustment? Mines has an Allen set screw and looks like you turn it to adjust thrust. The purple arrow is the fiber thrust bearing?

I haven’t even look into hss tool grinding yet. Lots to learn there and I have just been using what the lady sold me from her dad to keep it simple.

wdTom, I will certainly give the stone sharping a try once I start grinding my own tools

I haven’t had a chance for the dial indicator inspection yet. I will post my finding once I am able to do it. Having a newborn provides very little free time now. I just wiped the ways down and tinker with attachments to look into which one to start selling if they don’t work on my machine.

To my surprise the atlas mill attachment works on this lathe! Was curious and took the tool holder off to see how I would mount the mill. Was supper easy and other SF owners out there may find it useful info. Only issue is the degree reading doesn’t overlap with the SF degree call outs. The mill has two set screw and each one has a taper pin to secure to the roll holder compound.

Setup of my lamppost tool holder

Atlas mill attachment

Mounted

I don’t have a mill yet so it will be useful one day. But I will need to source a draw bar, collet holder and collet to mill safely from what I gather reading about it. I maybe able to make the draw bar if anyone has one which they would be willing to share the measurements.

Lastly I tried the taper attachment with the machine off. It’s not working. The cross feed screw is still attached. Is there a way to disconnect it easily to get the the tool holder to follow the taper attachment?


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[jim rozen]

Is the blue circle the ball thrust adjustment? Mines has an Allen set screw and looks like you turn it to adjust thrust. The purple arrow is the fiber thrust bearing?

Basically yes. The spindle is constrained axialy in the headstock - it cannot move left (where the cutting force wants to push it) because the loose ball thrust bearing, on the right side, takes that force. It cannot move right because the take-up nut - blue circle -bearing on the side of the bronze bearing via the fiber washer - purple arrow.

The fiber washer is a crude bearing designed to buffer the steel of the take-up nut from the bronze spindle bearing. There's not typically much force trying to move the spindle to the right during cutting operations. The take-up nut on this machine was designed to be a simple sort of snug 'prevailing torque' type of adjustment done with a spanner pin wrench (holes on the perimeter sort of visible) but has been butchered in the past with what was probably a pipe wrench.

Caveat: you can see a key, in a keway, visible to the right of the smooth surface of the journal on that spindle. I had this dismantled to make a replacement gear that fit in that location, driven by that key. Also a keen eye will see missing teeth on the smaller back gear, integral with the cone pulley. Later I replaced that gear as well.

I bought this machine years ago for a small price - it had been stored in a barn, covered in oily sawdust. When I run out of projects I work on re-habbing for fun. Probably the next bit will be to replace that take-up nut with a nice split nut with a pinch bolt. Based on this discussion!

Oh, and the reason the milling attachments' graduations don't line up, is because the milling attachment is made for an Atlas lathe, and either fits neat, as -s or was adapted by a former owner to this machine.

 

[animal12]

I Don't know about the new lathes like the one you got there , but the earlier ones had a major design flaw where you could lock the 1/2 nuts & turn on the cross slide feed at eh same time . Lot's of these lather found new owners with the brass key that rides in the lead screw slot & locks into the apron feed worm gear broken or missing . Simple part to make . I think mine is @ early 1999's .
have fun
animal

 

[Joe Michaels]

An oil stone which works well for stoning HSS tool bits is an "India Medium Hard" stone. I use one which is sometimes called 'penknife' sized, about 1" wide x 1/2" thick x 3" long. After grinding a tool bit, some stoning of the side, top, & nose will do wonders for both surface finish and tool life. Even a roughing tool, ground with a sharp point, will benefit from stoning. When I grind a roughing tool, aside from stoning the side/top to produce a sharp cutting edge, I stone the nose to produce a slight radius. An absolutely sharp, pointed nose on a tool is likely to break off or dull quickly and the surface finish will suffer. Stoning a very slight radius swill prevent this and produce a much better surface finish.

Another use for the small oil stone(s) is to 'kiss off' or 'stone' mating machined surfaces before assembling mating parts together. Examples of this are stoning the base of a milling vise and table of the machine, or your milling attachment/cross slide saddle. The reason for doing this is to remove any minute burrs or 'dings' (dents/raised metal) which can happen on machined surfaces due to handling or storage, or some previous person pulling things together with a steel chip or two in between things. I use an "Arkansas Hard" stone for this, which is a white stone, so smooth you'd swear it would not cut or remove any metal. The test of a surface for burrs and dings is to run the 'heel' of your hand (where your palm meets your wrist) lightly over a surface. This area of your hand is less likely to be callused, and will also present a larger surface area to swipe over the surface you are checking. If you feel something with the heel of your hand, it is an area to be lightly stoned or 'kissed off' with a fine oil stone. Scratched areas on machined surfaces often have burrs worked up along the edges or ends of the scratches. The purpose of the stoning is to take down these high spots, but NOT to go deep enough to make the scratch disappear. Another test is to lightly drag your index finger's nail over a surface where there are scratches. If your nail catches in these scratches, stone the area lightly. Your finger nail may have been catching on burrs plowed up at the edges or ends of the scratches. You Are not refinishing furniture or gunstocks here, your objective is not appearance, but to restore machined surfaces to what is known as 'good bearing contact' with each other. Dings or raised burrs on a machined surface create localized high spots and prevent this good bearing contact. Aside from compromising accuracy of assembled machine parts (such as an angle plate or vise on a machine tool's table, or your milling attachment on the cross slide saddle), rigidity of the assembled parts is also compromised.

Most machinists and toolmakers will have a few small oil stones in various shapes, sizes and grits/hardness/abrasive types in their chests. If you eat sardines, smoked mackerel, smoked or kippered herrings, or similar, save the tin and wash it out well. Break the sharp edges on an anvil or similar by peening down with a light hammer. You now have a little tray to keep your oil stones in, preventing their oil from messing up the felt in the drawers of your machinist chest or other storage location.

 

[jim rozen]

I Don't know about the new lathes like the one you got there , but the earlier ones had a major design flaw where you could lock the 1/2 nuts & turn on the cross slide feed at eh same time . Lot's of these lather found new owners with the brass key that rides in the lead screw slot & locks into the apron feed worm gear broken or missing . Simple part to make . I think mine is @ early 1999's .
have fun
animal

Point worth emphasizing. My SF lathe has a repair where the left-hand leadscrew bracket was ripped off the bed by just such an event - halfnuts + bed feed at the same time.

That's another outcome for that mistake. As mentioned, there's no lockout so don't do that.

 

[ejwan]

Can't believe it's been a year since I last visited. I been focus on raising up my son (18 months old now) and will certainly teach/pass the machine on to him.

Thank you to all the guidance and feedback thus far! I will certainly look into it so I can better myself.

I finally found the time to tinker on the machine again. I could not remove the screw on backplate with my 1/2 impact and the biggest Allen socket I had clamped to the 3 jaw. Bought a plasma cutter awhile back and made a temporary plate to weld the nut to.



Borrowed the 1" impact and socket from some rail guys I know



It finally did the trick!



Now that I know it's not seized. I am looking into cutting threads since I read it's not a common size and make new backplate for a 4 jaw chuck (still need to locate a decent chuck).

I also tinkered with the taper accessory and got it to function. It's not as smooth but I will look into it more when I can find some extra time.

 

[animal12]

Does your power crossfeed work ? There's a brass/bronze key with ears on each end that shows up missing or broken on alot of these lathes . My lathe needs a new thrust bearing for the spindle but I have been unable to source one . The old guys at the bearing house's I talked to said they have never seen a thrust bearing that size . WHen I took my spindle apars a couple of the balls from the thrust bearing came out in 2 pieces . So not being able to source a new bearing I bought a bag of loose bals the same size & will be rebuilding my thrust bearing with those . Unfortunatly ine of the critters that likes to cruze around in my old shop was playing on the tray that I had the shim's on & made 2 piles of shims into one pile . No problem , just more work for me .

 

[Joe Michaels]

Back about 1964, I got a Seneca Falls lathe from a shop that was being demolished, machine tools along with the building. I was just a kid of 14, and it was my first lathe. Unfortunately, the demolition crew had broken the legs the lathe had stood on, and a number of other parts were missing. Hunting in the piles of building debris and junk turned up some of those missing parts. Great education for a kid wanting a screw cutting lathe. One thing that was missing was the key that transmits the power from the lead screw to the worm for the power feeds. Not knowing much at the time, I took a piece of bronze brazing rod and bend 'ears' on it in the vise, and filed until it just fit the worm. Worked fine for running the lathe's power feeds. Once I had that solved, I then discovered the clutch cone was missing. By this point, we had the lathe down the basement of my father's house and on a wood bench, with a 1/3 HP motor belted up to it. I took a bronze fuel filler cap from a junked military generating set, and turned that into the clutch cone, using the lathe itself. Eyeballed the two holes for the anti-rotation pins, eyeballed the approximate angle of the taper in the worm gear. I then had power feed working. It was at that point, I discovered there was no 'mechanical interlock' to prevent throwing in the half nuts/lead screw along with the power feed. Had to make another key out of brazing rod. Lesson learned.

Regarding loose ball bearings and bearings which use them: it has been my own experience that, over long periods of running, hardened steel balls will often shape the grooves in the races to conform to their own shapes/diameters. Bicycle wheel hub bearings were an example of this, as were the bearings in a number of blacksmith forge hand cranked blowers. Sometimes, I'd have a forge blower apart and see that the grooves in the races did not look so good. I've cleaned them up with crocus cloth and oil stones, and then miked the balls. At the bearing supply houses, I was then able to buy loose steel balls a little oversized from nominal. I've reassembled the bearings with these slightly oversized balls. The balls initially ride on line contact with the grooves in the races, and by taking up on the 'cones' over time and running, the bearings 'bed in' and run quite well. Another little trick that is as old as time itself is to use some grease when assembling a bearing with loose balls (or loose needles). The grease will hold the balls (or needles) in place until things are fully assembled. With a thrust bearing on a lathe spindle, trying to assemble it dry is asking the balls to defy the laws of gravity or needing another pair of hands. One of those magnetic pans that auto mechanics use would be a good thing to put under the thrust bearing when you go to assemble it onto the lathe. Any balls dropped will be caught before they bounce off and become MIA.

 

[jim rozen]

When I put loose balls into an assembly, I usually put a tray of clean dry sand under it, so the greased balls land in that, instead of on my shop floor, so they don't get *really* filthy with random particulate crap, which they would if they hit the floor!

Most times when the geartrain is locked up (engaging the half nuts AND the longitudinal feeds at the same time) the item that breaks out is the left side leadscrew bracket - it tears away from the bed. my SF machine has a repair in that exact place.