Tell me about this 14-1/2 x 6’

[rwdenney]

Do yourself a favor and clean the paint off your gearbox plate. It will be easier to see and make changing gears quicker.

Actually, I have replacements for all the plates. I just haven't installed them yet. The gearbox plate had nice red paint in one spot, but it's so worn down that it would have to be repainted. The plate wasn't actually painted with the lathe color, I don't think, but has been scrubbed so much that a lot of the background paint is just worn off, giving it a color I call Olde Aluminum, which is pretty similar to Olde Machinery Gray. (The paint companies get extra money for those extra e's). I just bought a modern replacement, which doesn't exactly match the original font, etc., but which is much easier to read.

I have new plates for the lubrication and headstock bearing adjustment also, and even boxes of screw pins to secure them.

Before installing the one on the gearbox, I may go ahead and pull the gearbox and get all the grime out of it.

Rick "better install them before I misplace them " Denney

 

[SLK001]

Before installing the one on the gearbox, I may go ahead and pull the gearbox and get all the grime out of it.

Yes, the gearbox is heavy with felts. The single tumbler version is more prone to wear from poor lubrication. Also, once apart, you should be able to punch the old screw pins out from the inside.

 

[rwdenney]

Last evening, I cleaned up the 4-jaw chuck. I could find no label on the body, but all the parts are stamped with the Skinner logo, and the Skinner catalog in VM identified it as a 1910, with a forged steel body and 10” in size.

I needed it to hold the toolpost mounting plate I found in the pile o’stuff. I’ll machine the T-nut from Shars at a later date, when I have a milling capability.

The plate was flame-cut from a piece of 1/2x2” CRS flat bar, and drilled for a 3/8-16 bolt for probably a boring-bar mounting block. (The 14-1/2 has a compound slot that is nominally 17/32x2-1/16”.) I cleaned it up on the grinder and sander, and then mounted it in the 4-jaw. I used parallels to position it normal to the lathe axis and then indicated it to center on a 3/8” bolt in the threads. That hole was not straight but I indicated it as close as possible to the hole and that was good enough.

Then, I used the new 16.5mm drill from McMaster, and also the 18x1.5 taper tap with my spring-loaded tap follower in the tailstock. It’s really nice to be able to drill and thread holes accurately—something I could never do with my craptastic drill press.

I’m very glad I didn’t get a smaller toolpost than this CXA.

I’m using the sides of CNMG inserts in a neutral holder for facing cuts. I was told the South Bend lacked the power and speed to use double-sided negative-rake inserts like the CNMG, but here is my first use of it:

(0.040 DOC, sloooow feed rate, maybe 225 RPM, so not pushing any boundaries. )

Next project, probably for the new year, will be a dovetail base for the milling attachment. I’ll use that to fab a taper attachment connecting bar—the steel for that is in hand and the design is in head.

Rick “

” Denney

 

[rwdenney]

Okay, recalling my previous observation of non-standard speeds…

I received a tachometer for Christmas, and finally got a moment this evening to measure the lathe speeds. The heavy 4-jaw chuck is mounted with a chunk of steel clamped in it, so it was a heavy load.

(With this heavy load the highest speed takes some coaxing. I’m wondering if rewiring the single-phase motor for 240 will give it a bit more zip. The motor is a 60’s or 70’s Dayton 5K482 2-HP motor. These are good motors still in production and a new one is over a grand. This is NOT the motor installed by the first user, according to the serial number card. That one was a 2-HP 3-phase motor wired for 550 VAC at 25 Hz, and supposedly running at 1410 RPMs.

In the stock configuration, the published speeds range from 181 to 800 RPMs (27-121 in the back gears). My speeds are 250, 400, 625, and 1000 (38, 60, 94, and 150 in the back gear).

In the highest gears, my measured speeds are tracking the rated loaded difference in the motor speeds. 1750 is 24% higher than 1410, and 1000 is 25% higher than 800. But in the lowest gears, the motor is turning a bit faster—1785—but the lathe is going faster than predicted. 250 is 38% higher than 181. These percentage differences are preserved using the back gears, so I don’t think it’s spindle bearing drag notwithstanding my impression that the motor is barely able to drive the top speed.

It would appear that they just moved the motor pulley over to the Dayton motor when the lathe was converted for use outside a steel plant.

The percentage difference increases smoothly in the four cone sheaves, so I have to think the effect is linear with belt speed.

Anyway, I have now marked the actual speeds on the inside of the pulley cover.

By the way, the tach has a wheel that will report surface feet per minute, which is really handy.

And that 10” 4-jaw chuck is fairly impressive spinning at 1000 RPMs. (Yes, it’s a steel chuck and rated for it).

Rick “no plans to use the highest speeds except for small stuff held in a collet chuck” Denney

 

[SLK001]

I’m wondering if rewiring the single-phase motor for 240 will give it a bit more zip.

If it can be rewired, then 240V will be your better bet. Operating a 2 HP motor on 120V is an "iffy" proposition.

It would appear that they just moved the motor pulley over to the Dayton motor when the lathe was converted for use outside a steel plant.

That should have been all that was needed.


As for your tach, pictures, or "it didn't happen"!

 

[rwdenney]

If it can be rewired, then 240V will be your better bet. Operating a 2 HP motor on 120V is an "iffy" proposition.

I agree. The rated starting current draw should be popping my 20-amp breaker routinely, but it isn't, even once when the motor stalled on start when I had the spindle belt too tight. That surprised me quite a lot, and I was really surprised (I think I mentioned it) when I saw that it was using 120 VAC back in Uncle's hanger. I need to run another circuit for 240 so I'm not having to roll stuff over the cord. The only other 240VAC rolling tool I have is a 3-HP cabinet saw--my other tools are 1 HP or less.

That should have been all that was needed.

It depends. The serial number card stated that the motor was to be supplied by the customer, but it also showed (in handwriting rather than typing) the operating characteristics of the motor used. As previously mentioned, the lathe was sold to Beth Steel to be used in the "Elec Sup" department of what was at the time the world's largest steel plant. 25-Hz power was (and still is) used by electric trains on a large portion of the Amtrak Northeast Corridor line, supplied at much higher voltages using overhead catenary. Amtrak sells a lot of that power to other users of that line, including SEPTA and NJ Transit. The Sparrows Point Shipyard where this lathe was first delivered is in Baltimore, near the southern end of that line, which extends down to Union Station in Washington DC. I do not know if Beth Steel shared power with the Pennsylvania Railroad (the original owner of that line; they were emulating the 11-KV, 25-Hz power used by the New York, New Haven and Hartford Railroad starting in 1908), but it's certainly possible. And it would mean transformers, motors and other power equipment wired for that frequency would be locally available. It's not impossible that Beth Steel generated power for the Penn, given that the Penn started using it in 1915 and the Sparrows Point plant started operation in 1887 under Maryland Steel (Bethlehem bought it in 1915, and it was one of their four Baltimore shipyards). The reason for using 25-Hz power was so that they could increase transmission voltages using the equipment of the day. They currently transmit power from substation to substation at 138KV.

This lathe was delivered in June of 1945, only a few weeks after the surrender of Nazi Germany and while WWII in the Pacific theater was still quite hot. Beth Steel was building liberty ships at Sparrows Point, and they continued to grow into the 50's, supplying steel for rebuilding and in response to post-war prosperity. Meaning: the plant was large and active for quite a while after this lathe was delivered.

So, for the "it depends". I don't know when Beth Steel liquidated this lathe, but I have to assume it was in the 60's or 70's, when the plant was shrinking rather than growing. It would have been outdated by that time, but I suspect it was used for as-needed repairs of other machinery in the plant, not for production (where it would have been considered too small and where being outdated would have been more of an issue). Of course, when they sold it, they would have had to convert it for use on the regular power grid in order to find a buyer, or the buyer would have done it after the purchase. I suspect both would have been counting pennies, and would have used the pulley that originally came with the lathe for use with a 1410-RPM motor. Normally, the pulley would be replaced to provide the specified speeds for the lathe. Appropriate pulleys are easy to make and easy to buy in whatever size would be needed. That tells me that it was probably the buyer that replaced the motor.

I have no idea if it was ever wired for 240.

There is a round three-phase power receptacle on the back of the base unit next to the switch-arm mounting, wired how and for what purpose I don't know.

I haven't messed with the wiring, but I need to go ahead and do that. Normally, I do that first as a matter of safety--I'm apparently more picky about wiring safety than previous owners of the stuff I've bought.

As for your tach, pictures, or "it didn't happen"!

Yeah, yeah, yeah. I was squeezing it in between spousal assignments, and the holidays are over. Maybe I'll sneak out there tonight.

Rick "pic of the tach in the 'What did you buy today' thread" Denney

 

[rwdenney]

…As for your tach, pictures, or "it didn't happen"!

Here’s the tach measuring slow speed with the back gears, 38Hz:

You can see the reflector target stuck to the chuck adapter.

Here’s the same pulley without the back gears:

And here’s top speed:

Here’s the motor speed:

It’s handy, for sure.

Rick “standard Amazon cheapie” Denney