Oddball thread on faceplate. Would like to find it a home

[Rudd]

I've got a 13 5/8" diameter faceplate that is threaded nominally 1 7/8" x 8". I followed up a lead on Oliver wood lathes, but have not found anyone with that thread, but several with 1 7/8" x 6, tho the book they have states 1 7/8 x 8. Last fellow said his Oliver spindle was 2 11/16" overall length, so much too long for the plate I have even if the threads were correct.

The 1 7/8" x 8" is undersized for a wartime 13" SB with that advertised spindle thread, it won't thread on more than most of a turn, and the register is too big for the SB spindle.

Register is 1.903 diameter.
length of register is about .39".
length of threaded portion about 1.36.
Makes the whole faceplate about 1.75" thick.
1.725 minor diameter on the female threads.

Faceplate is slotted, all Oliver plates I have seen have many holes for securing work, not slots. This makes me think it is for a metal lathe.

Would like to get this thing to someone who can use it.
Thanks

 

[SouthBendModel34]

13" South Bend "O" series? As in Model 34 ?

If it matches, I call "Dibs!"

John Ruth

 

[DMF_TomB]

i have made a custom tap for face plates before
.
also if screw pitch is off it will thread on 1 or 2 threads but get tighter. i had that happen cause i misread the change gear chart on a lathe. i was off just enough that it took time for me to realize why wont it screw on more than 1 or 2 turns but gets tighter

 

[Rudd]

I checked this thing with a thread gauge.
The Model O is the only other possibility. John, you've got the dimensions, do you have the Model O to check against? It weighs about 45 pounds.
I had a suspicion it might be some other SB.

 

[johnoder]

The 1 7/8" x 8" is undersized for a wartime 13" SB with that advertised spindle thread, it won't thread on more than most of a turn, and the register is too big for the SB spindle.

You guys are suggesting the SB "O" 13" 1 7/8"-8 is different from the slightly later 10 & 13" 1 7/8"-8 ?

 

[Rudd]

I am waiting for John to confirm the dimensions I gave above. I've got a 1 7/8" x 8 GH8 tap, it wont even start. I have no idea what the typical H limit is for something this big. Tap is 5 fluted, so measuring it would get interesting.

 

[SouthBendModel34]

Rudd,

Just to be precise, the "O" is the Series. It covers lathes with single-wall aprons and various swings. The Model 34 is a particular Model within this Series.

I've never removed the 4-jaw that's stuck on my PRIMARY 1918 South Bend 13" Model 34 Series O. I've had enough sense to stop after I sheared off a woodruff key in the back gears. I've been soaking it in Kroil and PB Blasters for years. Maybe it's time to give it another crack.

I also have a JUNKER SB Model 34 - that one could be measured. That's not at my home; measuring will have to wait.

John Oder:

Your input is always eagerly sought ! The seller, Rudd, has stated that it is 1-7/8 x 8 but does not fit a WW TWO-era SB 13.
I'm seeking information as to whether it might fit a WW ONE SB 13, specifically a Model 34.

1-7/8 x 8 is, as stated by Rudd, an uncommon spindle thread.

As I understand the SB Series O spindle, it registers on the face of the spindle, not on the shaft. I would be happy to be corrected if this is not correct.

John Ruth

 

[johnoder]

John Oder:

Your input is always eagerly sought ! The seller, Rudd, has stated that it is 1-7/8 x 8 but does not fit a WW TWO-era SB 13.
I'm seeking information as to whether it might fit a WW ONE SB 13, specifically a Model 34.

I owned a 13" Series O in the dim mists of time - over fifty years ago. IT JUST SEEMS INCONCEIVABLE to me that SB would bother to make two differing 1 7/8 - 8 threads separated by maybe ten or fifteen years - makes no sense, but I have no data to support that assumption

 

[Monarchist]

I owned a 13" Series O in the dim mists of time - over fifty years ago. IT JUST SEEMS INCONCEIVABLE to me that SB would bother to make two differing 1 7/8 - 8 threads separated by maybe ten or fifteen years - makes no sense, but I have no data to support that assumption

Might not have BEEN SB, even if their name is on it. HS shop ordered two CI backplates, 10" SB, 10" Logan, same 2 1/4"-8 thread to add 4-J to the initial slender-budget purchase with 3-J only.

Fell to me to fit them. They both had to be put onto faceplates and have the threads picked-up-on, then lightly chased. Threads, not registration area.

Exact same symptom as here.

Only go on a turn or so, and my best B&S thread-gauge confirmed for sure the TPI was DN on. Thread form was spot on. As happened it was the diameter that was undersize. 1959, IIRC. Not much data, but two-for-two, and two different makes of lathe, both brand-new that calendar quarter.

Was there once a commercial practice of shipping undersize in case spindles were worn, or had been messed with?

If a 15-year-old HS kid newbie could do it, it was surely not as hard to correct as the reverse - oversize threads on an ID!

 

[k3vyl]

My WW2 vintage 13" SBL has a spindle nose thread diameter of 1.870 with the register measuring 1.8855. It bears the SN 142442,and was shipped to Bethlehem Steel at Fore River Mass 2/4/43. It has the war board tag and the anchor near the SN. Catalog no 8113-B.