1-7/8 x 8 backplate for 10R Spindles


v.gearheardt@...
 

 


I have a little used SB, used by USN, 10R, 36” bed, with a 1-⅞” spindle. It has the original 5”, 3 jaw, but only one set of jaws and the run out is bad. They made very few small spindle lathes so If you want a new 3 or 4 jaw, there aren't any unless you change out to the larger spindle, which I don’t need for my work.

Here was my solution:

I purchased a 1-3/4 x 8 , 6” dia cast iron backplate from Little Machine shop for $53. As I was unsure of my internal threading skills,I purchased a 

1-⅞ x8 tap for final threading/cleanup. You need to first increase the bore (check the spec in Machinery Handbook), and then I ran enough threading  runs to get my tap started. If you are good with internal threading or have a machinist friend, the Tap is not needed. 


I purchased a Shars 3 jaw for approx $100, and for a total cost of $150, plus $60 for my “tap insurance”, I have a new, 6”  1-⅞ 3 jaw at 6”. 

Easy to machine the backplate to fit indent in 3 jaw. 


If anyone wants to buy my little used 1-⅞ x 8 TAP, I will sell it for $35 including postage.

 


Thomas Tallant
 

I  Will buy the 1 7/8 tap fro you will pm address to you need info to send payment.

On Mon, Sep 13, 2021 at 12:11 PM <v.gearheardt@...> wrote:

 


I have a little used SB, used by USN, 10R, 36” bed, with a 1-⅞” spindle. It has the original 5”, 3 jaw, but only one set of jaws and the run out is bad. They made very few small spindle lathes so If you want a new 3 or 4 jaw, there aren't any unless you change out to the larger spindle, which I don’t need for my work.

Here was my solution:

I purchased a 1-3/4 x 8 , 6” dia cast iron backplate from Little Machine shop for $53. As I was unsure of my internal threading skills,I purchased a 

1-⅞ x8 tap for final threading/cleanup. You need to first increase the bore (check the spec in Machinery Handbook), and then I ran enough threading  runs to get my tap started. If you are good with internal threading or have a machinist friend, the Tap is not needed. 


I purchased a Shars 3 jaw for approx $100, and for a total cost of $150, plus $60 for my “tap insurance”, I have a new, 6”  1-⅞ 3 jaw at 6”. 

Easy to machine the backplate to fit indent in 3 jaw. 


If anyone wants to buy my little used 1-⅞ x 8 TAP, I will sell it for $35 including postage.

 


wlw19958
 

Hi There, 

I have three of the 10R's at present.  One I converted to 10L by changing
the spindle over to an L00 taper (because I have a lot of L00 tooling). 
The other two are original 1-7/8" x 8tpi spindles.

I can do internal threading but long ago I bought a 1-7/8 x 8tpi tap just
in case.  I noticed that my tap is slightly bigger than the thread on the
spindle.  Not really a problem but it will leave a shallow helix groove on
the register area of the backing plate because the crest of the tap threads
are slightly taller than the SBL spindle threads. 

The 10R has a stronger spindle than the 10L but the through hole is only
slightly larger that one inch (I believe it is something like 1.050").  The
original SBL collets only go up to 11/16" but if you mount a collet type
chuck, you can get up to 1" capacity.

I've always wondered why SBL offered the 10R.  The larger capacity of
the 10L and its ability to use 5C collets made it a superior seller to the
10R and the only difference was the spindle. 

My theory is that the 10R was the "original" Heavy Ten but when the
Cataract lathe came out with the number 5 Cataract collets (5C),  They
were in high demand in the industrial world.  SBL reacted by changing
the spindle in the Heavy Ten so that it could accept 5C collets and could
be more competitive (i.e. the 10L)

So I look at the Heavy Ten's as the 10R  (R meaning "regular spindle") and
the 10L (L meaning "large spindle").

Good Luck!
-Blue Chips-
Webb


Thomas Tallant
 

Did you sell the tap? Sent pm no reply still wont it it if available.

On Mon, Sep 13, 2021 at 4:11 PM wlw19958 <wlw-19958@...> wrote:
Hi There, 

I have three of the 10R's at present.  One I converted to 10L by changing
the spindle over to an L00 taper (because I have a lot of L00 tooling). 
The other two are original 1-7/8" x 8tpi spindles.

I can do internal threading but long ago I bought a 1-7/8 x 8tpi tap just
in case.  I noticed that my tap is slightly bigger than the thread on the
spindle.  Not really a problem but it will leave a shallow helix groove on
the register area of the backing plate because the crest of the tap threads
are slightly taller than the SBL spindle threads. 

The 10R has a stronger spindle than the 10L but the through hole is only
slightly larger that one inch (I believe it is something like 1.050").  The
original SBL collets only go up to 11/16" but if you mount a collet type
chuck, you can get up to 1" capacity.

I've always wondered why SBL offered the 10R.  The larger capacity of
the 10L and its ability to use 5C collets made it a superior seller to the
10R and the only difference was the spindle. 

My theory is that the 10R was the "original" Heavy Ten but when the
Cataract lathe came out with the number 5 Cataract collets (5C),  They
were in high demand in the industrial world.  SBL reacted by changing
the spindle in the Heavy Ten so that it could accept 5C collets and could
be more competitive (i.e. the 10L)

So I look at the Heavy Ten's as the 10R  (R meaning "regular spindle") and
the 10L (L meaning "large spindle").

Good Luck!
-Blue Chips-
Webb


v.gearheardt@...
 

sorry,
sold