ER32 chuck onto old lathe

[RedOrZed]

Doing up an old lathe, looks at lot like a "Lineker & Winfield", also acquired some ER32 collets from the local auction, and a tray of assorted offcuts including some bits of ali plate.

Spindle nose is 3/4 UNC, 3/4UNF on the rear. Every thing else is BSF or BA.

Got an ER32 backplate from RDG tools, but it's meant to be mounted on a rotary table so it has no real register on the back. Going to be a bit of a laugh making it run reasonably true.
s.

 

[zzr1200]

Spindle nose is 3/4 UNC, 3/4UNF on the rear. Every thing else is BSF or BA.

Are you sure it's UNF/UNC, some Whitworth (tpi) threads are almost the same, apart from the thread angle???

 

[RedOrZed]

Are you sure it's UNF/UNC, some Whitworth (tpi) threads are almost the same, apart from the thread angle???

I will have a double double check!

 

[MattF]

Adding the collet chuck is worth doing. They're marvellous things. I rarely put the 3 jaw on mine nowadays.

 

[RedOrZed]

Are you sure it's UNF/UNC, some Whitworth (tpi) threads are almost the same, apart from the thread angle???

The spindle nose is 3/4 x 10 TPI, which is the same as WW and UNC, but the fine thread on the other end is 3/4 x 16 TPI, UNF not BSF.

 

[RedOrZed]

Adding the collet chuck is worth doing. They're marvellous things. I rarely put the 3 jaw on mine nowadays.

Cool, not something I've used before, I don't think these are quality collets, but interesting to try.

 

[RedOrZed]

Are you sure it's UNF/UNC, some Whitworth (tpi) threads are almost the same, apart from the thread angle???

It's always worth more investigations...the nice Burnerd 4 jaw chuck that came with the lathe, is indeed 3/4 WW, a tap fits it quite nicely. The UNC tap binds after a couple of threads.

Good to find that out now before making any more backplates.

But the locking thread on the other end, there's no way a 16 TPI UNF nut would go on if it were 3/4 BSF? I'm bafflated!

 

[Agroshield]

But the locking thread on the other end, there's no way a 16 TPI UNF nut would go on if it were 3/4 BSF? I'm bafflated!

You have a thread that is 3/4" 16tpi. Unless you measure the flank angle of that thread, you cannot say for sure if it belongs to any thread series. Given that it is a lock nut on the back of the spindle, why does it have to fit in a pre-defined thread series?

3/4"- 16 with a (60 degree) UN thread form happens to be called 3/4 UNF.
3/4"- 12 with a (55 degree) Whitworth thread form happens to be called 3/4" BSF.
3/4"- 16 with a (55 degree) Whitworth thread form does actually fit into a known thread series: BS31 conduit thread (https://www.casa.co.nz/electrics/Conduit/BS-Conduit-Threads.htm).

 

[RedOrZed]

You have a thread that is 3/4" 16tpi. Unless you measure the flank angle of that thread, you cannot say for sure if it belongs to any thread series. Given that it is a lock nut on the back of the spindle, why does it have to fit in a pre-defined thread series?

3/4"- 16 with a (60 degree) UN thread form happens to be called 3/4 UNF.
3/4"- 12 with a (55 degree) Whitworth thread form happens to be called 3/4" BSF.
3/4"- 16 with a (55 degree) Whitworth thread form does actually fit into a known thread series: BS31 conduit thread (https://www.casa.co.nz/electrics/Conduit/BS-Conduit-Threads.htm).

I do love this place for interesting knowledge!

My thread charts don't cover BS Conduit. It's a 1920s style lathe, it really didn't cross my mind to look for conduit. Cheers!

 

[RedOrZed]

You have a thread that is 3/4" 16tpi. Unless you measure the flank angle of that thread, you cannot say for sure if it belongs to any thread series. Given that it is a lock nut on the back of the spindle, why does it have to fit in a pre-defined thread series?

3/4"- 16 with a (60 degree) UN thread form happens to be called 3/4 UNF.
3/4"- 12 with a (55 degree) Whitworth thread form happens to be called 3/4" BSF.
3/4"- 16 with a (55 degree) Whitworth thread form does actually fit into a known thread series: BS31 conduit thread (https://www.casa.co.nz/electrics/Conduit/BS-Conduit-Threads.htm).

It seems 3/4 x 16 is a popular wood lathe spindle nose thread.

 

[Agroshield]

It seems 3/4 x 16 is a popular wood lathe spindle nose thread.

It is, and AFAIK, the wood world uses the UN thread form (so the thread would be 3/4 UNF). 3/4 UNF is also used on Sherline and Taig lathes.

A wood lathe that had a thread on the left of the headstcok would be called an 'outboard' spindle thread and would also normally be left hand thread. This is so the chuck does not unscrew or so you do not have to go stand round the back to use it.

 

[RedOrZed]

It is, and AFAIK, the wood world uses the UN thread form (so the thread would be 3/4 UNF). 3/4 UNF is also used on Sherline and Taig lathes.

A wood lathe that had a thread on the left of the headstcok would be called an 'outboard' spindle thread and would also normally be left hand thread. This is so the chuck does not unscrew or so you do not have to go stand round the back to use it.

A fairly badly made 3/4 UNF nut did the trick. The thread isn’t in great nick after 90 odd years, the difference between probable 55 or 60 degrees thread isn’t really there any more. I have ordered English thread taps anyway.

 

[RedOrZed]

First thing to consider is whether you want/need a ‘through-the-spindle’ fitment or would be satisfied without that.

Most lathe spindles have a taper - mostly Morse - at the chuck end. If so, all that is needed is a draw bar to secure a suitable collet holder for the ‘non-through-spindle’ option.

EBay has provided another ER collet backplate, this one meant to be mounted as a chuck so has a lovely backplate register.

Local auction house has some lovely small collets this weekend so looking to see what can be done with them - they are the drawbar type.

Assuming my bids win…

 

[RedOrZed]

Cut the tenon to fit into the rebate and turned the outside mostly to size. Next job is to turn it over, turn down the rough bit to a good sized neck and drill for mounting screws.

 

[RedOrZed]

Done it!

Added motor from the shelf, leather drive belt from the eBay, set of ER32 collets up to 20mm from local auction. Oh and QCTP

Not checked the runout yet as only just finished!

 

[RedOrZed]

Next up, screw-cutting and making a tailstock.

 

[garryhallam]

Did you manage to find any backplates 3/4 12bsw? I have a faircut junior and has the same spindle nose thread

 

[RedOrZed]

Did you manage to find any backplates 3/4 12bsw? I have a faircut junior and has the same spindle nose thread

I've just acquired the taps and the right sized drills and made my own backplates out of aluminium plate. Cut slightly oversized and finished on the lathe itself.

Although, there are a number of wood lathes which use the same thread

 

[RedOrZed]

Faircut & Truecut Lathes

Smart lathe, how do you find it?

 

[RedOrZed]

3 jaw chuck

There is a box of chuck jaws that definitely probably contains both sets