# Holding Small Rods?



## jouesdeveaux (May 15, 2016)

I am TOTALLY new to machine work and have a Grizzly G8688 about to arrive. Does a mini-lathe such as this one need special equipment to work  on (threading) small rods, say 1/16"~ 3/32" in diameter?  Do I need to buy collets, a collet chuck, and a draw bar?


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## coffmajt (May 15, 2016)

jouesdeveaux said:


> I am TOTALLY new to machine work and have a Grizzly G8688 about to arrive. Does a mini-lathe such as this one need special equipment to work  on (threading) small rods, say 1/16"~ 3/32" in diameter?  Do I need to buy collets, a collet chuck, and a draw bar?


With that small size material you will be limited on how much material you can stick out of your 3 jaw chuck, but it will work just fine.  If you intend to thread long distances along the rods, then you should have a follow rest or just single point a few threads on the lathe and finish using a die .Remember to use some quality cutting oil when threading. -- Good luck with your projects


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## Andre (May 15, 2016)

Make sure your chuck can close down tight enough.


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## kd4gij (May 15, 2016)

Collets would be the best choice for that small dia.


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## jouesdeveaux (May 15, 2016)

coffmajt said:


> With that small size material you will be limited on how much material you can stick out of your 3 jaw chuck, but it will work just fine.  If you intend to thread long distances along the rods, then you should have a follow rest or just single point a few threads on the lathe and finish using a die .Remember to use some quality cutting oil when threading. -- Good luck with your projects



I intend to make stainless steel 0.083" D  rods 2~4" long with 4mm of thread on each end.  They are used in certain kinds of Sheaffer fountain pens of the 1930s-40s. I repair them and I'm running out of supplies from NOS and old junkers.


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## Andre (May 15, 2016)

If the threaded section is only ~4mm in length (.080") a HSS split adjustable die should work quite well. Pick a good grade of stainless and use some thick cutting oil.


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## jouesdeveaux (May 15, 2016)

Andre said:


> If the threaded section is only ~4mm in length (.080") a HSS split adjustable die should work quite well. Pick a good grade of stainless and use some thick cutting oil.


OD of the thread is 0.056". The diameter of the rod is 0.083". Are HSS split dies made that small?


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## Ulma Doctor (May 15, 2016)

a collet will be the best idea to hold the shaft.


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## Andre (May 15, 2016)

jouesdeveaux said:


> OD of the thread is 0.056". The diameter of the rod is 0.083". Are HSS split dies made that small?



#0 screw thread OD is ~.060". Measure the pitch of your required threads to be cut, if it happens to be 80 TPI you are in luck, 0-80 split dies are available. Threading #0 in stainless might be pretty tricky though.....Hmm.


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## Firestopper (May 16, 2016)

I have turned,knurled and threaded on small diameter stock using a 6" 3 jaw scroll (limited to 1/8") chuck with good results,however it took me well over 15 years to purchase a 5C scroll chuck and set of collets. I can't believe it took me so long to add the 5C system. Its much faster and safer when machining multiple parts close to the chuck. Parting has also improved as I can get up close and personal with out worry of crashing into jaws and preserving my hands and fingers when polishing.
I like the scroll type of chuck with a spider supporting the longer stock through the spindle.

Although not an example of  small diameter stock but the same set up can be accomplished with smaller stock. The scroll chuck setup can be change back to jawed chuck fairly quickly without dealing with a draw bar. I will say a draw bar system is faster but more tooling to store when not in use. The spider lives on the input end of spindle and only the cap screws (jaws) require removal when pulling the end cover for maintenance.
For fountain pen turning, this would be a game changer IMO.


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## jouesdeveaux (May 16, 2016)

firestopper said:


> I have turned,knurled and threaded on small diameter stock using a 6" 3 jaw scroll (limited to 1/8") chuck with good results,however it took me well over 15 years to purchase a 5C scroll chuck and set of collets. I can't believe it took me so long to add the 5C system. Its much faster and safer when machining multiple parts close to the chuck. Parting has also improved as I can get up close and personal with out worry of crashing into jaws and preserving my hands and fingers when polishing.
> I like the scroll type of chuck with a spider supporting the longer stock through the spindle.
> 
> Although not an example of  small diameter stock but the same set up can be accomplished with smaller stock. The scroll chuck setup can be change back to jawed chuck fairly quickly without dealing with a draw bar. I will say a draw bar system is faster but more tooling to store when not in use. The spider lives on the input end of spindle and only the cap screws (jaws) require removal when pulling the end cover for maintenance.
> ...


Thanks, Firestopper. This is very useful.


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## RJSakowski (May 16, 2016)

jouesdeveaux said:


> I am TOTALLY new to machine work and have a Grizzly G8688 about to arrive. Does a mini-lathe such as this one need special equipment to work  on (threading) small rods, say 1/16"~ 3/32" in diameter?  Do I need to buy collets, a collet chuck, and a draw bar?



For working on small stock on your Grizzly G8688  lathe, an ER collet chuck may be a better choice.  An ER20 collet can hold work down to 1mm  and as large as 13mm diameter and ER collets have a wider clamping range than 5C collets.  The ER chuck will also be closer to the headstock than a 5C cuck, giving you more rigidity and useful working length.


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## jouesdeveaux (May 16, 2016)

RJSakowski said:


> For working on small stock on your Grizzly G8688  lathe, an ER collet chuck may be a better choice.  An ER20 collet can hold work down to 1mm  and as large as 13mm diameter and ER collets have a wider clamping range than 5C collets.  The ER chuck will also be closer to the headstock than a 5C cuck, giving you more rigidity and useful working length.


Does an ER 20 Collet chuck on a mini Gizzly require a draw bar?


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## BGHansen (May 16, 2016)

jouesdeveaux said:


> Does an ER 20 Collet chuck on a mini Gizzly require a draw bar?


No draw bar needed.  The ones I've seen mount to the lathe spindle and "behave" much like the collets on a Dremel tool.  You unscrew a clamp nut, place the correct collet into the collet detail, loose fasten the nut, insert stock and tighten down the nut with a spanner wrench.

Do a search on the site for "ER 40 collet chuck and spanner wrench" and look for the post by Mark Frazier.  Mark (as usual) did an excellent job stepping through building one.  They are available commercially from Little Machine Shop and others.  A little googling should turn up many sources.

Bruce


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## jouesdeveaux (May 16, 2016)

Yes. ER 32, 20, or 11 would be the right size for me. I saw them at Little Machine, some with a straight spindle. Many thanks!


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## RJSakowski (May 16, 2016)

jouesdeveaux said:


> Yes. ER 32, 20, or 11 would be the right size for me. I saw them at Little Machine, some with a straight spindle. Many thanks!


While you could mount an ER collet chuck with a straight spindle using your 3 jaw or an ER collet chuck with a Morse taper adapter, the best way would be to mount it to the spindle face on your G8688 lathe.  
Using a 3 jaw chuck with a straight shank  will extend the chuck from the headstock and you will lose the ability to pass long pieces through the spindle.  You will also have increased runout as 3 jaw chucks usually have intrinsic runout.  That can be overcome by using a 4 jaw chuck and dialing in the concentricity.
A Morse taper shank would reduce runout but you lose the ability to pass long stock through the spindle.  There is also a possibility of working the Morse taper out from the the spindle socket unless a drawbar were used.  
An ER chuck mounted to a backing plate which is mounted to your spindle face gets your work up close to the headstock and should give you good concentricity.  The central bore will also be available for passing long stock through the spindle bore.
It looks like the chuck is a direct mount to the spindle face on the G8688 lathe. http://littlemachineshop.com/products/product_view.php?ProductID=2532&category=-421559299


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## jouesdeveaux (May 16, 2016)

RJSakowski said:


> While you could mount an ER collet chuck with a straight spindle using your 3 jaw or an ER collet chuck with a Morse taper adapter, the best way would be to mount it to the spindle face on your G8688 lathe.
> Using a 3 jaw chuck with a straight shank  will extend the chuck from the headstock and you will lose the ability to pass long pieces through the spindle.  You will also have increased runout as 3 jaw chucks usually have intrinsic runout.  That can be overcome by using a 4 jaw chuck and dialing in the concentricity.
> A Morse taper shank would reduce runout but you lose the ability to pass long stock through the spindle.  There is also a possibility of working the Morse taper out from the the spindle socket unless a drawbar were used.
> An ER chuck mounted to a backing plate which is mounted to your spindle face gets your work up close to the headstock and should give you good concentricity.  The central bore will also be available for passing long stock through the spindle bore.
> It looks like the chuck is a direct mount to the spindle face on the G8688 lathe. http://littlemachineshop.com/products/product_view.php?ProductID=2532&category=-421559299



Yes. Little Machine explicitly lists that ER 32 chuck  as compatible with machines that have a 80 mm flange chuck mount,  including the G8688. I think we're well on the way to solving this tooling problem. Next is how to count very tiny TPIs!


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