Holding Small Rods?

[jouesdeveaux]

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.

View attachment 129041 View attachment 129042

Thanks, Firestopper. This is very useful.

 

[RJSakowski]

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.

 

[jouesdeveaux]

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?

 

[BGHansen]

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

 

[jouesdeveaux]

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!

 

[RJSakowski]

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

 

[jouesdeveaux]

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!