If you have ever needed pin jaws but didn’t have them, or don’t want to take the time to change out the jaws, you can make you own quick change pin jaws out of scrap pieces of wood.
You need a 3" x 3" x 1 ½" block of wood, Pine works fine.
Make a tenon on one side of the 3" x 3" block Hold this tenon in your 50mm jaws and turn itround.
Drill a ½" hole (the size of the piece you need to hold, in my case it is a ½" dowel) in the center about ½" to ¾" deep.
Remove from the chuck and cut a slot with your band saw thru the side past the hole.
Make this slot about ⅛" or more wide so it will tighten around the part you are trying to hold.
Finish with sanding sealer or CA. 
This will make the hole you drilled smaller, rougher and harder.
I also make a complementary piece for the live center to use when turning dowels or as a jamb chuck.
The live center end is again a scrap piece of wood.
I have a 1"-8 live center so it is easy to make this end too.
Using a 2" x 2" x 1 ½" piece of pine, drill a 1" hole the depth of your 1"-8 center. Place this on your headstock, You might need to use tape around the spindle to make it fit tighter while making it round and drilling.
Turn it round and drill the same size hole as your dowel.
Finish with sanding sealer or CA to make the pine stiffer.
Place this on the your live center
Now you can place the dowel between centers and turn anything you want to.
I have made several for different size dowels.
