- Joined
- Jun 12, 2014
- Messages
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So I do a lot of parts were I am not turning and then cutting off the piece, I also had issues with small diameter work trying to push out between the jaws on my 3J scroll. The 8" Bison combo has narrow jaws and can hold stock down to 0.2" diameter, so even for small work it holds parts much better than my 3J scroll. The Bison combo also repeats to about 0.001" on parts so takes a very small tweak to zero down a part, and I has very low skew when holding parts compared to my other chucks. Typically my 5C is my go to for small work, I may do 8-10 operations on the same piece so it is a lot easier and safer for the hands. I use my 5C about 50%, combo 40% and my 3J PBA scroll maybe 10%. I prefer the holding power of the combo and can work down to surprisingly small diameter materiel, and the flip side with say hot rolled with a rough exterior I can center it up better then a 3J scroll. It all come down to a mater of preference and type of work one does. My forth lathe chuck is the PM 8" 4J independent which I only use for large stock or I am generating a lot of swarf and grit in roughing large stock. The jaws are way too wide and course for most of the work I do. Wouldn't consider a 6J for my type of work.
Combination chuck is a real oddball, but if I just wanted to leave one chuck on the machine as a doall, it would be the 8" Bison combo. I didn't purchase it with that expectation, it was a replacement for the crappy 4J independent that use to come with the lathe and I was not a big fan of removing work from the independent and then having to realign everything with the next op. The lathe also came with crappy 3J scroll (also part of the package) that wasn't even usable. In subsequent years they dropped these chucks for good reason.
Example of a small bronze bushing that needed to be centered and then threaded, also some other machining on the mating part that was not true and so needed to be offset in the chuck to true up. Of note the outer jaws marks on this piece are not from this chuck, it was part of a remnant that was being reused so I could just do a skim cut for the diameter.
Combination chuck is a real oddball, but if I just wanted to leave one chuck on the machine as a doall, it would be the 8" Bison combo. I didn't purchase it with that expectation, it was a replacement for the crappy 4J independent that use to come with the lathe and I was not a big fan of removing work from the independent and then having to realign everything with the next op. The lathe also came with crappy 3J scroll (also part of the package) that wasn't even usable. In subsequent years they dropped these chucks for good reason.
Example of a small bronze bushing that needed to be centered and then threaded, also some other machining on the mating part that was not true and so needed to be offset in the chuck to true up. Of note the outer jaws marks on this piece are not from this chuck, it was part of a remnant that was being reused so I could just do a skim cut for the diameter.
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