New lathe questions (chucks and QC setup)

Spot shooter said:
Tad,

I agree - which is why I’m planning on getting the PM 14x40 ultra precision lathe, with a DRO, 3 & 4 Jaw and drill chuck for the tailstock... all very high percision spec.

:)
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Caveat Emptor

When it comes to metal working, and especially the machinery, lathes, mills, grinders, perishable and non-perishable tooling, and their level of precision is very relative to ones perception of what high-precision "Is". The foreign companies tend to use the word.. "precision".. for everything from drywall screws to lathe chucks. Also keep in mind there's the PRC and then there's Taiwan. Their products can be anywhere JUNK to some of the best available. Taiwan of course being the leader.

You will notice the large tooling houses have multiple price and quality levels. Some of them with only 2 choices others have 3-4. Just keep in mind that there is no "cheap precision" items in this business.
 
And keep in mind if you machine the whole part in one shot in a decent 3-jaw and part off the section in the jaws the tolerance is very good over that piece.
 
Good job

R.G. Robinett said:
Ripped some 2x4s and glued/screwed them to a plywood sheet, then screwed the whole thing to the wall.:eek: I could live without some of those insert-holders didn't know what I was buying at the time . . . and got some duplicates :eek: Just wish I had purchased a better lathe - the Grizzly isn't as well-made as my old worn-out SB. RG
View attachment 21424
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That is a good looking rack. I like the top view to show what you’re grabbing.
 
I'm lucky enough to have three lathes in the shop one wears a 4 jaw one a 3 jaw and one a 6 jaw adjust true. My particular 6 jaw which is the case with most does not hold very small stock in fact the 3 jaw holds smaller stock so it gets used more often so if going with a 6 jaw I would suggest having a set of narrow pointed jaws so that you can get down to small diameters. A collet closer or some sort of way to hold collets is almost necessary in my opinion in a gunsmith shop and while I have a D-6 mount adjust true collet chuck I find it getting used less since I picked up a set of collet blocks which can be vised or chucked on, one is square and one is hex. The 4 jaw and 3 jaw probably get equal use and as most have said the runout on a 3 jaw is rarely an issue but sometimes it is frustrating in some cases such as chucking a previously machined part where the surface being cut needs to run true with the surface being chucked on .001-.002 is usually not a big deal but a lot of 3 jaw chucks run out .003-.005. If I had one lathe it would wear the 4 jaw most of time I'd rather indicate the work than change out chucks any day.
 
Like most have already said 4 jaw first. I have 2 lathes and Tru set 3 jaw for each, 4 jaw for each, and a 6 jaw Tru set for the Heavy 10. The 4 jaw is on the Heavy 10, 99% of the time. I have an ER32 collet holder and collets in increments of 1/32 (1/16”- 7/8”) that I can use to hold small parts and center to.0001 on any of the chucks.

Chet

er32 holder.jpg er32 collet.jpg
 
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