What do I need to know about chucks before buying a four-jaw?

I didn't get a faceplate with the lathe. Unfortunately. Fortunately... I did realize this when purchasing it...
 
Mauser lover said:
How dare you?! Talking me into cheaper tools!? I came here because I thought everyone here was in the business (or hobby) of talking everyone into more expensive tools!

Really though... Thanks for that suggestion on the sizing, and the help so far with all my questions. It seems that these size lathes generally ship with a six inch three-jaw and an eight inch four-jaw and a twelve inch faceplate (as far as tooling for holding workpieces go). I only got this six (ish) inch three-jaw when I purchase it, but I'd guess that it should be able to handle an eight inch four-jaw chuck.

I'm going to be short of time for the next couple of months, but I'll try to pull that backplate off this weekend and have a look at the spindle and see whats going on back there...
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Oh, just hang around us for awhile and give us an opportunity. We will definitely help you spend your money - it is our solemn responsibility to do so! However, most of us will try to help you do so wisely and that was my intent here. Here is an excerpt from Logan Actuator on sizing chucks for their lathes: http://www.lathe.com/faq/#_Toc95180284

What is the right size chuck for this lathe?
2.13.. Logan supplied a 5” 3-jaw chuck and a 6” 4-jaw chuck for their 10” lathes. Logan supplied a 6” 3-jaw chuck and a 6” 4-jaw chuck for their 11” lathes. Larger chucks were available, but they are impractical on these lathes because the jaws would hit the bed when the chucks were opened. Larger chucks are also heavier, so they put a strain on the spindle and spindle bearings. In general, use the smallest possible quality chuck for the job.

I always thought this to be wise advice. I own an Emco 11" lathe and while I could easily fit an 8" 4 jaw chuck on it, I prefer a 6.5". I don't do huge work pieces that would require an 8" chuck and given that the max safe operating work piece weight for my spindle is 99# when held by the chuck alone or 176# with tailstock support, I don't see that I would benefit from that large a chuck.

My point is that you should think carefully when choosing tooling for your lathe. If you have a need for a large chuck and your spindle and bearings can handle the weight (the combined weight of the chuck and the work piece) then go for it. However, if you are choosing a chuck based on what will fit or that you think you might need it "someday" then hmmm, think twice. In over 30 years on a hobby lathe I have never needed to turn a work piece that would require an 8" chuck. Obviously, your needs and the needs of others will vary but just be clear on Need vs Want.
 
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Must..... Build.... Cannon!

Joking, but it is good to hear that perspective every now and then! I don't have any solid specs on what my spindle/bearing will take, so it is as much a guess at this point as anything else, as far as my part goes.
 
Don't take it too seriously. Most 12" lathes come with an 8" 4 jaw chuck. The spindle should be able to handle it.
 
Okay, got the chuck off, the major diameter of the threads on the spindle LOOKS to be 2 1/4 inches in diameter with my highly calibrated Stanley tape measure. I am pretty sure eight threads per inch is correct though, unless there is some metric equivalent that is SOOOO close... Here's a pic in case it helps... or not.

I was putting off buying another caliper, 'cause I've got one already, it is just three thousand miles away! Moving three quarters of the way across the USA one pickup load at a time has its disadvantages... I've got one coming now anyway, because I don't like living without something akin to precision measuring instruments.

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Sounds good. Would it be good practice to make my own backplate? Or not worth it?
 
They are ALL crazy! No matter how sane one seems, she will turn out to be a headache....oh wait, you said "chucks", not "chicks"... in that case, I agree with Mikey, except I only use a 6", and so far I haven't needed anything bigger.
 
Alrighty... It's going to be a while before I pick up a chuck though, probably. Either a really good deal has to come along on the fleabay, or my tool fund needs to get replenished enough to purchase a decent deal or a brand new one. The trouble with being into machining as a "hobby" is that the funds put into it have to be justifiable at the time! That and I'm just slow.

Thanks for the help all!
 
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