What are my options for chuck replacement?

I have a Grizzly 7x12 lathe that I bought a few months ago. It came with a 3 jaw chuck.

I want a chuck that can grip larger diameter work pieces. I guess I can just bore out the work piece and grip it from the inside with the internal jaws the chuck came with, but I just want to get a chuck that can open up considerably more. Do I have options or am I stuck with this one?

Also, a quick question about 4 jaw independent chucks. People keep recommending them, but wouldn't it be a pain to have to find the center every time you put a work piece in, compared to a 3 jaw chuck that automatically centers the work piece?

 

I have an 0XA QCTP and I'm using 1/4" HSS blanks. Can I use 3/8" blanks with 0XA QCTPs?

If your OXA set fits SIEG C4 & SC4 lathes, then you can go up to 1/2", I even made my own tool holder that hold 16mm(.629") bits.
https://littlemachineshop.com/products/product_view.php?ProductID=4101&category=

 

An afterthought, or change of subject, or whatever you want to call it. There are times I will remove work from the chuck and then come back weeks later to make another cut. Sounds like you are facing a similar situation. I have a notch cut, on several chucks actually, on the outside corner. If something is "experimental" or if I don't really know what I'm doing, I will make a "sharpie" mark on the work so it can be put back where it was the first pass.

This doesn't always work as expected. But for tolerances of a few thou, the chance is worth the attempt. If I'm making a wheel, I try to do it in one chucking. On something more forgiving, it does pay to try.

 

1/4" cobalt bits are available, I've seen them on ebay and vendors like MSC and Fastenal

 

I have a 7x 14 and I actually use a 5" 3 jaw and love it. The spindle thru hole is only good for about .75" but with the 5" I am able to chuck a 1" piece a couple inches deeper until I max out the MT3 diameter. It will reduce the length that can be turned outside the jaws. The independent jaws are more accurate but I have a project that I have to make several pieces of varying diameters with fairly loose tolerances so I opt for the scroll type. LMS sells the adapter fully machined for the 7 X flange.

 

put a 4" on it, but remember the larger chuck you put on it you may have clearance issues with bed or carrage. use some brains when doing it.I was going to get a 4" for mine then I just got a new 9x20 and bought 2 extra chucks&back plates for it 5"&6" chucks.(5 is 4 jaw). you can remove your chuck and if your lathe does not have a removable back plate just messure it and make a plate to bolt to it and then square it up to the size for the larger chuck, make sure you index everything!!!( add marks so you always got it back where it should be.) it's not hard to do at all.just make sure you have interfearance fits so it centers up with no slop.

 

Buy a 3 jaw adjustable scroll chuck with 2 piece jaws, this will allow you to flip the top jaws or turn soft top jaws to fit the work.
You can also weld stock to soft top jaws then machine them in place to hold an odd part, the adjustable nature of the chuck body will enable you to remove any runout when the jaws are changed.
Like so, 6" long bars welded to soft jaws then machined in place.

 

I do agree with the 2 peice jaws.that's what i bought for my 9x20. well i bought both since the price was right at the time, wish i had bought more and a 6 jaw chuck...sometimes when we are thinking it blinds us from seeing.

 

This doesn't matter anymore since I sold my 7x12 and I ordered a Precision Matthews 11x27

It comes with a 6" 3 jaw and a 6" 4 jaw independent chuck