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

Hi Mauser,

I'm retired and I agree with you about funds. You might have noticed that I mention that I pick up bits and pieces from scrap yards, thrown out junk etc. In fact anything that could be re used. It helps economise the pennies. :)

Didn't you mention that you had a faceplate ! Well if so you already have something that can be utilised to hold odd shaped workpieces.
Basically a large chuck. Now you just have to be creative. But do so with safety in mind !
 
No, my mention of a faceplate was a slip of the tongue, er... fingers. I meant to say backplate. The ONLY thing I have to hold workpieces is a six inch three-jaw chuck, with its matching backplate.

Although, now that you mention it, I could just get a faceplate and make do until I really NEED the four-jaw... I'll keep my eyeballs peeled...
 
I have the Enco version of that lathe. It is a 2.25x8 TPI spindle (double check yours with calipers tho). Check out small tools in Euclid OH (They have an ebay page). Their China brand "SAVON" 8" 4 Jaw chuck came with a backplate for under $150. I've been pleased with it.

Not seeing the 8" right now, but here is the 6".

https://www.ebay.com/itm/SAVON-6-4-...224731?hash=item282332d11b:g:rU8AAOSw44BYEhui


Also if you want some info on your lathe (and my struggles) here is a little read:

https://www.hobby-machinist.com/threads/enco-12x36-lathe-rebuild-picture-heavy.68660/#post-574827

Edit: I use my 4 jaw at least 75% of the time. It is a worthwhile investment, maybe second to a Quick Change Tool Post (QCTP).
 
Actually... that looks pretty good!
But.... whats this? From the ebay page, "IMPORTANT: The adapter pilot needs machined to our specifications."

What are they talking about? What needs to be machined, and whose specifications? I think I'm going to bookmark them!

Hey, you got your lathe without four-jaw or faceplate too! Yours looks pretty significantly different than mine, at least in the ancillary bits. Mine doesn't have nearly the gearbox yours has! Also, if I remember correctly, my spindle bore is something like a quarter inch bigger (which is what kinda sold me on this particular lathe, when I saw how big it is. Aftermarket modification? Bad engineering? Dunno, but it's big.). Mine is not a gap-bed like yours or the Grizzly, either.
 
Hi Mauser,

Yes you will have to machine the faceplate to suit the chuck ! There is a recess in the back of the chuck that the faceplate will have to be machined to suit. This recess locates the chuck concentrically and determines the accuracy. Though for an independent four jaw is not as critical as it is for the three jaw self centering chuck.
 
Mauser lover said:
Actually... that looks pretty good!
But.... whats this? From the ebay page, "IMPORTANT: The adapter pilot needs machined to our specifications."

What are they talking about? What needs to be machined, and whose specifications? I think I'm going to bookmark them!

Hey, you got your lathe without four-jaw or faceplate too! Yours looks pretty significantly different than mine, at least in the ancillary bits. Mine doesn't have nearly the gearbox yours has! Also, if I remember correctly, my spindle bore is something like a quarter inch bigger (which is what kinda sold me on this particular lathe, when I saw how big it is. Aftermarket modification? Bad engineering? Dunno, but it's big.). Mine is not a gap-bed like yours or the Grizzly, either.
Click to expand...

For the first part, the face a pilot diameter (the little nub sticking out on the front) are left slightly oversize so you can take a truing pass with your lathe once seated on the spindle. I also found that the internal diameter on my backplate was a touch small. The process is, mount the backplate backwards on your spindle (thread it on) and bore the internal diameter +.0005 over the diameter behind the threads on your spindle. Take it off, clean the threads really well, then thread it on the correct way (make sure it fully seats on the shoulder of the spindle). Then take a skim cut all the way across the face (use the power cross slide) and turn the pilot to -.0002 to -.0005 of the chuck mating feature. then bolt your chuck on. It isn't hard and eliminates axial runout. You should do this with any threaded spindle attachment.

It looked at first glance to be similar to mine, sorry that I didn't catch that it was significantly different.
 
Thanks for the explanation on that.

I've had several people tell me it is similar to something else, but they always end up being a little bit different. And some of the stuff seems like it could be just an older model (lack of a gap bed, metric thread, maybe just an older production run?). Who knows at this point! I've gotten quite a bit of good information from those "similar" lathes' manuals though. So, it's always good to read through their manuals and at least get an idea of what's going on.
 
All the face plates I've seen that have been finished to suit a particular lathe spindle have already been machined to suit the register.
Are you saying that even though they are threaded, you still have to machine them to suit your machine register ?
 
Sorry that question was directed to Macardoso.

We both posted at the same time.
 
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