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View Full Version : I need a 4jaw chuck backplate. Reccomendations??



bennypapa
05-31-2007, 12:50 PM
I have a 6" 4jaw independent chuck that needs a back plate.
I will be mounting this chuck on my 12" Atlas lathe with the 1-1/2"x8tpi spindle nose. I'll need to machine the register in the back plate bore and the outside of the backplate to fit.
I'd rather not cut the threads.

Can anyone make a suggestion for a supplier of such an item?

I have had my eye on an Enco item
http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=950461&PMAKA=274-0122

I thought maybe I could make that work.

I need guidence please.

Thanks.

Bennypapa

topct
05-31-2007, 01:22 PM
Try here,

http://www.littlemachineshop.com/

http://www.littlemachineshop.com/products/product_view.php?ProductID=1919

Ignore the drilled holes, they use that same picture for several back plates.

ProGunOne
05-31-2007, 01:52 PM
http://www.cdcotools.com/

The above place has them for $38.00

Forrest Addy
05-31-2007, 03:15 PM
"I'd rather not cut the threads.

You're gonna have to some day. Internal threading might seem intimidating but it's not hard once you get the hang of it. Make spindle thread gage and a couple of trial pieces from scrap before you commit.

The whole idea of owning machine tools is to make stuff we either can't buy or hate to buy for one reason or another.

bennypapa
05-31-2007, 09:57 PM
At my current skill level I can't do the threading but I need to get the 4 jaw chuck up and running for a project I have in mind. For now I just need a back plate.

I get your point about learning the skills but I am pressed for time and don't have the time to learn right now.

Thanks all

Ben

J Tiers
05-31-2007, 10:09 PM
Seconding Forrest here......

Threading a backplate blank to 1 1/2-8 was about the 5th operation I ever did on a lathe, and it came out fine. I still use that backplate.

As an HSM, you have the option of being a "checkbook machinist" or learning stuff. If you DON'T thread it, you go another step down the path of checkbook machining, and you lose a learning experience, a confidence builder, an accomplishment.

I know, I know, you'll learn that "later"..... meanwhile you need to get this backplate done. Yep, good argument, but I bet you don't need it that fast, or you'd buy a complete backplate ready-done.

if you want to get good at this stuff, you need to take the attitude that whatever comes up, you DO IT if you have the equipment. How else do you build up the skill that you claim you don't have?

No matter if you don't know all about how, that is what textbooks are for, learning the "how". It isn't as if anyone was born knowing everything, any more than you were.

How you learn is by doing. How you DO is by trying, and that comes after the need, and some study of the possible ways of doing it.

Since every text on lathework has an extensive section on threading, you should be able to get a good grounding in how, after which it is up to you to DO it and learn.

Sorry for the rant, but if you simply tackle everything as and when it comes up, you will learn faster than if you shy away from tougher stuff, not to speak of the "can-do" attitude you will build up.

JCHannum
05-31-2007, 10:34 PM
There is no guarantee that the finished backplate will match your spindle. Different manufacturers over the years have used slightly different thread dimensions, and even though they are all 1-1/2"-8, they aren't, and the register may not match.

There is a good chance the boughten back plate may still need cleaning up, and you will then be faced with picking up the thread, which can be more difficult than threading from scratch.

Making a couple of practice threads is not wasted effort, as the threaded stock can be used for other tooling such as face plates or dog plates down the road. You will need them at some time too.

Alguy
06-02-2007, 03:34 AM
I agree with Forrest and Tiers and JC , go get some round stock and give it a try, one of the first tools i made was an endmill holder that screwed on the 1 1 1/2 spindle i was a bit overwelmed by the major and minor dimensions for that thread and still have some problem s with it, i made it just fine it took a few hours and finally got it, this was my first tool i made on the lathe i had very little experince , also the spindles on the south bends and atlas are not exactly the same , i own both they will interchage but how they fit is different, so if you do get a backing plate it may need some finishing,
Dont be afraid to try it, for confidence building use any round stock you have try to cut some threads for a nut you have , if you mess up no big deal , just try agian but you will get it sooner than you think , then you can add 1 more skill learned, then you will be hooked (grin);)