Clausing 6300 x 12"

Re: Clausing 6300 x 12"

Hey Paul,
Do mean a head stock?
A head stock for this type of lathe?
Ed
 
Re: Clausing 6300 x 12"

Ed, if I were tackling that job, I'd chuck the od, as you have done, then machine the ID complete, threads and all. Face that end as part of the operation. Bore through at finished size. Then make a threaded "spud", a facsimile of the spindle you want to fit. Measure the thread with wires, and make the spud identical to it. In fact, you could make the spud first, and use it as a thread for the nut. Now chuck the spud and screw the new nut onto it for finishing the OD and back face. Take the spud, with the nut screwed tight on it over to the mill and put the spanner holes in it, along with the beauty slots if you want them. You're done when you get the nut off the spud.
 
Re: Clausing 6300 x 12"

P1140001.JPGWell heres what i have, Never got around to getting the rest so it prolly was scraped.

I'm keeping the spindle thread protector.

P1140001.JPG P1140002.JPG P1140003.JPG P1140004.JPG P1140005.JPG
 
Re: Clausing 6300 x 12"

Hey Tony,
That's sounds like a good plan of attack for this chapter of my lathe rebuild. But I'll tell you what, I know a guy who has a hardness tester and I know he'll let me test this piece of 4130. I think that should be my first move because my concern is that I do this job right.
So I'll see if I can get this piece over to him later today or tomorrow. And I'll take a pic of the reading and then you can make a recomendation. Because I don't think there's any way to tell wether this piece is off the shelf Q & T'ed. And after all we talking about hardness, aren't we?
Meanwhile, I can start maching the spud.
The other concern I have is that I don't know how squarely I can mount it in the chuck. It seems to be deformed at the O.D.
I tried turning it and it was pretty wobbly. But I guess from your advice you think I should face it then machine the bore first then cut down the O.D.
Ed
 
Re: Clausing 6300 x 12"

Hi All,
I wonder why this website keeps getting hacked ....
Anyay, I did put this piece of 4130 on a Rockwell Phase ii hardness tester after a few tries we were able to come to an average of 50 on the B scale.
So if I 'm reading that chart that Tony sent me, I guess we're looking at the approximate tensile strength of no more than 73,000 psi.
I'm not sure if I am figuring this correctly.
Ed
 
Re: Clausing 6300 x 12"

Offhand, I'd say that bar is not Q&T. Here is a chart on 4130:

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=m4130r

And here is a bit of research into metallurgy of low alloy steels. Maybe you can catch a bit of info there. It's more than you really need to know, but knowledge is a good thing.

http://www.tppinfo.com/defect_analysis/yield_strength.html

In my judgement, that piece is not recommended for making the nut you need. The problem is getting it heat treated. Most treaters have a minimum for a furnace run that will probably be more than you want to pay. Maybe you could hold out for a more suitable piece, unless you have a friend in the ht business.
 
Re: Clausing 6300 x 12"

Hey Tony,
I know that you are now the head hancho here at hobby-machinist so I was wondering if your new resposibilities prohibit you from answering questions.
I am really enjoyng the exchange we are having and as a result, I have had to do some researching and soul searching on this whole heat treating process.
So, my question today is probably a dumb one but, what the heck, here goes:
When I see the Rc behind a number, are you reffering to the Rochwell hardness tester "C" scale? I think I already know the answer to this but I am just in need of confirmation on this.
And what whould be the recommended range of hardness for my perticular application? .... I just thought of something ...
I'll take my old spindle nut to my friends shop and put it on the Rockwell hardness tester. DUH! ...
I understand if you choose not to answer my question.
Ed
 
Re: Clausing 6300 x 12"

Ed, part of being Head Honcho means I'm not prohibited from ANYTHING!:cool: Certainly not from answering questions. That's why I joined here in the first place.

Yes, Rc means Rockwell hardness scale "C". If you search a little online about metal hardness and measuring it, there is quite a bit....more than you will need for this particular project. There are reasons behind each of the different scales, but that's a long story.

For your spindle nut, the original could be pretty hard. Some steels retain their toughness even though they are hard. Your 4130 is capable of a great compromise between hard and tough. It's difficult to alloy a steel that will allow both. The nut you are making should be high 30's to mid 40's Rc, In my opinion. That's still machinable, with a little patience and good tooling. If you felt like it needed to be harder, it wouldn't hurt it, but I would never recommend that 4130 be used in that way in the 50's. Bad spot in the compromise. Plus difficult to machine with common tooling.

Measuring the old nut is a good idea, but don't be surprised or disheartened if it is harder than you can practically work your new piece. Plus it's not impossible (thought unlikely I think) that it would be case hardened. You won't usually see that where there is the possibility of people hitting a part with a hammer or something. Just stick with 30-40 range, as above, and you'll have a perfectly serviceable nut.
 
Re: Clausing 6300 x 12"

Well, it does machine very well as it is in it's current state.
I wonder what that means.
 
You must log in or register to reply here.
Back
Top