# Made some Soft Jaws.... (pic heavy)



## mdocod (Sep 14, 2009)

Figured I'd share this project with yall. This was fun for me, as it was my first "real" project requiring good precision that I have done in metal. 

First, a Thank You to CPF member PrecisionWorks who pointed out the fact that I could do this for my new indexing table since the jaws are 2-piece. It hadn't occurred to me at the time I bought it, but as soon as that idea started spinning around I realized I just had to make some custom jaws specific to my work....

I chose 360 brass (ultra-machinable). I am really happy with the way it cuts. I could definitely see using brass for future projects as this was just plain fun. No issues with heat or wearing out cutting tools like working in steel. Having experimented in steel and discovering that it's a royal PITA on a small machine I was a little concerned about the brass... After taking a 0.075x~0.550" pass at top RPM (~3300) as fast as I could turn the hand-wheel (estimated 20-25 IPM) I fell in love with 360 :thumbsup:

I actually started by making a set of jaws from plastic just to give it a try first. Practice on cheap material first 







That started as 1.25" diameter round rod acetal homopolymer (Delrin). Figured I'd use what I have laying around. They turned out perfectly functional and I learned a few things long the way that came in useful for the final build with brass. I may actually cut a specific step into these and use them for occasional operations that don't need a lot of strength. 

Here's a few picts of the project:






When I bought the machine, I never thought I would use that tilting head feature for anything...






First slot in the bottom:





After some more work:





One Jaw complete:





Also used the tilt-head feature to put a chamfer along the edges. 

Test fit:





I was really happy with the fit. The final piece came out really close to everything I was shooting for and fit just like the jaws that the unit came with, requiring force to drive into position but not excessively, (line up, and drive home with the bolts by alternating). 

And here they are:










After confirming that everything fit, I put the indexer back up on the table and got everything dialed in. I centered and zeroed the indexer off of the bottom half of the jaws, then installed the soft jaws to cut my steps into:






I think they turned out very well. I've already started using them and the results are fantastic compared with using my old 3" "cheese" indexer. 

I basically gave myself enough material hanging off both ends of the soft jaws, and am leaving the other side alone for now, this will leave me with freedom in the future to cut different steps as needed. 

-Eric


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## wquiles (Sep 14, 2009)

Eric,

Those look GREAT! 

Nice job :thumbsup:

Will


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## precisionworks (Sep 14, 2009)

> Those look GREAT!


My thoughts exactly 

After a while, you'll start to keep the jaw sets on a board with labeling for each job or component. I've seen shops with well over a hundred sets :twothumbs


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## StrikerDown (Sep 14, 2009)

Pic Heavy?

I think Will will agree, no such thing!

M,

Very nice looking work!


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## wquiles (Sep 14, 2009)

StrikerDown said:


> Pic Heavy?
> 
> I think Will will agree, no such thing!
> 
> ...



Well, yeah, pic heavy posts are kind of my thing ... and I only post the "good" pictures :devil:


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## gadget_lover (Sep 14, 2009)

I've considered making a set of 2 piece jaws for my 3 inch, 3 jaw scroll chuck. You make it look so easy to do the top part. 

Nice work

Daniel


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## Rothrandir (Sep 15, 2009)

Nice work!

Man, I love the look of brass...


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## dom (Sep 15, 2009)

Great idea and nice job.
Will you mark them " 1,2,3" to match back up if you take them off?

Cheers
Dom


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## mdocod (Sep 15, 2009)

Hi Dom,

Interesting question;

I don't think it's necessary since the bottom half of the jaws seem to be plenty accurate, and the steps I use were cut with the jaws installed on the chuck by an end-mill off-set of center, rotating the chuck around to cut them out. In theory, no matter how I re-install my jaws, I should land within about a thousands, which is actually over-kill accuracy for my needs.


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## Tac (Sep 15, 2009)

Great job! I've only done soft jaws for a lathe once, usually I stick to the "easier" to make mill vise jaws. 

However brass is new to me (For jaws), I usually just use aluminum. Might have to make some later.


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## precisionworks (Sep 16, 2009)

For machining, Alloy 360 (aka CDA Alloy 360, Alloy C360, free cutting brass, etc.) is as good as brass gets. It contains lead which provides some lubrication & makes it a free machining alloy. You can run really high sfpm (any where from 500 to 1500 sfpm), and the tiny brass chips spray off the cutter like really warm water droplets. Using a small cardboard shield to deflect the chips makes it easier to work with.

Some good info here:

http://www.copper.org/applications/rodbar/alloy360/free_cutting.html


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## Mirage_Man (Sep 17, 2009)

Nice work dude!


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