bad 4 jaw

itowbig said:

oh yes but it will require making every one of them. i wont trust this chuck the way it is. . ive ordered and recieved a 4 inch 4 jaw from little machine shop . i just broke down and got a good one. my 3 jaw is 0.27 off and ive screwed it up now by trying to grind it true. so is flippin usless now too.

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mcostello said:

You mean You cannot use a 4 jaw for Hex stock? Must be doing something wrong.

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john_reese said:

It was practical to make new screws for a 12" steel body chuck. For a 4" cast iron (import) chuck it is not worth the investment in time.

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Nick Hulme said:

The 4" Pratt-Burnerd which came with my Super 7 had half the square socket broken off on top of one screw, but they used UNC screws so a trip to the bolt shop and I had 4 new, rather chunky grub screws with nice new hex sockets, the correct thread and length, and which just needed a slot in the right place to drive the jaws. I can't see why they need to make small 4 jaw chucks more complex than that [/QUOTE


My Myford Super7 B( Burnerd) 6" independent also had broken screws when I bought it.

Probably caused by trying to push work along with two opposing screws firmly locked. The Two Bees Syndrome- Brute Force and Bloody Ignorance.

One day I'll braze them but with care they still work.

2 years ago at the Ally Pally, I got a 4 jaw self centring chuck for the two Myford machines thought that if care was not taken that it would also be a possible candidate if non concentric or non square materials were being held.

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Cogsy said:

You'll get so good at dialling in on the 4 jaw you wont need a 3 jaw (unless you need to machine hex stock). The first time I mounted my 4 jaw I didn't take it off for 6 months, but now I'm lazy and my 3 jaw does most of my work.

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john_reese said:

It was practical to make new screws for a 12" steel body chuck. For a 4" cast iron (import) chuck it is not worth the investment in time.

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