# Stupid 3 jaw issue



## kg6bws (Jul 4, 2013)

Like an idiot, I didnt look up a how to first.  I wanted to flip the jaws on my 3 jaw chuck and removed them the same as you flip the jaws on a 4 jaw.  Now theyre way off.  When 1 jaw gets to the center, #2 is maybe 1/16" off and #3 is maybe 1/8 to 1/4" off.  How do I realign these?  Thanks.

Edit - Think I just found where I screwed up.  Going to go measure the jaws and move them around.  I now know theyre out of order.  Im guessing theyre different lengths to be able to work in the scroll and center themselves.  Gonna go use the old trial and error method of fixing idiocy. LOL


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## TOOLMASTER (Jul 4, 2013)

if they are in the right slot. just put pressure on all 3 and turn the key backwards til they drop into the same alignment, then tighten to check....if they dont line up you may need to swap 2 and try again


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## macrnr (Jul 4, 2013)

The jaws should be numbered. You turn the key and watch the scroll plate until the thread is just before the #1 jaw, at that point insert the jaw and turn the key until it is engaged turn the key and do the same to #2 and #3.


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## kg6bws (Jul 4, 2013)

Yeah thanks.  I was typing an edit same time you posted.  Gonna go try it out.


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## Maxx (Jul 4, 2013)

I start with the #1 slot when I see the thread start I insert the #1 jaw, slowly rotate the key until I see the thread start at slot #2 insert #2 jaw and rotate some more until I get to #3.


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## kg6bws (Jul 4, 2013)

Hopefully theyre numbered. Unfortunately I didnt pay any attention when I took it apart...


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## wlburton (Jul 4, 2013)

Tubal Cain has a good video on you-tube which explains how to take a chuck apart, clean and lubricate it, and put it back together.


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## 12bolts (Jul 4, 2013)

You cant "just flip the jaws" on a 3 jaw self centring chuck!
Because they are driven by a scroll gear the jaws are cut with curved teeth to mesh with the curve of the scroll gear. 3 jaw chucks come with a 2nd set of jaws for reversing.
But like others have said, match jaw #1 with slot #1 and engage 1st tooth, then #2, and then #3. Then they should alll line up together.

Cheers Phil


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## Maxx (Jul 4, 2013)

If the jaws are not numbered you can flip them upside down and look at the thread.
The first one has the thread closest to the tip, third will be furthest from the tip.


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## kg6bws (Jul 4, 2013)

12bolts said:


> You cant "just flip the jaws" on a 3 jaw self centring chuck!
> Because they are driven by a scroll gear the jaws are cut with curved teeth to mesh with the curve of the scroll gear. 3 jaw chucks come with a 2nd set of jaws for reversing.
> But like others have said, match jaw #1 with slot #1 and engage 1st tooth, then #2, and then #3. Then they should alll line up together.
> 
> Cheers Phil



HAHA!!  So I noticed! :banghead: 

Its all good now though. Took a few tries but managed to get it all back together correctly.

Thats what I get for getting ahead of myself.  Another learning experience to add to the list.


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## Bill Gruby (Jul 4, 2013)

Both inside and outside jaws should be stamped 1-2 or 3. The numbers match with the numbered slot on the chuck. If you assemble them in that order you should have no trouble with them.

 "Billy G"


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## kg6bws (Jul 4, 2013)

Bill Gruby said:


> Both inside and outside jaws should be stamped 1-2 or 3. The numbers match with the numbered slot on the chuck. If you assemble them in that order you should have no trouble with them.
> 
> "Billy G"



THeyre not, which is what screwed me up.  I didnt pay attention when I took it apart and couldnt find any markings on the check at all, body or jaws.  Now that I know which goes where Im going to put some punch marks to keep them straight.


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## macrnr (Jul 4, 2013)

kg6bws said:


> THeyre not, which is what screwed me up.  I didnt pay attention when I took it apart and couldnt find any markings on the check at all, body or jaws.  Now that I know which goes where Im going to put some punch marks to keep them straight.



It will only go together and work one way. Pretty obvious when you get it wrong.....


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## itsme_Bernie (Jul 4, 2013)

You can flip some three jaw chuck jaws.  The "teeth" are almond shaped.

If you sit the jaws upside down, scroll teeth looking up at you, sitting right against each other, you will easily see the order they go in by the teeth.  Especially looking at the innermost tooth.

The innermost tooth on the Jaw #1 will be the closest to the tip of the Jaw.  Then two, the three.  

When you install them, put Jaw 1 in slot 1.  If the slots aren't numbered, it may not matter- wherever it goes most easily.  Turn the chuck key -backwards, WHILE pushing the jaw in.  When it "pops" down, turn to the right until you see the first thread of the scroll reach the next slot.  There is two.  
Same thing for three.

Bernie


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## Ray C (Jul 4, 2013)

Thanks Bernie...  I just didn't have time to respond to this one today and you described it very well.

One other thought.   If you remove all the jaws and look at any one particular slot while turning the key, you can see the leading edge of the scroll thread.  When you see it, back up a tiny bit and put jaw #1 in there then chase it around and insert the other 2.  The starting point is basically irrelevant but...  In some cases your jaws fit better in some slots over others or, the jaws might have less runout.  Do the merry-go-round routine and see if any particular positioning is better and holds pieces with less rounout.  If that's the case, make note of where your #1 slot is and always use it.


Ray




itsme_Bernie said:


> You can flip some three jaw chuck jaws.  The "teeth" are almond shaped.
> 
> If you sit the jaws upside down, scroll teeth looking up at you, sitting right against each other, you will easily see the order they go in by the teeth.  Especially looking at the innermost tooth.
> 
> ...


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## dickr (Jul 5, 2013)

That's not idiotic that's experience and I'd really be amazed if everyone one here thats worked with lathes hasn't done the same thing. Where would you be without a mistake to learn from. It's part of getting better. 
dickr


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## TOOLMASTER (Jul 5, 2013)

I have a brand new lathe that the outer jaws don't fit...the place i bought it from won't fix it either..won't buy from them again..had to buy a new chuck set:angry:


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## george wilson (Jul 5, 2013)

I did see an old 6" South Bend chuck that had reversible jaws,but only that one chuck. The teeth were foot ball shaped,and were not as strong as normal teeth.

Likely done as an economy measure that was not universally adopted because of weakening of the teeth in the jaws.


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## itsme_Bernie (Jul 5, 2013)

dickr said:


> That's not idiotic that's experience and I'd really be amazed if everyone one here thats worked with lathes hasn't done the same thing. Where would you be without a mistake to learn from. It's part of getting better.
> dickr



That's how I know how to write it so clearly!!!  Hah  


Bernie


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## kg6bws (Jul 6, 2013)

Yup, experience.  But boy did I feel a little stupid once I pulled the jaws out and thought for a second about the meaning of it being a "scroll chuck".  )

Ahh well, live and learn.  Its back together now, properly, so its all good.


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## markknx (Jul 13, 2013)

It will only be supid if you do not learnfrom it. I know someone that did the sameanic:And he feels a little better now.:whiteflag:

QUOTE=kg6bws;130473]Like an idiot, I didnt look up a how to first.  I wanted to flip the jaws on my 3 jaw chuck and removed them the same as you flip the jaws on a 4 jaw.  Now theyre way off.  When 1 jaw gets to the center, #2 is maybe 1/16" off and #3 is maybe 1/8 to 1/4" off.  How do I realign these?  Thanks.

Edit - Think I just found where I screwed up.  Going to go measure the jaws and move them around.  I now know theyre out of order.  Im guessing theyre different lengths to be able to work in the scroll and center themselves.  Gonna go use the old trial and error method of fixing idiocy. LOL[/QUOTE]


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## gmcken (Sep 14, 2013)

I had a set of three jaw chuck with no marking.  Marked them with a cutoff wheel.  A center punch will also work with a dot for 1, 2 dots for 2 ; etc.


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