Jaw alignment on fiber rotary.

[Neville Stewart]

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For the life of me I can't get these jaws to contact equally. What the heck am I doing wrong?

[Chris J Anderson]

Hi Neville.

Remove the jaws then insert jaw no1 in slot no 1.
Then turn tool as if loosening jaws.
Turn until yiu hear and feel the thread click under jaw 1.
Then insert jaws 2 and 3.
Start tightening while holding light pressure on all jaws.

This should fix it.

If not you may have 2 jaws the same which is incorrect.
Stack them and you should see that each thread is lined up differently.

Hope this helps.

[Doug Fisher]

Chris' reply is should help you.

I am a rotary chuck newbie too and have struggled with this. I wish I had bookmarked the link at Youtube but there was a tutorial on three and four jaw chucks that was great. It was by an instructor at a Kansas City area community college and he showed a method where you start turning the key and visually watch in the channel number one for the beginning of the scroll spiral to just appear to enter the slot 1. You put in the jaw for one. Then you advance the spiral around and it will catch the first thread on jaw one. Continue advancing the spiral until it just starts to appear in slot two. Put in jaw 2 and turn the key so the spiral catches jaw 2. Do the same for three. If you did it right, they will be aligned when you crank them all together.

I can't find the video I referenced above but if you want to see how the chuck works internally, this is interesting and you will see what I am referring to when I talk about the start of the spiral. It is on the big flat disc they show after they go inside the chuck:

https://www.youtube.com/watch?v=AT3_w03TZhg

Don't forget that each of your jaw pieces is numbered from 1 to 3. I have the same chuck and my jaws (both sets of 3) are stamped in the slots along the side. Your chuck's three slots should also have a number of them. Match the pieces to the slots! I used a marker on the outside of the chuck's slots and each jaw piece to make it easier to recognize which is which.

Doug

[Gary Hair]

Because they aren't even close, I'm guessing you have them in the wrong channel. Check that first and ensure they are where they should be. I do it a little different than the other two replies but it will get you to the same place. I hold all three jaws in place with one hand and turn the key with the other. When all 3 snap into place with #3 being last, turn the key to tighten them and they should all align. The key is having #3 snap last as it means that they are all in the same starting point. That's how it works for mine anyway.

[Kev Williams]

Note-- ONLY the jaws are numbered, the channels in the chuck are typically not numbered, so there's no particular 'starting' channel. The spiral gear inside doesn't care where you start :)
All that matters is that the jaws are in the correct 'rotary order':
while looking at the front of the chuck, the jaws go into the channels as shown:
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This is how they must be clocked. If not they'll never line up. As for the starting 'snap' position, I back off the chuck holding all 3 jaws until the #1 jaw falls, then tighten them in.
I've never tried it Gary's way using #3, but I believe it works too, but what won't work is #2 falling in first...
Anyway- Turn them in until the tops of the edges jaws are flush with the outer edge of the chuck, they should ALL be flush. If so, you're good to go...

for those who might not know where the jaw are numbered:
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Also note you'll have 2 sets of jaws, 1 set clamps from the stepped side, 1 set clamps from the long side. They'll only fit the chuck one way :)

>>edit<< I just tested my chuck, and I found that to zero the jaws, the #1 jaw MUST drop first. If #2 drops first, 2 and 3 will align but #1 will be too high, and if #3 drops first, 1 and 2 will align but #3 will be too low...

[Doug Fisher]

>>he channels in the chuck are typically not numbered,<<

Kev - I have no doubt you are correct about your chuck but I have the same chuck brand as the original poster and each of my slots is numbered. They are not the easiest stamps to see but each slot is stamped with a number from 1 to 3. The following picture shows the location of the stamp. This picture is of the #2 slot. If there is a lot of grease or dirt it could make the mark hard to see.



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[Chris J Anderson]

I agree Kev, the slots really shouldnt need to be numbered, only the jaws.

But I guess in a high speed machining situation they would as the chuck would be balanced with the jaws in a known slot.

[Kev Williams]

I did say 'typically' not numbered (never say never!) ;)

The numbers WILL help those will no experience working with chucks to get the clocking order correct. I scratched numbers into the chuck on my cylinder engraver when I first got it, but now the jaw order is second nature. Once you're used to the clocking order, the numbers in the slots won't matter.

[Neville Stewart]

I might never have figured that out. I was resigning myself to Chinese precision manufacturing. Thank you all - N