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Discussion Starter · #1 ·
Very disappointing day. During a tear-down of my recently acquired Powermatic 66 Cabinet saw, I discovered a very damaged center trunnion. The part number is 3810018. Anyone knowing of where I can find a replacement, please let me know. I do not know the exact year of manufacture of the saw, but I have narrowed it down to the 1980’s prior to 1987.
The photos show the damaged trunnion. Seems someone did not take time to remove build-up caked on sawdust and the pressure broke the teeth? I was also told that the seller was pretty sure the saw was from a High School shop, which may explain part of the problem?
PLEASE help if possible. Thanks!
 

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where's my table saw?
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If you can't find one ....

Any full service machine shop can add brazing material to the old one and recut the teeth. I've had trunnions brazed on an old Craftsman table saw and I've brazed my own cracked horizontal metal saw casting together when it broke. It's a great process used in many repair applications, but you need an good machinist to recut the teeth. Probably this method will be more expedient than finding another piece for that machine.


Here's another guy named Keith, my all time favorite machinst on You Tube, a real talent:
https://www.youtube.com/user/KEF791/playlists
 

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Why are you thinking it needs replaced? I mean, yeah, something there is obviously broken, but from here it doesn't seem like it'd be enough to affect function. The majority of the load should be carried right near the center, and it doesn't look like the missing piece extends that far in. Have you tried working the machanism? If it feels okay, I'd be inclined to leave it alone. If it ain't broke enough to be broken don't fix it after all
 

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Discussion Starter · #4 · (Edited)
This may be NORMAL design of Trunnion GEAR?

Very disappointing day. During a tear-down of my recently acquired Powermatic 66 Cabinet saw, I discovered a very damaged center trunnion. The part number is 3810018. Anyone knowing of where I can find a replacement, please let me know. I do not know the exact year of manufacture of the saw, but I have narrowed it down to the 1980’s prior to 1987.
The photos show the damaged trunnion. Seems someone did not take time to remove build-up caked on sawdust and the pressure broke the teeth? I was also told that the seller was pretty sure the saw was from a High School shop, which may explain part of the problem?
PLEASE help if possible. Thanks!
After having a day of trepidation over the way the trunnion gear looked... I decided to do some looking around for pictures to compare...?

See the pictures (under "My Photos" on the left under my profile name)

What I found were several good pictures of the same area of the trunnion and NOW believe that my trunnion may be OK and just is the way Powermatic designed it?

See photos and then compare to the one I posted...
 

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After having a day of trepidation over the way the trunnion gear looked... I decided to do some looking around for pictures to compare...?

See the pictures (under "My Photos" on the left under my profile name)

What I found were several good pictures of the same area of the trunnion and NOW believe that my trunnion may be OK and just is the way Powermatic designed it?

See photos and then compare to the one I posted...
That also wouldn't surprise me, may be a clearance issue
 

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David
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I think it's just made that way, probably for clearance as was mentioned earlier. I went back and looked at my restoration photos and thought I had another shot of this but the only one I have is the one below. It clearly shows a reduction in width of the gear. You may find something useful in my restoration as you go through the process - http://www.woodworkingtalk.com/f12/restoration-powermatic-66-table-saw-71249/

Bumper Auto part
 

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I think it's just made that way, probably for clearance as was mentioned earlier. I went back and looked at my restoration photos and thought I had another shot of this but the only one I have is the one below. It clearly shows a reduction in width of the gear. You may find something useful in my restoration as you go through the process - http://www.woodworkingtalk.com/f12/restoration-powermatic-66-table-saw-71249/

View attachment 278665
You may be right. Adjusting the resolution of the picture there doesn't seem to be an jagged edges consistent with a break.
 

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Discussion Starter · #9 ·
I agree! I may have OVERREACTED!>?

I think it's just made that way, probably for clearance as was mentioned earlier. I went back and looked at my restoration photos and thought I had another shot of this but the only one I have is the one below. It clearly shows a reduction in width of the gear. You may find something useful in my restoration as you go through the process - http://www.woodworkingtalk.com/f12/restoration-powermatic-66-table-saw-71249/

View attachment 278665
Now that I have had a chance to see pictures of other Trunnions from the Powermatic 66, I agree that it is the way it is DESIGNED!

I will remove this post as I think my trunnion is just normal. There is some wear (after all it is over 30 years old) but all in all it looks to be very usable.

AND I did go through your restoration pictures -- GREAT JOB by the way!

THANKS to all who have helped me on this!
 

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Discussion Starter · #11 ·
Trunnion is A-OK

Don't feel bad, I think many of us have actually learned something from this post.
Yes I am learning ALSO! --- One saw part at a time! LOL

I have done a complete tear-down of the trunnion and the internal mechanisms of the PM66, and it is going well. The trunnion is in A-OK shape!

The arbor bearings will be replaced and I will be repainting the assembly parts.
 

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where's my table saw?
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I would have fired that engineer!

If you only need 3/4 of the gear tooth, as shown why not eliminate 1/4 of all the rest of the teeth? Conversely, if the full tooth is needed, why not make it continuous all the way across?

Obvious, there was a space war between the gear set and some other part on the saw OR why would they make it the way they did? Something is goofy in that engineering shop..... just sayin' and I own a Powermatic 68. I hope I don't find that same setup/mess under my saw.:|
 

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It had to have been more costly to manufacture with that scallop on it. I bet when the saw is assembled and operated the reason for the scallop will be revealed.
 
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