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OK. , Thanks for the responce Tony.

Good to hear Todd. The play I was referring to isn't in the pivot pin but the adjusting threaded rod. I was thinking that there might be a little play where the locking nut was and the two nuts on the other side of the middle piece. I was thinking that the nut had to have some space so that the rod could spin freely there. I'm not sure if I'm explaining what I mean clearly or not. Are most of you using the PC310 for this jig?

Chris, I use a makita (don't know the #) on mine. Here's a couple pictures of the new one I just made





I think the base of the PC310 is smaller and only requires 3 bolts for mounting so the circle cutter base can be smaller. As you can see on mine, I have 4 bolts much like many laminate trimmers have and they would interfere with the guide rods so I made mine a bit wider and run the guide rods outside of the trimmer base to avoid the mounting bolts.

I now understand what you are asking. The two lock nuts riding against the middle arm which the pivot rod is attached to. Because the arms (for lack of a better term) are made from UHMW or phenolic or.... they have some sliptivity to them (like that word? sliptivity?) so what I do is just snug up one of the nuts (it sucks the other nut up the arm) till there is no play but make sure that I can turn the threaded rod. There is no issue as long as it's set up right.

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Chris, its 15 mm acrylic. Some people don't like that way it machines and recommend polycabonate for stuff like this, I don't find it particularly difficult to work with though.

My pivot pin is 8 mm, and I doubled up the acrylic in the part where the hole for the pin is as I figured it might develop some slop there. I also use a work board under the guitar top when I use this jig, and it has a matching 8 mm hole for the pivot pin. So far, everything feels very tight and solid with this set up and I haven't felt a need to beef it up with bearings.

Oh, and remember to clamp the top to the work board before you cut the sound hole...

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Just finished it up. Video to follow sometime this week, I hope.

If anyone is interested I just posted a YouTube tutorial on making a Wells/Karol router base .
viewtopic.php?f=10117&t=18858
Might be a little boring for some of you.