Bushing disaster

Surface A is raised higher for illustration purposes.

Dale it would matter if the bushing sits high of the base plate but I can't see a problem if it is sitting a bit recessed into the plate.

When trying to use a Forstner bit to counter bore an existing hole like you seem to be planning, the only way that I found that works well is to use the larger Forstner bit to first drill a hole in a piece of thick (3/4" or thicker) wood. Then position and clamp this piece of wood to your work so that the hole in the wood is aligned with the smaller hole in your work. Then use the Forstner bit through the hole in this piece of wood to drill the counter bore. The wood piece will serve to guide the Forstner bit where there is no center point to guide it. I would not try this without using a drill press to drill the larger counter bore because the Forstner bit might bind if you try this with a hand drill and ruin the work. Doing it this way along with careful control of the bit depth should be successful in creating the counter bore that you want.

Another way would be to use a small bottom bearing rabbeting bit to make the counter bore, if you can find one this small.

Charley

Agreed. Instead of power drilling, I’m thinking of turning the bit by hand, very slow and carefully.

Dale: Couple of questions for you - is this an aftermarket plate and what was it predrilled? What router is it for?

I had a set of bushings that wouldn't fit the base plate of my PC690. I found that the hole in the base plate had tiny tabs that prevented the bushing from sitting flush. An exacto knife to remove those tabs fixed it for me.

Hi Vince, the router is a Ryobi 180PL, which really works nice. The subplate is from Eagle, and it is not predrilled at all.
I bored the mounting bolt recess on the wrong side. I had lots of room to redo a new set of holes, and without
any overdrilling for adjustability the centering was perfect!
My bushings are the cheapo HF, and I cut all the collars to 1/4”. I wonder if all these bushing sets are intended to
be used with special templates?

Before I went any further I’d see if bushings from a different source might fit flush.

If you are wondering why Porter Cable type bushings come in different lengths, I think it’s because they were originally developed for their Omnijig dovetailing fixture.


In woodworking there is always more then one way to accomplish something.

Dale,

Turning that bit by hand is going to take you forever to cut the hole to the depth that you need. Just carefully set the depth stop on your drill press and drill a test hole in scrap the same thickness as your work piece to be sure that you have the stop set correctly. Use the wood block with the hole to guide the bit, and your bushing recess will turn out perfect. I have done this several times without a problem.

Charley

In this project I show how I routed the hole and rebate using a circle routing jig.

That omnijig looks fantastic.
Charley, I have no DP, table, or bandsaw.
Harry, I could not see how you made the bushing holes, freehand?
There is enough of the good bore remaining to align the Forstner bit, I just
need to make a little jig to keep the shaft vertical, while I very very carefully remove
enough plastic for the bushing to seat and be stable. Will post picture if successful.

Would it be easier to file down your brass bushing instead of opening up your counterbore?

By hand it would take forever, a metal-turning lathe would have been perfect. The big Forstner bit has arrived, so I
hope, with patience, it will turn out ok. Will post a picture. Thanks for the idea.
Dale