Can't Get PC 690 Cut Depth Adjustment Ring to Work

[jim evans]

I have been using a PC 690 router for a couple of years. I use it with the fixed base on a small Rockler table. I've never figured out how to make the fine adjustment ring work. See picture

always have to adjust by rotating the router body in the base. This is a very course adjustment making it difficult to get the cut depth set right.

When I try to use the fine adjustment ring it doesn't seem to do anything at all -- it just turns and turns but the blade does not rise or lower. What I am doing wrong?

jim

[DonkeyHody]

Jim, The only thing you are doing wrong is confusing the purpose of the ring. That is not a fine adjustment ring, it is simply a place-marker. You turn it so that the zero mark lines up with one of the reference marks on the body of the motor. Then you twist the motor so the reference mark moves to the desired mark on the ring. The ring is just a friction fit and is not threaded at all. There is no fine adjustment other than a very slight twist of the motor in the base.

DonkeyHody "Every man is my superior in that I can learn from him." - Thomas Carlyle

[marcj]

Hi Jim, The router table you're using looks pretty cool. Are those magnets holding the wrenches in place? Go any other pics? Does the base just clamp onto your workbench?

[Morris Dovey]

| I always have to adjust by rotating the router body in the base. | This is a very course adjustment making it difficult to get the cut | depth set right. | | When I try to use the fine adjustment ring it doesn't seem to do | anything at all -- it just turns and turns but the blade does not | rise or lower. What I am doing wrong?

As DonkeyHody noted, the ring is only a scale. You _can_ do reasonably accurate adjustments with it if you zero it to the bit. For straight bits, it's fairly easy - upend the router and turn the body until the bit is fully retracted, lay something flat across the base, turn the body to raise the bit until it just barely touches the "something flat", and tighten the adjustment clamp knob. With that done, rotate the ring until its zero lines up with the line scribed on the body. Now you're ready to loosen the clamp knob and rotate the router body until the depth you want lines up with the scribed line. Now if you cut a dado, it'll be within a gnat's whisker of the depth you wanted.

For extreme accuracy (I did this the last time I used my 690) I set the router base-up on my bench, loosened the adjustment clamp knob minimally, and retracted the router bit as above. Then I set a 1-2-3 block on the router base, positioned the face of my depth gauge on the

1-2-3 block, extended the gauge until it contacted the router baseplate, and zeroed the depth gauge. Then I shifted the business end of the depth gauge to ride the router bit as I rotated the router body to raise the bit until the depth gauge indicated that I had the depth setting I wanted to cut. At that point I tightened the router adjustment clamp knob and re-checked. Sometimes the setting is slightly spoiled (slop in the system) when I tighten the knob and when that happens, I loosen the knob just enough to repeat the process. My depth gauge is the digital type that'll read 1/1000ths with a +0.0005" indicator and I normally work to those kinds of tolerances.

The factory-installed scale ring should let you repeatably set within a 1/100" of any of the marked divisions; and if you have/develop a good "eye", you should be able to do fairly well between divisions.

HTH

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

[jim evans]

Thanks for the replies. I understand now. My previous router had a micro adjust feature and I somehow assumed this more expensive and more widely used router would too.

From my perspective this isn't a very practical way to do fine adjustments under the router table. Even hand held it seems like it would be awfully easy to bump it out of position. Oh, well. Thanks again for the clarification.

jim

[jim evans]

The benchtop table was made for the 690 router. I use it because I don't have room for a full router table. I can store this one with router attached in my workbench below where I deploy it for use.

I don't have other pictures, but here is a different view from Rockler

here are more details wrenches have are held on with strips of sticky-back velcro -- hook on the table and pile on the wrenches.

jim

[JeffB]

I have a PC 690 base permanently mounted on my router table, and find it to be very convenient and plenty accurate. The gradations on that measuring ring are

1/64", I can fine tune the cut depth or repeat a depth setting to better than .005" (measured depth of cut in workpiece). It did help to make two more guide lines (with a 'Sharpie' marker) on the body of the motor halfway between the two that come from the factory - makes it easier to make sure one guide mark is visible from the front when the router is mounted under the table.

[CW]

That ring is just an indicator. Rotate the body to adjust.

[todd]

First, this router isn't really designed for fine adjustments while in a router table. I have the PC 690, but I also have a PC 8529 that goes in the router table. This router is designed for above the table micro adjustment. If you want to do micro adjustment on your router, you're going to need a router lift, but honestly, by the time you do that, you could get a plunge router with a micro-adjust feature for about the same price.

Second, I've always used the ring as a relative rather than an absolute guide. Say I'm at a particular setting and I do a test cut and need to go another 1/8" deeper. I set the ring at zero and then rotate the router until it gets to 1/8. Again, it isn't designed to tell you exactly how deep your cut is.

todd

[jim evans]

I agree. I started to say that in my original post. I only want to use it for relative adjustments not absolute.

I set up the cut coarsely, and make a test cut. That's when I need finer control that lets me adjust from the test cut to the correct depth in one easy well controlled step.

jim

[CW]

Unless you don't want a router lift in which cae, learn to adjust the 690. I use one in a table and have no problem at all.