Router Adjustment

I have a Porter Cable about ten years old and a Sears of even earlier vintage both of which use similar systems to set the height of the bit. The base has a spiral groove into which fits three pins on the otherwise smooth body. You screw the body into the base and the extent of the screwing determines the height of the bit. When you reach the desired height you lock the base to the body by turning a thumbscrew which contracts the base. I'm sure everyone has something similar.
The problem is that there's a ring around the base made out of plastic and marked with measurements such as 1/8, 1/4, 3/16, etc but I've never understood the reason for the ring. Logically it would seem to be some sort of micro-adjustment. You get it close to where you want the bit and then by rotating the ring you could move it (say) 1/4 and that would raise or lower the bit by that amount. But the ring just rotates; it doesn't raise or lower anything. In any event you'd be hard pressed to change the position of the body due to the clamping effect of the thumbscrew.
What am I missing here? I can't believe it's purely decorative.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
If you set the router ,base down, on a table and screw the top down until the bit contacts the table. Lock the motor in place. Turn the ring with the numbers so that zero is on the index mark. Now pick up the router, carefully unlock the motor and rotate it to the desired depth as indicated on the ring with the numbers on it. Hope that is clear enough. Cheers, JG
snipped-for-privacy@HopelessISP.edu wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

In case not, regard it as an indicator ring, not an adjustment ring. You must zero it manually - generally after you've the bit extension you feel you need - for it to give you an indication of how far up or down you go while tweaking. It in _no_ way substitutes for a true micro adjustment.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I believe the ring should remain stationary if you just move the motor in the base. There should be some point on the motor that you can use as an index mark. You turn the ring to zero it and then turn the motor. If you want to move it 1/8", for example, you would turn it until the index mark on the router aligns with the 1/8" mark on the ring.
Think of the watches out there that have the rotating ring around the outside.
Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
OneBungLung,
Usually there is a seam on the body of the motor that provides a definitive line. After you mount the bit, zero it in by rotatating the motor until the bit touches the wood. Lock the motor tight. Rotate the ring with the measurements on it until the 0 lines up at that seam. Now unlock the motor and rotate it until the seam falls on your desired depth of cut.
Chuck
snipped-for-privacy@HopelessISP.edu wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You get the height to an approximate, rough position, and lock it in place by twisting the thumb screw. Then, say you want to move the bit height up by precisely 1/16". Leaving the motor housing locked, rotate the plastic ring until you line up the "0" with the "scribe" mark on the motor housing. Now, to move the bit up (or down) a precise amount, you simply loosen the thumbscrew slightly, and rotate the motor housing until the scribe mark lines up with the amount you want the height to change. In other words, the plastic ring does not actually change the height for you; you have to do it yourself. But it does act as a "zeroable" guide to guide you to the precise amount of height change you need. I hope I haven't just confused you more.
Although it's an old system that's been around a long time, it works remarkably well. When people do have problems with it, it's usually related to the motor housing and/or the base losing "concentricity" with respect to each other, such that when you change the height, the bit actually moves laterally as well.
HTH.
snipped-for-privacy@HopelessISP.edu wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The purpose of the ring is to 'zero' the bit height level with the base, then twisting the body & ring as one you can set the cut depth without seperate measuring tools. I prefer to use setup blocks or a nice ruler to set my depth adjustments and ignore the ring altogether. . . .
snipped-for-privacy@HopelessISP.edu wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
There's a line scribed vertically in the body of your router. You may need to clean it a bit to see it ;) But you line up the 0 mark on the rotating ring to the scribe line, then you know how much you've moved the router up or down (depending on which way you turn it).
Mike
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The ring is just a depth scale - it doesn't adjust anything by itself. There's an indicator line on the router body. Turn the ring so zero is on the line when the bit is just touching the workpiece. Then (turning the whole motor, not just the ring) adjust the depth as desired.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.