# Unsure what is meant by thoughbore and counterbore



## RickPr (Jan 16, 2012)

I am looking for some assistance in understanding the following terminology.

" Fits base plates with a 1-3/16" through bore and a 1-3/8" counterbore. ". 

This statement is on the Lee Valley website and related to a Leigh Super Jig.


----------



## jschaben (Jun 21, 2009)

RickPr said:


> I am looking for some assistance in understanding the following terminology.
> 
> " Fits base plates with a 1-3/16" through bore and a 1-3/8" counterbore. ".
> 
> This statement is on the Lee Valley website and related to a Leigh Super Jig.


Hi Rick - pretty much what it implies. The through bore is the hole going completely through the base plate and the counter bore is the slightly larger circle around that that leaves the little lip.


----------



## RickPr (Jan 16, 2012)

Thanks John. My "bore" measures about 2 3/4 ". It doesn't look anything like the photo you provided. Do folks buy (or make) inserts to create the correct opening or do folks buy / make sub plates with the correct size opening? I will try and post a couple of Pictures. Not sure how yet.


----------



## bobj3 (Jan 17, 2006)

You need a plate like below

Milescraft 1201 Base Plate / Bushing Set for Routers - Amazon.com

===========


RickPr said:


> Thanks John. My "bore" measures about 2 3/4 ". It doesn't look anything like the photo you provided. Do folks buy (or make) inserts to create the correct opening or do folks buy / make sub plates with the correct size opening? I will try and post a couple of Pictures. Not sure how yet.


----------



## greenacres2 (Dec 23, 2011)

What router do you have? Looks like the existing plate is drilled/tapped for some sort of reducing insert. If you don't have that, then the Milescraft base suggest by Bob would work great (if you can figure out which of the Swiss cheese holes line up!!)


----------



## jschaben (Jun 21, 2009)

RickPr said:


> Thanks John. My "bore" measures about 2 3/4 ". It doesn't look anything like the photo you provided. Do folks buy (or make) inserts to create the correct opening or do folks buy / make sub plates with the correct size opening? I will try and post a couple of Pictures. Not sure how yet.


Hi Rick - Earl's right, those two threaded inserts on either side of the hole on your router will either take guide bushings or a guide bushing adapter made for your particular router. I don't know what router you have so will go along with Bj's suggestion about the Milescraft plate. Another alternative is nearly every woodworking place will sell a aftermarket plate to take the PC style guide bushings. Making your own is still another alternative.


----------



## RickPr (Jan 16, 2012)

Thanks everyone. It is clear to me now! Looks like this would be a suitable after market base.

Adapter Base Plate - Lee Valley Tools


----------



## jschaben (Jun 21, 2009)

RickPr said:


> Thanks everyone. It is clear to me now! Looks like this would be a suitable after market base.
> 
> Adapter Base Plate - Lee Valley Tools


Hi Rick - that one should work fine. You will also need a way to center it on the router base though. Sometimes a centering pin will be included with the base plate but I didn't that listed. Maybe a phone call to Lee Valley will make sure you are up and running.
Basically, to use guide bushings effectively the router bit and the guide bushing need to be running around a common axis, namely the armature shaft so everthing needs to be centered on that. Good Luck


----------



## RickPr (Jan 16, 2012)

jschaben said:


> Hi Rick - that one should work fine. You will also need a way to center it on the router base though. Sometimes a centering pin will be included with the base plate but I didn't that listed. Maybe a phone call to Lee Valley will make sure you are up and running.
> Basically, to use guide bushings effectively the router bit and the guide bushing need to be running around a common axis, namely the armature shaft so everthing needs to be centered on that. Good Luck


Thanks!


----------

