Thread: router bore

Not entirely clear what you mean by "router's bore." If you mean the shank size it takes, in Imperial sizes it's either 1/4 in or 1/2 in; you can determine that with a yard stick. Don't know if metric sizes are even used, but if so, it should also be an either/or situation.

Joe

Joe, although it is not commonly in use the 3/8" collet is still used for specialty applications. In Oz they use metric collets such as 8 MM which is close enough to a 1/4" as to be dangerous. Metric and fractional bits are not interchangeable and will not hold properly in the collet.
Jigs350, does this answer your question?

hi, it was mention to me in order to put a router base in a table i would have to know the through bore /counter bore for the size off bits is that right or am i missing the point. thanks for your reply. jigs350

G'day jigs 350,
I've been watching your post for a couple of days, not sure of what you meant, and not experienced enough to suggest any solution.
However, now its clearer, maybe you should "google" zero clearance router inserts and table mounting routers. They should get to the root of your problem.
Now that your question is clearer there are many experts on this forum that will be able to direct you exactly where you need to go.
I'm sorry that its not me, but at least now I understand what you mean by "bore"
Hang in there.
Regards,
Noel

Originally Posted by aniceone2hold

In Oz they use metric collets such as 8 MM which is close enough to a 1/4" as to be dangerous.

Sorry but 1/4" is 6mm.
I think the 8mm is closer to 5/16"

Aint conversions grand?

Al

Originally Posted by aniceone2hold

In Oz they use metric collets such as 8 MM which is close enough to a 1/4" as to be dangerous.

Mike, for the record we actually predominately use imperial shank router bits, 1/4" and 1/2". You can get metric (6mm and 12mm) but they are few and far between.

Gday Jigs, I'll have a dip.

I think you might be referring to removing the subbase on your router, and attaching a (typically) square plate to the bottom of the router, in order to set this plate with router attached into a router table.

This requires removing the screws that hold the thin (1/8" or so) subbase to the router, and using longer screws to attach the router table mounting plate.

These longer screws must be the same size & pitch as the original screws, a metric threaded type (eg. M5) or an imperial size (eg. 1/4"). This info will usually be in the manual, or you can find out the size by taking one of the original bolts into a bolt retailer, where you can also buy the longer ones.

The new ones will need to be long enough to go through the thicker plate, and screw around the original depth into the router's metal base. Too long and they may bottom out in the hole, too short and they may not engage sufficent threads in the base to be strong enough.

They will usually be a countersunk headed bolt, or "flathead" I think the yanks call them. If you are making the mounting plate for the router table, you will need to countersink the mounting holes, usually with a countersink bit or a larger drill bit, so the screw heads lie flush or slightly below the top surface of the mounting plate.

Hope this is the info you are after, as the other posters mentioned you could be after the collet size of the router, which is directly relevant to the router bits you will need for it, most common sizes are 1/2" and 1/4" here in Australia, 3/8" 8mm and 12mm and no doubt others elsewhere.

This info can be gleaned from your instruction manual, or by measuring the inside of the collet with a pair of vernier calipers.

The only other measurement I can think of is the size of the clearance hole for the centre of the router insert plate, this needs to be big enough to provide clearance for the biggest router bit you plan to use in it.

As this bit is often a lot bigger than your smaller bits, it is common for some plates to have various sizes of insert rings available that sit in a rebate around the hole, flush with the top surface of the table, and prevent workpieces tipping in when using smaller bits.


HTH................cheers................Sean

Another "bore" size that could be critical is for the "sub-plate" to hold raised guide bushings with a large lock nut on the router side of the main plate. That info would come with the bushing set, or measure from the set.

Thanks for the insight on other shank sizes, all.

Joe

Ok Jigs, now that I understand what you are after it is almost easy. Mounting a router to a table is easiest done with a mounting plate. Since you are in Canada the best options would be to purchase either a Rousseau plate or one from Oak Park, home of "The Router Workshop" as seen on PBS and www.thewoodworkingchannel.com Both styles are easy to install and easy to work with. I am a moderator on www.routerforums.com which is the official chat of "The Router Workshop." Let me suggest you visit by clicking on the link; you will see photo's of both styles mounted and be able to read feedback from members about which they prefer and why. This way you will be able to make an informed decision about how to mount your router.

Oz winner & Wood Butcher: Honest, I can do math. We have heard of some 8 MM collets that have had 1/4" bits installed... very bad news as you can imagine.

Scooter: Nice post!