Cutting a shallow circle.

[Andy Kev.]

Good Morning All,

I've just had my bathroom retiled etc. and I'm trying to upgrade the various ancilliaries from the level of supermarket junk. One element of this is to build a stand for toilet paper and brush holder. The new bog brush sits in a ceramic tube of about 5" external diameter. I have a roughly 10" x 10" piece of walnut which would do nicely as a base. The thing that's got me stumped is how to cut a circle of 5 and a fraction inch diameter and about 1/2" depth to accommodate said bog brush tube.

Obviously to mark the circle is straightforward and I could use forstner or centre bits to cut out the bulk of the circle but that would leave a sort of rippled edge defined by where the edges of the bits meet the circle. So I suppose the question is:

a. Is there a way to cut, say, the outer 1/4" of the circle cleanly and clear the rest out with the bits?

b. If not, how does one deal with the crinkly edge?

Although I have an electric router I very rarely use it and I imagine that the job would be way beyond my capabilities with that tool and frankly I try to avoid machines as far as possible. (They never seem to do jobs quite right which translates as "I'm rubbish with them".)

Thanks in advance,

Andy.

 

[marcros]

I think that a router or a lathe is the answer here, noting your reservations. Make a template and use a bearing guided bit.

 

[Phil Pascoe]

Cut your circle in a piece of ply large enough to be fixed down without the cramps getting in the way, mark it carefully and stick your walnut to the underside with double sided tape or hot melt and use your router with a bearing guided bit. If you have some other means of guiding the router make the circle in the ply the relevant size.
Marcross beat me to it.

 

[Cheshirechappie]

Lathe sounds like a fair idea, assuming you have access to one with the swing to accommodate a ten inch square.

If not, then removing the bulk of the waste with chisels, fairing the bottom of the recess with a hand router, and cleaning up the circular edge with a scribing gouge would be one hand-tool only way to do it, finishing with a small scraper.

 

[Andy Kev.]

Thanks chaps. It appears to be as I feared and it looks as if I will have to get a bearing guided bit. Then of course there's the matter of boning up in detail on how to use the damned thing, followed by practice runs on a bit of pine. It makes you wonder how they got by with a job like this in the days before power tools.

 

[Phil Pascoe]

They put their bog brushes in an old tin can.

 

[xy mosian]

a. Is there a way to cut, say, the outer 1/4" of the circle cleanly and clear the rest out with the bits?

As it's a one-off. Organise a compass, or divider, thingy with a cutting blade where the pencil would go. The blade will need to be stiff. A cut around the perifery of the circle followed up with a sloping cut inside the circle to meet the cut will define the edge. Repeating the process should get you down to around about 1/4" depth without too much trouble. Clear out the rest of the inside with whatever method you wish. A trammel may beeasier to organise than compasses.

HTH, xy

 

[sunnybob]

The router will give you the best finish, But with a router, its like painting something, preparation is everything.
You must hog out almost all of the inside wood first. Forstner bits and even chisels are good for this.
Flush trim router bits work best when they are only removing an 1/8" or so (at the most, less than half the diameter of the bit).
If you try to plunge the flush trim bit straight down into walnut, you will have an instant snakes and ladders board (minus the ladders of course)

Make the template deep, so that you can take three or even four shallow passes to reach depth and still have the bearing resting on the template.
Oh, and one more tip if you dont have much router time in.... Direction of cut is everything. If you go around the template with the blade spinning backwards, then CARP is the only outcome on walnut as it will shatter.

Hand held router on an inside circle you should start cutting and then move to the right until you get back where you started from.

Its a faff, but the end result will be perfect and well worth the effort.

 

[Phil Pascoe]

You must hog out almost all of the inside wood first.
Why??? That's what power tools are for. :?

 

[DoctorWibble]

Do you actually need a recess?
Aren't you just making a holder for the..er..holder?
Glue or maybe some sticky back magnetic sheet might locate it well enough...
And - look away now - won't a recess anyway simply collect run off down the sides of the holder? EEeuk!

 

[Phil Pascoe]

Only if you insist on cleaning the outside of the holder with said brush.

 

[bridger]

Not too different from letting a hinge leaf into a jamb. Mark the periphery, incise it with a sharp knife, chisel to depth.

 

[sunnybob]

Phil, routers dont like cutting into solid wood, They shimmy and shake and make a hell of a mess. They also wear out extremely quickly that way. Take out most of the wood and the router is a SUPERB finishing tool. Crisp sharp edges all the way round.
Also walnut is so brittle that it will chip like crazy under those conditions.

I have 5 routers and use them a lot, its not good to just stick'em in there.

 

[ColeyS1]

Cut a seperate piece of wood the internal diameter of the tube and just glue it to the block. No one will ever know the difference.
Coley

Sent from my SM-G900F using Tapatalk

 

[Phil Pascoe]

Phil, routers dont like cutting into solid wood, They shimmy and shake and make a hell of a mess. They also wear out extremely quickly that way. Take out most of the wood and the router is a SUPERB finishing tool. Crisp sharp edges all the way round.
Also walnut is so brittle that it will chip like crazy under those conditions.

I have 5 routers and use them a lot, its not good to just stick'em in there.

I've used mine for the past thirty years, and I wouldn't dream of wasting so much time. Routers cut solid wood - that's their raison d'etre - there is no reason why they should "shimmy and shake". A light cut to finish, fine. I have a 35mm square cutter that will at a push cut 35mm square in softwood in one pass - I've tried it. I wouldn't do it regularly, but it can be done.

 

[sunnybob]

Phil, youve used routers for 30 years. Even then you admit you wouldnt do it regularly.
the guy hasnt a clue about routers. tell him to dig in and he will never go back to a router.

 

[Phil Pascoe]

It's only 1/2"

 

[sunnybob]

Phil, forum advice is what it is, different opinions are taken (or left) by the man asking the questions.

 

[ColeyS1]

Just cause it's half inch deep doesn't mean you have to take it out all in one go, do it in 3,4,5 etc stages. If a router can't go half inch deep, it's not fit for purpose ! I've smashed out numerous hardwood stair strings half inch deep, no problem whatsoever..... only when I find out there isn't enough length for the correct amount of treads is there a problem :lol:
Coley

Sent from my SM-G900F using Tapatalk

 

[Phil Pascoe]

Certainly. I probably would take two passes, but it would be a pretty pathetic router that couldn't do it in one - I've plunged lock mortices in one. I certainly wouldn't entertain taking out the waste by hand - that's the whole purpose of the machine.