Cutting a shallow circle.

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phil.p":18f60t84 said:
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.
Exactly Phil, that's what they're designed for innit!

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sunnybob":2ifhsi4c said:
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.

Hello,

You are using the wrong router bit!!!!

Flush trim bits and many others do not cut with plunging, they are for edges only, no wonder you think they snake around etc.

You need a bit with a bottom cut. They will say as much in the description in the tool catalogue, or get one that specifically says it will mortice, or deep cut. An electric router is an optimal tool for doing the recess the OP needs without any hogging away with Forstner bits, chisels etc.

Mike.
 
Two hand tool only options;

1) As already suggested - remove bulk of waste with chisels, finish to depth with a hand router, trim curved edge with scribing (paring) gouge.

2) Accepting that not every tool kit has paring gouges, then remove waste and finish base as above, then trim to as near the line as you can get with ordinary chisels. That will obviously leave a slightly faceted circle, so trim a piece of scrap to have an curve that fits the circle desired, glue (or double-sided tape) a piece of coarse sandpaper to it, and finish the inside curve. Not too onerous, because there's not a lot to sand away, and walnut isn't too hard. Follow up with successively finer grades.

Version two is a bit of a 'bodge', but it could be done with a minimalist tool kit, and done with a modicum of care should be perfectly satisfactory for the application in question. Some thought about size of scrap used would allow a good handhold, so plenty of pressure where it's needed.
 
Sorry no help at all to the OP but CNC router every time, 10 minute job, oh I do love that machine sometimes.
 
Hello,

I would do it with a bit of hardwood​ used as a trammel and a couple of screws, one for the centre pivot point and the other as a cutter. If you have a grinder, shape the pointy end of a hardened steel screw into a square ended cutting spur, and go round and round, altering the depth of cut as you go. If you have no grinder find a screw that can be filed.

Once you have defined the depth of the circle, then got out the waste with Forstner bits, chisels etc.

I have cut discs of plywood like this in the past, so it works well and not as slow as it sounds.

Mike.
 
Thanks for all the replies. I'm happy that there's an alternative to the router and I'm going to do something along the lines suggested by xymosian, bridger, woodbrains and Cheshirechappie. One question for the latter: I've no objection to getting a paring gouge as there is sometimes a need to produce clean curved edges. Could you recommend a model and make which has the right sort of size for a circle of 2 1/2" - 3"?

I've been having a look round and there is one gadget which could probably do it in one go:

https://www.dictum.com/en/tools/woodwor ... cle-cutter

However, I quite fancy seeing how well I can do it using just hand tools. In the event of failure, I could always get the above.
 
I would mark and define the cut with a washer cutter in a brace, hack out most of the waste with gouges/firmer chisels, finish with a #70 router.

This method is dictated by the tools I happen to own.

BugBear
 
Bugbear,

that sounds interesting as I have 8" and 10" braces but I've never heard of a washer cutter, let alone one suitable for use with a brace. Could you perhaps provide a link to a picture of one in Action?
 
Andy Kev.":1vxxm9vx said:
Bugbear,

that sounds interesting as I have 8" and 10" braces but I've never heard of a washer cutter, let alone one suitable for use with a brace. Could you perhaps provide a link to a picture of one in Action?

It's just a pivot and a moveable knife (to adjust the radius). It's very similar to a tank cutter.

This one is very similar to mine:
ww.JPG


BugBear
 

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bugbear":2wm6rqjz said:
Andy Kev.":2wm6rqjz said:
Bugbear,

that sounds interesting as I have 8" and 10" braces but I've never heard of a washer cutter, let alone one suitable for use with a brace. Could you perhaps provide a link to a picture of one in Action?

It's just a pivot and a moveable knife (to adjust the radius). It's very similar to a tank cutter.

This one is very similar to mine:


BugBear
That's the sort of tool I like because you can see how it works just by looking at it. It also looks to be of good, old-fashioned, rock solid quality. I'll keep an eye out for one as it would be a useful thing for my braces.
 
Andy Kev.":q5loqkhb said:
That's the sort of tool I like because you can see how it works just by looking at it. It also looks to be of good, old-fashioned, rock solid quality. I'll keep an eye out for one as it would be a useful thing for my braces.

You might consider buy and regrinding a tank cutter in the short term - much commoner and easier to get hold of.

BugBear
 
Andy Kev.":1yhyugmr said:
Thanks for all the replies. I'm happy that there's an alternative to the router and I'm going to do something along the lines suggested by xymosian, bridger, woodbrains and Cheshirechappie. One question for the latter: I've no objection to getting a paring gouge as there is sometimes a need to produce clean curved edges. Could you recommend a model and make which has the right sort of size for a circle of 2 1/2" - 3"?

I've been having a look round and there is one gadget which could probably do it in one go:

https://www.dictum.com/en/tools/woodwor ... cle-cutter

However, I quite fancy seeing how well I can do it using just hand tools. In the event of failure, I could always get the above.

The only maker of new in-cannel gouges I can find is Henry Taylor - http://www.henrytaylortools.co.uk/wwchisel.html - but tracking down a retailer seems more difficult, Toolnut being the only supplier to offer the full range that I could find - http://toolnut.co.uk/products/chisels

The other option is secondhand, and there do seem to be quite a few around, both among the dealers and on that well-known auction site. The downside of those (speaking from bitter experience) is that the in-cannel ones have often been honed repeatedly by previous owners, but rarely is the primary bevel reground, so they end up with bevel angles more suited to morticing than paring. I solved this for myself by buying a couple of extra wheels of different widths for the hand-crank grinder, and reprofiling the periphery to a curve. That makes regrinds a doddle, but it obviously means spending on specialist kit for something that doesn't need doing very often. It still worked out cheaper than buying new gouges, though!

As for sweeps, I think the long (patternmaker's) paring gouges were made in about six different sweeps defined in the Sheffield List. I'm not sure whether the shorter (joiner's) scribing gouges were, but I'm fairly sure they crop up in more than one swee. Finding the right one secondhand is just a matter of guesswork, unless you can find a friendly dealer to sort through his stock for something suitable. In my case, I bought four long gouges from Bristol Design donkey's years ago, ranging in width from 1/4" to 1 1/4", and of different sweeps. I haven't (yet) found a job that one of them wasn't able to do, but to be fair that sort of job doesn't crop up often for me. I reckon for the bog brush holder, something about 1" to 1 1/4" width and middling to flat sweep should about do, looking at mine. My flattest gives about a 2 1/2" radius circle; they seem to work smaller radius circles than you'd think just by looking at them.

Sorry for writing an essay!
 
Hi Andy

On the basis you are not going to be using a lathe, and I assume you want to avoid power tools here's my £0.02.

Cut a circle in some 1/2" stock with a coping saw. Sand etc as required and glue it on. Not what you wanted but would get it done, you could use a contrasting timber.

Or, just cut a hole straight through your piece of wood with a coping saw and let in a cross bar of wood from the underneath to create the 1/2" reveal or some similar idea to create support. However, I'd imagine it wouldn't matter if the base of the bog brush holder touched the floor and you just used the hole as location.

Other options make we want to make the will to live but they'd work. Such as advancing a cutting edge on a trammel (Sounds like cutting through prison bars at WW2 prison though) and then removing waste with a chisel.

If I was using hand tools to I'd want to finish the base of the cut out with a textured finish, like carved bowls.
 
As it's a one-off I think a very respectable job could be done for this using nothing but hand tools; if you don't own a hand router, making a chisel router by sticking a chisel through a piece of scrap. It would be hard graft but it's certainly possible if the need is there.

That said, would a non-circular recess do it for you Andy? I was thinking a hexagon or octagon with the required diameter across the flats. Would make the edges a lot easier to do if going without power tools.
 
I just get the feeling this is getting way more complicated than it needs to be. Any chance we could see a pic of the tube please ?

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Complicated you say Coley..... *twirls moustache and adjusts monocle....

Well.... there is another option. :D
I'm only posting this because it triggered a memory and for general reference really . If you are as rich as Croesus or you had to make a lot of bog brush stands without any other electrical (routing) means you might look at this gear from Fine Tools. It's only 34.5 Euros. Plus because your 5 nabit inches is a bit more than 120mm cutting range, you'll have to buy the extension bar (7.40 Euros) and then a pillar drill if you don't have one. :D

https://www.fine-tools.com/kreisschneider.html

Or like others say, use a drill and a forstner / auger bit or a coping saw. Personally I'd use a files to clean up the edge cos I'm so metal and I'd cut right through and leave a small gap so any spillages (water or otherwise) don't sit in the wood base. And they will, after time. Maybe put some of those tiny sticky rubber feet on the bottom.I'd pay a bit of attention to getting a warlike finish. (Especially if you have young kids.... Uric acid is an acid even if it's a mild one and it's gonna work wonders over time.)
 
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