# rounded corner, inside and out



## gav (Oct 12, 2009)

My wifes cousin wants me to make some shelves in the style of her coffee table.
It has those modern curved corners you may have seen somewhere.
There's a pic of the coffee table and of a sketchup drawing I made.
The shelves will be made from 22mm thick mdf (their choice)
According to sketchup, the inside radius would need to be 10.2mm and the outside radius would need to be 32.2mm. I'm pretty sure it would still look the same if those radii were 10mm and 32mm.

In my my mind it would be a relatively simple job if I had a round over bit that had a 32mm radius, but I can't find one. Also i would need something like a core box bit with a 10mm radius.

Has anyone made this type of corner before ?
How would you guys go about it ?
Anyone got sources for bits that size ? I can handle 8mm, 12mm, and 1/2 inch bits.
Thanks for any advice given.


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## jschaben (Jun 21, 2009)

gav said:


> My wifes cousin wants me to make some shelves in the style of her coffee table.
> It has those modern curved corners you may have seen somewhere.
> There's a pic of the coffee table and of a sketchup drawing I made.
> The shelves will be made from 22mm thick mdf (their choice)
> ...


Hi Gav - I think I'd do that with a template and flush trim bit, either hand or table... I'm probably missing something but an inside radius on a shelf?? Is the center area of the shelf relieved somehow? If you can get inch base bits, 3/8" core box are fairly common and would be pretty close.


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## RJM (Apr 11, 2010)

gav said:


> My wifes cousin wants me to make some shelves in the style of her coffee table.
> It has those modern curved corners you may have seen somewhere.
> There's a pic of the coffee table and of a sketchup drawing I made.
> The shelves will be made from 22mm thick mdf (their choice)
> ...


What if you started with a 64mm diameter rod, and cut it into 1/4 sections. Add the inside radius, glue and blend (see attached). You may need to adjust the 1 mm "extra" height. Make a test piece.


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## bobj3 (Jan 17, 2006)

Hi

I like it, but why not just buy or make some big round over molding and b4 you put it place run it over cove bit in the router table then just glue it in place..

http://www.ebay.com/itm/1pc-1-2-SH-...635424991?pt=Routers_Bits&hash=item20be8648df

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RJM60 said:


> What if you started with a 64mm diameter rod, and cut it into 1/4 sections. Add the inside radius, glue and blend (see attached). You may need to adjust the 1 mm "extra" height. Make a test piece.


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## gav (Oct 12, 2009)

jschaben, the shelf is more like a box on the wall I guess. It would be a smaller version of the coffee table pictured.
How would you go about cutting a 30cm long piece with your method ? My largest flush trim bit is about 5cm long and that's the biggest I've come across around here. I guess I could then glue 4 of those sections together to get the length I require. Probably that's more work than I am willing to do as I need 16 corners to make 4 shelf boxes, that's 64 pieces ! Come to think of it though, I do know someone with a small cnc router.hmmm

RJM60, had the same idea. Then I realized I don't have a way to make a 64mm round and it's not a standard item. I also figure that a bandsaw might be best for quartering it, and I don't have one of them either. Your method to join all the pieces together was exactly what i was thinking also. 

I found a cove cutting bit that has the radius I need that I can order, and also a 1 1/4 (close enough to 32 mm) radius round over bit from MLCS, but I think by the time they are shipped here the cost will be too much for the job. 

Another idea I had was to use a straight bit for the outside diameter and make a jig similar to the ones some people use to rout the curve on the fronts and backs of guitar necks.
Anyone used this method ? see pic..









Thanks for the brainstorming guys !


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## jschaben (Jun 21, 2009)

gav said:


> jschaben, the shelf is more like a box on the wall I guess. It would be a smaller version of the coffee table pictured.
> How would you go about cutting a 30cm long piece with your method ? My largest flush trim bit is about 5cm long and that's the biggest I've come across around here. I guess I could then glue 4 of those sections together to get the length I require. Probably that's more work than I am willing to do as I need 16 corners to make 4 shelf boxes, that's 64 pieces ! Come to think of it though, I do know someone with a small cnc router.hmmm


Hi Gav - I'm reading it that you are putting the curve around the 22mm dimension which, I think, would be the depth of cut. Guess maybe I still haven't got it yet.


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## Cherryville Chuck (Sep 28, 2010)

Cut the outside roundover in 2 passes with a 16mm bit (if you can find one) from 2 sides. It should work if it doesn't have a bearing or if you take the bearing off.


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## gav (Oct 12, 2009)

bobj3 said:


> Hi
> 
> I like it, but why not just buy or make some big round over molding and b4 you put it place run it over cove bit in the router table then just glue it in place..
> 
> ...


Yep Bob, that's exactly what I want to do, but can't buy such a moulding here, and buying and importing a large round over bit would be perfect if it wasn't so time and cost prohibitive.

Here's another drawing to make it a bit clearer as to what I'm trying to make.


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## gav (Oct 12, 2009)

That's the edge moulding that would then be joined to the 22mm mdf at each corner to make a box that would be mounted on the wall.


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