How would you radius outside corner to make this rounded box joint?

[Vtshopdog]

[attachimg=1]

Hello, have been reading here since I got my first Festool(s) about 5 years ago but never had reason to post.  Thanks to many for much great information, I've read and learned a lot.

I'm hobbyist about to start a coffee table project and for the skirt I want to copy this nice looking rounded-corner box joint from a Thos. Moser catalog.  I'm just fine building the box joints, but a bit concerned about rounding off a corner with end grain facing two directions.  Build will be in Lacewood which I've used a fair amount - it tends to machine very well and is forgiving - but the table will have a glass top and be in my living room.  I'm going to look at it every day so want good results.

I have thought of a few options:

Router:
Having at it with a router (either a corner template with pattern bit or even a simple round over bit) seems like an invite to blow out some of the endgrain.  Or maybe not??  I wouldn't find out until trying on a sub assembly that will take a day to build, seems risky.

Bench Sander:
Seems likely to work ok, maybe a bit slow (but only have to do four corners, right?)  (Also faster that blowing it apart on router and starting over). Issue here is the table on my Rigid sander is about 12x18 and the table skirt will be about 30x30.  Clumsy to handle, have considered building some sort of table extension or support device tho.

Rough cut corners 45 degrees on miter saw before rounding:
Would speed up either method and maybe reduce blowout.

Run away!!
Final option is to just live with good old 90 degree corners that I know how to make

Thinking I can build a couple sample corner joints from the off cuts from my stock and mess around on those, but if anyone has input would very welcome.

Thanks

 

[threesixright]

Just don’t run.

Sent from my X using Tapatalk

 

[Vtshopdog]

I only run with scissors or a running sawzall in my hand.

 

[mrFinpgh]

How tall is that apron?

You could definitely do a radius template and go after it that way w/ a  router.  Maybe see if Pat Warner wrote anything about that.

A combination of block plane, rasp, file, and sandpaper is probably a less risky approach, in terms of blowout.  You might not get 100% exactly the same on each corner, but I don't know whether that matters to you.

[member=4358]derekcohen[/member] did a similar profile on a dovetail joint for a recent project.  I believe he used a washer as a template and block plane to get most of the rounding done.  That was a wide joint, but I'd expect the same would apply here.

 

[Gregor]

A 'a simple round over bit' should work nicely when clamping sacrificial pieces to both sides to get no tear out at the ends, in the center it should be no problem.

Doing some tests on corners made from scraps sounds like a very good idea, to find the best approach.

 

[nclemmons]

My worry with a router is tearout as you have grain going in both directions on both sides.  I've done a few projects in Lacewood and it's nice to work with but I'd still worry about tearout.

I'd personally do the 45 degree cut and then use a belt sander followed by a random orbit sander,  Do you have a stationary 12" disc sander by chance?

 

[Vtshopdog]

My worry with a router is tearout as you have grain going in both directions on both sides.  I've done a few projects in Lacewood and it's nice to work with but I'd still worry about tearout.

I'd personally do the 45 degree cut and then use a belt sander followed by a random orbit sander,  Do you have a stationary 12" disc sander by chance?

I don't have a disc sander but do have a combo oscillating belt/spindle bench sander - using that tool is probably plan "A".

Cutting the box joints on an Incra Positioner so once it's set up I can make extra pieces really fast.  Usually have to cut some extras to dial in setup on the Positioner anyhow, so can glue those and try it out.

 

[tjbnwi]

Belt sander.

Tom

 

[waho6o9]

I agree with  mrFinpgh and I would use files, rasps and sandpaper.  One of my favorite rasp is a Shinto rasp, very effective.
One side is coarse  and the other side  is fine.
View attachment 1

 

[Jiggy Joiner]

A bench mounted belt and disc sander, would make that a quick and easy job. There’s other ways but, a bench sander would be my choice.

 

[Stone Message]

If the frame piece is manageable and you have a bandsaw then do a curved cut leaving about 1-2 mm for sanding.

Failing that and you have a really good jigsaw with a long enough blade then do a curved cut but watch that the cut remains upright as some jigsaws will wander a bit.

Without any of that take a 45 degree cut using any saw that you have (yes, even a hand saw) in order to get rid of as much of the waste as you can.

With one of the above done take it to your disc sander and here I assume that the rig allows for a nice square finish. In order to get a really accurate and repeatable rounded finish you might consider making a jig that forms a trammel. Your jig design needs to allow the trammel point to move a fraction closer to the sander as you progress through the work.

If your disc sander leaves a less than desirable finish (which is probably likely) then either use a finishing sander with 180 grit or get a long piece of 180 grit sanding sheet from a roll and then, gripping at both ends, use it like a strop to complete the job.

Good luck.

Peter

 

[Rob Z]

To follow up on waho6o9's comment, I just bought a Shinto rasp and used it last weekend to round the corners of a project similar to yours.  It is amazingly fast at removing material. It won't get you to the finished surface but it will rough it out for you as fast or faster than anything else.

 

[derekcohen]

[attachimg=1]

Hello, have been reading here since I got my first Festool(s) about 5 years ago but never had reason to post.  Thanks to many for much great information, I've read and learned a lot.

I'm hobbyist about to start a coffee table project and for the skirt I want to copy this nice looking rounded-corner box joint from a Thos. Moser catalog.  I'm just fine building the box joints, but a bit concerned about rounding off a corner with end grain facing two directions.  Build will be in Lacewood which I've used a fair amount - it tends to machine very well and is forgiving - but the table will have a glass top and be in my living room.  I'm going to look at it every day so want good results.

I have thought of a few options:

Router:
Having at it with a router (either a corner template with pattern bit or even a simple round over bit) seems like an invite to blow out some of the endgrain.  Or maybe not??  I wouldn't find out until trying on a sub assembly that will take a day to build, seems risky.

Bench Sander:
Seems likely to work ok, maybe a bit slow (but only have to do four corners, right?)  (Also faster that blowing it apart on router and starting over). Issue here is the table on my Rigid sander is about 12x18 and the table skirt will be about 30x30.  Clumsy to handle, have considered building some sort of table extension or support device tho.

Rough cut corners 45 degrees on miter saw before rounding:
Would speed up either method and maybe reduce blowout.

Run away!!
Final option is to just live with good old 90 degree corners that I know how to make

Thinking I can build a couple sample corner joints from the off cuts from my stock and mess around on those, but if anyone has input would very welcome.

Thanks

Straightforward with a handplane, rasp or sandpaper. This is the same, but a dovetail. I've done it a few times ....

Step 3: shape the ends

I used a larger washer than this one this time to mark out the curve (as the radius needed to be reduced) ...

Then began planing ...

Refined with a block plane ...

... and finished with sandpaper.

Easy peasy

Regards from Perth

Derek

 

[Stone Message]

Hi Derek

I am not so keen on the retro design of your piece but I have to congratulate you on the beautiful workmanship and attention to detail. It is a lovely piece and will be a superb family heirloom.

Well done.

Peter

 

[derekcohen]

Thanks Peter. The coffee table was a wedding gift for a nephew. He chose the design. The small side table I designed for my wife as she liked the rounded dovetails of the first piece.It scored second place in the local state furniture competition.

More here:http://www.inthewoodshop.com/Furniture/HTFinalPictures.html

Regards from Perth

Derek

 

[Bob D.]

Derek, how do you ensure you don't plane too deep in the middle of the piece. With a block plane of length that is less than half the length of the joint this seems possible. At/Near the ends you can see the guide lines drawn on the top or bottom of the sides, but given the height what do you do to keep from planning into the radius near the middle of the joint. Need to monitor how much material is removed to be sure you don't get carried away.

Did you establish the ends then place a straight edge or steel rule along the length of the joint and keep working until the desired profile is obtained. Or did you maybe make a gauge block with a radius to match the outside of the corner and monitor it that way.

I've never tried something like this and curious how to go about monitoring progress when planning.

 

[RKA]

I have to say, I didn't see this in the picture VTshopdog posted, but looking at the last picture Derek posted the effect of the long grain transitioning to end grain on the opposing pins and tails is visually striking.  I'll have to file this idea away in the back of my brain...hopefully I can recall it when the time comes. 

 

[Gregor]

[member=4358]derekcohen[/member] Very nice design and execution, I like it.

 

[derekcohen]

Derek, how do you ensure you don't plane too deep in the middle of the piece. With a block plane of length that is less than half the length of the joint this seems possible. At/Near the ends you can see the guide lines drawn on the top or bottom of the sides, but given the height what do you do to keep from planning into the radius near the middle of the joint. Need to monitor how much material is removed to be sure you don't get carried away.

Did you establish the ends then place a straight edge or steel rule along the length of the joint and keep working until the desired profile is obtained. Or did you maybe make a gauge block with a radius to match the outside of the corner and monitor it that way.

I've never tried something like this and curious how to go about monitoring progress when planning.

Bob, it begins with careful marking out. Then controlled planing - watch what you are taking off, and use the longest plane you have to maintain flat. Use a straight edge to check your progress. See my photos. They contain all the guidelines.

More here: http://www.inthewoodshop.com/Furniture/AnotherCoffeeTable5.html

Regards from Perth

Derek

 

[Bob D.]

Thanks, somehow I missed the longer plane in your photo above.