Best way to shape a large rounded corner - Woodworking Talk - Woodworkers Forum
 
Thread Tools Display Modes
post #1 of 8 Old 03-19-2018, 10:55 AM Thread Starter
Junior Member
 
Join Date: Mar 2018
Posts: 4
View steve4king's Photo Album My Photos
Best way to shape a large rounded corner

Hello experts!

I'd start by saying that I'm a novice woodworker, but that may be giving myself too much credit.


I'm building a bed and want to create rounded corners that measure 8" tall, 0.75" thick, with a radius of 2.5".

I've thought of a few ways to cut this but the 8" height introduces challenges I'm not sure how best to handle.

Here are my(bad?) ideas..

1. Cover a 4x4x8" post of scrap wood with hardwood(red oak) and use a 5" hole saw on a drill press to cut the full 8" depth.. but then I would still have to somehow remove that center core each time I max out the saw as well as shape the outside..

2. Create corners by bonding oak boards, then freehand the inside corners with a drum sander, (3x6" sanding drum attached to a drill press or bench grinder) and the outside corners on a belt.

3. Make the corner of several layers totaling 1/4" of walnut(I don't believe oak bends so well) steam bent then bonded on top of a stack of hardwood shaped with a jigsaw.. however, I'm thinking uniformly steam bending something 8" tall is going to be very difficult regardless how thin it is.

I'd really prefer not to have to do these in smaller sections as I don't want to see joints here..

I'm strongly leaning toward #2 right now, but before I start.. is there a better way I haven't considered?

Thanks!
-Stephen
steve4king is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 03-19-2018, 11:32 AM
The Nut in the Cellar
 
Jim Frye's Avatar
 
Join Date: Aug 2016
Location: Northwest Ohio
Posts: 1,043
View Jim Frye's Photo Album My Photos
Sounds like you want to make a cove with an inside radius of 2 1/2". I would do this (and have done it before) by cutting the cove on the table saw. The setup is a bit complicated, but doable with just a couple of jigs. I'm sure there are videos showing how to do it, but basically, you pass the workpiece diagonally over the saw blade raising the blade a wee bit at a time. It requires a pair of guides clamped to the saw table at an angle that will product the appropriate depth of the cove. If you use a blade with a flat top grind, you will have minimal sanding for clean up. I have pictures of the setup, but I'll have to edit them for this site. If you want, I'll post later this evening when I have time.

Jim Frye
I've gone out to find myself. If I return before I get back, have me wait for me.
"Sawdust is Man Glitter"

Last edited by Jim Frye; 03-19-2018 at 11:41 AM.
Jim Frye is offline  
post #3 of 8 Old 03-19-2018, 03:42 PM Thread Starter
Junior Member
 
Join Date: Mar 2018
Posts: 4
View steve4king's Photo Album My Photos
Thanks Jim. Just knowing the terminology is a big help.

https://woodgears.ca/cove/

Interesting. That handles the inside curve nicely.
Shaping the outside will still largely be done with a sander.
But that shouldn't be as difficult.

Thanks!!

Last edited by steve4king; 03-19-2018 at 04:41 PM.
steve4king is offline  
Sponsored Links
Advertisement
 
post #4 of 8 Old 03-19-2018, 03:57 PM
The Nut in the Cellar
 
Jim Frye's Avatar
 
Join Date: Aug 2016
Location: Northwest Ohio
Posts: 1,043
View Jim Frye's Photo Album My Photos
Good Grief!!! I'm getting very forgetful in my advancing years. I forgot I wrote an article on this a long, long time ago. Here's the link to it. Pictures included in the .pdf file linked in the article summary. It was written for the Ryobi BT3000, but the technique would work on any saw. I followed instructions that were printed in an old issue of Wood Magazine, so I claim no credit for inventing the process.

http://www.sawdustzone.org/articles/...for-the-bt3000

Jim Frye
I've gone out to find myself. If I return before I get back, have me wait for me.
"Sawdust is Man Glitter"

Last edited by Jim Frye; 03-19-2018 at 03:59 PM. Reason: added text
Jim Frye is offline  
The Following User Says Thank You to Jim Frye For This Useful Post:
steve4king (03-20-2018)
post #5 of 8 Old 03-19-2018, 05:37 PM
Senior Member
 
Join Date: Mar 2015
Location: Garland, TX
Posts: 4,232
View Toolman50's Photo Album My Photos
When I cut a cove, I only use one diagonal fence.
I clamp this temporary fence in front of the table saw blade.

If you don't have time to do it right the first time, when will you have time to do it over?
Toolman50 is offline  
post #6 of 8 Old 03-19-2018, 06:44 PM
The Nut in the Cellar
 
Jim Frye's Avatar
 
Join Date: Aug 2016
Location: Northwest Ohio
Posts: 1,043
View Jim Frye's Photo Album My Photos
Quote:
Originally Posted by Toolman50 View Post
When I cut a cove, I only use one diagonal fence.
I clamp this temporary fence in front of the table saw blade.
Yeah, that's the way most show it being done. Even the Wood Magazine article from February 1992 showed one guide positioned so the workpiece would be pressed against the guide. I added the second guide (the aluminum angle strip) for safety's sake. Use of the table saw to me back then was a bit new and this setup was outside the norm.

Jim Frye
I've gone out to find myself. If I return before I get back, have me wait for me.
"Sawdust is Man Glitter"
Jim Frye is offline  
post #7 of 8 Old 03-19-2018, 09:59 PM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 27,706
View woodnthings's Photo Album My Photos
I'm still not sure what you want to do ...

Based on this statement:
I'm building a bed and want to create rounded corners that measure 8" tall, 0.75" thick, with a radius of 2.5".

I'm building a bed ... OK, the headboard or the horizontal portion, the frame?

..with rounded corners .... are there 4 corners or 2? are they 90 degree corners? Do framing members run off these corners? How do you attach the headboard IF there is one?

.... that measure 8" tall, .075" thick ..... solid wood? laminated sections?

.... with an inside radius of 2.5" .... OK, what about the outside radius? Would that be 2.5" + .75" for a total of 3 .25"?


Obviously, the fastest way is to saw them out of solid stock using a bandsaw with a depth of at least 8". Solid stock will have structural issues because of the grain directions, so a lamination will be better. But, you don't want to have glue lines show...

There are some issue here that need resolution.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
post #8 of 8 Old 03-20-2018, 09:45 AM Thread Starter
Junior Member
 
Join Date: Mar 2018
Posts: 4
View steve4king's Photo Album My Photos
Clearly I didn't explain my conundrum very clearly. However, Jim somehow managed to figure out exactly what I was going for despite my vagueness. (Well done!)

Yes, the rounded corners I'm referring two will be the two corners at the foot of the horizontal frame. There will be a headboard, but it has no bearing on these corners.
The bed will be hardwood, no laminate. Horizontal grain for the majority of the frame, but I am intending to switch to vertical for the corners at the foot.

They will be 90deg corners, 2.5" inside radius, 3.25" outside radius, ideally cut from a single piece of 1.5"x 4.6"+ red oak hardwood, but since .75" is the thickest available at home depot I'll try bonding two of those first to see if the glue lines show.

The cove will only be cut down 2.5" on the inside, while the outside will be that 3.25" radius curvature the entire 8" length, that should leave these pieces very strong.

These will not be structurally significant pieces other than the fact that people will sit on the corners occasionally. The corners will be attached to the lateral edges via aluminum pegs(for alignment), and to the structural members via a single (isosceles) trapezoidal block

My question was really only about how best to cut the coves. I'm pretty confident in the rest of my design. I like the tablesaw cove method as it will be far more precise than a bandsaw and does not force me to cut the entire length of the board.(really happy about that!)

Quote:
Originally Posted by woodnthings View Post
Based on this statement:
I'm building a bed and want to create rounded corners that measure 8" tall, 0.75" thick, with a radius of 2.5".

I'm building a bed ... OK, the headboard or the horizontal portion, the frame?

..with rounded corners .... are there 4 corners or 2? are they 90 degree corners? Do framing members run off these corners? How do you attach the headboard IF there is one?

.... that measure 8" tall, .075" thick ..... solid wood? laminated sections?

.... with an inside radius of 2.5" .... OK, what about the outside radius? Would that be 2.5" + .75" for a total of 3 .25"?


Obviously, the fastest way is to saw them out of solid stock using a bandsaw with a depth of at least 8". Solid stock will have structural issues because of the grain directions, so a lamination will be better. But, you don't want to have glue lines show...

There are some issue here that need resolution.
Attached Thumbnails
Click image for larger version

Name:	Bed corners.JPG
Views:	50
Size:	37.5 KB
ID:	350122  

steve4king is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Advice for solid wood corner bookcase? mackman General Woodworking Discussion 9 06-07-2017 11:46 AM
Large roll out drawer material TxAggie94 General Woodworking Discussion 2 12-29-2016 03:40 PM
3/4 log corner sstuartjones Trim Carpentry & Built-Ins 1 02-23-2016 06:06 PM
Hidden storage in blind corner cabinet thewalnutguy Project Showcase 2 10-03-2015 11:42 AM
Installing baseboard on tile to hardwood step down at rounded corner islanti Trim Carpentry & Built-Ins 6 08-24-2015 09:54 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome