Cutting curves in braces

[vtframer]

The braces for a project i'm working on will be cherry with a curve.  My question is what size band saw blade should I use to make these curve cuts?  I don't have a lot of experience cutting hardwoods on bandsaws and assume than it may require a more rugged blade than normal?

Thanks

[Jim_Rogers]

If you're just doing a long gentile curve then it should be a problem with a standard blade. But you may need to consult your bandsaw user manual.

Jim Rogers

[bwstout]

When I make band saw boxes I use a 1/8 x 14TPI lets you make the tight turns. For just most curves and circles again will depend on how small they are I use a 1/4 X 6TPI. For making rounds to turn on the lathe I use a 1/2 or 3/8 3 or 4 TPI.

What blade use is mostly determined on how tight the curve or circle you are going to cut. Cherry from my experience cuts easy on a band saw even after it is dry.

[Brad_bb]

How many are you doing?  If not many, you can rough it out by hand with an axe or an adze and sand them.  If a lot, may be worth making a jig.  I've seen one jig that is basically a pendulum with the pivot point at the radius of the desired curve.  The pivot is a distance from the saw with an arm that attaches to the timber to swing it in an arc through the bandsaw.  

Another jig I've seen is this one by Moresun Woodworking.  A plywood template attaches to the bandsaw table and a corresponding template screws to the timber.  They act to guide the timber in the desired arc through the saw.  They don't have the vid on youtube, only on facebook.
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[vtframer]

Cool guys - thanks!  Yes my plan is to do a slight curve on all 30+ braces in the house.  They're be standard 3' braces (3x7 cherry) but my bandsaw is not a really nice one like in the video - it's a 1.5HP craftsman, so I'll need to get creative with building a larger table next to it.  

[curved-wood]

I cut my curves with a chain saw. The top plate are 8''x16'', 12 and 16 feet lenth. So I could not use a band saw. The steps are : chain saw , spoke shave, belt sander and router. The long one took about 6 hours each. The rafter are done the same way and took about 4 hours each.  Each time I use a Template for tracing.
 

 

[PC-Urban-Sawyer]

Curved-Wood,

That is a beautiful creation. Please give us more pictures of the building and other details such as purpose, size, how long it took you to do the work and anything else you'd like to share...

Herb

[curved-wood]

 < It is a 3 seasons gazebo built on a rock.Here a side view.
 An interior view<
You could see more of my work at: claudedrolet.com. A lot of possibilities with a portable mill . Note : I dont built for other so this is not a form of publicity. I wrote a book how to built curve structure with a wood frame but it is available only in french 

[Brad_bb]

I don't know if you have your material yet or not, but another option would be to use found curve braces.  That is, you take a 6-8foot branch and cut it flat on two sides leaving two live edges.  Branches or small trunks will typically have some sweep in them.  Then you scribe then into your frame.  I like using them.  It depends on the look you are going for.  If you want them all uniform, then cutting curves is the way to go.  If you like the natural beauty of found curves, do that.  



 

 

[curved-wood]

Those braces are very nice. How do you take your measurements for  your mortise and tenon

[Jim_Rogers]

Those braces are very nice. How do you take your measurements for  your mortise and tenon

Here is a story about how I do it:
How to make and use curved brace stock; by Jim Rogers 5-6-12.
 
 I was teaching timber framing to a group of students, and we were holding bimonthly sessions. One session only one student showed up. He and I talked over what could we do that was interesting or different for us to do.
 
We decided we'd cut some curved brace stock from a curved log that I had my logger bring in for us to use.
 
We took one curved log and put it on the sawmill and cut one side flat. We flipped it over and cut the opposite side flat. Then we cut it down the middle.
 
This is what the two "book matched" pieces looked like after we took them off the mill:
 


 
 
Next we took one and put it up on the saw horses, and shaved off all the bark using a draw knife.
 
We then picked out an already completed brace that we wanted to use as a pattern for laying out the locations for the tenons.
 
Here is the brace stock on the saw horses:
 

 
 
Here you can see the tools we used as well. They are a standard framing square, a combination square and a bevel angle gauge. And to help us with the layout line we used a straight piece of square metal tubing.
 
The first thing we did was we picked out the center of the arc. We then laid the standard brace on top of the curved stock and transferred the "working points" locations from the standard brace down onto the curved stock. These "working points" are the two ends of the hypotenuse of the right triangle.
 
Then using the square tubing we laid it onto the curved stock to represent this "hypotenuse."
 
This gave us a solid object that we could reference our layout tools against in order to draw the tenon layout lines. This worked very well for us.
 
We laid out the tenons and cut away all the extra wood from the curved brace stock.
 
We had already cut the standard mortises in both the tie beam and the posts and had test fit the standard brace into them to insure that these mortises and the brace were correct in size and length.
 
Once the long tenons on the curved stock were created, we measured them. Then we extended the mortises in the post and the tie beam to the length of these tenons plus a little bit.
 
We placed one end of the curved brace tenon into the extended mortise and checked to see if the extended housing was cut long enough for the long shoulder on the curved brace. We also cut the extended housing at a curve to match the bark side of the curved brace stock.
 
You can see this here in this picture of the tie beam just as the bent was being put together.


  
 
Here are the two "book matched" braces in the brace pile.


  
 
When they are in place they look very nice:


  
 
And a benefit to using a curved brace is it allowed more head clearance in the room:


 
 
I hope this short story has helped you to see how you could use a curved brace in your frame.
 
Jim Rogers

[Ljohnsaw]

Jim, very cool.  In that first picture, there is no size reference - I thought "boy, those 2x6 pieces are gonna be some wimpy braces" :D  Those are truly massive braces!

[Brad_bb]

Jim's way works using a template.  But if you have a found curve brace that  you want to use more of, have a longer brace, in other words not a standard brace length, you can scribe it.  

It starts by assembling the post and beam on blocks or ponies on the ground.  Much like Jim's method, you're going to layout and cut your brace first.  You'll lay your uncut brace stock on the post and beam assembly and adjust it to a position you are happy with and leaving enough wood to make your tenons.  


 
You need to start by marking points on the found curve stock on each side for the tenon shoulders.  Remember that there will be a housing in the post and beam and you have to adjust your tenon shoulders accordingly.  The live edge portion of the stock should be cut 90 degrees to fit in the housing.

Once the brace is cut, lay it back on your post and beam assembly and mark your mortise locations on the post and beam.  Now pull the post and beam apart and cut the mortises.  Once that's done, insert the brace into one of the mortises.  Mark your housing on the post or beam.  Pull the brace out and cut the housing(You can use a router).  


 
Check the fit with the brace.  You may want to put and overcut on the brace to make sure it goes in the housing without anything interfering at the bottom.No one will see the slight overcut as they will only see where it starts at the surface of the post and beam.  


 

 
Once you get down doing the first couple, it's just work after that.  Takes longer than a straight brace, but it can be worth it.  Shows you're skills too.  Disclosure:  The pics above are my project but I was not the one that cut these.

[curved-wood]

Very top jobs. It give some soul to construction. Brad: would be nice to save almost all the shape of the branch on your top photo. I like when poeple spend some time to do nice construction. It might take time but the joy of looking at it will last a life time.
Thanks for the nice pictures and the very specialized info