2012-05-26

3 ways not to cut curved rafters.

This week we had grand plans to get a bunch of rafters cut out.  I took Wednesday Thursday and Friday off of work to get some work done, then we were going to go camp and do some construction.  Well, so far everything has basically gone to plan and schedule up to this point.   In this post I will talk about three ways not to make round rafters.

We started out by taking apart a giant pallet.  it had about 60 boards worth of 1 x5.5 pine planks.  We pulled out all of the nails and ripped a 3rd of them in half so they made gluing up all of the boards.

Test fitting boards to make sure the rafters would all have enough material.

Libby stands with our other test fit stack.  We were able to get 20 rafters out of the material we recovered.  

Testing out the assembly bench.  In theory, we will be able to put a bunch of beams together in an afternoon. 

Glue, glue, glue.  Screw, screw, screw.  

Eric preps for an ariel attack.

Stacks of glued up beams.  20 of them.  This was a long Wednesday afternoon.
Thursday, Libby and I went down to Boston to have a picnic in the park with my little sister.   We then stopped by and saw Joe, Marry and the girls.  We had a good day and I found out no one else was going camping over the weekend.  We ditched our plans and decided to go see Libby's folks and the new plot of land they got on the lake.   I ended up working on Friday, a customer had an emergency.  We went to dinner with Libby's friends and got no work done on the cabin again.  The reason for building the cabin is to enjoy time with other people at camp.  We will take as long as it takes to enjoy our friends and family.  We got to Saturday morning and made our first trip to home depot.  We picked up material for the last four small rafters and some Giant circle cutting fixture material.


This is what A giant radius cutting fixture might look like if we had a working band saw.  

This is how the band saw would cut a giant radius if the band saw was running.  It just did not have the gumption to keep cutting.  

It was a neat set up.  We used two pivot points and the straps kept it balanced and elevated.  it would have worked great in theory.  Communism also worked in theory.  

Giant radius cutting fixture take two.  This time we made a giant triangle and the cutter would move.  It is robot approved.  We went to home depot to grab a new blade for the porta band and the second hinge to allow our giant triangle to work.  

JB and Betty check out the Makita Porta band mounted to the arm.  This should work....

It is a pretty level and stiff set up.  

And failure.  The blade does not have enough clearance to allow us to cut off the radius scraps without banging back into the saw.  

JB and Betty work on cord management.  No matter what cutting tool we use we will need to have a power cord..  

Plan C Sawzall mount is go for failure.  

I spaced up so we could have the clearance to cut out the rafters.  This looks secure....

So the vibration has enough umph to shift the entire bench.  When we swung the assembly back to the beginning of the cut, we saw that the entire work bench had shifted.  Our solution was to put a bunch of car batteries and bucket of bolts to try and hold it down.  

At the end of the cut, it was still close to cutting the part.   

Off to home depot for trip number three.  Lets try and get a better sawzall  blade.  

Time to cut some 38 degree angles for the rafters.    We did not have to cut all  the way through.  The curve should intersect and lop off the corners.

Holey blade deflection Batman!  This would not be a finish cut.  

The blade was cutting at an angle deluxe.  We cleaned up for the night and went to watch the Global Rally cross at Uno's.    
So that's three ways not to cut a big circle in beams.  Next we will try a ROTO ZIP and see if this will get the arc done in one cut. if anyone has any ideas on how to cut this, I am all ears.  Please leave your ideas in the comments.   

2 comments:

Ernie Schroder said...

Have you considered a router?

Unknown said...

Lay out your bearing walls on the ground. Swing your arcs on a pattern laying on your floor layout with birds mouth and plumb cut already on it. Use the pattern. Jigs saw and belt sand as needed