Monday, November 24, 2014
For the outlet end of the elbow I followed a similar process. I used the form block to mark the cut lines on the flanges.
To draw the cut line I started by using a straight edge to line up a block in the bottom of the opening so I could mark the bottom of the cut line.
I then cut off the scrap with the band saw like the inlet end, and ground the end square and smooth wit the belt sander. A little deburring and the end was done.
Sunday, November 23, 2014
I realized part way through that a red line was easier to see in the die hole than the pencil line I started with.
I could have used a supports for the shell while sawing. I was able to tip the shell for half the cut and support the flange with a block of wood for the other half of the cut.
To clean up the cut I just used the belt sander and deburred the edge.
They came out very good. They're starting to look like parts which could make the manifolds.
Wednesday, November 19, 2014
The next step is to trim the inlet and outlet ends.
Tuesday, November 18, 2014
The marking tool made a line which was easy to follow with the band saw, just outside the cut line.
For the outside curves the belt sander made it easy to grind to the line leaving a nice smooth curve.
I still have the inside curves to smooth up and then trim the ends.
Sunday, November 16, 2014
I've had a great idea for marking the trim line on the shells. It's kind of the reverse of scribing a line on a board with a marking gauge. Instead of the guide being on the scale, the guide is the rounded end of the block of wood.
For a scribe I used a coarse thread drywall screw. I drilled a hole at the distance for the flange on the lower shell and a hole 1/4" further out for flange on the top shell. The edge of the top shell wraps around the edge of the bottom shell to make a nice finished edge. You adjust the screw tip, for the line you want, to just stick out of the block. Run the block around the part leaving a nice even trim line.