Volo.

Jan 28, 2012
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I got the second super curvy layer glued up today so I'm done gluing up the frame parts and I started shaping and assembling the top tube. I'm still working out details and finding glitches in my plans.
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Honestly it feels like a bit of a long shot that I could have a ridable bike by the deadline but I'll just keep plodding along.
 
Jan 28, 2012
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I realized I needed to figure out my crank situation sooner rather than later and I'm pretty excited about what I came up with. I knew I wanted to use this sprocket but I didn't want to go with a one piece crank. This was one of those moments when I'm glad I don't throw much away. I have a box full of old cranks and I found one that was about the right shape and had a four bolt ring. This worked out so well it seemed like they were meant to go together. The sprocket center hole was the EXACT I.D. to self center on the new crank arm making locating it a breeze.
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Jan 28, 2012
258
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Trying to machine aluminum with woodworking tools is pretty frustrating but progress is being made. I had to make a head tube and since I didn't have a lathe I used a laminate trimmer. By wrapping a bearing with tape I was able to remove just enough material to get a perfect fit on the cups.
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Mar 26, 2012
7,279
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Maplewood, MN
That crank turned out well. I wonder how stiff that will be with the BB suspended below the frame in the cradle brackets. Although the brackets are aluminum, and they look fairly thick, so probably nearly as strong as a thin walled double butted chromoly frame would be.

Head tube looks like a nice fit. Adhesion for the connection to the frame?
 
Jan 28, 2012
258
1,149
That crank turned out well. I wonder how stiff that will be with the BB suspended below the frame in the cradle brackets. Although the brackets are aluminum, and they look fairly thick, so probably nearly as strong as a thin walled double butted chromoly frame would be.

Head tube looks like a nice fit. Adhesion for the connection to the frame?
You're not seeing the whole structure because its not made yet but its not suspended, its going to be cradled between that middle beam and the lower beam with three brackets. I know its not going to ride like some 80's aluminum road bike but according to my my computer models its going to have a torsional rigidity of 3.7 Newton meters per square inch (JK).
Part of what slowed me down on this project was deciding how best to bond metal to wood. Thanks to miracle of highly toxic marine grade adhesives I've found a way to get such a powerful bond that attempting to separate the wood from the metal resulted in a twisted piece of metal and splinters of wood.