Monday, May 16, 2016

UFS Assembly mostly completed & etc

Over this past weekend I got the final layers laid up onto the four UFS Assemblies.
After they cure I'll pull off the peel-ply and do some light sanding before adding some reinforcements around the pivot pin area and then they will finally be ready for the next step.

The plans call for three layers of 18oz over the top to join the side panels but since I'm working with thicker foam I needed to raise the crown a bit to compensate. This meant adding couple extra layers of fabric over the top. I chose to go with one layer of 9oz Carbon Uni and another layer of 12oz glass.

To better understand what I'm talking about, you'll notice in the picture below that the UFS "crown" extends ABOVE the beam side walls. The top piece of foam will have this area cut-out to accommodate the protrusion and is designed to eliminate a crush prone Fabric/Foam/Fabric glue joint in favor of a solid Fabric/Fabric joint.
The issue I'm working around is that the plans are designed for 5/8" (16mm) thick foam sheets, but since I'm using 3/4" (19mm) foam I will end up with this crown area being a few millimeters too low when I glue the top foam panel in place. The additional pieces of fabric over the top will help raise the height of this area a little and will strengthen the entire structure.
I still may need to make some accommodations by reducing the thickness of the top foam panel or more likely adding a few additional layers of fabric over the cut out area in the top panel to make up the difference. I really don't think this will be an issue and I will have a better idea of what needs to happen later on when the beams are assembled and I have the final measurements.


Some light sanding was done on these before flipping over to work on removing the wooden spacers at the top


Which are firmly wedged in place holding the side panels at the correct distance from one another

The one piece comes out easily

But the top one required some VERY careful drilling to weaken the wood without touching the laminate.

I then slowly twisted away at the wood fibers with a long scraper to break the wood piece bit by bit

And finally all clean and ready for further processing

Overlaid with one layer of 9oz. Carbon UNI


And now curing with one layer of 12oz glass 45/45.
Once this is cured, we'll go through one more sanding cycle and they will be ready for the next stage of beam assembly

While the UFS panels were curing, I did some prep work on the Lower Folding Strut blanks.
These are coming together really nicely and will eventually be cut into sixteen smaller pieces and glued to a solid glass panel.

Running a router bit along the edge to round it off

Carefully sanding down the solid glass area to ensure an absolutely flat and slightly angled surface before wrapping with Carbon UNI

And finally, I did some research on a good thin solid rim diamond blade that could be used DRY in my table saw. The Amazon description for the Hitachi 10" diamond blade says "WET or DRY", but I could not find that on the package itself so I may end up destroying it in the process.
But maybe if I go very slowly it won't build up enough heat to cause issues?
I did do a quick test on a piece of carbon cut off and it sliced a clean line through it like a knife through butter.





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