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1. Sand inside of tube by hand with 60-grit sandpaper (this took a long time: next time use a flapper wheel, 60-grit). 
2. Periodically see it if fits over the motor case. If not, repeat step 1.
3. Once it finally fits, sand with 220-grit sandpaper to give it a smoother finish.
4. Now it's time for the tube layup. Prepare the layup jig (make sure it's stable, put a pole over it and wrap it with Mylar so that once you start the tube layup, the tube doesn't stick to it)

5. Carbon fiber is difficult to work with because it snags and frays easily, so make sure whatever surface you're using is completely cleared off. Also make sure that this surface is large enough for the entire piece of carbon fiber, because the fiber will warp if it overhangs. 

   	Length (in)	Length + Offset (in)
   Outer diameter (OD) of tube
   Circumference of phenolic tube (OD x π)
   Length of phenolic tube

6. Mark a (INSERT DIMENSIONS) area on the carbon fiber using painter's tape and cut along the tape. It's much easier to cut on tape than cutting the fiber directly, to avoid snags and make sure the dimensions are correct. The dimensions were determined using the table above. 

7. MIX EPOXX, DO LAYUP
8. Let tube cure at room temperature for at least 24 hours
9. Sand tube

-layup had bubbles so we used a fiberglass-overwrapped tube instead

2. Root Bond and Root Fillet

Required Materials:

Did root bond using 5-minuteUsed System 3000 epoxy. fin can jig needs to be improved --> make sure to space layers evenly, use top layer with smaller slits. Holes were slightly too small so was difficult to adjust

Bevelled fins by hand. In the future, do this using mill

AFTER root bond, attached phenolic LE to G10 AFTER root bond, attached phenolic LE to G10 fin core (did after root bond because phenolic wouldn't have fit in the fin can jig)

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Says it takes 6 hours to cure, but if you're in a time crunch you can apply a new fillet every 3-4 hours. . Can use a heat gun to speed this up even more.

Sand fillets

Procedure:

Make sure to do fillets right the first time becayuse this time we had to fill them in again (using West systems + fast hardener + silica)

Procedure:

3.0 Progression of the Carbon Fiber Cut3.0 Progression of the Carbon Fiber Cut-outs Design

Last year, the tip-to-tip design called for 6 layers of 3 distinct sizes, 2 plies per size. This allowed for a tapering effect on the surface of the fins and the tabs at the top added extra layers above the fins (WHY?) 

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1. *Using tape, mark squares of carbon fiber (24 squares, 4 for each size cutout, making sure there is enough room to fit the cutout with ~1 inch margin on all sides) using the following table:

   Cutout Number	Dimensions of CF square
   1 (smallest size)	18" x 20"
   2	18" x 20"
   3	18" x 20"
   4	18" x 20"
   5	18" x 24"
   6 (largest size)	20" x 24"

2. Cut along tape and label which size cutout it is (1-6) on the tape so you keep them organized later when laser-cutting. 
3. Prepare 25 (24 for the cutouts, one extra) pieces of wax or parchment paper (if paper is too small, tape the pieces together so that they are the same size or slightly larger than the carbon fiber squares
4. On the extra piece of wax/parchment paper, use spray glue to test to see how far you should hold the glue from the wax/parchment paper so that when you spray, the paper just barely sticks to your finger. If you use too much spray glue, the carbon fiber will be difficult to remove from the paper and the fibers will be warped, ruining the tip-to-tip layup.
5. For the rest of the 24 pieces of paper, lightly spray the wax or parchment paper with spray glue. Use your finger to see if it just barely sticks to the paper. 
6. Carefully take a piece of carbon fiber (one of the squares you cut out earlier) and lay it gently onto the wax/parchment paper, smoothing out any imperfections and making sure the piece is square (and not warped into a diamond or other shape). 
7. Laser-cut carbon fiber 
   1. Select proper settings for carbon fiber (100% power, 4% speed)
   2. Select proper file (make sure the size of the carbon fiber square matches with the cutout file- this is why labeling the carbon fiber earlier is important)
   3. Place carbon fiber in bed of laser cutter
   1. Make sure there are no loose pieces of wax/parchment paper curling up, as this will get in the way of the laser-cutter
   2. If you have room, weigh down the carbon fiber (but only after testing the path of the laser cutter, or you may damage it if it runs into the weight)
   3. Turn on the exhaust
   4. Cut! (Start with a test piece to make sure it's being cut properly) You may have to cut twice, so make sure you don't move the carbon fiber or the cutout will be messed up when you cut it for the second time.
   5. If you see small areas smoldering (meaning slightly glowing, NOT a flame- fire is bad), keep the laser cutter door shut and wait until it extinguishes. Opening the door would cause oxygen to enter and the smoldering to get worse. 

4. Preparation of Vacuum Bagging Materials

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For the tip-to-tip layup, we used a total of 6 _______ boats of epoxy. Each boat weighed 118g, not including the mass of the epoxy boat itself, so the total mass of epoxy used for the tip-to-tip layup was 708g_____g.

6. Vacuum Bagging

Required Materials:

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• Increase from room temperature to 150F at a rate of no more than 2-5F per minute
• Hold at 150F for 3 hours
• Increase to 250F (no more than 2-5F per minute)
• Hold at 250F for 3 hours
• Increase to 300F (no more than 2-5 per minute)
• Hold at 300F for 3 hours
• Ramp down to 100F (no more than 2-5F per minute) --> decreasing temp takes a lot longer than increasing and lower temps are harder to control
• Do not shut down the oven and leave it to cool down

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Required Materials:

Procedure:

Vacuum bagging materials were difficult to remove, but not impossible

Used Dremel to get rid of CF on trailing edge and either end of tube (in future, taper trailing edge of G10 to get smoother layup quality)

Sanded CF on leading edge

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so that only phenolic remains

Cut off ends of tubes using Multimaster

need to: sand creases, sand phenolic down to be flush with CF

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Lessons Lessons Learned

• Make the phenolic slot thicker to account for fit between phenolic and G10
• When doing the tube layup, make sure there are no bubbles (use heat shrink to help with this)
• Make sure the fin jig layers are properly spaced and insert the fins and make sure the tip-to-tip distance is identical before doing the root bond
• Take care to do root fillets correctly the first time so you don't have to touch them up later
• Cooling the fin can to room temperature during the oven cure takes longer than you think it will
• Don't spray glue carbon fiber to wax paper until after it has been laser cut (wax paper will catch fire in the laser cutter)
• Make sure the cutout squares are large enough so that there won't be tape on the cutouts after they are laser cut (removing tape is difficult and causes frays)
• If any pieces of the cutout are still attached to the carbon fiber, don't pull on it- use scissors to cut or you'll get lots of frays
• Make sure you have enough wax paper
• Make sure you have SHARP scissors for the layup