We need to confirm the length of the roles. Standard sizes for freezers
seem to reach a peek around 70 +- 5 inches internal lenghts. Anything
longer than that we would basically need to make our own/get made. So the
decision would need to be made if we are going beyond that length. If
someone in PSAS could let us (LV4 carbon fiber team) know what is
desired/required in this it would be great. Our team will be meeting
tomorrow and we can figure out our options to meet your wants and needs.
- PC Composites, Machine Sciences, and Boeing have showed interest in
- Trapezoidal fins with a large sweep angle (70 degrees from
perpendicular) show a slight advantage over other fin types, based on some
preliminary OpenRocket testing.
PSAS meeting notes
- *Getting a freezer for the CF is our immediate bottleneck.* LV4 is in
charge of this, but there's no reason LV3 can't help.
- See Boeing notes about sizes.
- There are walk-in freezers in the SRTC. I'll ask about them.
- We should ask Machine Sciences if they would be willing to do the
machining for the NSR too. (After the stuff for LV3 of course.)
- Does the CF need so be stored in an inert atmosphere?
- No, according to Sandie, our Boeing contact, it just needs to be
vacuum bagged to block moisture and kept in a freezer.
- If we're worried about heating in the nose cone, we should look up
what temperature epoxy starts to be damaged at.
- N-class motors are essentially our design motors.
- During the PSAS meeting next week there will be a short introduction
to Github... in theory.
- Open question for the whole airframe mailing list and LV3: *what
stability margin caliber is too low?*
- Stability margin caliber is how far the center of pressure (CP) is
behind the center of gravity (CG) in units of rocket diameters.
Boeing meeting notes
- The Boeing CF comes in widths ranging from 6" to 60". They have 24"
wide rolls, which would be ideal. (The PCC rolls are 5 feet?)
- If Boeing donates material it will be 8276 (unidirectional) and
- "Cat 1" or "Category 1" material is super-primo aerospace grade.
- "Cat 3" or "Category 3" material is no longer fit for making
planes, but still pretty great.
- The prepreg they use isn't tacky at room temperature.
- They use tackifier (basically adhesive) to get it to stick to
things. Heating it might also work.
- They might not have any adhesive sheets to donate, since that's not
a thing they really use.
- *We need to make a list of the things we want from them, including
- The way material donations from Boeing work is this... They keep a
bunch of stock. Sometimes some of it goes unused and expires. Sometimes
they order a lot of stuff and their freezers get full. When this stuff
happens, they normally just pass it on to the University of Washington.
- Because we're not part of this default donation process, we need to
periodically ask if there's going to be a donation cycle soon. Leslie has
volunteered to do this.
- There *might* be future seminars on CF, composites, and material
psas-airframe mailing list
psas-airframe mailing list