PDR Notes

Date

24 Sep 2022

Attendees

Notes

Discussion items

Item	Who	Notes
General
Structures		AIRFRAME AND OVERALL STRUCTURE/WEIGHT Composite Airframe Potential Weight Reduction 3 Tubes for Avionics Accessibility Problem: Lots of mass forward, needed to bring cp far forward to compensate, not ideal discussions on moving reaction wheel/av bay upwards concerned of internal surface finish in nose cone don't want to add more components to fix stability issue can increase length of recovery tube Solutions: make rocket longer, shorten nose cone, better surface James May (RIT Student): Need More Space for Shock Cord >6 in More space will decrease integration time Easy way to add appropriate size is to add a 1ft long "Shock Cord" component to the recovery bay This space will be in addition to ~2" of space next to each bulkhead for recovery hardware (eye bolt, quick link, etc) Surface Finish Matters difference worst to best case is 1800+ feet difference in altitude Grace Dertinger (RIT Alumni): Need to shoot for smooth tube finish Estimate component weights Action: calculate exact recovery mass for drogue and streamer Jim Heaney (RIT Student) @paige Shock cord BOAT TAIL SECTION Motor does extend through boat tail @alex: @avi @payload @reaction Needs to submit a final size as soon as possible because space allocations are not changing Boat tail is assumed to be onyx If we cannot source this from MarkForged, need to find a new solution Action: find backup solution to manufacture boat tail, either on campus or not boat tail transfers all thrust to the rockt What are holes in fin guides? bottom portion of fin structure, to be discussed later Yevgeniy Gorbachev (RIT Student) : does surface finish on boat tail matter? @alex: surface finish was fine last year, not expected to impact anything Jim Heaney (RIT Student) : what if we don't have a boat tail? @alex: apogee drop 400 feet Jim: if we dont have capabilities to manufacture, should consider cutting altogether. @Jake: might be hard to assemble with tighter boat tail Jim Heaney (RIT Student) : look to charm boattail/motor retainer Grace Dertinger (RIT Alumni) can we send some components out now? Alex: ??? Will Merges (RIT Student): can we buy cots? Yes, need to find solutions soon NOSE CONE SECTION: basically the same as last year no avionics, so its CF Jim Heaney (RIT Student) male mold means you only control surface finish of inside this is not something we've ever done Alex: clam shell still gave us a shit surface finish can do it like water bearer transition, pre-preg quilt and spin Do we have a laythe? no this idea does not seem very fleshed out, more of a suggestion Jan will not be happy if you laythe foam in the machine shop Jake: lots of the problems last year were because of a BAD MOLD, not necessarily a bad method Seams are the hardest part to get right Blackouts was also not great @alex: can look into CF sleeves/socks Jim Heaney (RIT Student) : investigate cost of COTS nosecone? we have one in the basement @alex: might be hard to adapt to a cots nosecone, sizing wise Grace Dertinger (RIT Alumni) : we need to start prototyping or working on this method soon BULKHEAD SECTION adding fillets to bulkhead goal is 80-85% weight reduction easier to apply epoxy FEA completed @nate: need to complete more rigorous testing and FEA Grace Dertinger (RIT Alumni) Why use the lip? Nate: better for cleaner installation Jim Heaney (RIT Student) : could be a better adhesion Jim Heaney (RIT Student) need to do a test of this whether this actually works Jim Heaney (RIT Student) how is eye bolt secured? could be through bolted or threaded could save mass Jim Heaney (RIT Student) can 60 thou withold charge? @nate need to do more FEA @will, now that we are doing single bay, are we going to suffer from drilling more holes in this? could add collars around where these holes are @grace how long to machine? could make one in an hour All bulkheads identical except for nosecone consider ball end tooling Action: Go/no-go on a clear tube for checking adhesion RAIL GUIDES can buy cots tear guide design will be flown on an L2 before can look into teflon coating how much heavier is this? not significant need to quantify drag reduction benefits need to think about where these will be placed in the vehicle Can we make this replaceable with COTS? Is there even a benefit to this? any changes to how we are drilling holes this year alex butthead: was actually real easy FINS SECTION fin flutter FOS is 1.32 this is a very low FOS Need to check IREC documentation Jim Heaney (RIT Student) How are we manufacturing? We no longer have the PCB mill. Need determine manufacturing process FINISHING PROCESS better tow heat shrink method squeegy twice sand a lot Questions on how to reduce time? liberal coat is gonna help make sanding more effective Tools? not really, sand paper Wet sanding?? recommended for the last layer decreases the lifespan of sandpaper Need to do more research 2 week deadline on this research phase STRUCTURES TIMELINE only first semester is on the time line Need to keep track of time and materials used Paige: suggestion to wind CF, buy FG tubes estimate 50 hours 200 hours for void (yikes) @grace: should not wind FG if we cannot make a good finish do other teams wind FG? no Is it impressive? if its good ours was not. Is it a good use of our time to wind tubes? ongoing debate resolution: purchasing FG tubes as the primary, winding is to be R&D after done with IREC tasks ANALYSIS SECTION lots of tensile testing cant do compression (dangerous) physical and analytical wind tunnel
Payload
Avionics		FLIGHT COMPUTERS same as last year Need to buy soon Need to spec out batteries soon Bigger battery on BigRedBee Smaller battery on RRC3's AV Bay Delrin over plywood concerns over thermal properties of delrin mostly the same av bay as last year how will the av bay be secured internally reduce number of retention hole concerns about placement of holes REACTION WHEEL less spin is more better
Recovery

Action items

Structures

open rocket

Add ft of shock cord in open rocket
Surface finish is really important
Recovery components estimate
ras aero
Making rocket longer and shorten nose cone and making surface finish gets us to 11000 ft
Coupler attached to booster
Payload rests on coupler so update in or
Structures team needs to prepare for the case where we are unable to 3D print a boat tail at MarkForged
look into other 3d printing sources
Brainstorm weight reduction
Boat tail:
By CDR need finalized boat tail design and manufacturing contingencies
Look at charms boat tail and motor retainer
look into buying boat tail
Analysis of screws for motor retainer and thrust plate
Nose Cone
NEED TO look into nose cone layup method and mold
look into water bearer nose cone
Printing on graces big printer a nose cone mold
Look into carbon fiber sleeves
Look into bough nose cone go no go date Alex Speyer (RIT Student)
Ask about rules of coupler to nose cone
look in to nose cone sharp angle maybe glue tube to nose cone
Bulkhead
Reduce weight
FEA on reduced bulkhead move to 75 thou and add holes with collar for wires
Clear tube with bulkhead to show filets and test with old space race tube go no go Alex Speyer (RIT Student)
thread bulkhead and only have one nut
Rail guide
Smooth edges
Need to compare or not worth it

Fins / Fin Support Structure

Look into minimum FoS for fin flutter required by IREC
Look into alternatives to cutting fins (crushinator is out of operation)Finishing Process/Manufacturing
Need to keep track of what we are using when manufacturing
Look into finishing process
meeting to discuss finish
Structures Timeline
heat shrink wrap
Test flight date**
RND fG NEED MONEY Grace Dertinger (RIT Alumni)
Analysis
Grace to get wind tunnel access Grace Dertinger (RIT Alumni)
Wind short tube
Make samples
Tour of lab and meet up with Carter
Timeline dependencies
Avionics
look into batteries
Look into screw switches
Need battery requirements-for size of batteries
Powerup gps before we get to the rail so big gps battery
don't put rail button in line with rail
Clear Delrin laser cutting with construct
Look into delrin material properties
holes in delrin
delrin and rocket epoxy
FIX TIMELINE get things done this semester
Get mece for ave bay
Backplane has to fit inside the ave bay
Backplane to have physical standard by October 21st
Backplane
Backplane has to fit inside the ave bay
Backplane to have physical standard by October 21st
Pick connector to backplane
Sensor Mod
Data budget (how much do we need to hold for one flight?)
look into what hertz we want at what time in the flight
put reaction wheel chip and put on board
Have IREC team ensure data ranges of sensors chips works for everyone's needs
Add more sensors
Temperature in booster
Power Mod
Look into using something other than Buck converter directly to LDOs
Conversation of LDO to switchers
Power draw calcs review
verify EM noise to other modules is not an issue
Radio
Select antenna make sure fits in ave bay
break outs for sb gps
what is rf transmission of delrin
Autopilot Board
Deadline for all other breakout boards
Date for PDR within avionics this saturday and invite Joe
Date for CDR
Date for prototypes design 1
TIMELINE
Wednsday BOM for Grace
Payload
heat shrink antenna is important
Flower petals
Walk through design
design version 2
assign tasks
Start on the theory
- what is the speed
flush out how we are going to tell it deployed
electronics for the payload
electronics timeline
batteries talk
Reaction wheel
look into when launch L1 maybe do a private day at urge and find another place to launch
flight force balance
motor needs to be rated for high g environment
how fast will rocket spin
Recovery hardware spin survive worst case need to quantify
block diagram asap
sensor for oscillation kill switch
Recovery
look at streamer in open rocket
Look into streamer purchase
open rocket to determine decent rate of a streamer
order tender descender
duel redundancy of tender descender and ematches
Meeting to flush out open rocket

Other

test launch date and location
Design choices made and follow rules by CDR