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 idealdiscussions 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 surfaceJames May (RIT Student) : Need>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 Estimate component weights 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 onyxIf 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 retainerGrace Dertinger (RIT Alumni) can we send some components out now?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 insidethis 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 soonBULKHEAD 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?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 adhesionRAIL 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 yearalex butthead: was actually real easy FINS SECTION fin flutter FOS is 1.32this 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 processFINISHING 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? 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 usedPaige: suggestion to wind CF, buy FG tubesestimate 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 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 testingcant do compression (dangerous) physical and analytical wind tunnel Payload
Avionics FLIGHT COMPUTERS same as last year Need to buy soonNeed 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
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 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 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 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 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 heat shrink wrap Test flight date** RND fG NEED MONEY Grace Dertinger (RIT Alumni) 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 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 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 n oise to other modules is not an issue Select antenna make sure fits in ave bay break outs for sb gps what is rf transmission of delrin 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 heat shrink antenna is important Flower petals Walk through design design version 2 assign tasks Start on the theory flush out how we are going to tell it deployed electronics for the payload electronics timeline batteries talk 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
test launch date and location Design choices made and follow rules by CDR