CDR Notes From Questions

Owned by Gillian Doolittle (RIT Student)
Last updated: Nov 11, 2021 by Grace Dertinger (RIT Alumni)

Airframe Questions

  • Why not just buy COTS fiberglass they are not expensive?
    • The fiberglass is being done to keep the rocket mainly student made. (Should add next time that it is done as a learning experience)
    • Next Steps: Record material properties of airframe (not critical but good to know)
  • Has the team done any winding?
    • We are testing it recently but ran into snags.
    • Next Steps: Do more extensive testing try at a 6" tube size.
    • Next Steps: Continue looking into a new removing method 
  • What is a hold down?
    • It will be used to keep the fiberglass in the epoxy bath.
    • Next Steps: Print and test using the new addition to the x-winder

SRAD Motor Questions 

  • Does the spacing between the grain allow for over pressure that would then make a crack?
    • No the spacing helps to make it go through smoothly.
  • What is being mixed/ where is it being mixed/ where are materials being stored etc etc etc (I can not type that fast and Matt asks too much)
    • All answered in our EHS doc
  • Is there any concerns with voids in the grain?
    • We are going to try to do x rays, and through testing we will be able to see if there is any.
    • Next Steps: Reach out to the Brinkman Lab about doing it (Rob is a main contact)
    • Next Steps: Lay out plan if x ray machine is not available
  • Explosives transport license?
    • Next Steps: Define license: Who will be getting the license, how long will it take, is this feasible? 
    • Next Steps: Confirm transporting "homemade explosives" is allowed through the mail (wink)
  • Test site for motor?
    • URRG
    • Next Steps: Make sure URRG lets us do this and give them at minimum a month in notice
  • How will the grains be held apart?
    • O-rings
  • Any concerns with making the the core cylinder?
    • We will test with a dummy mix to learn
    • Next Steps: Look into using a slight draft angle for taking out the cores of the grains
  • When do you plan on getting the explosives license and if you can't what is the plan?
    • We can "technically" transport just the grains
    • Next Steps: What is the license process timeline what is the go/no go point for the license? 
  • Is the tubing rated for what it is being used for, is there a seam running down it?
    • No seam running down and as of right now not considering and going over the temp of the case as it seems like other teams do not.
  • IS the aluminum work-hardened? _Bob
    • Not currently just 6061 
    • Next steps: Verify that material can withstand without hardening. 
    • Next Steps: Find specific material properties and account for them in calculations. Verify the ones we currently have are reasonable and a safe over assumption.
  • WE melted an aluminum nozzle in testing i am concerned about the aft retention
    • That is a good concern and in the past was done weird (Brahm)
    • Next Steps: Fun an FEA

Recovery Questions

  • Can the team still compete in irec if you have to revert to a cots motor? is switching...
    • They are okay with it
  • 6.3g seems like a lot what's the test plan?
    • when the airframe is done we will test....
    • Next steps: what is the specific test plan?? and when will this be done? dates for the airframe and subsystems to shoot for
  • What's your plan for sealing the charge gasses out of the avionics bay
    • The wires leading go through bullheads and connectors which are sealed..
  • General
    • Nest steps: verify recovery FEA and components.
    • Nest Steps: Verify snatch and recovery numbers, has anything changed?

Avionics

  • No questions

Umbilical 

  • Be careful with the barrel jack there really isn't polarity protecting other than how you wire it
    • We will be careful -Jim
  • Do we need to clarify with IREC?
    • No it was in the app but we will ask the rules guys just in case
  • You have the barrel jack at a 90* but...?
    • Its pointing down parallel to rocket
  • Something about making irec better or expanding?
    • Current irec rules say umbilical's and payload must be separate 
  • I missed this question (ghd)
  • Next Steps: Run aero test on umbilical cover and edit 

Payload

  • What is the current state of the manufacturing? Has design been verified by the team before manufacturing has started? Are you using this CRD to verify the design or how are you going about it? Traditionally you release design after you "pass" a design review...
    • Purchased almost all the structural materials and electronics . Frame has begun manufacturing. 
    • Internal DR was done
    • Next Steps: define team "verification" this is a team effort if we pass something that we should have caught then its on all of us. Ideally have entire team formally "pass" the design  
  • Why did you pick these specific cameras?
  • In the event of the XREE..
    • Not have live feed no plan
  • That estimated battery life, you said you can... you can switch it on/off?
    • this estimation comes from the worst case..?(might have missed that)
  • How do we plan on recovering the sabot
    • We plan on retaining it. 
    • Next Steps: Verify force of shock cord will keep the sabot together on the rocket ride. FEA on rope..?

End Questions

  • Biggest risk for the project right now
    • Sold propulsion is biggest risk
  • How can we minimize this risk?
    • biggest herdal is ehs proposal through sike emission.
  • What happens if it doesn't get passed?
    • Then we go to COT
    • Next Steps: Get proposal out ASAP and define timeline 

Thoughts 

  • What is the overall schedule/timeline?
  • Was the purpose of this to verify the design and/or tell everyone what's happening and get feedback? 
  • What did we learn from all this? 
  • How can we improve for FDR? 
  • What needs to happen to get to FDR for each subsystem? Make timeline for people to shoot for.
  • What do each subsystems need? immediate and outlook (so we can get ahead and try not to get caught off guard) 
  • What is the difference between the CDR and FDR?