R-7 Test Results

The second, slightly more successful casing 2.0 test, and some 3D printing shenanigans

After a short Christmas break, testing resumed on the casing 2.0 design

Main iterations for this test are:

  • Better Fitting Nozzle Washer
  • Better Glue Application And Tolerances
  • Better Cast Fuel
C2.0 R-7 on the STTS with the ICBM Expansion Module next to it (I love A.C.R.O.N.Y.M.S)
Closeup of R-7 on ‘the pad’ (Notice the grey ring around R-7)
R-7 with igniter leads attached

These changes allowed R-7 to survive the burn with the nozzle in place, but moved the failure point to the side of the casing

Test Date: 28/12/2020
Pre-Test Weight: 38.74g (With igniter)
Post-Test Weight: 20.21
Peak Thrust: 718 g
Burn Time: 2 Seconds

As you can see there was a minor structural failure on the casing, resulting from pressurized flames under the nozzle finding a different path trough the 2 layers of PVC

The Breach with the surrounding material ablated away
The Nozzle held up well, caked fuel not withstanding

A solution for this might be a different case material, not design
Possible materials include: Fire Retardant Cardboard or Aluminum (Aluminium)
Further Research Is Needed

(The naming scheme of the rockets has also been changed from R* to R-*, I did this by accident but I think its quite cool so I’m keeping it)

I have also acquired a 3D printer (A Creality Ender 3 V2 to be precise), and have been experimenting with 3D CAD Design

Notice the grey ring around the rocket on the STTS, this is a custom designed and printed part that makes sure the rocket does not wobble during testing
(The small holes are for venting potential casing leakage and are intentional)

I intend to make much if not all of the main rocket body from this

Stress Testing shows it can handle a lot of physical impact force

It is great to be able to design and develop a part in half an hour instead of days

I also got a old phone from a relative (Many thanks), and have repurposed it into a wrist mounted PDA of sorts, using a 3d printed brace

Active with the checklist open

I am using this as a pre launch / test checklist and it helps tremendously with organization and efficiency
It still needs some work with the mounting system, but that can be ironed out

I am also hereby setting a goal:
If / When I manage to make 5 Rocket Motors that behave in much the same way (Thrust profile, max power, burn time) and produce a minimal thrust of 500 g, I will focus my efforts on launching 1 up in a (probably 3d printed) rocket

I hope to achieve this early to mid 2021 (I was oh so optimistic back then)

As always, the raw data (In a 7-Zip archive):

I also recommend Notepad++ for viewing and editing

4 thoughts on “R-7 Test Results”

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