A lot of time without posting, but I have been reading you every day.
After some rushed attempts last summer solstice, I decided to make some serious but leisurely progress.
This were some of the rockets I made last solstice.
First I needed was some real tooling, so:
lathe.PNG 1.31MB 2 downloads
And of course, I had to learn to machine. All my experience hands on was a few hours learning to face a lot of years ago. All my experience was with CAM software, complex geometries but not challenging to machine.
So, this is my first attempt to a 15mm core burner tooling:
15mm_Tooling_1.PNG 944.06KB 1 downloads
The spindle is stainless steel, all the other parts are aluminium. I must redo the spindle, I'm having troubles machining the draft correctly. Nozzle diameter is 7mm.
So, now that I had the tooling, I needed some way to test the motors and get meaningful data and not only rely on eyeballing the launches.
stand1.PNG 1.04MB 1 downloads
stand2.PNG 703.31KB 0 downloads
Almost all material used was scrap I had laying around. I only purchased the 40KG load cell, and the sparkfun openscale . I need to calibrate it more preciseley, but for now it´s enough to make comparisons. Error not seems to be more than 10g.
So, time to make some motor and test it.
15mm core burner.
60/30/10 BP, milled, pine charcoal.
Total fuel (including delay): 31g
Total weight: 64g
Sample rate: 80SPS
20180304-TestA.PNG 31.73KB 0 downloads
20180304_TestA.txt 310bytes 3 downloads