L1 in my future

Something wrong with numbers, you can't accelerate by 4m/s in 2" distance.

If you are good at aligning things, you can screw third button into the other centering ring. Or just use longer rail


-Alex

I'll run them again and make sure no other parameters changed.

UPDATE: Right - there were other differences in the simulations. When I re-ran, almost no difference in off-the-pad velocity. So I'm looking at 11.3 m/s (37 fps) with the rod as is. If there is a longer rod available, that's going to be the best choice for this rocket.

Should have caught that - thanks Alex.

Almost ready to go. I installed the motor retainer, bottom rail button, and the weld nut for the upper rail button. Need to get some Loctite at Home Depot tomorrow so I can pop the upper button on. Everything but the nose cone has 2 coats of primer and is smooth to the touch. Debating whether to finish painting it now or wait until after a good first flight.



CG measurement was done with motor casing holding a dummy mass to simulate launch (coins in a plastic bag, weighed accurately on my Dymo 10lb postal scale). Nose weight of 104 grams was added to put CG approximately 1 caliber (4") ahead of CP. There's a discrepancy between the manufacturer's claim of 48" from nose CP and what OR says (47.25"), so I will likely add a few more grams of nose weight just to be safe. CG moves forward about an inch when I simulate the post-burn motor weight (slightly over-stable).

Simulations with H123W are green. Performed both short rail (42-48") and long rail (60-72") runs in OR.

Now to see if it actually flies! Amesbury July 27 would be the first possbile L1 attempt at a CMASS launch. Unless I get impatient and decide to drive to Berwick between now and then.

- Matt

Thanks Bill. Initial flight will be a single deploy for my L1, so the nose will be fixed (tight friction fit).. Then I'll reconfigure for dual deploy for my L2. Not surprised that the plastic eyelet on the nose can fail - it's pretty flimsy.

The other question is, is Amesbury even suitable for this rocket for single deploy? Simulations show it going 1400', so I'm concerned about losing it...

- Matt