As I said before, it has been quite some time since I posted, but this time some good news.
As I started mentioning my Stretch Blobbo here, I've decided that I might as well let you all know that it has finally flown. It took me nearly six months to get a day that wasn't either raining or blowing over 20mph, but the flights, two of them finally happened. I used an Aerotech E-30T7 on both flights. First flight was almost perfect. I got just a tiny bend at the top of the body tube where the shock cord tried to create a zipper. But the ejection charge basically occurred at apogee, so no damage. Most of my damage is cosmetic because of the surface the rocket lands on, Lucerne Dry Lake Bed, which is rock hard.
Two problems occurred. One was that I discovered that my nylon parachute got singed. Fix is to pack the dog barf, instead of leaving it fluffed. On second flight there was no problem. Second problem was that my knot up at the eyelet screw was not a good one, and as the model descended, the shock cord kept slipping with the nose cone slowly becoming the lowest part when it impacted the ground. Fix was just to loop a knot over what I had. On second flight, no slippage.
So, it was a total success on the two flights, with just minor problems, that were easily fixed. Both ejection charges went off at apogee, something I was really worried about.
I think I mentioned before that I had installed a lot of nose weight to put the CG well ahead of the CP. It turns out that I was informed that these short rockets are designed differently, and that the CG isn't needed as far forward. I was told that something around a 30 percent body diameter difference should work fine, and it did. The flights were arrow straight, coming off the launch rail perfectly. Unlike many rockets I saw fly this morning, mine did not waver or tilt off of vertical. Anyway, the change in nose weight was accomplished by my purchasing an eyelet bolt with lock nut and two washers. I also added one ounce of lead weight. What I did was smash a one ounce fishing weight into an oval, drill a hole in the center, then used the washer and lock nut to secure things to the 1/4 inch ply. I had cut off the plastic loop on the nose cone. Actually I cut off the entire bottom of the nose cone, then inserted basswood block hard points inside, then screwed the 1/4 inch thick ply to those hard points. This allows me to remove nose weight if I decide to put some kind of payload in the nose. I would have preferred to have had a 1/4 inch ply ring glued to the inside, but I don't have the skill to create such a thing. It was difficult enough making the 1/4 circular nose plug.
I have a couple of Aerotech E-44T8 motors I will use on my next two flights. I believe that the rocket will fly just a bit higher with this motor.
Once I have those two flights in, I will then graduate to my Mascow Mini DX-3 for about four flights. I could not get a dual deployment set up with two altimeters, so I decided to use the motor ejection charge as the first step. I purchased a Jolly Logic Chute Release, and have ground tested it, with good results. So, this is going to be my dual deployment setup. If all goes well on the four flights with the Mini DX-3, then I will order a larger kit to graduate to my Level One model.
So, so far, so good with my come back in model rocketry. Just wished that it hadn't been so hot. It was near 100F when I left around 10AM. I'm not a heat person