Mini Alpha

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
...well, I'm both an Alpha guy and an altimeter guy, so you had me from the beginning....

As for sealing that hole....only if you really want to. After all, you're still getting good apogee data. It's just that the first time I saw that dip in a plot and said "there's no way the rocket actually did that!" that I had to first see how I could induce it to happen, then set up the test to isolate a cause.
 
The hook was rendered useless when I decided to stage it, so I cut most of it off. today I will flush cut it and seal the hole. Great catch and research. I may just make a bigger Alpha......Not sure. Would be cool to make a bigger Alpha with D engines and make stages for it. Yes stages as in more than one. Not sure. I have materials for this project and my 3D printer foo is very good..... I want to experiment with laminated fins to reduce weight. Like 1/32 balsa core with lightening holes and then 1/32 ply skins or the opposite. Ply core with lightening holes and 1/32 balsa skins. 3/32 thickness overall.
 
Ok weather was amazing this morning and I had a slim window of opportunity with life and went for a flight. Since the flight the weather got worse.
Boost was perfect and flight was uneventful, EXCEPT the f#@$ing parachute. Going with a streamer or a better quality parachute. The Estes chutes seem to be to stiff.
Rocket went 94.1601ft and here is the graph from the altimeter.
This was a test flight on a 1/4A3-3T.
I have the booster almost done, it needs paint and custom decals. I have motors for all upcoming flights.
Looks like the ejection pressure wave propagates all the way to the altimeter and gets registered as a rapid drop in altitude and back to normal after "the event".
The second chart is the two flights compared. There is a big difference between 1/4A3 and 1/2A3.
I also noted the ejection was violent and the motor ejected also (was friction fit in with painters tape). The motor burnout spike is gone but the ejection spike is huge.
Ill try another 1/2A3 when I can.

1678047016268.png

1678047036488.png
 
It would be interesting to apply the filter ("Filtr button") just to see what it does to that 1/4A flight....but I expect it'll just smooth over the obvious ejection-charge-pressurization downward spike. The shape of the curve around apogee doesn't need any real filtering, it would appear.

Another short Estes delay, too....the spike is well left of 3s on the time line, especially since the boost doesn't start until about 0.6s.
 
I was looking at the short ejection time also, I thought I was seeing something. I guess I was right about that and chalked it up to me being tired. The filter just minimizes the spike.
1678062723869.png
 
Wow, I'm kinda surprised by the filter result....but I have spent far less time with Adrels and Adrel-generated data than I have with FS devices or AltimeterThree (or PerfectFlite Pnut). Only the Adrel and the Pnut (and probably other PerfectFlite devices) give the option to see both filtered and unfiltered data in their graphs, though you can get raw pressure data from FlightSketch devices, MicroPeak and AltimeterThree to make your own altitude calculations/plots. The Eggfinder ION stores both filtered and unfiltered data but you have to download and plot them —either one or both — yourself.

Estes delays, except for the re-released C5-3, all tend to run short — or that's been my experience backed up by LOTS of flight data. And since the internal pressurization made such a clear spike at ejection here, you didn't even need accelerometer data to see it clearly.
 
Yep I wanted to see 100ft, but it was not in the plan. Next 1/2A3-4 and 1/2A3-6, 1/2A10-3. Finally I will do the same program for two stages. I will have to go down the end of the road and launch in the field this looks it's going to get some altitude that is too big for my property.
 
Good weather today slight breeze got the Mini Alpha and booster prepped and altimeter installed and sssssssssssssssssssssssssssss off the pad it went about 150' and arched over. Hmmmmm not good then ssssssssssssssssssssssssssssssssssssssssssssssssssssssssss to the dirt!!! boom!!! smoke................Long walk......I'll let the photos tell the story. Damage is light expanded tube, broken 3d printed nosecone. Rocket is worth $3-8, Altimiter $110 for complete setup. Battery is toast and Altimeter blinks 5 blinks...............................

So, upon further investigation this turns out to be human error. I packed and loaded everything last night LATE!!!!!!! So I was tired. I looked at my motor pile and I know I bought two packs of booster motors. Check out the photo below. The boosters are unopened but I see some upper stagers in there. So this is what happened, in my slumber I loaded a upper stage motor as the booster and a single stage motor as the sustainer. So the flight profile was correct and the out come is also correct. Human Error. Damn!!!! BTW I connected the Altimeter to the computer again and the Magic Smoke came out!!!! I need a new one.

Sucks to be me!
 

Attachments

  • IMG20230318093226.jpg
    IMG20230318093226.jpg
    5.9 MB · Views: 0
  • IMG20230318093430.jpg
    IMG20230318093430.jpg
    9 MB · Views: 0
  • IMG20230318093503.jpg
    IMG20230318093503.jpg
    3 MB · Views: 0
  • IMG20230318094612.jpg
    IMG20230318094612.jpg
    2.8 MB · Views: 0
  • NoData.jpg
    NoData.jpg
    168.2 KB · Views: 0
  • IMG20230318104522.jpg
    IMG20230318104522.jpg
    3.2 MB · Views: 0
Last edited:
Fixed rocket, printed nosecone, fitted an 1/4A3-4T and put the little Altimeter in and let her rip.................................and 19Meters (62.34ft). Altimeter works and the smoke was not from the altimeter I may have touched the connector with the tweezers and they caused a temp short across the battery. Getting new battery any way from NCR.
1679163375942.png
 
Glad to hear you figured out the Adrel. Five blinks (at least while it's on the USB adapter) is just "I've been reset, but I've no new data to report" so is perfectly normal for a flight that didn't go high enough to trigger a launch detect. It's pretty hard to break those tiny things, fortunately.

I crashed a K-12 Farside clone once by putting the middle motor of the three (three stages) in the wrong way around when taping them together.....fortunately I was at Sixty Acres in the spring and the field was pretty soft, so it was repairable.
 
Thanks, I could not find where it identified the 5 blinks in the literature. So now I know and it all works. Too windy today 20-G38Kts all day. Had to deal with the family all day.......errrrrrr
 
It may not say in the instructions. I marked up what Matt was using and he's incorporated some of what I gave him (if you see a picture of a screen with competitor number "9040" on it, those pics came from me) but I've noted the 5 blinks signal when using one of mine recently. I need to run one through a whole cycle of use from initial power up through flight, downloading and resetting to get the LED-blink indications straight as I'm helping administer the altimeters at the WSMC in July.
 
Ok great. I thought it was smoked.....But as I now know it is ok. I will get another to get more data from a rocket with a payload bay. Just a little bigger than the mini Alpha, want good flights with small motors. I really like the 13mm motors they are great if you are willing to make good designs. the 1/4 is a little on the light side and is probably better for the BT5 rockets.
 
Okay mini Alpha update weather is perfect The engines were loaded we had a quarter alpha on the second stage and A10 0 on the first stage and the boost was perfect it staged and then proceeded to leave visual sight. Booster tumble recovered back to the yard tracking smoke was seen Pop was heard no parachute was ever noted and vehicle was never tracked to the ground. Vehicle is considered lost along with the electronics telemetry package inside which cost about a 8 times more than I paid to build rocket. And that wasn't even the big motor that was the smallest one for a second stage to say at least the performance was impressive seeing that it went ballistic and it'll probably never be found because that field behind my house is due to get plowed any day. I will send up the recovery drone tomorrow The venerable phantom 3 and we'll do a two battery research and if it's not found it's a write-off.
 
it it's a big field it's an extremely small rocket and the colors aren't really conducive for recovery especially in a nose down situation I am thinking I'm going to have to build a better alpha with a more reliable recovery system
 
Besides this rocket had six flights and had only one recovery under chute it's had a very how should I say it dismal success.
 
You need to tell your drone to look for something like this :) :IMG_2174.JPG

This was after a shock cord failure in December of 2019. This Alpha, ragged as it is, is still flying. I think the next flight will be #106.

(Yes, I know, the drone won't know what you're looking for)
 
Something new is happening down in the rocket shop 3D printers whirring away. Keeping with the same 18 mm diameter and a mini alpha it might get a slight stretch to accommodate what I'm doing and it might not I'm not sure.
 

Attachments

  • IMG20230321210201.jpg
    IMG20230321210201.jpg
    3.3 MB · Views: 0
1679448676453.png

I'm looking at my new design and similar specs are noted but I'm going to try rear deploy streamer. Going to do multiple tests before the two stage event ever takes place. Printed most of the parts, tomorrow I will lase out the fins and get some super HI visibility paint. Lick my wounds and get another altimeter. This design has very good performance, I was impressed with the small motors and how high it went.
 
Coming along, I'll cut the fins tomorrow and sand the rings so they are smooth. Then paint it.
 

Attachments

  • IMG20230321233551.jpg
    IMG20230321233551.jpg
    2.8 MB · Views: 0
Last edited:
Same weight, but has improvements.
Like:
Payload Bay,
Rear ejection,
Plywood fins,
Streamer.
 

Attachments

  • IMG20230322192427.jpg
    IMG20230322192427.jpg
    3.1 MB · Views: 0
  • IMG20230322192422.jpg
    IMG20230322192422.jpg
    3 MB · Views: 0
Mini Alpha is getting paint now, raining cats and bawlz so the paint is drying sloooooooooowwwwwww. Selected red because the fluorescent colors did not impress me. Red gloss and I got some filling to do after some sanding..............Not perfect but the last one was lost to the Gods. So I dont care too much.
 
Back
Top