Congrats to Bernard and Neil!
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Thanks. First in a series, I hope.
Yeah! Here is a link to the article:
https://www.apogeerockets.com/Peak-of-Flight?pof_list=archives&m=education
Hope to see some more Biohazards around here.
https://www.apogeerockets.com/Peak-of-Flight?pof_list=archives&m=education
Hope to see some more Biohazards around here.
I only buy what I need from erockets.@kuririn, got any spare BT-80?
It'll cost me $9 for the Estes tubes, plus $15 for the Flip Flier they have on sale, plus $11 shipping, plus $80 for the Boyce rocket kit to use up the remainder of the BT-80.
Otherwise I'd be homeless in a tent at Diamond Head Beach Park.
Thanks guys. Hopefully my wordy approach wasn't too wordy.
Nice work to those involved 
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@neil_w, that is a fantastic design. Going to have to throw that into the backlog of stuff I want to build. Wanted to do something with some tube fins and that makes it a lot easier to accomplish
@BEC your article couldn't be more timely. Been looking at altimeters and was a bit worried and confused about poking holes in rockets. The article answered basically every question I had brewing. Thanks for taking the time to put all that down and for doing the research!
@BEC your article couldn't be more timely. Been looking at altimeters and was a bit worried and confused about poking holes in rockets. The article answered basically every question I had brewing. Thanks for taking the time to put all that down and for doing the research!
Yes, exactly. I really like seeing those test curves, some of the results were surprising to me.
The only additional test I would be interested in seeing is what happens when the vent holes are places close to the nose cone/body interface.
Bruce
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Not sure if it really makes a difference, but I usually put the vent holes in a spiral pattern up the tube. That way no 2 holes are at the same level. The thinking is that holes at the same level might possibly allow airflow through the tube which isn't what we want.
Interesting thought. Sometimes I'm really careful and lay the holes out with a fin marking guide and mark the distance from the top of the tube so that they are nice and symmetrical and sometimes I just "eyeball" it, so they're not perfect (see the MAV in the Apogee article, for example). In a dedicated payload section the holes are so small (and I generally use three) so flow through the tube isn't too likely. In the body....well, usually there's recovery system stuff partially blocking one or more when the rocket is ready to fly. Still, I'll need to think about that a bit.
I like graphs, which is one of the reasons I really like recording altimeters and therefore why AltimeterThree and the FS Mini are my two favorites to use these days. Easy to use and to get graphs on the computer that I carry with me anyway. The others require more equipment....
Getting the data all on one graph was a challenge. It wasn't until I found a piece of software called MagicPlot that I could do it without driving myself crazy. There is some behind-the-scenes stuff to do to get it to work, especially with the Adrel, since all its Windows program exports to a .csv file is a list of altitude readings. I have to create a time index based on knowing the sample rate.
Hmmmmm....testing vent holes close to the discontinuity caused by the nose cone/body interface. That would be interesting. I think if one is only worried about getting a good apogee value (and the flight has a reasonably "normal" profile), then it would have to be something really significant (I'm thinking vents right below the base of an Honest John nose cone or something here) to mess it up significantly. But the data might look a bit odd at other times.
I used to be far more concerned about placement and smoothness than I am now, seeing as I worked at Boeing and walked by 737 fuselages on the siding next to the office on the way in and saw the very carefully smoothed areas around the static ports for the air data system every day. That, of course, was also for airspeed, and in an airplane having bad airspeed data can lead to a very bad day for all aboard. Pressure altitude, by itself, without airspeed, is an easier problem to solve. That said, what I wrote in that piece is what I do.
I did get close, though.....
I used to live in Kent near the Renton facility. I wonder if the Fry's there is still open?
Yeah, Bruce beat me to it. The Renton Fry's had been in a state of appearing to be going out of business for several years, actually....but the entire chain shut abruptly not long ago.
I used to work in Renton as I suggested in my prior post....close enough to walk to that Fry's. Of course the Fry's itself was built on the site of what was once the Boeing Renton 10-65 building, which housed full scale mockups and a goodly portion of the Electrical organization when I hired into Boeing until ~2001.
I used to work in Renton as I suggested in my prior post....close enough to walk to that Fry's. Of course the Fry's itself was built on the site of what was once the Boeing Renton 10-65 building, which housed full scale mockups and a goodly portion of the Electrical organization when I hired into Boeing until ~2001.
Pieces coming together. How long should the tube coupler AC-24 be?
OMG, I actually remember you starting that build just before I went on a 5 year hiatus...I was even an early responder LOL! I think it looked great as an Estes kit!
Absolutely FANTASTIC work guys and great to see it recognized and shared with others!
Geez this just reminds me of how slowly I build in comparison to other folks. Or maybe it's the Hawaii air that makes for speedy building.
Do you have Rocksim? Referring to the Rocksim file is the easiest way to see the details. If not, I'll try to describe here.
- The transition is specified as described in Tim's videos, four parts starting here: https://www.apogeerockets.com/Advanced_Construction_Videos/Rocketry_Video_13. Note that I have built a lot of cardstock transitions but never a complete assembly in quite this way. My suggestion is to watch those videos to see exactly how he does it, then adjust according to your preferences. I had the length of the shoulder as 1.5" in the design I sent Tim, but I don't think I would normally use such a long one in my own designs; I'd probably go for 1".
- The pod tubes are spec'ed as BT20, 2.25" long on the long side. However they're not a critical component and you can change dimensions any way you like. I can't quite tell what you have there in the pic.
- That ring came out good.
- Be prepared to sand the ring holder fins to adjust fit of the ring. Of course this comes much later.
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Congrats Guys!
I haven't had a chance to read the articles, but I'm looking forward to doing that. I've got VPN issues right now, and I've got to get them resolved first.
I haven't had a chance to read the articles, but I'm looking forward to doing that. I've got VPN issues right now, and I've got to get them resolved first.
I find I’m the most productive with building after 9pm, especially after 11. To me, it’s like reading a book before bed.Geez this just reminds me of how slowly I build in comparison to other folks. Or maybe it's the Hawaii air that makes for speedy building.
Do you have Rocksim? Referring to the Rocksim file is the easiest way to see the details. If not, I'll try to describe here.
I don't know if that was super helpful regarding the coupler. See if you can figure it out from the videos, else come back here and ask again.
- The transition is specified as described in Tim's videos, four parts starting here: https://www.apogeerockets.com/Advanced_Construction_Videos/Rocketry_Video_13. Note that I have built a lot of cardstock transitions but never a complete assembly in quite this way. My suggestion is to watch those videos to see exactly how he does it, then adjust according to your preferences. I had the length of the shoulder as 1.5" in the design I sent Tim, but I don't think I would normally use such a long one in my own designs; I'd probably go for 1".
- The pod tubes are spec'ed as BT20, 2.25" long on the long side. However they're not a critical component and you can change dimensions any way you like. I can't quite tell what you have there in the pic.
- That ring came out good.
- Be prepared to sand the ring holder fins to adjust fit of the ring. Of course this comes much later.
I would say this is an Expert build, almost like the Starship Nova. I find the hardest part is going through my parts for the necessary bits. I’ve had to improvise somewhat such as a piece of dowel to attach the eyelet screw to. Also fitting the centering rings inside the coupler is a challenge.
The shoulder is an important component because it determines the length of the NC section, if I understand it correctly. Did you see I’m adding a clear payload section (for the inevitable insectronaut)?
I used the cut out tube guide which fits a BT-50. I could shrink it down to a BT-20. Maybe later...
Let's just say the build is a lot easier with an off-the-shelf transition.... but Tim doesn't sell any.
Yes I did.
In my design the exposed part of the payload section body tube is 7" and the transition is 1.5". So go 8.5" + length of shoulder. In your case that would imply a piece of BT50 8.5" - (length of clear payload section) + length of shoulder.
In the future I will need to ask for the opportunity to review it before publication. First time I saw the finished product is when he sent it out to the world, and I am distressed to hear about the errors.
I'll post a BT20 cut guide here tonight.
I appreciate the exposure from being published in POF, and I'm glad that I know of at least two or three in-progress or pending Biohazard builds.
On the other hand, I'm very frustrated at the errors in publication, and the thought that someone out there who doesn't know me and doesn't know how to contact me will try to build straight from the plans and will run into problems.
So I'm really not sure why I don't just publish the plans here on the forum in the future. Yeah, fewer people will see them, but then I can retain control over final content. Sort of like a free plan pack. Is there any reason I am missing that someone would be more inspired to build from plans in POF vs. something I post here? Asking honestly.
On the other hand, I'm very frustrated at the errors in publication, and the thought that someone out there who doesn't know me and doesn't know how to contact me will try to build straight from the plans and will run into problems.
So I'm really not sure why I don't just publish the plans here on the forum in the future. Yeah, fewer people will see them, but then I can retain control over final content. Sort of like a free plan pack. Is there any reason I am missing that someone would be more inspired to build from plans in POF vs. something I post here? Asking honestly.
Honestly, I'm enjoying the build more than the 25 free plans that Tim provides. That battle ax rocket from last month looked like a beast, and I'm hesitant to build it.
The Biohazard is a challenging build. Anyone attempting it should realize they're building from scratch and need a big supply of parts in order to make it work. Heck, I've built several of my rockets from Jimz and YORP scans of fins. When it's time to mount the ring, I anticipate having to use several tools in my list of swear words.
The Biohazard is a challenging build. Anyone attempting it should realize they're building from scratch and need a big supply of parts in order to make it work. Heck, I've built several of my rockets from Jimz and YORP scans of fins. When it's time to mount the ring, I anticipate having to use several tools in my list of swear words.
