Reminiscing: How rocketry electronics have changed in 25 years!!

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prfesser

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Reminiscing: read a post on altimeters and it occurred to me that today's goodies are unimaginably far ahead of the electronics used back in the mid-90s when I started. Back then many fliers used motor ejection, even on large rockets, simply because of the cost of (and probably unfamiliarity with) electronics, which weren't extremely common in the early and mid 90s. One of the early manufacturers I do recall was Adept; their altimeters started around $100 (almost $200 today). Until around 1997 all altimeters used pressure sensors for altitude detection. I don't know which, if any, units had dual-deploy capability, nor what that capability cost. (any Oldguys™ who want to chime in with more info?)

The only thing I bought from Adept was a bare-bones timer kit for about $25. No launch detection, no battery holder, no screw connectors, just a small board with a 555-based timer. If memory serves, resistors were used to set the time. (Never used it, it got thrown away when they cleared out my lab 🤬). You had to solder a battery connector and figure a way to start the timer.

Some units had electronics that would detect launch; on others you had to figure a way to start the unit such as pull-wires or a broken or burned-through wire. I recall seeing one or more that had a spring-loaded microswitch with a spring-loaded lever that supposedly wouldn't activate the switch except on strong acceleration. For a while, one approach was to have a microswitch that would bear against the launch rod (no rails back then); when the rocket cleared the rod the switch would snap open/closed, starting the unit. Use of that method ended when (I think) someone used it on a pad that had a rod slightly too small for that switch, and it "detected launch" on arming... Mercury switches to detect apogee were already on the way out.

Most of the early altimeters had no "mach" inhibition, though that changed as more and more fliers were attempting high-altitude machbuster flights. Newer units could be set to ignore the pressure change at mach, often by simply ignoring any pressure change that occurred in the first 2-3 seconds. I recall at LDRS in Amarillo, a full-scale Arcas flew on an N motor. Either the altimeter didn't have a means of inhibiting ejection firing through mach, or it wasn't set properly. The main came out around 760 mph... :oops: :(

I bought the first accelerometer-based altimeter that came out. The Cambridge(?) was about 38 mm wide and 200 mm or so long, and retailed for about $200, or almost $400 today. I don't recall whether it had dual-deploy capability but I don't think it did. As it used an accelerometer, mach inhibition wasn't needed. After using it successfully on several flights I trashed the first one by using it just as an altimeter (no e-ejection) in a rocket that had a bonus delay. :( Bought another and destroyed it on its first flight by mounting it upside down.:mad: Stupidity was really expensive back then...

Today: altitude-only units, some of which fit a BT-5, for as little as $25. Which also buys a dual-deploy altimeter kit no bigger than your little finger. Flight computers handle multiple events and can be activated or accessed by phone. Altimeters that don't require e-matches. Affordable GPS transmitters and receivers. Onboard transmitter/receiver for live readout of altitude, deployment etc. Inexpensive tilt sensors. Chute release that doesn't require BP.

One wonders what the future will bring.

Best -- Terry
 
Agree, lots of improvements over the years. It's amazing what we can do now.
In the 90's I got an Adept altimeter as a gift and on the first flight in a LOC Starburst, it landed at the top of an extremely tall tree in a park. I took my 16' extension ladder to the park and it wouldn't even get me to the first branch of this massive tree. We tried using fishing poles to get a line around the shock cord...no luck. Since I've always tended to over build and make rugged stuff, it stayed in the tree for years.....never did see it come down since we moved out of state.
 
Not 25 years, more like 35 years.

If I remember correctly, I purchased this altimeter from North Coast at a Danville launch. I flew it in a LOC 3.1 at Blackrock. I do not remember who built those units.1989.jpgimg20200121_11212301.jpgimg20200121_11203635.jpg

Those are not my fingers, their Ron Schultz, the DOC of LOC. :)

Hopefully, someone remembers more than I do, about those units

Roy
 
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I was lucky to first BAR when electronics were fairly accessible. I didn't have much money, but I bought a DIY kit from a reputable manufacturer (can't remember which. . .maybe Perfect Flight???) and soldered it together. I think the kit might have been $50 and the pre-built was $65 (or maybe that one was only a kit. . .way too long ago). It was a DD Baro type and would easily fit in a BT80 or larger AV bay.

Since then, I added a few data logging altimeters when I had a bit more money. The Raven 1 (first round) was my most feature-filled altimeter, but I did have another datalogging altimeter from a smaller shop.

For the club, I bought a few of the original Jolly Logic altimeters so we could fly NAR altitude competitions easier.

More recently, a friend and I bought some Eggtimer stuff, but have yet to fly any of it. We hope to resolve that at NSL.

I intend to buy something from Featherweight again before Freedom Launch, most likely, as I think Adrian helped to move the ball forward with features and size and helped grow the altimeter 'industry' for rocketry. Not saying others like the Eggtimer or Jolly Logic wouldn't have happened anyway, but I think Adrian offered something pretty different and once the market showed it liked it, maybe that helped influence others to do their own take on it. I could be completely wrong, but I like my version. (and as mentioned above, I buy from various vendors, so spreading the joy for various products that do specific things differently works for me).

Sandy.

PS: I imagine the major intent of the thread is deployment electronics, but wireless launchers and cameras are a huge advance as well. I wish we could still get good quality 808 cameras like in the mid-2000's. . . I owned 8-10 of them and regretfully they are all dead. I am not aware of a solution, but need to find the right camera solution (given the supply chain. . . yuk) for 2 cameras to fly in September. I'm pretty sure its going to cost way more than the 808's. . . :(

S^2
 
Any cost savings brought about by improvements in electronics will be balanced out by increases in motor costs.
LOL, that is SO true! I used to test stuff with G's and H's, now anything smaller than a full J doesn't cut it. Obviously, that makes testing more expensive... and "interesting" too.
 
LOL, that is SO true! I used to test stuff with G's and H's, now anything smaller than a full J doesn't cut it. Obviously, that makes testing more expensive... and "interesting" too.
Hold on! Don't tell me you're not deducting the cost of test motors as a business expense! Though I guess that doesn't cover the actual cost...but it helps! :)
 
After acquiring an old NCR, I printed off the 1989 catalog. Check out these offerings for electronics! 16516285201087600567332889645276.jpg16516285644942200999982379151044.jpg
Pretty crazy. From what I gather, transolve was the bees knees of electronics in the day. When I got into the scene 13 years ago, transolve was pretty much gone.
Ken
 
Hold on! Don't tell me you're not deducting the cost of test motors as a business expense! Though I guess that doesn't cover the actual cost...but it helps! :)
Isn't biz-expensing motor cost the reason everyone starts rocket businesses!? Still, it's really easy to get back to zero profit (or less) when you have to buy motors to test things.
 
PS: I imagine the major intent of the thread is deployment electronics, but wireless launchers and cameras are a huge advance as well. I wish we could still get good quality 808 cameras like in the mid-2000's. . . I owned 8-10 of them and regretfully they are all dead. I am not aware of a solution, but need to find the right camera solution (given the supply chain. . . yuk) for 2 cameras to fly in September. I'm pretty sure its going to cost way more than the 808's. . . :(

S^2
Absolutely correct! I was there for the first flight of Videocam, a 7.5" Astrocam upscale, which had a VHS-compact camera installed---it just barely fit---with a mirror pointing down. Somewhere I have the video; it was a Yellow Jacket (sparky) L. Gorgeous flight, but the idea of having to build such a large rocket, for just a single low-resolution camera...
 
Hey ho! O.G. here! I think I still have the electronics magazine project to build your own altimeter. Transolve showed up with it weeks later. I called him to verify the origin and he admitted it. He was a private aircraft avionics guy. Tommy Billings was awesome, I had (and mostly still have) everything he made. A very relaxed guy who would answer any questions and spend an hour or two on the phone. Alex Boyce snd I got the first two ES236 staging timers with hand written instructions. I still have mine, but Alex blew the math and scattered it over a boulder out in the desert the next day.
Scott Bartel came up with the Blacksky 2 timer thru various iterations, I have 'b' model, maybe two. He kept nagging me to join Tripoli and claimed he would have everybody tackle me and hold me upside down to shake the money out to join, so to this day, I still blame Scott for making me poor.
Obviously, things progressed thru G-Whiz, Perfect flight, Missile works, Xavien, etc. I was witness to the question Cris asked us at a launch "What do you guys need for on board avionics"? The man is an absolute wizard and one of the most fun guys I've ever flown with. He came back a couple of weeks later and just blew my mind. Right out the gate, he had a damn near infinite combo you could trigger 5 events with. Then he flew an Estes Dude at an LDRS!
So yeah, stuff has changed for the better. No more mercury switches, but I do miss thermalite and flashbulbs. I have stories, prolly way to many. Good times, good times!
 
Hold on! Don't tell me you're not deducting the cost of test motors as a business expense! Though I guess that doesn't cover the actual cost...but it helps! :)
Of course, but spending money still reduces the "P" side on the P&L statement. Not like I'm getting rich anyway... :)
 
Oh, I did buy a Parrot, serial no. 12. You had to dump the data into Excel for processing. It flew a number of times then it lost it's memory. Featherweight had moved on to bigger and better things so it couldn't be reprogrammed as he didn't have the equipment anymore.
 
I'm pretty sure that Transolve and Adept were contemporaries. Though I didn't get into the High power hobby till 1991 so I don't know much before then.

I bought my first altimeter, and Adept Alts-2 at Danville in the Spring of 1992 just after I did my HJP cert flight(back in the days of no levels of certification), where I bought most of my altimeters in those days. I think I got them from Ross Dutton(sp?) the owner of Magnum. It was dual deploy as was my next one the Alts-2-50K. Then there was a series of Alts-25 units at least three maybe four of them, all dual deploy. I uh, had a couple of spectacular failures that didn't leave much to clean up other than tiny pieces. Pretty sure it was operator error.

I still use one of the Alts-25's to this day. The later units had a mach inhibiter built in. I used it at LDRS-29 in California for the Wildman N-10,000 Drag race for which I got the highest altitude at 14,887 agl.

I did own one Transolve at the same time as I bought the Alts-2-50K. It was also dual deploy. I used it successfully for several DD flights, but I disliked the reporting system for reading altitudes. It beeped out a certain code and the code corresponded to a chart that gave a range of altitude measurements. Memory is a bit dim, but I think they were in like 400 foot ranges like: 400-800 feet, 800-1200 feet, 1200-1600 feet, you get the idea. It might have been 300 foot ranges, but its been so long that I don't remember for sure.

I really ought to get me a new altimeter one of these days.

Brad
 
The pictures look a lot like those for the project in Radio Electronics, October 1990.
I was a big fan and long-time buyer of Radio Electronics. My first computer was back in '78 from the RE articles. Built many things from there over the years. As to that October '90 edition, it is currently sitting on my desk at work! I kept a few of the good mags for posterity.
 
How many of you had this for your first launch controller.

DoorBell-Pushbutton.jpg

45+ years ago we ran lamp chord wire (with spring clamps) from the battery in the station wagon
to the door bell button, and then two wires with alligator clips to the igniters.
 
How many of you had this for your first launch controller.

View attachment 517022

45+ years ago we ran lamp chord wire (with spring clamps) from the battery in the station wagon
to the door bell button, and then two wires with alligator clips to the igniters.
My first launch controller. Nobody else in my area knew anything about rockets. I built this using the information from the Estes catalog with my own finishing touches in about 1968. It was a metal42D92175-4A95-429F-9660-8C1047D57865.jpeg tin with a metal spray can cap as the guard around the push button. Lightbulb for continuity.
 
My first launch controller. Nobody else in my area knew anything about rockets. I built this using the information from the Estes catalog with my own finishing touches in about 1968. It was a metalView attachment 517032 tin with a metal spray can cap as the guard around the push button. Lightbulb for continuity.

You still have this!? (pack rat)
 
I went to electronics in 1995 for all my high power flights. Started with the Adept RAS2. At over $200 each with a memory module they were expensive. I still have the catalog, an order from 2001, and the RAS2 instructions. I went to Perfectflite when they came out. The same thing but much less expensive.
Adept Catalog 1.jpg
 
I still have a Cambridge IAX-95. It would do dual deploy and My first try at that was with the Cambridge for my level 2. Now I fly the Quantum from Chris at Eggtimer and just can’t see any reason to use the old altimeter because It is just to big and way behind in technology.
 
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