I (sort of) broke the tripoli L record on an L1040

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mperegrinefalcon

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I was at NSL and launched a minimum diameter L1040 in a head end dual deploy setup.
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I had a telemetrum and and a runcam thumb pro 4k in it.
The telemetry said it hit 37,521ft and 2718fps, 181ft higher than the previous record.
I had telemetry the entire flight, but no GPS after launch. I had 6 in soln, and 9 in view on the pad, so the telemetry is barometric. I am not sure what happened there. I have used telemetrum products for a long time and never had this issue. Usually I just loose GPS during boost and then while coasting re-aquire it. I lost telemetry at around 4300ft, probably because of a berm blocking line of site.
If anyone has an idea what happened I would love to hear it.
The sections seperated at apogee, and it descended drougeless at around 150fps.
Winds aloft were 50-60 mph out of the west, so best guess is it landed 2-4 miles to the east. It went a little south after liftoff too, so probably a mile or 2 south.
I drove all around looking for it with no luck, couldn't even pick up any radio.
I got some video of it, but it is not very good. I will have to cut it down to upload it here and cant do that on my phone.
If anyone else has photos or video of the launch I would love to see it. I launched around 9am on Saturday, just after a bunch of M flights. I was at bank 5 pad one, the 10ft tower all the way on the left looking from the flight line. The LCO miss read my bad writing as an L1010 when saying the motor, and my name is Matthew Slater.
Hopefully someone finds the rocket and turns it in to the folks at SLVROC.
Here is a screenshot from the video and the screen from ALTOS. I will try to get a better one once I am on my PC.
Screenshot_20240527-203029_AltosDroid.jpg
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I know the Telemetry data can't be sent in and I know I will not get the record for it since I did not recover the rocket, but I have no reason to disbelieve the barometric telemetry data. I still consider it a success because it held together through the boost, and the drouge deployment worked. I can only assume the main worked as well.
I do not know what I could have done to make sure the GPS worked.

Thanks for reading
 
Last year the same thing happened to me. How well was your AV bay sealed from the black powder charges?
Av bay was set up the same way I always do. Terminal blocks with 15min epoxy sealing the hole the wires went through. In all my tests no residue was inside the av bay. I know the drouge deployment worked for sure. It had a stable descent rate the entire way down.

It was weird, I have something like 20 flights on telemetrums and never seen this. It had strong GPS lock in the tower, it is like the GPS completely stopped working after launch though. I maintained telemetry through the whole flight though.
I tested the functionality on the ground too. I took it to a local park and the tracking pointed me to within about 30ft.
 
Awesome flight! What was the simulated altitude and max speed? Do you have a photo(s) of how you set up the av bay?
Altitude by Openrocket is 40,242 with max velocity of 2589 fps. 33.4 gees max accel.

By Rasaero II it was 39,526ft with max velocity at 2434 fps.

Telemetry data says it hit 37,521 and 2718fps, though this is all barometric data sent over telemetry. It wiggled a bit after exiting the tower, which cost some altitude.

The runcam thumb in position and plugged in.
Below it is the battery box for the telemetrum.
4-40 screws and nuts are the mount for the altimeter. I designed into the print standoffs for the altimeter and hexes for the nuts to nestle into. No need for a wrench, the nut just fits into a shaped divit.
IMG_20240528_232943.jpg

On the side is a featherweight magnet switch. The telemetrum is mounted above the battery for the camera, which has a BEC to step down from 2s lipo to 5v. Testing showed it has a 30 minute recording life at 1440p 60fps, but no LVC so the battery gets burned out with a flight. The camera will save the footage after loosing all power though.
There is no lid for the camera battery. It is designed to use the wall of the coupler to hold everything in place.
The wires look messy in this picture, but they are much cleaner when in the coupler.
IMG_20240528_232651.jpg

The prototype design below is very similar to the final product. A bit of tweaking dimensions and adding the bay for the magnet switch and the screw mounts for the camera cover. The cord to power the camera passes through the hole in the bottom of the camera mount.
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Here is the only video of this rocket that I know of. There was such a delay from the box that both the photographers trying to capture it were too early. I just have to hope it gets found and returned to me for the on board footage.
If anyone was there and has another video of it, I would love to see it.
View attachment l1040 - Trim.mp4
 
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How much altitude do those wiggles really cost? I haven't the slightest intuition about it.

Hope you get the rocket back. Sounds like it was a great flight all things considering.
I don't really know how much altitude they cost, but any aoa on the fins will cause extra drag while the fins correct.
It was a great flight. The rocket held together, drouge deployment occured, the new tower I made worked well. Pretty much everything except the GPS worked.
 
I'm not familiar with the Altus Metrum gps antennas, but I have been using epoxy to secure mine down per the eggfinder manual. Are the AM antennas more durable than those?
 
I'm not familiar with the Altus Metrum gps antennas, but I have been using epoxy to secure mine down per the eggfinder manual. Are the AM antennas more durable than those?
Not familiar with the eggfinder antenna. I have flown a telemetrum to 63 gees before without issue. This flight would have been around 30-40 gees so I don't believe it would have. The GPS antenna falling off would certainly explain the lack of GPS though.
I have yet to download the Telemetry from my phone to watch back the flight.
 
I've been hearing issues of folks with the Altus Metrum units that are made with the temporary substitution of hardware are having more difficulty acquiring lock. I think the TM4.0 might be in this group.

I need to do some delving.

In any case, awesome to hear your semi-success. I have a similar flight I'd like to accomplish on the same motor, but I need to build the rocket first. Then find time to get out to Argonia for some flights. Be a few years. I hope you're able to attempt this flight again - whether it be a rebuilt rocket or re-flight if you find the rocket. Good luck!
 
I’ve had launches just under 20k recover drogueless to a main at 1000 end up 2.5 miles away from the launch site.

How far out/away did you search? Hope you find it or someone finds it for you.
 
I also had some trouble with a featherweight GPS at NSL. Luckily got one or 2 packets at 1700ft agl which got me close enough to find it. Is it possible that with all the noise of all the different telemetry systems it reduces range?
 
I’ve had launches just under 20k recover drogueless to a main at 1000 end up 2.5 miles away from the launch site.

How far out/away did you search? Hope you find it or someone finds it for you.
I searched 2-7 miles from the launch site.
Someone flew an M685 to 45k right before me and landed 5 miles to the southeast.
I drove along every public road in the area.

My descent rate was fluctuating from 80-300 fps. I would bet it averages out to around 150fps though. The winds aloft were about 50-60 mph out of the west and it would have been falling for about 3 minutes in those winds. It weather cocked a little over the crowd (east) and had a bit of an angle to the south. If it was 5 degrees that puts it .6 miles south.
I would guess it is 1-2 miles south and about 3-5 miles east of the launch site. Which would be in this general area.Screenshot_20240529-144529_Maps.jpg
I drove all over and was not able to pick up telemetry again. It has to be in a ditch or could have landed in one of the holding ponds. I was all over the roads in the area.
I might be able to go back up and find a campground to stay at while I look around more.
I have faith that if a local finds it they will turn it in to the hobby store or Matt Abbey. I talked to the owners of the property in this area so they know to call me if they find it.
 

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I also had some trouble with a featherweight GPS at NSL. Luckily got one or 2 packets at 1700ft agl which got me close enough to find it. Is it possible that with all the noise of all the different telemetry systems it reduces range?
I do not know how that would effect my GPS signal.
I had telemetry the entire flight until it dipped below 4300ft, just no GPS position whatsoever.
There were others on telemetrum channel 3 there, and my tracker list got populated with a bunch of different trackers with no callsigns, which I have not seen before. The app kept switching to the other trackers and I had to switch it back. I am going to email Bdale about that to see what he thinks.
 
I tried to attach the .telem file so you all can replay the flight or look at the data but I cannot attach it. Any suggestions on how to do that?
 
I tried to attach the .telem file so you all can replay the flight or look at the data but I cannot attach it. Any suggestions on how to do that?
If it is not encoded as binary data, just append '.txt' to the existing file name and you should be able to upload it. Or you can just change the extension to .txt and anyone who downloads it can change it back to .telem – but that's only if it's ascii data.

Bummer about your flight. I also had some trouble with tracking last weekend at a different launch, but fortunately another tracker got a lock on it.

You should be able to come up with a pretty good estimate of distance from pad (assuming a vertical flight) by building a spreadsheet that computes drift by summing horizontal velocity vs time aloft. You should be able to get wind aloft estimates from Windy or a similar site, and build a descent profile that calculates potential drift. You also might try using this thread:

https://www.rocketryforum.com/threa...iction-based-on-winds-aloft-forecasts.185800/

to compute how far it may have drifted. In almost every case that I've flown to high altitudes and lost tracking, the rocket drifted far further than I guessed. Some fairly simple math might give you a much better search radius.

Good luck!


Tony
 
If it is not encoded as binary data, just append '.txt' to the existing file name and you should be able to upload it. Or you can just change the extension to .txt and anyone who downloads it can change it back to .telem – but that's only if it's ascii data.

Bummer about your flight. I also had some trouble with tracking last weekend at a different launch, but fortunately another tracker got a lock on it.

You should be able to come up with a pretty good estimate of distance from pad (assuming a vertical flight) by building a spreadsheet that computes drift by summing horizontal velocity vs time aloft. You should be able to get wind aloft estimates from Windy or a similar site, and build a descent profile that calculates potential drift. You also might try using this thread:

https://www.rocketryforum.com/threa...iction-based-on-winds-aloft-forecasts.185800/

to compute how far it may have drifted. In almost every case that I've flown to high altitudes and lost tracking, the rocket drifted far further than I guessed. Some fairly simple math might give you a much better search radius.

Good luck!


Tony
Thanks for sending that, I will try it out. I have been trying to figure out Rocketpy but I have no experience with Python.

I went through the calculations manually and got winds aloft data from FL480 to FL120 where I lost telemetry data on it (apogee at FL 450). I used the time in each layer to determine the descent rate and calculated the distance traveled based on the winds aloft. It took off to the south southeast weather cocking a bit. from the video it seems to be about 5 degrees off of vertical, so apogee maybe 0.5-1 mile to the south southeast?
The math I did showed it would be 3.8 miles on a bearing of 96 degrees from apogee. This distance is provided it went the same speed as the wind it was in, which wouldn't necessarily happen.
I would think the area to search would be 1.9-4 miles from the launch site on a bearing of 90-100 degrees. I would think somewhere around 3 miles would be most likely.
There are a lot of relatively small ponds in the area and my projected path takes it over one of the larger ones, at about the three mile distance.
I will have time to head up there next weekend to look for it.
 
Maybe a zip file of the .telem file will work. If anyone checks it out and has problems let me know.
 

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