LOC Vulcanite vs Estes Partizon build challenge

A replacement Aerotech 29/40-120 RMS showed up yesterday to replace the case that suffered blistering from the G138 flight. Thanks Aerotech for a hassle-free process! We'll have to think twice about how to best protect the case if another G138 flight is in the future.

High Altitude Prep

The Vulcanite payload bay got a quick and dirty dual deploy installation to test out a cable cutter system in preparation for high altitude flights on H and I motors. Instead of the typical two rod sled arrangement, this incorporated a single threaded rod from the nose cone to the bottom of the eBay forming a long skinny compartment. A single wing nut on the end allowed for quick access. An eyebolt and terminal strip provided external attach points for the shock cord, parachute and cable cutter e-match wire.




Launch on an Aerotech G79W-7 kept the flight in sight to verify when (or if) the cable cutter fired. Just after apogee, the ejection charge fired and a half second later the cable cutter fired. The plan was to reset the Adept 22 altimeter main parachute charge output to fire at 600 feet instead of the preset 1200 feet. But, alas, this was not done. Thankfully, the cable cutter did not fire before the chute was out of the booster tube.

Upon landing inspection, the Adept altimeter beeped out 1,610 feet while the Jolly Logic altimeter read 1,088 feet. On retrospection, the large volume eBay may not have had sufficient venting causing the Adept to read high.

So, a little more work on the system and the Vulcanite should be ready for higher flights. And with the successful eBay arrangement, a second will be constructed for the Partizon.

Cable Cutter Test #2

The Vulcanite got another cable cutter shakedown flight as the search continued for a 29/360 case for the next drag race with the Partizon. With a kick from an Aerotech H220T, blue flame cracking smartly, the boost to 2,500 feet appeared to be nominal. At motor eject, the parachute, tightly wrapped inside a kevlar chute protector burrito style with a tie wrap snugged down to hold everything in place, miraculously pulled itself out like a squid from a jar and deployed.

The good part was full parachute deployment. The bad was the failure of the system to function properly. There should have been at least 30 seconds of free fall with the chute still closed before the cable cutter would let it loose. From 2,500 hundred feet and a near perfect windless day, recovery was no problem. Had the flight been on an I200 to an estimated 4,000 feet on a windier day, recovery would have been a hike or a total loss - neither acceptable.

Nice thread! I am bummed that I have not been following it.


Awesome that you are taking the time to compare them.

I200 Duel On

Picked up another Rouse Tech 29/360 RMS to complete the twin launch capability required for the V vs P experiment to continue.



The I200 is the largest Aerotech 29mm motor the Partizon can fit with its stock configuration other than the new single use Aerotech I205W. The I205's five Newtons of extra thrust will not provide a measurable difference in altitude and didn't seem the justify $16.00 extra cost for two. CTI has an I243 that would be the ultimate 29mm thrust experience but with only one 29mm 6 Grain XL case and no propellant, we'll stick with the Rouse Tech and Aerotech supplies on hand.

Wow, just looked up the CTI I243 - 100 lbs of initial thrust(!) vs 68 for the AT I200. With similar burn times, the Vulcanite sims to 4,320 feet after getting pounded with 32gs off the pad. The lighter, draggier Partizon sims to a lower 3,913 feet but is quicker with a max velocity of mach .82 and getting a 38g crush right at the start. With no fin reinforcement, could it handle speeds close to mach 1?

Mr G said:

Wow, just looked up the CTI I243 - 100 lbs of initial thrust(!) vs 68 for the AT I200. With similar burn times, the Vulcanite sims to 4,320 feet after getting pounded with 32gs off the pad. The lighter, draggier Partizon sims to a lower 3,913 feet but is quicker with a max velocity of mach .82 and getting a 38g crush right at the start. With no fin reinforcement, could it handle speeds close to mach 1?

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Wow! That's a pretty serious 29mm motor!

Reverse Charges

It would have made Watson proud to see my Holmes-like sleuthing into the despicible plot to kill off my dueling rocket project. Having thunk every minute since this weekend on the prevarication caused by an unruly premature ejection of the otherwise impeccable and upstanding Adept 22, leading to laundry wafting from stratospheric heights, I was determined to solve the riddle of unexpected consequences.

So, like any good dyslexic I deduced a probable cause was nothing less than crossed wires - the Vulcanite's electronic apparatus must have been put together differently than that of the freshly designed one in the Partizon. If the two were compared it would be obvious that, in a fit of dementia, some wire would be installed out of place - exactly opposite from what it should have been. Elementary, my dear Watson. Examining the offending circuits against the pristine model of perfection showed, what?... the same design! Blast, my theory was expelled like a Vmax load.

With head in hand, it was back to the proverbial drawing board. Scratch, scratch, scratch.., why.., why didn't I think of that earlier? Adept provides a schematic diagram of the wiring installation. Let's have a look see... Okay, the left wire is connected to the right wire, the right wire is connected to the red wire, the red wire is connected to the terminal block... And of course, the single charge was set for after the motor ejection when the cable cutter would do its magic on the way down. That's the apogee charge, right?


So, mystery solved, lesson learned, embarrassment will fade over time. Now, repeat after me (to myself) 100 times; apogee charge is the first one, main charge is the second one.

Cost of Getting High

While there are those with sharper eyes and longer legs who can track and chase high-flying motor eject rockets over hill and dale, this rocketeer would rather invest in a more complicated dual deploy system in the hopes that out of sight high flights return quickly somewhere nearer to the point of departure. So lets look at the cost of this particular upgrade from the stock configuration to a cable cutter system.

Here is a breakdown:

$45.00 Adept 22 altimeter
$2.00 9v battery (in bulk pack from Costco)
$13.25 Dog House Rocketry Altimeter Bay Wiring Kit
$30.00 Archetype Rocketry Cable Cutter system
$1.50 Crazy Jim ejection charge lighter
$.50 Black powder .1ml
$4.00 Homemade sled, threaded rod, hardware

$96.25 Total

Ancillary costs include the larger motors and cases above the Partizon manufacturer recommended motors. Recurring costs include a new lighter, black powder and battery.

Worth it? Compared to a lost rocket? - you betcha. And the knees thank you.

You know that is a DDC2, right? It does not record altitude.

Good eye, blackbrandt. It is indeed a DDC2 that was purchased with the Adept 22 as a back up. For the drag race, the rocket with the DDC2 will also get the JL AltimeterTwo so we can get altitude readings from both. I just grabbed the sled closest to me and wasn't paying attention.

Believe it or Not?

With one Aerotech I-200W motor liner jammed half way in the case the night before launch, the choice was made to fly the Partizon solo to see if it could handle the power and speed. So down to the TCC launch, cable cutter set, and off it goes into the wild blue.

On recovery, the Adept 22 beeped out 4,375 feet and the Altimeter Two 4,453 feet. That was way higher than the Open Rocket simulation of 3,557 feet. What was more surprising was the Altimeter Two reading of 824 mph. That would be more than Mach 1! Can that even be possible? A thin wall Estes kit with no glass, no reinforcement of any kind?

The I200 that was left at home with the stuck liner was disassembled and inspected. Turns out plastic liners are not always manufactured to the same tolerance so it can take some sanding to get everything to fit properly.

Knowing now what it takes to launch and recover just one rocket that flies to over 4,000 feet, I have rethought the drag race scenario. While it would certainly look cool seeing dual lift offs from the pad, trying to keep track of both flights to that altitude could be difficult. Even worse, if one or both were to drift out of sight into vegetation or other obstruction, the likelihood of successfully recovering both would go down exponentially.

Since the real test was how the Partizon would handle such a strong motor, and that is now successfuly concluded, I am inclined to test the Vulcanite on its own using the same setup. That way all the concentration is directed in one place. And with a 38mm hole, there are even larger motors to consider if speed or altitude exploration is in the cards.

That's the rub, the Estes rocket taps out where the Loc rocket keeps going. Put a J600 in that bad boy! Better stick a tracker in it because you're not gonna see it.

Mr G said:

Believe it or Not?

With one Aerotech I-200W motor liner jammed half way in the case the night before launch, the choice was made to fly the Partizon solo to see if it could handle the power and speed. So down to the TCC launch, cable cutter set, and off it goes into the wild blue.

On recovery, the Adept 22 beeped out 4,375 feet and the Altimeter Two 4,453 feet. That was way higher than the Open Rocket simulation of 3,557 feet. What was more surprising was the Altimeter Two reading of 824 mph. That would be more than Mach 1! Can that even be possible? A thin wall Estes kit with no glass, no reinforcement of any kind?
View attachment 265956View attachment 265957View attachment 265958

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WOW! Good to know. I'm surprised it handled the speed. Solid building techniques no doubt!

The Open Rocket flight simulation showed 557mph max velocity and max acceleration of 27.2 G. Someone mentioned that the Altimeter Two tops out at 23 Gs and that top speed could be skewed if Gs were higher. So, we probably shouldn't trust the 824mph. That's okay, 557mph (Mach 0.73) is still movin' out in my book!

That is a pretty incredible flight for a Partizon. It's a fairly lightweight MPR for that kind of HPR flight. Great job!

Mr G said:

The Open Rocket flight simulation showed 557mph max velocity and max acceleration of 27.2 G. Someone mentioned that the Altimeter Two tops out at 23 Gs and that top speed could be skewed if Gs were higher. So, we probably shouldn't trust the 824mph. That's okay, 557mph (Mach 0.73) is still movin' out in my book!

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I mentioned that in the launch thread, but 557mph is still very fast. Great flight!

Prepping the Vulcanite for next weekend's TCC launch. The objective is to match the Partizon set up to get comparative results. So, we'll stuff it with an AT I200 and a cable cutter and let 'er rip. With a smaller diameter and a bit more weight, the Vulcanite has the potential to surpass the Partizon's 4,400 foot flight.

When the cable cutter didn't release at 600' all we could do was wait for the inevitable "thump" when the two separate sections hit the ground. The launch was ideal, the Vulcanite flying upwind on the I200W to apogee and the puff of smoke indicating an event.


Examination of the electronics showed the cable cutter charge did not fire. There were no loose wires or any other indication of failure since the same unit successfully deployed in the Partizan. The battery registered 8.5 volts before being mounted.


The altimeter beeped out 4,179 feet, about 300 feet lower than the Partizan. Given its smaller diameter, one would think it would have flown higher. Launch conditions between the Partizan and Vulcanite flights were similar so that should not have made a difference.

So down it came with no chute from over 4,000 feet and all that's left to do before the next flight is to clean off the dirt and figure out what caused the cable cutter failure. Who knows, there may be a larger 38mm motor waiting in the wings for a mile-high flight. Clearly, this is one tough bird!

Mr G said:

When the cable cutter didn't release at 600' all we could do was wait for the inevitable "thump" when the two separate sections hit the ground. The launch was ideal, the Vulcanite flying upwind on the I200W to apogee and the puff of smoke indicating an event.
View attachment 274430

Examination of the electronics showed the cable cutter charge did not fire. There were no loose wires or any other indication of failure since the same unit successfully deployed in the Partizan. The battery registered 8.5 volts before being mounted.
View attachment 274429

The altimeter beeped out 4,179 feet, about 300 feet lower than the Partizan. Given its smaller diameter, one would think it would have flown higher. Launch conditions between the Partizan and Vulcanite flights were similar so that should not have made a difference.

So down it came with no chute from over 4,000 feet and all that's left to do before the next flight is to clean off the dirt and figure out what caused the cable cutter failure. Who knows, there may be a larger 38mm motor waiting in the wings for a mile-high flight. Clearly, this is one tough bird!

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Wow! That's up there! And a great recovery technique. Hopefully you didn't have to walk far.

With the chute wrapped tightly all the way down, there wasn't much drift. Landed about 200 feet from where it started.

A practice round to test the altimeter/cable cutter combination at the December Snow Ranch launch again tested the robustness of the Vulcanite airframe. Up it went on a G61W...
[video=youtube;8PSDe4dQRFM]https://www.youtube.com/watch?v=8PSDe4dQRFM[/video]
And down it came, just like before, burrito wrapped tightly.
This time it bounced.

Upon inspection, the Jolly Logic cover was gone and the payload section appeared to have suffered stress as some of the paint was gone along the tube spiral. Testing the tube's integrity by applying pressure resulted in no abnormal give - impressive!


When taking out the altimeter, it was noticed that the new 9v battery had a kink in the case that wasn't there before. Another indicator of the impact force.


So the conundrum continues on why the cable cutter did not fire. We'll check the continuity of the igniter first, and then delve deeper if necessary.

The flight with the G61 was a warm up for a long burn I49 that has the same initial and average thrust. With an 8-second burn, the I49 would take the Vulcanite to an altitude of 4,800 feet. But not until the deployment dilemma is solved.

Sounds like you need a new altimeter. Or at least need to test/verify the old one throughly.

Finally got around to testing the cable cutter igniter by hooking up a fresh 9v battery to the wires. It functioned as advertised, therefore eliminating any question there. That results in the altimeter being the issue. I'll have to send it back to the factory unless anyone has a simple method to diagnose what failed.

Repairs to the Vulcanite should be made in time for the next Snow Ranch launch. We'll swap in the other altimeter and see what an Aerotech I49 will do for it - and we'll bring the binoculars.

Had to add a charge well and wiring to the payload bay bulkhead as the I49 is plugged and there is no ejection charge. Since it's an end burner, the I49 has constant low thrust making for a very slow lift off speed. It's going to have to be calm with a long rail to assure a clean departure. Sure don't want to chase it if it leans over and then burns for 7 seconds.

Mr G said:

Had to add a charge well and wiring to the payload bay bulkhead as the I49 is plugged and there is no ejection charge. Since it's an end burner, the I49 has constant low thrust making for a very slow lift off speed. It's going to have to be calm with a long rail to assure a clean departure. Sure don't want to chase it if it leans over and then burns for 7 seconds.

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That would be a very long walk...

See you you at the launch!

Over and Out

The I49N is different - an end burner, Warp Nine propellent, plugged, a single giant grain and it burns forever. There was some breeze at the time of lift off so fingers were crossed that the Vulcanite flight was going to go up and not over. It didn't take long for ascent speed to build up with a resulting nominal flightpath-whew!

After following another rocket descent by mistake, someone pointed us back toward the launch pads. Sure enough, there it was...but with no chute deployed. The first channel of the Adept altimeter had fired at apogee separating the booster from the sustainer but again not the second to release the chute from the cable cutter.



This time - the third time - one of the fins broke along its base making it unrepairable. So, while one tough bird, enough abuse clipped a wing and will keep it grounded. It may be the extra weight of the 38/360 case was enough to produce a fin-killing force on impact.

On the up side, a personal goal was inadvertently met when seeing that the Altimeter 2 read 5,522 feet - over a mile high. So the flight performance was over expectations but the Vulcanite is now out of service.

Mr G said:

Over and Out

The I49N is different - an end burner, Warp Nine propellent, plugged, a single giant grain and it burns forever. There was some breeze at the time of lift off so fingers were crossed that the Vulcanite flight was going to go up and not over. It didn't take long for ascent speed to build up with a resulting nominal flightpath-whew!

After following another rocket descent by mistake, someone pointed us back toward the launch pads. Sure enough, there it was...but with no chute deployed. The first channel of the Adept altimeter had fired at apogee separating the booster from the sustainer but again not the second to release the chute from the cable cutter.

View attachment 282085View attachment 282086

This time - the third time - one of the fins broke along its base making it unrepairable. So, while one tough bird, enough abuse clipped a wing and will keep it grounded. It may be the extra weight of the 38/360 case was enough to produce a fin-killing force on impact.

On the up side, a personal goal was inadvertently met when seeing that the Altimeter 2 read 5,522 feet - over a mile high. So the flight performance was over expectations but the Vulcanite is now out of service.

Click to expand...

Wow! Amazing flight on an I...