LOC Vulcanite vs Estes Partizon build challenge

qquake2k said:

I just got the email. The launch at Snow Ranch is a go for this Saturday! Be sure to call the hotline Saturday morning to make sure they didn't cancel it at the last minute.

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Yeah, saw that as well. My buddy is going down to get his L1. He's already bought his L3 rocket kit, so he's well on his way. I'll likely make it down for the next one... I've got 2 each of all the 29/40-120 reloads to do "side by side" comparisons on the two builds in the photo above.

Swatkat,it will be fun to compare numbers. I hadn't noticed how close the LOC Hi Tech was to the others.

Mr G said:

Swatkat,it will be fun to compare numbers. I hadn't noticed how close the LOC Hi Tech was to the others.

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Agreed, now to just wait on the motor delivery to arrive... *paces*

What is the "final" weight on your Partizon? The insert said 19Oz... but mine is 16.8 Oz. with everything on it, including an extra basswood ring to seal off the A/V bay in the top tube and a metal eyehook. And I didn't go light on the paint or the glue....

I'll be weighing it tonight and will let you know. I have some spare AT SU and reload motors you could get from me if yours don't show up in time.

Coupler and Bulkheads

The Vulcanite comes with a bulkhead plate to glue onto the upper body tube to create a payload bay. Wanting to have maximum flexibility, the bulkhead plate is being matched with an inner bulkhead plate that will be temporarily attached to the coupler by an eye bolt on one end and a cord hooked to the nosecone for the first few launches. The Partizon calls for all the body tubes to be glued together. This one is being modified to be like the Vulcanite. It was quite a trick to make inner and outer bullhead plates as the coupler wall was almost unmeasurably thin.

The adjustable circle cutter has proven to a formidable tool for making bulkhead plates. Measuring is a bit of a challenge but even if the first attempt fails, once its set making exact duplicates is quick and easy. A little depression from drill bit marks the center of the plate for aligning the desired diameter hole.


An assortment of bulkhead plates for now and later.



Beware of leaving blue tape on the couplers. Over a few months the tape melded with the cardboard and pulled some up as it was removed.

Out at The Ranch

The clouds parted as we drove east from the Bay Area (we drove into clouds coming over the first pass!) to arrive late morning to a pristine Snow Ranch launch site.

1/8" rope threaded through nosecone and bulked plate with a loop at the end hold the payload bays together. The stock shockcord was then attached to the bullhead loop, parachute and then a 1/8" Quicklink. A flame resistant blanket was fed through the 1/8" Kevlar rope coming just out of the booster tube that was then fitted on the Quicklink.


With the rockets stuffed, the weigh-in proceeded - the Partizon weighing in at 19.0 oz., the Vulcanite at 24.8 oz. Both were close to their factory estimated weights. Flight cards were filled out indicating the first drag race would be with Aerotech single use F26-6FJs. An Aero Pack 38mm to 29mm adapter would be inserted in the Vulcanite to properly secure the 29mm motor.

After further review, it seemed that the heavyweight Vulcanite (30.3 oz with motor and adapter installed) might struggle off the pad with not enough oomph - only 8 lbs maximum thrust pushing a 2 lb rocket, lower than the recommended 5 to 1 initial thrust to weight ratio. So a designated hitter was called in, the G40-7 with twice the thrust, to get the job done.


With revised flight cards in hand, the duo were transported to the mid-power pads for side-by-side igniter prep.

Then, with the wind calm and sky clear...

5, 4, 3, 2, 1... LIFTOFF!
[video=youtube;TgPIO70_MY0]https://www.youtube.com/watch?v=TgPIO70_MY0&list=UUsAe0gUpUawCPQdK0r0S0YA[/video]

Announcer got it mixed up. The "LOC" is on the left and the "Estes" is on the right. Keep that in mind while listening to the commentary.

So, do you agree with the reasoning for which one went higher?

Awesome... My motors literally came in at noon today, but my friend from work got his L1 today at the Ranch and said it was perfect flight weather. My parents made a surprise trip into town though, so a trip down not having engines and leaving them behind wasn't in the cards this time. Hoping January provides us with good weather. Or that my contact at Aerojet comes through on a local field with SARG and we get to fly there.

Also, let me know your engine and altitude numbers for the Partizon. I'll see if I have the same motors and report back as well. Your Vulcanite seems a lot heavier than the Hi Tech (which also came with a bulk plate). I'm pretty sure mine are robust builds. (half a 16Oz. bottle of titebond used on the two builds). I'm planning on L1 cert'ing on one of the two rockets, but will see which one is the more "reliable" flier on a high-impulse G before the attempt.

By The Numbers

To help with the launch review, following is data collected from the Jolly Logic Altimeter 2 installed in the Partizon. A heavier altimeter set up using an Adept 22 and nine volt battery was not installed in the Vulcanite as the weight disparity would then have been even larger.

Burn time (burn) 1.3 sec
Average Acceleration (Aacc) 5.5 g
Peak Acceleration (Pacc) 21.3 g
Top Speed 247 mph
Coast to apogee (CZAP) 5.5 sec
Apogee 1562 ft
Apogee to Ejection (A2EJ) -0.1
Ejection Altitude (EALt) 1529 ft
Descent Speed (dE5c) 13 fps
Flight Duration (durA) 85.1 sec

Damage Report

Using the stock parachutes and the ground being relatively soft, both rockets showed no damage from landing.

There was primer chipped off the Vulcanite booster tube. The only explanation that comes to mind is that when the ejection charge blew, the payload bay stretched the bungee and then whiplashed back against the booster. No marks were found on the nosecone or payload bay.

The bungee will be replaced by a much longer length of 1/8" Kelvar cord when the Vulcanite is outfitted with the dual deploy cable cutter set up.

Awesome, thanks for the flight specs. Again, sad I didn't make it down to this launch. I'll let you know when I'm headed down to the Ranch, I'll need to get my L1 here at some point and it'll be on one of the two rockets. Then we'll have a good amount of data on the Partizon and two very similar LOCs.

Comparison data

OpenRocket files were created for a look at the data between the Partizon and Vulcanite flying on the Aerotech G40-7 to see if we could correlate the numbers with what we saw in flight.

OpenRocket Data Partzon Vulcanite
Mass (with motor) 1.56 lb 1.82 lb
Altitude 1454 ft 1376 ft
Flight Time 92.1 s 76.6 s
Time to Apogee 9.24 s 9.41 s
Optimum Delay 6.95 s 7.12 s
Velocity off Pad 29.6 mph 26.8 mph
Max Velocity 233 mph 207 mph
Velocity at deployment 3.7 mph 9.62 mph
Landing Velocity 12 mph 13.9 mph

It appeared on the video that while both had a good vertical line at liftoff, the Vulcanite arced over a bit during coast phase. The Partizon, on the other hand, maintained near vertical flight all the way to ejection. Watching the drag race, it would be easy to agree that the Vulcanite topped out 75 feet less than the Partizon, as predicted.

The difference in altitude could be simply explained by the Vulcanite's extra weight, everything else being equal. It may be that it's smaller diameter (and presumed lower drag profile) really didn't have much effect at the speeds and duration for this flight.

The Altimeter 2 housed in the Partizon indicated a little higher altitude than OpenRocket. This may have been due to the speed variance of 247 mph actual compared to the calculated 233 mph.

Does anyone else have more or different observations on performance based on the comparative data? Will the Vulcanite see higher altitudes than the Partizon when we bump up in motor size?

Looking at the OpenRocket numbers with an Aerotech F26-6 in the Vulcanite, it's good we didn't try it. The lift off speed would only have been 18.7 mph, way under the recommended minimum 33 mph safe lift off speed! As it was, we were below that with the G40 but it was calm wind conditions.

G or H drag race next?

With an initial systems check using single use Aerotech G40s successful on both rockets, it time to turn up the heat a bit and get some more altitude. There are a few higher power options for which there are matching 29 mm SU motors or 29/40-120 reloads. After that it becomes a mishmash of motors that might be close in Ns but will be of different size or diameter since the Vulcanite can take 38mm loads. So here are a few options:

G79W/G79W
G138T/G138T
H97J/H73J
H128W/H123W

Open Rocket indicates the G79 won't really be very different than the G40 in terms of speed or altitude. The G138 Blue Thunder, on the other hand, is a fast-burner and will produce 23g's off the pad compared to the G40's anemic 9 g's. And that's good for an altitude of close to 2,500 feet.

The H73 uses a slower burning Black Jack propellent that would push the Vulcanite off the pad even slower than the G40 at 25 mph. So this one is questionable, but it is an H motor...

The 29mm H128 and 38mm H123 appear well matched at the outset and are often the motors of choice for Level 1 certification flights. But the H123 has 66% more total energy with 235 Ns compared to the H128's 156 Ns. That equates to the Vulcanite topping out at 3,200 feet, 900 feet higher than the Partizon. Not much of a contest there.

So what combo would you like to see next? Slow with dense black smoke, tame or wicked white, blink of an eye blue or something else? Your choice - what'll it be?

'Course once we have these guys broken in, then we'll have to ramp it up to the max in the Partizon - an I200W against an I211W in the Vulcanite - now that will be some rip-snorting plumes of white!



Mr G said:

G or H drag race next?

With an initial systems check using single use Aerotech G40s successful on both rockets, it time to turn up the heat a bit and get some more altitude. There are a few higher power options for which there are matching 29 mm SU motors or 29/40-120 reloads. After that it becomes a mishmash of motors that might be close in Ns but will be of different size or diameter since the Vulcanite can take 38mm loads. So here are a few options:

G79W/G79W
G138T/G138T
H97J/H73J
H128W/H123W

Open Rocket indicates the G79 won't really be very different than the G40 in terms of speed or altitude. The G138 Blue Thunder, on the other hand, is a fast-burner and will produce 23g's off the pad compared to the G40's anemic 9 g's. And that's good for an altitude of close to 2,500 feet.

The H73 uses a slower burning Black Jack propellent that would push the Vulcanite off the pad even slower than the G40 at 25 mph. So this one is questionable, but it is an H motor...

The 29mm H128 and 38mm H123 appear well matched at the outset and are often the motors of choice for Level 1 certification flights. But the H123 has 66% more total energy with 235 Ns compared to the H128's 156 Ns. That equates to the Vulcanite topping out at 3,200 feet, 900 feet higher than the Partizon. Not much of a contest there.

So what combo would you like to see next? Slow with dense black smoke, tame or wicked white, blink of an eye blue or something else? Your choice - what'll it be?

'Course once we have these guys broken in, then we'll have to ramp it up to the max in the Partizon - an I200W against an I211W in the Vulcanite - now that will be some rip-snorting plumes of white!



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The G79 is a nice motor, but if you are looking for something significantly different from the G40, that might not be it. I would think they would leave the pad faster than on the G40, but overall altitude and speed might be pretty similar.

Personally, I'm not a huge fan of Blue Thunder, because I like motors with more effects. But I guess speed is an effect too, so that might be a good choice, especially if you feel like you've done White already.

You would really have to consider the conditions with that H73... A slow takeoff speed and a long burn can really be a bad combination! Don't crash them before you get to try the I's! But if you felt conditions warranted trying it, this would be a cool flight, and might be my favorite choice.

The H128 vs H123 is too mismatched for a good comparison, I think. They would both be really nice flights, but the motors are so different. I guess it depends on what you are trying to compare.

Dark Horse

Slipping into the mix is a dry fitted Rocketry Warehouse Scarab 54 just out of the Christmas wrapping. Not getting touched until the Rocketpoxy and Aeropack 38mm retainer shows up in another holiday inspired shipment.

a friend of mine used to torture his Vulcanite on J-350's & J-570's it really used to scoot !!!

Looks like G138s will be used in tomorrow's drag race. That'll get them up to about 2,400 feet, still in view and at a relatively low recovery altitude. Anything larger and we'll go dual deploy.

We're planning just the one flight as we have a number of other projects to get launched including a Saturn V/Saturn 1B drag race, a couple of 3" LOC kits, an Aerotech Arcus, and few others. Should be a full day.

Hopefully later, we'll line up another 29/360 case that we can borrow for an H268R and/or I200W in both - that's the largest size that will fit in the Partizon. That will get them up to 3,500-4,000 feet. Then we can see how well an Estes kit can handle some serious thrust and aerodynamic forces compared to the LOC kit.

January 3 Drag Race

Set up for a day at Snow Ranch. The Partizon is top right and the Vulcanite (now gold color) is two over.

The planned G138 drag race took place as expected. Both rockets performed nominally with no damage to the airframes or fins although the motors were another story. First, the flights. The Altimeter Two was housed in the Vulcanite this time and recorded the following:

ALT (ft) 2266
SPEED (mph) 354
BURN (sec) 1.1
P ACC (g) 20.5
A ACC (g) 14.4
C ZAP 10.3
AP2E (sec) 1.3
E ALT (ft) 2238

So, compared to the G40 flights, these flights were 700 feet higher and 107mph faster. They were high enough that is was impossible to see which one went higher.

The Vulcanite got off first in a flash of purple fire, the Partizon following quickly behind. The delays had been drilled out to 10 seconds based on the Open Rocket profiles. The numbers show ejection was 1.3 seconds after reaching apogee - not bad. Open Rocket had calculated an altitude of 2467 and max speed of 400mph so we were in the ball park.

When we pulled the motors for cleaning we noticed discoloration and marring on the cases (see thread https://www.rocketryforum.com/showthread.php?121649-G138T-Blistered-Case&highlight=g138 for more of the story). The G138 is the maximum for the 29/40-120 case. From here on out we will use the 29mm high power cases.

Adding some color

The Vulcanite gets the first shot of red accent color over the gold base. We are using Krylon spray paint that comes in a good assortment of shades and is available at many local stores. Blue painters tape was used for defining the lines. Some bleed through meant we'll probably use some 1/8-inch pinstripe trim tape for coverup and higher definition between colors.

LOC Vulcanite between Estes Partizon (L) and Aerotech Arcus )R) part way through its finish paint process.

The paint jobs are looking nice. It's not easy putting those kinds of curves on a nose cone.

Thanks, TB. There are some great curvy paint jobs out there that inspire me to try albeits slow and laborious work. The Estes PSIIs are all going to follow something similar to what grimacer did some time back. See https://www.rocketryforum.com/showthread.php?33662-Estes-Pro-Series-II&highlight=grimracer+estes. I already have the extra large PSII decals from Mark at Stickershock like on this Nike Smoke.

Mr G said:

Adding some color

The Vulcanite gets the first shot of red accent color over the gold base. We are using Krylon spray paint that comes in a good assortment of shades and is available at many local stores. Blue painters tape was used for defining the lines. Some bleed through meant we'll probably use some 1/8-inch pinstripe trim tape for coverup and higher definition between colors.
View attachment 252099
LOC Vulcanite between Estes Partizon (L) and Aerotech Arcus )R) part way through its finish paint process.

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Have you thought about trying Tamiya masking tape for the curved lines? It's more flexible, and it comes in narrow widths.

https://www.hobbylinc.com/cgi-bin/s8.cgi?str_s=masking+tape

Looks really nice. I added my own PVC screw retainer design to the Hi-Tech (works very similar to the Estes ones) but it does add about 2.5 Oz of weight to that rocket. While a good thing for 38mm, sims show the added weight keeping it much lower than the Partizon now. I HAVE to make it to the next Snow Ranch launch to put them both up.

Good suggestion on the Tamiya masking tape. I'll have to try that out.

Full Dress

The last of the trim paint dried and both rockets got a once over with Meguiar's swirl remover that cleaned up a few minor imperfections and brought out a nice sheen.

The Partizon is the next in the series that is getting a special large decal treatment. Here it is going on.


The Partizon and Vulcanite together ready for more action.

Mr G said:

Full Dress

The last of the trim paint dried and both rockets got a once over with Meguiar's swirl remover that cleaned up a few minor imperfections and brought out a nice sheen.

The Partizon is the next in the series that is getting a special large decal treatment. Here it is going on.
View attachment 252995

The Partizon and Vulcanite together ready for more action.
View attachment 252996

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They look great!

When is the next drag race?

Next possible date for Snow Ranch is March 7. After that TCC on March 21. Tough when business trips get in the way of important scientific research (aka fun, fun fun).

Thanks for the complements on the paint jobs.

Just saw that the LUNAR Snow Ranch launch has been postponed to Feb 14 which is a day that now works. Does anyone have a 29/360 case they could lend for a drag race? A pair of H268s or I200s would be fun to watch!