What did you do rocket wise today?

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Ah, your weight is gonna be a lot more than my Trident kit. That kit is good for about 1000 ft on 3x C6-5, with a total weight of about 275g (including motors).
My 318 is coming in at 306g without motors, the .ork file from Mach 1 states 281.373g, so I came in sort of close. I'm getting about 620 ft on C6-5's, and just under 1200 ft on a trio of Quest D16-8.
 
My 318 is coming in at 306g without motors, the .ork file from Mach 1 states 281.373g, so I came in sort of close. I'm getting about 620 ft on C6-5's, and just under 1200 ft on a trio of Quest D16-8.

Your extra is probably glue and paint. I always update have to update my sims for those. What's the body diameter? That's a pretty big different in altitude (620 vs 1000) for the same engines and approximately same mass.
 
Where do you fly? Tumble recovery, which includes nose blow, is a different story on a rocky desert "field" than it is an a soft, grassy one.

If you check some of the simulated speeds, tumble recovery and streamer recovery aren't terribly different, unless you use a really huge streamer. When I sim an Estes Alpha III, it actually descends *faster* on a streamer, up to a certain size of streamer. I assume this is because the streamer prevents the "tumble" rotation that would otherwise slow down the rocket.
 
Make sure you use some bright braided fishing line instead of clear mono-filament, as it totally is invisible at some distance so you won't know where you shot over the branch.

Unfortunately I already spooled up some monofillament, and with how annoying the spooling was, I'm not doing that again. Also, I don't fish. Can you guess?
 
The rattlecan shaker is called a MixKwik.

Ordered mine through Amazon but have seen it available from many other outlets.

Essentially is is a clamping system that holds a rattlecan to a reciprocating saw “blade”.

Haven’t received it yet so I can offer no review of well it works...or not.
Too bad..only on reciprocating saw..which I do not have...I have .just a jigsaw..There is an adapter for a drill but $42.00...I just tale my chance with my 30 seconds shake..comes out good ...great..if it does not..so be it.
 
Building some 3 dimensional laminated cardstock fins... 4 pieces of 11 mil paper, glued with Gorilla Wood Glue, wrapped around a wooden form and clamped.
More here: Fins Redeux

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Too bad..only on reciprocating saw..which I do not have...I have .just a jigsaw..There is an adapter for a drill but $42.00...I just tale my chance with my 30 seconds shake..comes out good ...great..if it does not..so be it.
The $42 drill shaking mechanism was purchased by a rocketeer here on TRF. He also posted a photo of the unit and he had mounted the drill to the workbench for a semi-permanent installation.

I ended up buying a Milwaukee battery-operated single-hand reciprocating saw to serve the purpose and other general shop and landscape uses. For me it was just another Milwaukee tool in my collection. The convenience factor was the main point in the purchase decision. Don’t much care for corded hand tools and gardening devices. YMMV.
 
The main tubes are 38mm (2.6"), 31 grams is not insignificant mass at this level...

Uh, 38mm is only 1.6", by the way. 2.6" would be 66mm. Anyway, my Trident is a 41.6mm body. I simed adding 31g and my apogee goes down to 800 ft. I wonder if the aerodynamics are significantly different between the two rockets. Is your mass including engines? Dry mass on mine is only 198g.
 
I've been working on my scratch build. This started when I messed up a section of my Trident build (later completed) and was left with a cluster motor mount of 3x18mm tubes. Not one to let things go to waste, I decided this was a perfect time to start my first scratch build.

The rocket will be just under 1 meter tall, with a BT-70 body and three square-ish fins (see later picture). Clustered on 3x18mm engines, obviously. The original trident uses the three tubes directly as exterior tubes, so to mount this into a BT-70 I had to purchase 3x18-into-BT-70 centering rings and then shape them with a dremel in order to get them to fit correctly. One forward centering ring, and two rear centering rings to anchor the through-the-wall fins.

scratch_MMT.jpg

Recovery bay tube (above) and payload bay (lower).

scratch_tubes.jpg

The coupler between the engine mount tube and recovery tube has a baffle of two half-circles which I made from a bulkhead. I was originally going to put in a support cross member, but decided against it. The kevlar part of the shock cord should fall into one of those slots fairly nicely.


scratch_baffle.jpg

Measuring and cutting the slots for the TTW fins was perhaps the hardest part of this entire thing. Having centering tube guides was extremely helpful. Estes doesn't have a BT-70 size one, so I bought one (under 'TARC tools') from RocketryWorks. They include a nice laser-etched plywood keychain in their orders.

The cut below is the worst of the three, but I can clean it and fill up the small gaps.

scratch_slots.jpg


The nosecone is balsa, and I've already added a CWF protective coat. I need to be able to hang stuff inside the payload bay, and the nosecone had an excessively large hole in the bottom. So I CA'd a plywood bulkhead to the end, and it has a place to thread an eyescrew. This thing won't experience any strong forces (like shock cords) and I think it will hold up just fine.


scatch_nose.jpg


The fins are 1/8" balsa with TTW marks for differing external-to-internal body sizes. They're from Apogee. I had to glue a piece of balsa back on one after misjudging the distance. I'm having to glue into the valley between two 18mm body tubes for each fin, which brings a particular kind of challenge.

I'm going to either CA or paper these fins, I haven't decided which.

scratch_fins.jpg
 
Uh, 38mm is only 1.6", by the way. 2.6" would be 66mm. Anyway, my Trident is a 41.6mm body. I simed adding 31g and my apogee goes down to 800 ft. I wonder if the aerodynamics are significantly different between the two rockets. Is your mass including engines? Dry mass on mine is only 198g.
I typed 2.6, then knew it was wrong and thought I fixed that :facepalm: ... at 306g dry, with engines it was 375g I think. Are you using OR or rocksim? I just ran a quick and dirty, the sim hit the ground and I realized the model had no parachute. Added a chute, still used actual weight... I'm using defaults in rocksim 10, still need to tweak to a longer rail etc., but don' think that will change things much.
 
I typed 2.6, then knew it was wrong and thought I fixed that :facepalm: ... at 306g dry, with engines it was 375g I think. Are you using OR or rocksim? I just ran a quick and dirty, the sim hit the ground and I realized the model had no parachute. Added a chute, still used actual weight... I'm using defaults in rocksim 10, still need to tweak to a longer rail etc., but don' think that will change things much.

I'm using OpenRocket. There's the issue; I was using a wet mass and you were using a dry mass. At 375g total wet mass you're definitely going to have a lower flight, makes complete sense.
 
My 318 is coming in at 306g without motors, the .ork file from Mach 1 states 281.373g, so I came in sort of close. I'm getting about 620 ft on C6-5's, and just under 1200 ft on a trio of Quest D16-8.

Mine is 310g without motors, parachute and still needs 2 layers of paint. I did use the heavier Loc nosecone.
 
Waiting to hear if I am heading up to North Branch MN this weekend for a high power launch.

I have been working on "Lead Sled" making up another Ebay setup, this time with a RRC2x and RRC2+ with screw switches and lipo batteries. I also built a new booster for this rocket with a 54mm mount and tailcone motor retainer.
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I have not been able to fly much this season for one reason or another. I hope to attend the remaining 3 high power launches then get out at least every other week for some low power launches.

I will be bringing the 1/4 scale Viking 7 rocket up as well, but do not plan to fly it. I need to work on the booster to ebay tube fit and finish. Then ground testing continued for the ejection charge after talking with the local motor guy about the project.

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~John
 

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I got a collection of rockets off of Craigslist - started but complete Estes Saturn V, Estes Orbital Transporter, Trident, Trident II, Sprint (all complete unstarted), Built Centuri Sky Lab and Screaming Eagle, built Estes Interceptor and Saturn 1b (1/70 - 4 engine cluster) It had the escape tower broken off and missing 1 fin. Also got about 20 engines D size and 1 E composite motor, a huge bag of misc size body tubes and a big bag of couplers, engine blocks and spacers. Paid $125 for it all!!!!!!
 
The coupler between the engine mount tube and recovery tube has a baffle of two half-circles which I made from a bulkhead. I was originally going to put in a support cross member, but decided against it. The kevlar part of the shock cord should fall into one of those slots fairly nicely. View attachment 427237
Is it me or are those half moons slightly less than a semicircle? It looks like there will be a sliver of open space in the middle where hot ejection particles could go straight through.
 
Finally back in the shop...helped my son finish up his star orbiter build (he can't let me hold the high flight record in the house) so it will be ready for next club launch. He also built a viking out of our bulk pack, my daughter built her hi-flier (she has a HFXL, and this one is going to be a matching downsize), and I started on my baby bertha. The commanche 3 is built and fitted, just need to get decals installed.

Question: I've been looking for an Estes Leviathan kit, and the OOP ones are pricey when they come up on Ebay. Anyone purchased Vander Burn Rockets before?
https://www.vander-burn.com/product/estes-leviathan-clone/24?cp=true&sa=true&sbp=false&q=false

They are selling a Leviathan and a Partizon clone (not to mention the HFXXL which would be awesome to add the HF collection) and I am wondering if anyone has used these kits and has had positive reviews?
 
Question: I've been looking for an Estes Leviathan kit, and the OOP ones are pricey when they come up on Ebay. Anyone purchased Vander Burn Rockets before?
https://www.vander-burn.com/product/estes-leviathan-clone/24?cp=true&sa=true&sbp=false&q=false

They are selling a Leviathan and a Partizon clone (not to mention the HFXXL which would be awesome to add the HF collection) and I am wondering if anyone has used these kits and has had positive reviews?
I got a couple of the upgrade kits- plywood fins, centering rings... not a full kit, but no issues, great fit.
 
Last night at the HARA meeting, the officers revealed that our landowner is allowing two day launches at his field! Even offered to let us store the club trailer by his house.

We're thinking of Saturday under research rules and Sundsy under NAR rules. May even see a return of Soutbern Thunder if events work out
 
If you check some of the simulated speeds, tumble recovery and streamer recovery aren't terribly different, unless you use a really huge streamer. When I sim an Estes Alpha III, it actually descends *faster* on a streamer, up to a certain size of streamer. I assume this is because the streamer prevents the "tumble" rotation that would otherwise slow down the rocket.
OK, add streamer to what I stated. Still, landing on grass or landing on rocks makes a big difference in what recovery method is adequate.

Is it me or are those half moons slightly less than a semicircle? It looks like there will be a sliver of open space in the middle where hot ejection particles could go straight through.
Yeah, I didn't want to be all negative and nit-picky. But since you've started...

It seems to me that even full half circles might not be enough. If a straight line path is blocked only by a hair's width, I wouldn't be comfortable. I haven't build one with a baffle of this sort. I do have one sitting in my salvage box that a friend leaving the hobby gave me. It's build with three plates, and each one goes about two thirds of the way across. It's made for BT-70 (I think) and I'm sure I'll use it one of these days years.
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Finally back in the shop...helped my son finish up his star orbiter build (he can't let me hold the high flight record in the house) so it will be ready for next club launch. He also built a viking out of our bulk pack, my daughter built her hi-flier (she has a HFXL, and this one is going to be a matching downsize), and I started on my baby bertha. The commanche 3 is built and fitted, just need to get decals installed.

Question: I've been looking for an Estes Leviathan kit, and the OOP ones are pricey when they come up on Ebay. Anyone purchased Vander Burn Rockets before?
https://www.vander-burn.com/product/estes-leviathan-clone/24?cp=true&sa=true&sbp=false&q=false

They are selling a Leviathan and a Partizon clone (not to mention the HFXXL which would be awesome to add the HF collection) and I am wondering if anyone has used these kits and has had positive reviews?
I've got one their Cherokee-H kits. Great kit, parts seem to fit fine. Only wish on my end is that they make one with 38mm motor mounts, as I prefer to use Loki hardware/reloads.
 
We went to the park with 3 rockets loaded with A, B, and C motors.

PSX_20200807_165956.jpg
First up was the orange Wizard with an A8-3. Launch was perfect with a straight flight to 344.3 ft according to my Flight Sketch Mini. The rocket was recovered a few steps away from the pad.
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Next up was my trusty Mach 1 Exiter with a B4-4. This one didn't light, I removed the igniter and found it was charred, but never ignited the BP. I replaced the igniter and it didn't light again. The 2 igniter fizzled weakly outside the motor. I guess this is expected with the new batch of Eates igniters. I only had the one extra with me, so the rocket was set aside for another day.

PSX_20200807_170953.jpg

Last for the day was the maiden flight on my Mach 1 Haymaker. I loaded it with a C5-3. It veered off with the wind shortly after launch, but was recovered safely. I think it just needs a longer rail or D motor. The Flight Sketch Mini reported an altitude of 252.3 ft. A Jolly Logic Altimeter 3 showed 239 ft.

PSX_20200807_160952.jpg

 
Is it me or are those half moons slightly less than a semicircle? It looks like there will be a sliver of open space in the middle where hot ejection particles could go straight through.

Because I cut a perfectly-fitting bulkhead in half, the missing material is indeed a very small space in between. On the other hand, the engine tubes are radially outward from the center, being in a cluster configuration, and as such the tubes are fairly well covered. On the third hand, I'm also using a nomex chute protector. On the 4th hand (we're all aliens here, right?), this was mainly an exercise in me seeing if I could construct a basic baffle layout, not a high-quality attempt at one - I would have bought one if that was the desire.
 
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