Mystic Buzz L1 build and fly

[The Red Darren]

Last week I received my Mystic Buzz kit from Chris' Rockets here in Georgia.

I've started my build and will document for feedback here. For background, I've built and successfully flown an NRC Archer with up to G77 motors.

I could L1 with that rocket, but I'd rather do something "lower and slower" -- plus it's time for something bigger anyway.

Here's the summation of my progress


Level 1 Documentation

Kit: LOC Mystic Buzz (4” diameter rocket)

Motors:

• Level 1 attempt: HW100

Build Details:

• New kit purchased from Chris’ Rockets.
  • Planned modifications:
  • Motor adapters (54mm to 38mm and 29mm).
  • Screw-on, removeable nosecone for future E-bay/Camera/Dual deploy upgrades.
• Received and inspected, verified complete.
• Downloaded instruction manual
  • Read thru completely
  • Test fit all components following the instructions without glue
  • With some sanding of centering rings and fins, all fit snugly and properly
• Motor Tube Assembly
  • Lightly sanded motor tube in centering rings area motor tube to improve bond.
  • Measured, marked, and aligned all centering rings.
    • Four centering rings required proper placement to snugly bind to 6 fins.
    • Dry fit included ensuring proper final alignment with full dry assembly including fins
  • Tacked centering rings (minus the aft ring) to the mount with superglue. Confirmed alignment.
  • Using 30-minute epoxy, glued the centering rings (minus the rear center ring to allow internal fillets) to the motor mount.
  • Built internal fillets around inaccessible points for strength
• Allowed drying overnight
• Tightened and epoxied in the eyebolt
• Installed the shock chord on the eyebolt using the provided sewn loop

• Fig 2: Glued Motor Tube minus aft ring.
• Motor Tube Mounting
• Fit the glued motor tube into the body tube
• Using JB Weld, formed fillets around the accessible centering rings

 

[MarsLander]

Like to see how you are adapting 54 to 29…

 

[The Red Darren]

Good question -- I saw this thing on a at first glance.

https://www.discountrocketry.com/modelrocketsus-29mm-motor-mount-adapter-p-2240.html

If that's not a good option, I have some ideas to make something -- and I haven't started to search the boards yet.

I may only end up doing the 38mm adapter tho... I just want something to give me a range of high midpower options to test fly at my club (probably after my L1 cert).

 

[loopy]

That should be fine. Similar design to the LOC/Precision adapter. Just make sure whatever you pick is compatible with your motor retention.

Plenty of great L2 motors in 38mm, honestly. Don't really need to go down to 29mm from 54mm.

 

[The Red Darren]

It's actually the availability of non-HP "G" motors that is driving 29mm... But that is a decision for much later.

Progress this evening:
The motor tube glued into the body tube and internal fillets done with 30 min epoxy.
Dryfit the fins to ensure they will all go in properly after epoxy cure on the motor mount

Started sanding the seams and mold marks of the nosecone prepping for primer.
Sanded the fins slightly rounding the leading edges, prepping for sealer.

 

[-Slick-Ice]

The H242-6 and I357-8 are my go-to motors for the Mystic Buzz.

Can I suggest picking up an H219? or the 38/240 or 38/360 with RAS kit? I don't think the H100 is enough motor for this rocket. I am seeing 41FPS on the rail and maximum acceleration of 4.6G.

 

[thzero]

i284?

Is a fairly big rocket for Level 1, so you'd have to go up to the lower Is probably to get where you want to be.

 

[thzero]

Might look at the i180, i211 and i284.... but those are all RMS cases. I205 and I140 are single uses, might try those too if you don't have RMS cases.

 

[The Red Darren]

I had not run sims yet and chose the HW100 because it seems a popular choice for similar rockets.

Simming, the HW100 is on the light end of passable -- although my sim shows 5.3G max and 35mph off the rod.

As long as my weight comes in properly, this line looks great to me for a Cert Flight (H219T) -- I can drill it for 8s delay.

Name Configuration: Simulation 4 [H219T-10
Velocity off rod: 57 mph
Apogee: 1374 ft
Velocity at deployment: 39.2 mph (note, motor delay can be drilled to 8s, reducing deployment speed)
Optimum delay: 8.01 s
Max. velocity: 229 mph
Max. acceleration: 13.4G
Time to apogee: 9.04 s

I haven't messed with reloadable motors yet so I'm heavily leaning toward an Aerotech single use for L1. I do plan to buy a reloadable case for my Archer to learn -- but for now the plan is to keep it simple for L1.

Progress today -- finished internal fillets with 30-min epoxy. Dry fit all the fins again to ensure they all fit and no epoxy fouling the seats. Will be gluing the front fins in tonight with JB Weld. I cannot access them to put internal fillets on the front fins. I'll use some generous external fillets on both fin sets for strength.

 

[The Red Darren]

Here's a shot of the front fins glued in and the rear fins tacked.

The blue marks are Rail button locations.

Working on fillets now... best part of the job

 

[waltr]

I haven't messed with reloadable motors yet so I'm heavily leaning toward an Aerotech single use for L1. I do plan to buy a reloadable case for my Archer to learn -- but for now the plan is to keep it simple for L1.

A good single use for L1 cert flight is the H283ST. This is a 38mm motor and has a lowish total impulse of 201Ns. This will increase speed off the rail considerably compared to an H100 and also has a lower total impulse which means flight is not as high which is a plus for recovery.

 

[-Slick-Ice]

The front rail button is typically placed near the forward CG. I would thread it into the forward centering ring.

 

[The Red Darren]

Thanks for the advise. Have both suggestions in notes.

As for the weekend, its Happy 4th Filleting ---



Even as a noob around here I know glue selection is on the same level as politics and religion -- so just saying I went with JB Weld for this model because it's strong enough for the intended use, I like the consistency for this application, and I've worked with it before so it's familiar.

So far, happy with the results....

 

[darrenf]

A good single use for L1 cert flight is the H283ST. This is a 38mm motor and has a lowish total impulse of 201Ns. This will increase speed off the rail considerably compared to an H100 and also has a lower total impulse which means flight is not as high which is a plus for recovery.

That's what I level 1'd with on a PML Andromeda. Went about 800'. No worries about RMS issues should I screw that up. Bad enough I screwed up the delay drilling and it ended up going a bit long for my liking, but still recovered safely.

 

[The Red Darren]

I added the H283ST to my sim list for L1 flight. Thanks!

Finishing decisions --

I choose how much work to put into finishing by deciding how "close" the rocket will look good. I like doing colorful schemes but my pre-work patience has its limits.

I'm going for a 10 yarder which means:
4-5 coats of primer, sanding between each -- ending with a nice shiny finish with 800gr paper.
2-3 coats of paint
3-4 coats of clearcoat time dependent.

A few things I don't do for this level:
Fill the paper seams
Only 1-2 fillet fills/sand
1 fin seal and sand (I use 2 coats of building primer for the rest)

BTW -- the rocket weighs just under 4lbs in its current state including the stock metal motor retainer.

 

[-Slick-Ice]

JB weld will work fine. It just costs a lot.

 

[The Red Darren]

Prepping for paint... Shot of my one fillet fill and sanding ready for primer coat.

Not sure how much I'll bother to document of the prime/sand/repeat steps.

Next photo may be of the painted project..

I do need to order a 54mm to 38mm conversion kit. Will start looking into those today.

 

[loopy]

I tend to get the motor adapter that matches the retainer I'm using. If I'm using an aeropack retainer, I get the aeropack adapter.

 

[ECayemberg]

I tend to get the motor adapter that matches the retainer I'm using. If I'm using an aeropack retainer, I get the aeropack adapter.

Prepping for paint... Shot of my one fillet fill and sanding ready for primer coat.

Not sure how much I'll bother to document of the prime/sand/repeat steps.

Next photo may be of the painted project..

I do need to order a 54mm to 38mm conversion kit. Will start looking into those today.

View attachment 654651

Looks like you used the stock T-nuts with clips setup for retention; a solid, old school reliable method! If so, the standard LOC adapters work great: Loc adapters. I put a ring of masking tape on the motor tube on the front end of the motor tube to prevent the motor from kicking out/aft at ejection; works every time!

Agree with others on the higher thrust options. An I357T is a great choice for this rocket/ an L1 shot. A baby I with plenty of thrust to keep it straight, burnout early to give you the trademark split fin whistle!

 

[The Red Darren]

I did put the stock T-nuts in. I have been planning to use an aerotech retainer but didn't see a good reason not to go ahead and install the stock system.

That's easy to change later.

I am progressing thru finishing. Here's a shot of the base color coats done. Gloss white base with chrome nosecone (chrome nosecones are kinda my thing)...

The rocket next to it is my NCR Archer I've been flying for practice.

 

[-Slick-Ice]

Looking at your construction I have zero doubt about your rocket "surviving" the thrust of H219T or H283ST. You could maybe get away with less on a dead calm day but this rocket does want to fly into the wind.

As stated by Eric the I357 isn't a monster motor for this rocket and in my opinion is the proper amount of spice without a tracker. The LOC cardboard adapter will also work great if you put a ring of tape on the front.

I don't know much of an ejection charge the 38mm DMS comes with since I have never used one in a 4" rocket. If is like 1.5g it should be fine. I am using like 1.75g but I also have a 25 foot shock cord because of our trees.

Running some numbers on the H219 (47% H) I would expect a 6S delay This motor seems very similar impulse and thrust curve as the H242 (46% H) and H283ST (24%). If you are not getting that result in either OpenRocket or RockSim, please give us the simulation and finished weight without motor so we can look at it.

Good luck on your L1!

 

[The Red Darren]

Thanks Slick -- I like the H283ST a lot.

Plan is to L1 ASAP (which will probably be next month given my schedule) and then fly it on a good "whistle" engine for our event in South Georgia in November.

Between those events I'll be practicing with a Jolly Logic on my Archer to provide a "dual deploy".

Fins are painted....

 

[Tim51]

Thanks Slick -- I like the H283ST a lot.

Plan is to L1 ASAP (which will probably be next month given my schedule) and then fly it on a good "whistle" engine for our event in South Georgia in November.

Between those events I'll be practicing with a Jolly Logic on my Archer to provide a "dual deploy".

Fins are painted....
View attachment 655667

Cool. Showing my age here but I'm getting a strong Evel Knievel vibe with those stripes!

 

[Donnager]

Cool rocket.

I built an Ultimate Buzz and put the rear fins on backward.... Actually I put one one backward, when it was permanent, I decided to do the others the same (dernit).

I can do better, but mine flies very well. You should be happy with this rocket. Flew mine on a K535 and you could hear a whistle, but it was pretty high when the motor cut off.

 

[The Red Darren]

Cool. Showing my age here but I'm getting a strong Evel Knievel vibe with those stripes!

I agree! Now that you point that out, I wish I would have done the rest of it with Red and Blue stars all over.

Instead I went with some horizontal stripes which almost seem a bit busy..

.

Need to settle on the adapter (probably will go with the LOC) and build that over the next week.

A few clear coats and external finishing will be done.

Empty weight is just over 4lbs with recovery gear.

 

[Tim51]

Instead I went with some horizontal stripes which almost seem a bit busy..

Still looks good - horizontal stripes are a classic LOC look

 

[The Red Darren]

This is mostly a waiting game until a nearby L1 launch comes up --- which looks like early September.

I bought and finished the LOC 54 - 38 adapter. It fits and looks great.



I refinished the nosecone using gloss black paint and graphite powder. I like the finish but the black undercolor is a bit dark. I may retry with a Gloss grey since I have some time.



Also, I decided to 3D print a fairing and retainer for the rocket. This is a single piece screws into the stock screw holes, provides an aft fairing, and retains the 38mm rocket motor and adapter. This a PLA trial. The actual piece will be fiberglassed for strength and heat tolerance.

 

[The Red Darren]

Rocket is ready to go and L1 scheduled at the South Carolina Launch tomorrow.

I didn't end up finishing the 3D printed fairing yet... will be using the standard screw retainers for this one.

Report to come!

 

[The Red Darren]

L1 Completed. My video of my L1 flight wasn’t very good though.

I flew again with an H550 and if you crank the audio you can hear a faint whistle of the rocket after cutoff. It’s not as loud or as long as in person but it is there.

L1 complete. This rocket will go up again in November on an I motor.

View attachment IMG_2611.mov

 

[kjhambrick]

Congrats @The Red Darren !

Beautiful rocket and a nice boost on that H550 !!

-- kjh