Hyperloc 835 Build (updated kit) - Level 2 kit

[downhill_D]

305 mph reported by RRC3

 

[downhill_D]

April Flight report:
Excellent. Winds 8-10 mph, clear skies.
J425-14 again! This motor cooks rich red! Love it!
2594 ft
340 mph
Peak Acceleration 14.4 G's

I have reserved a J460 for the next flight. This rocket is ready for bigger stuff.

 

[downhill_D]

So the J460 is as an excellent motor however the rocket prepper (me) neglected to fill the charge well EMPTY space with dog barf. Since the system was not set up for ejection charge redundancy (rrc3 did not have charges) I lost all my on board electronics and the whole rocket (except the fin can and harness). Lawn dart from about 2800ft but no one was hurt. A club friend helped me dig it out of the ground and I have since updated my written rocket prep protocol to include packing the empty space in a charge well. The eggtimer gps was effective in giving last coordinates for finding the rocket but it did not survive. I also think it is important that during my “forensic” study of the construction and pieces left I realized a few major improvements to be made in construction, mostly in the adhesives department. I only needed to order a new ebay, slotted tube, chutes and a nosecone. I actually had all other parts. The fin can survived due to the rigidness the 2 part foam provided and because of this I can remove the fins and reuse them. The fin can was about 15 ft away after the forces finished crushing the cardboard and it popped off, I presume. Luckily I still have switches and a strattologger to rebuild with. The chutes were all individually slightly friction melted together in their respective nomex blankets. A massive lesson in forces and physics.

 

[Theory]

Sorry to hear that.

Best news here (after no one being hurt) is that you learned from what happened. I’ve crashed many rockets and have been fortunate to learn from each incident.

Will come back better the next time and armed with more knowledge than before!

 

[downhill_D]

So over the weekend I:

built the new ebay, payload section and extended body tube section and the motor mount. I decided to cut new fins after consulting my build thread (this thread). JB weld is messy to grind and the fins were all slightly warped so I decided to cut new ones which will be much easier. My build will remain the same with the exception of the fiberglassing of the fins, for this I will be using the west systems 105 for my laminating instead of the 30min epoxy (wrong purpose). I am hoping my sig wood will be less warped than the stock fins when it arrives. I’ll be using the sig brand 5 ply, 1/8”, NOT their lite ply, for this application.

 

[Tim51]

So over the weekend I:

built the new ebay, payload section and extended body tube section and the motor mount. I decided to cut new fins after consulting my build thread (this thread). JB weld is messy to grind and the fins were all slightly warped so I decided to cut new ones which will be much easier. My build will remain the same with the exception of the fiberglassing of the fins, for this I will be using the west systems 105 for my laminating instead of the 30min epoxy (wrong purpose). I am hoping my sig wood will be less warped than the stock fins when it arrives. I’ll be using the sig brand 5 ply, 1/8”, NOT their lite ply, for this application.

Good job - I admire you for getting back on this particular horse so quickly - it usually takes me a while to face repairing a badly damaged airframe. My rocket store has a couple of corpses laid out still waiting the Frankenstein treatment after some considerable time.

 

[downhill_D]

Good job - I admire you for getting back on this particular horse so quickly - it usually takes me a while to face repairing a badly damaged airframe. My rocket store has a couple of corpses laid out still waiting the Frankenstein treatment after some considerable time.

Thanks, it was my favorite so far for the “J”motors and my future “K” flier BUT V1.2 will be better. I got new forged eye bolts since the originals got bent in the crash, new chute for the “friction melted” ones and new ply should arrive today, perfect weekend for some fiberglassing the fins and building the rest. I DO have a few frankensteins waiting some repair but this one was important for our altitude, field size etc for me to learn. Now I can try that eggtimer classic I built and never used.

 

[downhill_D]

So since it is a three day weekend for me I, traced, cut, squared and sanded three fins and cut some fiberglass fin skins today. Maybe by Sunday or Monday I can start mounting the mmt and fins to the bt. The grain was impossible to get 90 degrees to fhe airframe as this fin design is long but I am galssing them and they are 5 ply. Thank you SIG! This ply is expensive (covid) and flatter than my stock kit and cut easily with the japanese razor saw, the same blade has cut dozens of ply fins. Nice saw.

 

[downhill_D]

Finished the motor mount, opened the slots on the body tube to allow the fiberglassed fins to fit and finished the payload section and av bay. The main paint finish was done ahead of time to break up painting into smaller sections. Fillets, foam and some final paint and this one is ready to wire up and ground test.

 

[downhill_D]

Finished the electronics bay finally. Located and drilled the hole for the power switch (remove before flight) rod. Strattogger CF with a venom fly 300 lithium and missileworks momentary switch. No tracker for now till I get another built.

 

[downhill_D]

So the maiden flight for this newly "scratch" built hyperloc 835 (built to original LOC spec) was a bit of a problem. The first ignitor popped but did not ignite; when it was safe to remove I found it hadn't even lit. There was a break in the compound (the bare wire and insulated portion were folded back and then dipped) but most of the ignitor compound was intact. I used a new ignitor and the motor lit and the rocket went up as usual. However, the DMS J425 motor had a 14 second delay and we heard a loud crack soon after take off. The ejection charge had gone off early, about 8 seconds into flight. This tore the drogue chute upon opening on the way up and the main did not release (chute release) on the way down. It fell from 1980 ft. (2835 ft. predicted) to the ground about 60 ft from the pad within the range safely (altitude reported by strattologger). It sustained a kink in the body tube just above the fin can but luckily with a new coupler + stiffy coupler and a new body tube it is now repaired and ready for flight, again. I have notified aerotech and will file a mess report on the motor. Surprisingly, my new fin can, fiberglassed fins and the payload bay and nose cone were all perfectly intact.

If this had been a reload instead would YOU remove from the rocket and inspect the innards before attempting to ignite a motor again? I could have shifted the grains and flipped the delay if there were any indication of contaminant from a failed ignition with my reloads but DMS motors are sealed so it is never an option. I see more advantage to using reloads now, and my electronics for deployment. Anyone have thoughts on this?

 

[downhill_D]

I have recently added an additional switch to this rockets electronics bay in preparation for designing a level 3 project down the road. This rocket now has two switches both required for flight. The original brass rod switch is still installed but I added a newly built egg timer wifi switch as well. In order to arm the system I need to pull the key and then power up the wifi switch. At any point I want to abort the flight I have a mechanical switch and/or a wifi switch in place to do so. However, I want to add an external (visual) led for the wifi switch since it could be on and I would not know. Is this how a dual switch should be set up?

 

[downhill_D]

Spent a good half-day at the local rocket approved city park and finished up very important ground testing for the main. I don't know why I waited so long to trust DD charges over engine ejection but I knew this step was very important. I learned a lot more about my build and prep from my ground testing. My BBQ paint on the bulkheads worked great at protecting the wood and allowed me to clean residue off later. I found a small gas leak between the switchband and the upper body tube I later sealed. I also added minimal amounts of atv high temp sealant to any air gaps on the bulkheads and made an atv gasket at the washers of the bulkhead (booster side) to really seal off the electronics a bit better.

I will NOT need to use my "fold over" technique with the flat nylon shock cord. I usually fold the nylon into neat stacks of 5-6 fold overs with rubber bands on either side to take some of the extra energy out of the engine deployment and to keep things neat coming out. The main/payload will not need this additional technique and I should not try to slow it down. I found (in ground testing) the nose cone could not fully extend the shock cord so they will not be used in the payload bay. My homemade ejection charge tubes (alloy tubes j/b welded the bulkhead) on the bulkhead worked great. I will post some pictures and maybe a video later. Potential flight in a few weeks, depending on winds.

 

[ZeroCooL]

Well downhill_D I finally did it! Level 2 cert complete on the Joker, my HyperLOC 835. Took me awhile but what a great flight!
View attachment VID_607350929_125221_094.mp4
View attachment VID_607350928_202923_484.mp4

 

[downhill_D]

Well downhill_D I finally did it! Level 2 cert complete on the Joker, my HyperLOC 835. Took me awhile but what a great flight!View attachment 523591
View attachment 523592
View attachment 523593

Nice flight! Good propellant choice…what was your maiden motor?

 

[ZeroCooL]

Nice flight! Good propellant choice…what was your maiden motor?

CTI J280 Smokey Sam. If you look closely at the up video you can see a bit of wiggle from the not completely flat fin issue we both had early on. Not enough to cause any problems but it certainly got the heart racing.

 

[downhill_D]

Finally getting around to flying this Hyperloc again, we have good weather now and winds should be very light. I will be using the onboard electronics to control my main and drogue. 2 too many failures with standard motor delay, Back to ground testing and results will be posted.