Cluster - how big?

[DeeRoc29]

52 E12's.

 

[cerving]

Yeah, I missed the flight of that one at ROCStock last November... I was out retrieving a rocket. Video would be nice...

 

[DeeRoc29]

Yeah, I missed the flight of that one at ROCStock last November... I was out retrieving a rocket. Video would be nice...

Not my video.

 

[DaHabes]

I've been using "normal" Estes igniters. Last time (6 lit) I think I used the new silver igniters (Star Fire or somesuch?).

I never use stock Estes igniters. They need to be enhanced. You can dip them in a pyrogen dip, but the simplest is to just dip them in Testor's aluminum paint. They are much more vigorous and light up right away. All the engines should all start if you treat the igniters.

Make sure you use at least 12V, and if you really want to make sure you have enough juice, swap out whatever batteries you normally use for a 3 or 4 cell LiPo with a a decent C rating.

 

[dpower]

I've been flying my Hydra VII on 7 motors for 15 years. Mostly Estes BP motors, but more recently, on 7 Q-Jet motors. For BP, I used to use Q2G2s, but they went OOP. Now I use MJG BP starters, or Estes Sonic Igniters (from AC Supply). For Q-Jets, the stock starters work fine. On probably 90% of the flights, all motors go. I use a 12v relay system, with a small SLA, about 5 AH. I fly an upscale Hydra VII on a combo of D12 and CTI E31 motors.

 

[mtnmanak]

Here is a new US Rockets Swarm Jr I just finished. It is a 12 x 24mm dual-deploy cluster. I am calling it the "Ukrainian Swarm".

 

[Gemini Junkie]

I just built this rocket with 7-24mm and 9-18mm. I hope to fly it in 2wks. I may have to fly it naked as it it too cold to paint. It’s made from Loc 3 and 4 inch tube, the adapter and fins are also from Loc. The nose cone was printed by James Cramton of the Rocketry Works out of Tucson. He does great work and reasonably priced.

 

[Five]

What's the biggest cluster (highest number of motors) you've successfully gotten to ignite at once? I've got a 7-engine Fat Boy I've been trying to light up. So far, I've gotten 4, 5, and 6 motors to light off at once, but never all 7. I've found it takes a LOT of current to get them all going at once (wired in parallel). We tried our wireless system for the first flight but it just wouldn't light even one. We tried using a flash pan with limited results (4 lit). I've been using "normal" Estes igniters. Last time (6 lit) I think I used the new silver igniters (Star Fire or somesuch?). I've been thinking about putting a small dab of starter mix on each nozzle and using a better flash pan.

Here are some videos of flights:

at Sayre (1st flight) 4 motors lit


at Argonia - AirFest 27 - no video yet - 5 motors lit

at Pawhuska (High Fronteer) 6 motors lit

I have been in the same search of some type of system that will ignite more than your basic three cluster Estes motors.

 

[jimzcatz]

What's the biggest cluster (highest number of motors) you've successfully gotten to ignite at once? I've got a 7-engine Fat Boy I've been trying to light up. So far, I've gotten 4, 5, and 6 motors to light off at once, but never all 7. I've found it takes a LOT of current to get them all going at once (wired in parallel). We tried our wireless system for the first flight but it just wouldn't light even one. We tried using a flash pan with limited results (4 lit). I've been using "normal" Estes igniters. Last time (6 lit) I think I used the new silver igniters (Star Fire or somesuch?). I've been thinking about putting a small dab of starter mix on each nozzle and using a better flash pan.

Here are some videos of flights:

at Sayre (1st flight) 4 motors lit


at Argonia - AirFest 27 - no video yet - 5 motors lit

at Pawhuska (High Fronteer) 6 motors lit

You are using the wrong ignitors. All clusters should be using low current ignitors such as flashbulbs or ematches. There are ematches that will fit in estes motors. You can light a dozen of them on a single AA battery. The same with flashbulbs.

 

[jimzcatz]

I have been in the same search of some type of system that will ignite more than your basic three cluster Estes motors.

It's not the system it's the ignitors

 

[DaHabes]

What's the biggest cluster (highest number of motors) you've successfully gotten to ignite at once? I've got a 7-engine Fat Boy I've been trying to light up. So far, I've gotten 4, 5, and 6 motors to light off at once, but never all 7. I've found it takes a LOT of current to get them all going at once (wired in parallel). We tried our wireless system for the first flight but it just wouldn't light even one. We tried using a flash pan with limited results (4 lit). I've been using "normal" Estes igniters. Last time (6 lit) I think I used the new silver igniters (Star Fire or somesuch?). I've been thinking about putting a small dab of starter mix on each nozzle and using a better flash pan.

Here are some videos of flights:

at Sayre (1st flight) 4 motors lit


at Argonia - AirFest 27 - no video yet - 5 motors lit

at Pawhuska (High Fronteer) 6 motors lit

If using Estes igniters, dip them in Testor's silver paint. The aluminum particles in the paint make them burn much hotter, else buy the BP igniters from Electric Match - MJG Technologies .

You must use 12V system to get enough current. Ideally, use a 4S LiPo with a high current output (25C+) instead of 12V lead-acid or Ni-Cads as they will push a lot of current at once.

A flash pan should work fine but you really need to use enough BP to get a big enough burst. Check out Boris and Paul's Aeronautics and Space Administration for more info on lighting large clusters, especially with a flash pan.

 

[boomtube-mk2]

Motoreater, 54 & 8 29s, Ultimates, 7 24 or 29 or 38s, Fat Boy, 12 13mm. Biggest cluster was the Fat Boy on 4 Rx C20-8s and 8 A3s. Dipped starters for the C20s and fuses to the A3s lit from the C20s. For the pictured flight, these are all A3-4s Only the center 3 go through the top CR, the rest are vented between the motor tubes. All are still flyable, and except for the Fat Boy, all have electronic ejection. MUCH safer if all the motors don't light.
View attachment 483849 View attachment 483850 View attachment 483852

With all those motors in the back, how much weight do you have to add up-front to maintain stability?

 

[Rocketjunkie]

With all those motors in the back, how much weight do you have to add up-front to maintain stability?

None. Ultimates have 6 fins and the Motoreater is my own design. I build with large enough fins to be stable with any motors in the tail. The Fat Boy, to keep dimensions stock, did require nose weight of 100g. This was sized for 12 Rx C20s. Flies OK on 12 A3-4Ts.

 

[RocketRev]

One gentleman wrote me that he manages 9 motor clusters regularly with his single-pad Wilson F/X launch system.

Personally, I've only ever done a couple of 9-motor clusters myself years ago in the early days of WFX. I think they were both a central 54mm K-1100 Aerotech reloadable surrounded by 8x single use 29mm motors, a combination of 2x Aerotech H-125's, 2x F-100(?) Silver Streaks and 4x Aerotech G-80's. I just wanted to see if it could be done. All nine motors lit as planned each time. Recovered easily with Adept altimeter though I don't remember which one. Probably an Alts-2 but it might have been the Alts-2 50k. Come to think of it, they were both 7x motor clusters lit on the ground. On both flights, I lit the Silver Streaks with about 8 inches of thermalite each borrowed from somebody. They lit about a hundred feet off the ground to spectacular effect!

I really miss those Silver Streaks. They were a great motor with seemingly ALL Sparks! Huge showers of sparks from a non-composite motor. I did lots of 3, 4 and 5 motors clusters with Silver Streaks. Anybody besides me remember the Danville Dare Drag races of Mini-Mags on 38mm Silver Streaks? Lots of fun!

Brad

 

[TonyL]

I did a thirteen M1300 cluster one time. All lighting 'at the same' is relative. All lit, but one was very late. I agree that it comes down to the igniter and in hindsight a BKNO3 [or similar] dipped ematch based igniter is probably the best plan for composite propellant. I tried the ematch-plus-pyrodex pellet [plus the original pyrogen] with dual matches and individual batteries for each match [26 circuits in two banks of 13] and there was about a second of variation in ignition time. If I was to do it again, I would still do the redundant and separate firing circuits, just with a much faster igniter.

the other Tony

 

[Rocketjunkie]

I really miss those Silver Streaks. They were a great motor with seemingly ALL Sparks! Huge showers of sparks from a non-composite motor. I did lots of 3, 4 and 5 motors clusters with Silver Streaks. Anybody besides me remember the Danville Dare Drag races of Mini-Mags on 38mm Silver Streaks? Lots of fun!

Brad

I flew my Motoreater on a central K1100, then 4 H268s, and finally 4 H180s. Flown at a Freedom Launch for the red, white, and blue flames.
Video of my 5 stage rack rocket with G160s

 

[Five]

Anything after 3 staged motors is called domino rally

 

[Sooner Boomer]

Digging through old web pics, I found this. It's my friend, Jim Brazzel (Braz) having just flown his 60 C motor Warloc. I think he got them all to light!

 

[SDramstad]

I have flown a 30 motor rocket named “Flash Daddy” filled with c6-5. Used a flash pan with 4 or 5 grams of pyrodex powder. 27 of them lit.

 

[Gemini Junkie]

Digging through old web pics, I found this. It's my friend, Jim Brazzel (Braz) having just flown his 60 C motor Warloc. I think he got them all to light!