Larger clusters

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Well-Known Member
Jun 2, 2011
Reaction score
I know there's many techniques for lighting large numbers of motors (flashpan etc.) but with kits such as the Hydra 7 how easy is it to light 7 motors each with a standard Estes ignitor?

I know the launch system needs to be one beefy piece of equipment that can put a lot of power into the ignitors but how many motors have people lit in this way? What batteries were used?
You need at least a 12V launch system to have enough power to light them all. Clip whips are also a great help when doing cluster rockets.

Might have misconveyed a bit, a system used to light 2 motors may not be able able to light 7 at the time, I'm looking for info on systems that can light that number (maybe more?) motors.
I have tested my 10 motor cluster cables with a 12V launch controller and all lit just fine.

Sweet, what amperage is your battery? It's amps not volts that fires ignitors.
The controllers I use have external cables for battery hookup. I use car batterys when I go launch. Ive even used two 6V 8 AH batteries wired in series and it was capable of lighting off 4, didnt try more but dont see why it shouldnt.

My relay systems have successfully lite 8 motors using indiviual igniters many many times. you are correct the system needs to be beefy. I use a DPDT 40amp per contact Power relay as the heart of the systems. Heavy STRANDED copper wire between the relay and battery, Large Amp/Hr battery and keep the igintier to relay micro-clip wire length as short as possible in wire no lighter than 16gage.
If you'll visit in the library section you can find a series of Tech-Tips. Tech-Tip 006 BP motor clustering will take you step be step through the process of successful multi motor ignition. including parts lists and wiring diagrams you may find helpful. I've been flying cluster over 30 years and can still count the number of unlite motors on my fingers. I strongly believe in the system and the methods outlined.
Hope you find this helpful.
Ment to give you this pic of the Works inside the cabinet:)

Note the large red and blue wires,, these are #8 thhn stranded copper that connect the relay to the external battery drop cables of the same wire to the battery. no Voltage or amperage lost at all:D
Originally posted by Mike
Sweet, what amperage is your battery? It's amps not volts that fires ignitors.

yep, that's why, as a cluster fiend, I always drool when I hook up to my truck battery... ..."450 cold crankin' Amps"..... " :D
Some good info. Also depends on what type of ignitor your using. Seen a couple of spetacular failures on large clusters when folks used high current ignitors.

If in doubt check the ignitor cluster on the LCS you're going to use. No excuses!

In the duh catagory "do you think I'm going to waste 5 ignitors" from a guy that just burned a couple of L's for no result. BTW that was 5 hi current ignitors.

I built the systems used at LDRS on the main range. The systems were designed to deliver 20A continious and over 30A for 5-10 seconds ( after that the relayer breaker would trip ). Everthing was overbuilt. Like 40A relays , 12Ga internal wiring , and you get the idea. Each relayer had a pair of 17 amp hour gel cells. The whole idea was to be able to deliver more current than any reasonalbe ignitor or combination would need. Other than the usuall ignitor issues ; had no LCS issues on main range.

Bottom line : Test it!

If you are planning on igniting a Hydra 7 on all 7 motors I would advise you to buy the cluster cables Dbarrm sells , they are top class! Wiring up all 7 estes ignitors is a hassle and shoving quickmatch ect in is a pain in the butt!
You can build yourself a good system using a decent size motorcycle battery. They are small, and provide efficient power supply.