I have a rocket using a cluster of three Estes D12 motors.
Two attempts at launching it so far have failed due to igniter failure.
I did check and it was igniter failure rather than the lead connections to igniter.
What is the most reliable method of igniting all three motors?
- I have some Klima igniters (similar to Quest I believe with a bead separator). Are they more reliable than the Estes igniters?
- I have also bought a quick match. Unfortunately there were no instructions with it and I can't find any guidance on the Internet as to how they are connected and used. Trial and error is not an option. Can anyone give me a link to a site that explains quick matches in detail, or a previous thread on here (I've also searched for that).
I'm told a quick match is a reliable option. Is it?
All advice welcomed. Four wasted motors so far.
SO.
Clustering is as much ART as it is Science: That said the reliability of multi motor cluster ignition is directly related to the METHOD used to check, install, recheck, wire all igniters as well as the Launch system used and the amp rating of the battery.
My club nick-named me Mrcluster several decades ago because during that time I was clustering just about everything that would take more then one motor, most of my Upscales are various # clustered D12 models
Using plain old estes solar igniters you MUST use a relay ignition system which moves the battery from the controller side of the system to as close too or under the Launcher. For small clusteres (up to 4 motors) a small 12V 7amp/hr Hobbieco Gel-Cel used by RC flyers works wonderfully. For clusteres up to 12 BP motors a larger 12volt Gel-Cel is highly recommmended in the 26 and up amp/hr rating.
A Relay ignition system is not all that complated or expensive to build, and once in place will last as long as you are still flying. (I regularly use a DPDT 10amp "RangeBox relay" I made back in the early 90's). See plan attached.
Clip whips No matter how well constructed are at best ONLY an extension of whatever ignition system you are using. I must Stress this a bit as many think adding a clip whip is all that is necessary for good Cluster ignition.. That is simply NOT TRUE. Clip-whips regardless of the number of clips should be as short as practical for your launcher system but in no case should it be longer then about 16-18". I like to use #16 Stranded copper wire for my clip leads as it will carry the maximum current with little resistance while still being light enough to allow the lead to lift with the models first motion without ripping the clips from some of the slightly slower lighting motors.
Whatever Igniter you happen to be using the Method of installing, retaining and checking is the very most important part of reliable Multi-motoer cluster ignition.
Check, Check, Check every single igniter you plan on using for you cluster. It is a very good Idea to prepare your clustered model motors in advance of going to the field, say the night before. This gives you the opportunity to have a good hard surface to work on, fewer distractions and plenty of time to concentrate on this operation.
Check the igniter continuity before it is inserted in the motor, after taping the wadding ball/tape igniter installation, and One last time at the launch pad as you hook up the clips & relay. This eliminates the possibility of a broken igniter during these operations. I DO NOT recommend using Igniter plugs to secure cluster motor igniters as they can allow the igniter to slip enough to break contact with the propellant which will cause a ignition failure every time. The old Wadding ball (BETWEEN) the igniter leads tamped firmly in place with a sharpened dowel, Nut-pick, or small file end followed by an over wrap of 1/2" masking tape will securely hold the igniter in place against the propellant during countdown,igntion and a bit of first motion as the model begins to raise from the pad. Since starting this method back in 93 I have had 100% cluster motor ignition. Before using this Ignitier retention method I had 13 unlit cluster motors between 1974 and 1993 having logged over 1000 2-7 motor flights.
For Much more in depth BP Cluster info I strongly suggest downloading Tech-Tip 006 "Clustering BP Motors" from the Library section of
www.narhams.org website. I wrote this Tech-Tip article some time ago but it has been updated periodically to keep it current.
Quest Q2g2 Igniters have made Small BP clusters almost easy but every with them 3 and over motors really still need a relay ignition system and careful Cluster motor preperation to ensure all motors light.
The really nice part of using a Relay Ignition System is it doesn't Toast the Aft end of your models as the old BP/Flash-pan method does or rely on finding hard to get Flashbulbs while allowing the use of almost anyones current igniter/starters.
Hope this helps....If you need any further assistance please do not hesitate to post or drop me and e-mail to
[email protected]
View attachment RangeBox Relay-a2c_Rev Drawing & Wiring_01-31-96 Rev.06-23-10.pdf
View attachment Cluster Wiring Diagrams-2c_Dwg(Revised)_09-17-12.pdf
