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spartan777
05-07-2006, 01:32 PM
i tried launching the estes thunderstar the other day, and went through 6 fuses, failing to launch every time. this rocket uses two engines, is there any trick to getting 2 engines like this to work? thanks in advance.

dwmzmm
05-07-2006, 07:44 PM
i tried launching the estes thunderstar the other day, and went through 6 fuses, failing to launch every time. this rocket uses two engines, is there any trick to getting 2 engines like this to work? thanks in advance.

Flying clusters is a skill and an art. If you want a really easy way to ignite clusters, and don't
mind spending a little more, use the QuickBurst Hot Shot igniters. They're virtually foolproof
and work every time. You also must make sure you're using the proper launch systems
geared for plenty of power to the igniters, although the Hot Shots don't need that much to
work.

I did a product review of the QuickBurst Hot Shot in the EMRR...just go to that site and look
up the manufacturer, QuickBurst, and then Hot Shot. There's a link to QuickBurst as well.
Good luck, and keep trying. Nothing is more satisfying than watching clustered model rockets roaring through the air!!

JRThro
05-08-2006, 08:19 AM
i tried launching the estes thunderstar the other day, and went through 6 fuses, failing to launch every time. this rocket uses two engines, is there any trick to getting 2 engines like this to work? thanks in advance.
Did you have the igniters (fuses?) wired in parallel, and were you using a 12 volt launch controller? The regular Estes launch controller is very unlikely to be able to launch even a 2-motor cluster.

PaulK
05-08-2006, 10:38 PM
Ditto jrthro. The estes 6V controller is barely strong enough to launch a 2 motor cluster, with fresh alkaline batteries. Build yourself a 12V contoller, or jury rig the estes controller to a 12V battery. Search rocketryforum.com for "cluster", and you'll turn up a wealth of information about how to reliably launch clusters.

-Paul

dwmzmm
05-09-2006, 09:39 AM
Ditto jrthro. The estes 6V controller is barely strong enough to launch a 2 motor cluster, with fresh alkaline batteries. Build yourself a 12V contoller, or jury rig the estes controller to a 12V battery. Search rocketryforum.com for "cluster", and you'll turn up a wealth of information about how to reliably launch clusters.

-Paul

Several years ago I purchased a QuickBurst NOVA launch controller for all of my model rocket flying needs. I got only the control box and did all the other wiring myself, purchasing
the power & launch cords from the Dollar Store, the plugs from Radio Shack. The length of
the launch leads are such that I can set up for 50', 75', 100', etc.

JRThro
05-09-2006, 01:07 PM
Several years ago I purchased a QuickBurst NOVA launch controller for all of my model rocket flying needs. I got only the control box and did all the other wiring myself, purchasing
the power & launch cords from the Dollar Store, the plugs from Radio Shack. The length of
the launch leads are such that I can set up for 50', 75', 100', etc.
Cool, Dave. I really need to set up the 12 V, 4.7 amp-hour battery and charger that I got at Wal-Mart a while back in a tackle box sort of enclosure, so I have a nice, portable 12 V controller at my disposal.

Oh, wait. I have an Estes Command Control controller that I've never used.

Why is it that I almost always have so many "pending" projects on my mind that I never get around to doing any of them?
:confused: :rolleyes:

dwmzmm
05-09-2006, 08:35 PM
Cool, Dave. I really need to set up the 12 V, 4.7 amp-hour battery and charger that I got at Wal-Mart a while back in a tackle box sort of enclosure, so I have a nice, portable 12 V controller at my disposal.

Oh, wait. I have an Estes Command Control controller that I've never used.

Why is it that I almost always have so many "pending" projects on my mind that I never get around to doing any of them?
:confused: :rolleyes:

The Estes Command Control controller is very adequate for this purpose. I still have my vintage Estes controller from 1970 in my collection:

http://www.ninfinger.org/~sven/rockets/nostalgia/70est100.html

Found it over a year ago when I went to my Mom's place in Louisiana and "something" told
me to go look up in the attic. I found several boxes of fantastic modroc collections dating
back to when I started in the hobby in 1969, including the Estes controller for the 12 volt
system. The continuity light still works, but I know the wiring will need an overhaul before
I could consider using it again. I used this controller to launch many very memorable
flights for about 12 years before I went "AWOL" from the hobby after 1982. That's another
long story...

Rocketfather
03-27-2008, 02:29 AM
Curious to ask.

Why does everyone up the voltage to 12 volts, when estes launchers are 6 volts?

I have a Tool box designed launch controller and I took 6, 6 volt batterys and placed them in parellel with each other and they work great with clusters at 6 volts. Plenty of power.

Please let meknow. I have a lot to learn here


Rocketfather

barone
03-27-2008, 07:21 AM
Okay...someone help me out here. If you put batteries in parallel, the voltage stays the same but the amperage increases?

K.M.Knox
03-27-2008, 07:33 AM
You are correct in that line of thought unless I am mistaken. So six 6 volt batteries would be overkill as for firing some BP clusters with Estes ignitors. A couple of them in series or parallel should do the job just fine also...

tbzep
03-27-2008, 07:40 AM
You lose more to resistance with the 6v parallel than you will with 12v series. Your home is wired at 120v/240v, but the power lines are usually 7200v or higher that run by your house. The big power lines are over 100,000v because it's more efficient.

STRMan
03-27-2008, 09:47 AM
The following is my speculation based upon my experiences as an electrical engineering aid in a previous career. If this doesn't translate into model rocketry applications, I'm sure I will be set straight.

When igniting clusters, it is important that all the engines ignite as close to simultaneously as possible. Ignitors have a set resistance. Higher voltage will get them up to temperature quicker. If you have a random variance of resistance between two ignitors at 6 volts, the difference in when they get up to ignition temperature will be greater than if both ignitors have 12 volts applied to them.

I can't wait unril the first time I try to launch my Semroc Hydra 7 (http://www.semroc.com/Store/scripts/RocketKits.asp?SKU=KV-29) .

Doug Sams
03-27-2008, 09:56 AM
Why does everyone up the voltage to 12 volts, when estes launchers are 6 volts?Assuming tolerable series resistance in the path of the 12V solution, more voltage will reach the load - ignitor - and hence more current will flow in it thus heating it faster and more reliably. If the two 6V batteries have good (low) output resistance, and the switches, clips, wires, etc, have good conductivity (low resistance), then the (series 12V) situation will be close to optimal.

By paralleling the 6V batteries (instead of chaining them in series) what really happens is the output resistance is cut in half (for two, cut to 1/6 for six), but the resistance of the wires, clips, etc, remains the same, and you now have half the voltage with which to push current thru all those resistors to the load, and will get less current to the load as a result. By paralleling, you would have lowered the net resistance a little bit and the forcing voltage a lot, with the net result working against you.

A couple examples: 9V alkalines have fairly high output resistance, so paralleling them will typically benefit you. But 6V lantern batteries will have quite low output resistance, so the increase in voltage from putting them in series will greatly outweigh the slight increase in series resistance.

Overall, the keys are nice fat batteries (which will have large internal contacts and thus low internal resistance), 16 or 18 gauge wire, clean clips with soldered connections, and good switches in the controller (or a relayer).

With Estes ignitors, 6V will light them, but that tends toward the lower limit of operation. 12V will light them faster and tends to be optimal. Going higher risks burning the bridge wire too fast for the pyrogen to light.

My two cents.

Doug


.

Royatl
03-27-2008, 10:44 AM
Curious to ask.

Why does everyone up the voltage to 12 volts, when estes launchers are 6 volts?

I have a Tool box designed launch controller and I took 6, 6 volt batterys and placed them in parellel with each other and they work great with clusters at 6 volts. Plenty of power.

Please let meknow. I have a lot to learn here


Rocketfather


http://www.esteseducator.com/Pdf_files/1924_launch.pdf