Micro Maxx Ignition

I wrote an article about launching MicroMaxx rockets with out a Quest launcher. It is up on my website on the hints and tips page.

Andrew

Very cool Andrew, nicely written. I find the broken tooth pick method works very well as an igniter plug though some have reported CATOs. I have never had a problem with it.

As far as MMX boost gliders go I have quite a few, from my downscaled Orbital Transport to several that were designed for competition flying. 35 seconds is a respectable time for MMX. I've personally had durations of over a minute with a couple of my designs and atleast one that soared away. The right conditions make all the difference in achieving good durations.

I hope to make it to a launch soon, it seems like alot of family stuff has fallen on the third weekend of the month lately. Bro Joe has refurbished several HPR builds so we may be making a trip to a HPR event in the near future.

Keep on truckin'

accooper said:

I wrote an article about launching MicroMaxx rockets with out a Quest launcher. It is up on my website on the hints and tips page.

Andrew

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Andrew;
while your website posting is well done it makes me a little sad you've been having such a hard time all this while since I've been Preaching the old Wadding ball and Tape method bare igniter installation for 5 or 6 years. See "How to" Pictorial below.
The tooth pick method is OK as long as they are NOT used to try to hold the igniter in place with any more force then the weigh of the model sitting on top of it. I've seen more then a dozen over pressure MMX catos caused by the tooth pick method. (photo of one Cato'ed MMX-II motor below)

I know I've posted this pictorial in the files section of the MicroMaxRockets yahoo group and here on TRF in both old and new formats. I'm pretty sure the page has been reposted several times truely sorry you missed it it's the only way I fly MMX motors I don't even open the old plug igniters anymore.

I'd rather make a 100 or so 30ga (.0100") dia. igniters while watching a 30 minute TV show. I've experimented with smaller gauge nichrome (32-38ga) but always seem to come back to 30ga as it doesn't dissapear quite as quickly laying around on the table or out at the field.
Guess we need to recycle some of the older MMX equipment & tip posts.

Do you have a preferred vendor for the Nichrome wire? And will it ignite with the standard Quest 9v controller? I have a bunch of engines with no ignitors back from my early MMX days and the silo launch base, and would love to find a cheaper alternative. Knock on wood, but it has been awhile since I experienced a failure using the stock quest pad and the stock controller.

I am new to MicroMaxx but that sounds like a good Idea.

Andrew

CenturiKid said:

Do you have a preferred vendor for the Nichrome wire? And will it ignite with the standard Quest 9v controller? I have a bunch of engines with no ignitors back from my early MMX days and the silo launch base, and would love to find a cheaper alternative. Knock on wood, but it has been awhile since I experienced a failure using the stock quest pad and the stock controller.

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I've found using either the old Hockey puck(Silo pad) or newer pistol grip Quest controllers it's the 9v battery that fails quickest. Using Duracell Ultras or better Eveready Lithium 9v's you can get quite a few launches from a fresh Battery. Dead Shorting (heating bare Nichrome or other igniters) is the very worst thing in the world for 9V batteries litterally distroying them from the inside.
A very easy fix is to purchase or make a Battery drop cable that will allow the use of either controller with a remote 12V Gel-Cell battery without any other alteration to the controller. I've been using these set-ups almost as long as Micro's have been around with no adverse effect to the either type controller.

If you must stay with 9v power source it might be to your advantage to go with a slightly smaller diameter nichrome say 32 or 34 gauge as it will heat red hot quicker then standard old faithful 30ga.

There are a number of sources for Nichrome TRF's Shread Vector sells Nichrome on-line, Personally I buy 1/4lb spools from McMaster-Carr. They really aren't all that expensive. once purchased you'll have plenty. To bend and cut you will need a decent pair of Needlenose pliers and diagonal cutters.

I still sell nichrome wire. 30, 31 or 32 ga in 25 foot coils. $5 each and add $1.88 for postage and handling for the first coil (add $.50 extra for additional coils).

It is the type A nichrome wire with zero iron content for a rust-free lifestyle.

I never use the toothpick as it will blow the motor to bits quite often. (cato, not CATO). I use a small bit of soft balsa wood scrap to hold the nicrome wire in the motor. It will not clog and it blows of the nozzle at ignition like a soft Estes igniter plug.

shreadvector said:

I never use the toothpick as it will blow the motor to bits quite often. (cato, not CATO).

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Define "quite often", I've launched hundreds of MMX rockets using a toothpick plug without a single CATO. I guess I'm just lucky.

Jeff:
You must be holding your mouth right when you fly LOL!
We've had more the a dozen "Little Boomers" even though several memeber tell folks not to stick the toothpick in to hard. Toothpicks are simply to hard, as Fred mentioned a sliver of soft balsa or wadding ball securely hold the igniter in place while having enough give, not so thight as to over pressure the motor.

Some folks say the wadding ball & tape method is too tedious for them, I like it because I can pre-prep a bunch of motors MONTHS in advance if I wish, at home rather then trying to do it out on the field. Just take a motor out of the case, unfold the nichrome ears, insert in the model, Check the recovery system and we're ready to fly. I can't remember the last time I had a misfire. Hung a few models on the rod but 0 misfires.

JPVegh said:

Define "quite often", I've launched hundreds of MMX rockets using a toothpick plug without a single CATO. I guess I'm just lucky.

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With the MicroMaxx II-1 motors with the clay nozzle, if you don;t cram the toothpick in too tight, it will pop out without overpressurizing the motor. If you cram it in too tight, it will overpressurize and the casing will blow apart. Since this will vary from person to person, it is best to use a bit of soft wood like balsa scrap instead of the rigid and hard toothpick. Simple for anyone to use without failure.

With the MicroMaxx I-1 motors with the plastic casing and nozz-hole, they will clog and blow apart very easily if you install the toothpick even a tiny bit too tightly. the casing will not fail, but the propellant will all blow through the top and it will be loud.

Micromeister said:

Jeff:
You must be holding your mouth right when you fly LOL!...
...Some folks say the wadding ball & tape method is too tedious for them, I like it because I can pre-prep a bunch of motors MONTHS in advance if I wish, at home rather then trying to do it out on the field. Just take a motor out of the case, unfold the nichrome ears, insert in the model, Check the recovery system and we're ready to fly. I can't remember the last time I had a misfire. Hung a few models on the rod but 0 misfires.

Click to expand...

Luck certainly could be one explanation but I think technique has more to do with it. I don't mash a toothpick in there but rather place it with just enough friction to hold it in place and sometimes the plug will fall out which is a hassle but more often than not everything stays in place thanks to propperly supporting the clips. I do not recommend that anyone do as I do but it has worked well for me.

The wadding ball method has its merits as you have explained. Being prepped ahead of time is certainly a time saver and worth any perceived bother. Back in the days before plastic plugs I too employed the balled up toilet paper plug with Estes motors and have used it a few times since. You can't argue with success.

JPVegh said:

Luck certainly could be one explanation but I think technique has more to do with it. I don't mash a toothpick in there but rather place it with just enough friction to hold it in place and sometimes the plug will fall out which is a hassle but more often than not everything stays in place thanks to propperly supporting the clips. I do not recommend that anyone do as I do but it has worked well for me.

The wadding ball method has its merits as you have explained. Being prepped ahead of time is certainly a time saver and worth any perceived bother. Back in the days before plastic plugs I too employed the balled up toilet paper plug with Estes motors and have used it a few times since. You can't argue with success.

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10-4:
Just one slight Safety issue correction to the post. Wadding balls should be FlameProof Wadding not toilet paper,paper towel or what-have-you which can smolder and cause grass fires. The tiny amounts used on our Micro motors is even less of a concern then those used in standard 1/4A-E BP motors but we must always err on the side of safety first.

Micromeister said:

10-4:
Just one slight Safety issue correction to the post. Wadding balls should be FlameProof Wadding not toilet paper,paper towel or what-have-you which can smolder and cause grass fires. The tiny amounts used on our Micro motors is even less of a concern then those used in standard 1/4A-E BP motors but we must always err on the side of safety first.

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Absolutely correct sir, safety first. I've referred to Estes style flame proof wadding as TP since I was a kid but those not familiar with my terminology could take it literally. Thanks for pointing that out and thanks for sharing your experience.