Micro-Maxx Motor Ignition

[Mad Rocketeer]

Flew some Micro-Maxx rockets with a friend and 4 kids (one of them mine). I lost one on a three-way drag race. Found the two standard sized rockets, but lost the little one. We hadn't arranged ahead of time who would track which bird. Live and learn. I bought two of the blow-out sets, so I still have 19 rockets left.

I know there are some real fans of Micro-Maxx here. That's really what convinced me to buy these. I noticed two things though.

1.) These puppies fly a lot higher than advertised. At least it looks that way. No way I could fly them from my back yard, etc. I thought they'd go maybe 100 - 150 feet up. Looked like a lot more than that. They're small, so it could be partly illusion, but even so they went a good deal higher than I expected or would like to chance on a tiny field.

2.) The igniters are a royal pain. Darn near an imperial pain. I got a flight out of about one in three. Can't remember the last time a solar igniter didn't perform for me (assuming the clip hadn't come loose or something like that).

Bending out the wires at the base is tedious but no large hassle. What's difficult is keeping the igniter positioned while getting the clips hooked on and getting it inserted properly in the motor. I had to lie flat on the ground to hook them up, and I still couldn't see the end of the motor when the rocket was near the igniter. Raising the igniter to hook it up higher usually made the clips fall off. Etc. Round and round. I could prep, launch, and retrieve three or four standard rockets in the time it took to get the Micro-Maxx stuff wired up, burned through with no launch, wired again, picked up where it fell, wired again, un-squash the nicrome wire loop, put back on, unshorted, picked up again, wired again, inserted again, and finally launched.

When they go, they're fun, even though they're pre-built. I look forward to making some pen rockets and eventually Micro-Maxx clusters. (Would flash-in-the-pan work well for Micro-Maxx clusters?)

I could add tape to the igniter holders to make that tighter and less prone to falling out. Heck, I could even tape the igniter to the holders/pad each time, though that would be more time-consuming.

What's really needed is a better way to wire these puppies up. My thought was this. Critique and let me know if I'm on a better track here. I could:
A.) Pull the nicrome wire out of the plastic. (Would it break or slide out?)
B.) Stick the loop of wire into the motor just like a solar igniter.
C.) Secure the wire in place with tape, a tiny bit of wadding, or maybe a toothpick, making sure the wires don't short. (Maybe modeling clay would work here.)
D.) Use a clothes pin or similar as a stand-off to make sure the rocket doesn't touch the pad. (I might need some sort of micro-sized blast plate too, since the usual igniter module won't be under it.)
E.) Wire the rocket up and let it go.

There really needs to be a better way. Is this it?

Thanks.

 

[sandman]

I bend the ends of the nichrome out so I can get my launcher clips onto them then I tape the igniter to the launch rod and set the rocket down on the igniter.

Sometimes you need to space it out with some scrap balsa for custom models.

Works every time!

 

[Mad Rocketeer]

Originally posted by sandman
I bend the ends of the nichrome out so I can get my launcher clips onto them then I tape the igniter to the launch rod and set the rocket down on the igniter.

Sometimes you need to space it out with some scrap balsa for custom models.

Works every time!

Taping will definitely have to be part of the plan, unless I come up with a way to clamp it (maybe with a modified clothes pin or some such) to do it faster.

When you say "space it out", do you mean to get it higher up for fin clearance? Where would the balsa go? With the igniter taped on, seems like the rocket could be as high on the rod as you like just from that. I think I may be missing your meaning.

Seems like having the rocket a bit farther up off the pad would be a good thing, just so I could look under it better to get the loop into the motor. The loop is sometimes too wide to begin with, and it squashes easily enough to be difficult to detect whenever it isn't aligned just right. I'd need to make sure I didn't leave it too little rod for stability though. Probably not a problem, as these light rockets accelerate well, even with such small motors.

 

[Micromeister]

If you're having trouble the the old type plug igniters. There are a couple ways around them.
a) Use a pair of needle nose pliers to bend the thick igniter base wire out far enough of easy installation on a set of standard micro clips, As Sandman mentioned earlier. Don't worry if the plastic pins breaks off it, bend the wire out until its sticking way out from the side of the plastic plug.
b) Bend a1/4" Z offset in your micro launch rod about 3/4 to 1" from the bottom of the rod so you can swivel the rod around to get the model centered over the igniter bend. This well make you insertion job a lot less taxing
C) Dont' use the crudy Plug things. I fly almost exclusively Micro-Maxx now. I haven't used a plug type igniter in almost 3 years. your can use up to a 2" piece of 30gage bare nichrome wire. Bend a 3/8"+/- in the center of a 1" to 2" long piece of burn solar igniter lead, (Look at that! We've been throwing away perfectly good Micro-Maxx motor igniters) then 90degree bend out the attachment ears. insert in the motor like back in the old days with a Tiny piece of wadding as a little 1/4" masking tape. You can perprep micro just like you do your standard models.

If you are looking for all the info you could possible need on Micro models and Micro-Maxx motors come join us at: MicroMaxRockets yahoo group. In the files and photos sections there are tons of How-To's and ideas for making flying micros as easy, problem free and enjoyable as any mod-Roc can be.

I know I have a photo of the plug, new Q2 and my home made bare nichrome igniters here somewhere, I just can't remember where I stuck it at the moment, I'll post it here later when it comes to me Sorry about that.
Hope this helps

 

[r1dermon]

i've never broken 100ft with a micromax. usually they barely tip the top of the trees, about 60-70ft. even that low, they're still a little tough to track. but they land within 50ft, no matter which way you point them. lol.

 

[Micromeister]

You must be flying the little plastic Bricks I've have closed track minimum dia. models with closed tracks to 255 feet. My micro interceptor will get over 100' every time I fly it. The hardest part is getting them to slow down far enough not to break the 50-70lb kevlar shock lines

 

[Mad Rocketeer]

Micromeister:

I was hoping you'd ring in on this topic. I've seen you mention the MicroMaxRockets Yahoo group before. I may try that. With $80 invested in the two blow-out kits, I have an incentive to make it work. Besides, even with the plastic bricks (which I consider freebies that came along with the motors), they were fun when they actually flew.

The issue I saw was mainly relating to igniter insertion. The rockets were a piece of cake to prep, and the engines seemed to work fine. The igniters seemed to work well enough as long as they were inserted correctly (at least as far as I could tell). The trick was in getting them to fit right without being able to see the wire loop or the motor opening. The wires are soft enough that doing it strictly by feel will take practice.

I had problems with bending the wires at the base out at first, until I realized that I needed to bend them way out.

I definitely think that using wires without the fat plastic holders will work better. Great idea to use old igniter wires. I never realized what I was wasting! I'm going to need an idea like this since I had several igniter failures but no motor failures. That's left me with fewer igniters than motors.

Often when my solar igniters flare, they burn the wire in two. Is one lead long enough, if bent in the middle into a loop and turned out at the base to take the clips?

Pre-prepping the motors and igniters is the best idea, as long as the weight of the clips and wires doesn't pull the igniter wire loose. My thought on that would be to poke a dowel rod or similar stick in the ground beside the pad and use a clothes pin or two to support the weight of the launch controller leads and clips on the stick. That way, the leads would swing over to the motor rather than dangle from it.

Does this sound workable?

Also, has anyone tried extracting the nicrome wires out of the plastic holder blocks? Are they loose enough and strong enough, or do they just break if you try?

A Micro-Maxx rocket that snaps 50 pound test Kevlar?? Is that a heavy cluster bird or what? I'm amazed.

I didn't actually track my Micro-Maxx bricks for height, and I know they can fool one because they're small, but they sure did seem to go way up there.


Thanks all, for the good advice. Keep it coming. I have a lot to learn about Micro-Maxx. I'm itching to do the Bic pen rockets. Just something very cool about that. Hmmm. With transparent fins, it could be cooler still.

 

[BobH48]

Originally posted by Mad Rocketeer
Often when my solar igniters flare, they burn the wire in two. Is one lead long enough, if bent in the middle into a loop and turned out at the base to take the clips?

I have found that when using solar igniters with 13mm motors and an Electron Beam controller, that often the pyrogen burns and lights the motor but the igniter remains in one piece. Those can be saved and used as Mico-maxx ignitors.

 

[Stymye]

When you say "space it out", do you mean to get it higher up for fin clearance? Where would the balsa go? With the igniter taped on, seems like the rocket could be as high on the rod as you like just from that. I think I may be missing your meaning.

the distance between the centerline of the rocket and the rod varies between different models,,so on some you have to space the ignitor holder out to line up better with the motor nozzle

 

[sandman]

Yea, what stymye said!

I use two wedges to vary the distance so it lines up with the motorm nozzle and tape the igniter on with masking tape.

 

[shreadvector]

Solar igniter lead wires will require a car battery (or nicad pack) to heat up. Do not make a loop, simply bend it in the middle to form a "V".

Semi-thin nichrome works best. 30 ga or 32 ga. 32 will heat up nice with the Quest controller and you only need about an inch.

I have very few problems with the QMX igniters supplied. You simply need to make sure the igniter is not shorted before you start (V section not touching itself) and then make sure you position the model directly over the igntier and lower it until it is ALl THE WAY DOWN onto the igntier. Now here is where there can be a problem: if you straighten the lower end of the igntier wires away from the plastic holer, you might accidentally pull the entire wire DOWN throught eh plastic holder enough so that it does not touch the propellant inside the motor. make sure you push it back up. Snapping off the tiny plastic tabs at the bottom helps a LOT.

The new Q2 igniters may help, but you will have to be extremely careful not to short the wires above the glass bead. I've already seen kids having problems with them. I have yet to see actual instructions for using them, but I will be telling folks to spread the wires apart to prevent shorts. The problem is that the wires are so close together that when you insert the tac/plug (will they still be called "Tiger Tacs") in a standard motor the tac/plug pushes the wires together.

Originally posted by Mad Rocketeer
Micromeister:

I was hoping you'd ring in on this topic. I've seen you mention the MicroMaxRockets Yahoo group before. I may try that. With $80 invested in the two blow-out kits, I have an incentive to make it work. Besides, even with the plastic bricks (which I consider freebies that came along with the motors), they were fun when they actually flew.

The issue I saw was mainly relating to igniter insertion. The rockets were a piece of cake to prep, and the engines seemed to work fine. The igniters seemed to work well enough as long as they were inserted correctly (at least as far as I could tell). The trick was in getting them to fit right without being able to see the wire loop or the motor opening. The wires are soft enough that doing it strictly by feel will take practice.

I had problems with bending the wires at the base out at first, until I realized that I needed to bend them way out.

I definitely think that using wires without the fat plastic holders will work better. Great idea to use old igniter wires. I never realized what I was wasting! I'm going to need an idea like this since I had several igniter failures but no motor failures. That's left me with fewer igniters than motors.

Often when my solar igniters flare, they burn the wire in two. Is one lead long enough, if bent in the middle into a loop and turned out at the base to take the clips?

Pre-prepping the motors and igniters is the best idea, as long as the weight of the clips and wires doesn't pull the igniter wire loose. My thought on that would be to poke a dowel rod or similar stick in the ground beside the pad and use a clothes pin or two to support the weight of the launch controller leads and clips on the stick. That way, the leads would swing over to the motor rather than dangle from it.

Does this sound workable?

Also, has anyone tried extracting the nicrome wires out of the plastic holder blocks? Are they loose enough and strong enough, or do they just break if you try?

A Micro-Maxx rocket that snaps 50 pound test Kevlar?? Is that a heavy cluster bird or what? I'm amazed.

I didn't actually track my Micro-Maxx bricks for height, and I know they can fool one because they're small, but they sure did seem to go way up there.


Thanks all, for the good advice. Keep it coming. I have a lot to learn about Micro-Maxx. I'm itching to do the Bic pen rockets. Just something very cool about that. Hmmm. With transparent fins, it could be cooler still.

 

[Micromeister]

Stymye and Sandman bring up a good point which is one of the reasons to put a 1/4" or so Z bend in your micro maxx launch rod. The offset allows the rod to be swiviled in the base to adjust for different body diameters and motor placements. if you start the bend about 1" for the base end it will provide plenty of support for even the heaviest of the micro Plastic Bricks. If using the old silo launcher you'll never have to switch sides of the launcher.

Mad-Roc:
You sure can remove the plastic plug from the igniter, the then work like regular igniters and I pre-prep my micro's the night before a launch all the time, using the same old procedure we used backin the stone age, you know back before there was Dirt, bare nichrome center folded into the nozzle, a teeny tiny piece of wadding between the wires and a small piece of 1/4" maksing tape to secure the now folded out ears.
Yes, one leg of a burn solar igniter is all that's needed, remember you should keep the overall length of the nichrome to 2" or under according to the engineers at Quest. I usually use 1" pieces of 30 gage nichrome. which is the gage of estes solar igniter leads Of coarse thinner is better for getting into the MM-I motor "nozzle hole" whereas the MM-II will take some solar igniters and the new Q2 or old MRC FX smoke igniters right out of the pack. I've tested 32 and 34 gage nichrome, both work great, the only down side is the thinner the igniter wire the easier they are to drop and loose.

I thought I had a better picture then this, I'll snap one this evening of igniters I use. Heres this best I can show right now, if you look close at the micro-clips in this pic you can see the bare nichrome and note the coiled 16gae stranded red/black wire that allows adjustment for height above the launcher and centerline distance for different body diameter models. Also note the .050" dia. carbon fibre launch rod, form Totally Tubular. This 'rod" is stiffer then music wire or even the Stainless .049" wire I normally use. 12" sees to be the best overall length with 15 to 18" of gliders, and heaiver (14-17g) models.
Let me post the Yahoo group link here once again.
https://groups.yahoo.com/group/MicroMaxRockets
Once you join the group and log into the site, go into the Files and Photos sections. you'll find a ton of useful info, How-To's, plans, launchers of all kinds racks, pistons, towers, relays, parts making, and did i mention model plans? like Art Applewhites Bic pen rocket folded fincan plan, Art's micro saucer plans, along over 60 of my one page plans. Lots and lots of pic's of the finished models, launchers, parts and flights, in the photos section from all over on just about any kind of micro model you'd like to build
really nice folks to chat with as well
Hope this helps

 

[Mad Rocketeer]

Great feedback. Thanks!

BobH48: I do fly the 13mm motors, as well as the 18mm and 24mm, and now MMX, but I don't have an Electron Beam or similar 6v AA system. I have the 9v transistor radio battery systems that came with the MMX blow-out kits and my old Cox 12v D-cell launcher, which I flew my first rocket from lo these many years ago. Even so, I sometimes get intact wires on my Solar igniters. I don't recall getting any intact wires on my MMX launches, though I didn't check the successful igniters that closely afterward.

stymye & sandman: Ahh! Now I see what you mean. Makes sense.

shreadvestor: Will 12v worth of high quality alkeline D-cells do the trick? Are the Solar igniter wires harder to heat to MMX ignition temperatures than the MMX igniter wires are? The MMX wires do look a bit lighter then the Solar ones do, as I recall, though I never looked at them side by side. When I said "loop", I was thinking of a V or a long narrow U, not a closed loop. Micromeister's picture looks just like what I had envisioned. What guage are the MMX igniter wires? A lot of the MMX igniters were too rounded in the V to fit in the motors and had to be "sharpened" without causing a short and while bending out the base. Of course, failing to get them inserted (blindly) tends to squash the V, requiring reshaping. I was careful to insert the wires all the way (similar to what other igniters and motors call for), and I did pull the V down (making it too short) a time or two while bending out the leads, but I noticed and pulled it back up before trying to insert it. I didn't think of snapping off the tabs, but I'll do that in the future if I use the plastic holder at all. I've never seen the Q2 igniters.

Micromeister: The Z bend sounds good if I continue using the plastic igniter holders. It may be good even if not, just to have a handy way to stand the rockets off the base. I think I plan to use the wires with wadding and tape as you've detailed though. I like the idea of being able to see the motor while I'm inserting the wire, as I can with my other rockets. I haven't seen the silo launcher. I'm brand new to MMX, my first sight of one being when I opened the blow-out box.

I think my rocketeering days date back to dust. I don't recall using bare wire by itself. Wracking my brain, I seem to recall using bare wire wrapped around some sort of stick that was then folded and inserted into the motor. Not quite before dirt, but the dirt was thin enough to be dust. Good, if one leg will do it, then I'll have enough wire for two MMX launches every time I do a non-MMX launch, whether the wire burns through or not.

Where is a good place to see MM-II rockets and motors for sale? I've only just heard of MM-II here, and I'd like to take a look at them.

I can't wait to see the Yahoo stuff. Probably more info than I'll have time to absorb, with all my other time committments and rocketry interests, but I'll enjoy diving in anyway.

Great info, all! All good ideas are welcome.

 

[Micromeister]

RM:
The better your battery sorce the more fun you'll have, I've used an estes electon beam 4 AA battery for a few quick launches but don't recommend these controllers or batteris, If you have a 12V anything rechargble it will have a higher amp/hr rating the any set of energizer or duracel batteries you put togather. I personally recommend a small 12v 7amp/hr Hobbico gel-cel rechargable battery you can pick up at your local hobby shop for about 20.00.

Or there are several ways to alter the current controllers to allow use with any 12v rv motorcycle or gel cell battery you can get.

Heres that pic of the bare nichrome igniters, inside of a Quest MM Plug and a couple new Quest Q2 igniters.

Your correct there is much more info. on the specialty group then your going to get here. be sure to check out the FAQ file in the files section. Should answer most of your Micro- Maxxing questions.

 

[shreadvector]

Let's make sure we all know what wires I'm talking about.

The wires from the Estes Igniters that are hard to heat up are the two long wires that lead up to the tiny bridge wire (which is covered with pyrogen). The two long lead wires are the ones with the tape strip holding them apart. They are pretty hard to heat up without at least a 7.2 Volt ni-cad pack (with decent current capacity) or a car battery. A car battery incinerates them.

When desperate, I just pick up the used Estes igniters and use the two left over wires to make two new igniters. For standard motors, I roll a loop around a straightened paper clip. When inserting in the motor, place a small square of wadding or toilet paper over the igniter as you insert the plug. This is important since the wire will heat up to molten temperatures and it will melt the plug and it will fall out if you don;t use the paper as a heat sink. Also - make sure you don't hav ethe full weight of the micro clips and lauch lead wires 'pulling' on the igniter. It will pull out during heating. With no pulling force, they will ingite EVERY time. You need a high current launch system for that with a switch that can handle the current without frying.

The bridge wire on the Estes igniters (at the tip) is pretty thin. Probably about as thin as the QMX wire. Since it's so thin, it is fragile and needs to be protected. That's why it has pyrogen on top (which also sends out extra sparks & heat in case you did not get it to touch the propellant properly) and why the big wires are held by tape.

For replacement igniters for MicroMaxx motors I like the 32 ga nichrome. It heats up much easier than the Estes igniter left-over wires. You can bend it into a V and plop the Micro on top or you can secure it in the motor with a bit of tape. For the MicroMaxx II-1 motors, youcould even use a tiny wadding ball in the nozzle. The MicroMaxx I-1 motors have a tiny "nozz-hole" and the most you can do there is tape it or cram in a tiny balsa sliver. Be careful with the wood slivers. You can "constipate the nozz-hole" and make the motor blow through on ignition. It sounds like a firecracker but the casing remains intact since it all goes upward.

I have thin nichrome on eBay right now. The photo shows it being heated with a Quest controller and an ordinary 9 Volt Alkaline battery.

https://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2567&item=5929696991

Originally posted by Mad Rocketeer
Great feedback. Thanks!

shreadvestor: Will 12v worth of high quality alkeline D-cells do the trick? Are the Solar igniter wires harder to heat to MMX ignition temperatures than the MMX igniter wires are? The MMX wires do look a bit lighter then the Solar ones do, as I recall, though I never looked at them side by side. When I said "loop", I was thinking of a V or a long narrow U, not a closed loop. Micromeister's picture looks just like what I had envisioned. What guage are the MMX igniter wires? A lot of the MMX igniters were too rounded in the V to fit in the motors and had to be "sharpened" without causing a short and while bending out the base. Of course, failing to get them inserted (blindly) tends to squash the V, requiring reshaping. I was careful to insert the wires all the way (similar to what other igniters and motors call for), and I did pull the V down (making it too short) a time or two while bending out the leads, but I noticed and pulled it back up before trying to insert it. I didn't think of snapping off the tabs, but I'll do that in the future if I use the plastic holder at all. I've never seen the Q2 igniters.

 

[Micromeister]

MR:
Lets make sure we know what commerical we're reading
Shread is correct 32ga .0063" Nichrome will heat up "slightly" mili
-seconds quicker than 30ga .0080" nichrome which is also the main lead ga. used in estes igniters. We certanily aren't talking about the tiny 38ga. igniter bridge wire.
I'm using 34ga. .0050" nichrome bare in micro motor clusters for that very reason, slightly quicker heating. For single motors, any of the above gages work just fine with and electron beam or other controllers.
Like I mentioned earlier converting to a 12volt system will make life much easier but whatever your using to light estes igniters will certainly do the job for an individual launch days use.

As of bidding on bare Nichrome; 32 - 2" pieces...ummmm! you be the judge: that's about 5'-4" of 32 gage material.

1/8lb and larger rolls of nichrome wire can be purchased through
McMaster-Carr www.mcmaster.com, ups was about 3.00 on one of my recent nichrome purchases.

30ga .0080" Cat No. 8880K83 - 660 feet for $16.14 =.02445/ft.
32ga .0063" Cat No. 8880k84 -1015 feet for $18.28 = .0180/ft
Of coarse you do have to cut and bend the pieces to length yourself.
hope this helps and maybe saves you a few bucks

Ps Kevlar lines, Teflon streamer tapes, Stainless Launch rods, etc can also be bought through McMaster

 

[wwattles]

Originally posted by Micromeister

Ps Kevlar lines, Teflon streamer tapes, Stainless Launch rods, etc can also be bought through McMaster

It's also a good source for Kapton tape. Very strong, and nearly unburnable!

WW

 

[shreadvector]

The auctions of nichrome are for folks who want to try it out without investing $20+ for wire and shipping. it includes the full instructions with pictures (2 pages with lots of extra details).

Once you know what you're doing and need 10,000 igintiers, feel free to buy a spool of nichrome (but I suggest going through a wire supply company and buying it by the pound spool - about 2 miles or so of wire).

One of our "elder" club members who is an electrical engineer insists that the lead wire on the Estes igniters is not really nichrome. He thinks it is some kind of coated steel or cheap iron. I don;t argue with him about it. He mainly grouses about it since it sucks huge amounts of amps through the launch sysytem and he is convinced that the high current is annealing the 34C microclips (making them soft and helping them wear faster). Personally, I 'feel' they are much stiffer feeling than real verifiable 30 ga nichrome wire. And they certainly RUST big time when exposed to water. Ever see used Estes igniters left on the ground for a few days/weeks in moist conditions?

https://home.howstuffworks.com/hair-dryer3.htm

https://home.howstuffworks.com/toaster1.htm

I am forced to conclude that he is probably correct and that it is a thinly coated iron wire. it certainly heats up, but it sucks way more current than real 30 ga. nichrome. Beware. I have zero problem using the thick wires with my good old Astron Launch Controller with 35 feet of 18 ga leads hooked up to my car battery. Instant near-vaporization of the wire with molten bits melting their way into any plastic parts mearby (like the launch pad legs...).

It makes an excellent igniter demo that is very visable. Don't hold the wire over your pants or any live motors. It is like molten lava. or would it be magma?

 

[Micromeister]

Shread:
I am with you on the is it or isn't it Nichrome. I believe it is... the Ol'e Ohm meter tells me It's .30 gage nichrome, it vaporizes at about 5 or 6 amps like /.30ga Nichrome and since Nichrome usually contains approximately 24% Iron I guess it will rust
We should put some test pieces in water to see if our known nichrome wire rusts on exposed to water.

 

[shreadvector]

Yes, but real nichrome contains iron and does not rust. Like "CRES" (stainless steel) contains iron but does not rust. magic alloys.

Our old electrical engineer guy says he's tested the Estes wire and it sucks 20 to 50 amps when shorted. I did not grill him about actual test conditions: wire only? wire plus launch system (switches/leads, etc)?

I do know for a fact that we have a volt meter built into our club launch system and when I hit the button on the thick Estes igniter wire it drops the voltage by at least 2 volts - and we use a CAR BATTERY! That's like the effect of an automobile starter motor!

Time for a science project (or a call to Estes).

Originally posted by Micromeister
Shread:
I am with you on the is it or isn't it Nichrome. I believe it is... the Ol'e Ohm meter tells me It's .30 gage nichrome, it vaporizes at about 8 amps like Nichrome and since Nichrome usually contains approximately 24% Iron I guess it will rust
We should put some test pieces in water to see if our known nichrome wire rusts on exposed to water.

 

[Micromeister]

Originally posted by shreadvector
Yes, but real nichrome contains iron and does not rust. Like "CRES" (stainless steel) contains iron but does not rust. magic alloys.

>>>> Yet another misconception:
There are only "certain Stainless alloys that don't rust. Those with very high Nickel content with some other alloying elements. 300 series is very rust resistant and non magnetic however some of the 400 series will rust somewhat in moist locations and is magnetic in all conditions, it's still stanless..go figure. 18/8 stainless is non-magentic but will rust like all geewiz.
I say all this to show when we talk about an Alloyed material there can be many subtle variations batch to batch or manufacturer to manufacturer. I'm only aware of ONE alloy classifed as Nichrome; 60% nickel, 16% chrimium and 24% Iron. That's not is say someone out there somewhere doesn't have another higher or lower grade alloy, I'm just not aware of it in this industry.

Our old electrical engineer guy says he's tested the Estes wire and it sucks 20 to 50 amps when shorted. I did not grill him about actual test conditions: wire only? wire plus launch system (switches/leads, etc)?

I do know for a fact that we have a volt meter built into our club launch system and when I hit the button on the thick Estes igniter wire it drops the voltage by at least 2 volts - and we use a CAR BATTERY! That's like the effect of an automobile starter motor!

>>>>>>When a DEAD Short is closed in a circuit any volt meter will drop to or near 0. We're dumping everything the battery will push into a resistance wire which is specifically made to accept a cretain limit. If we're pushing 7 amps or 7000amps it's all going to the Short (site of resistance) at the speed of light...Well within that speed held back by the flow resistance of the lead wires. Thats why the smaller gage lead wires 26, 24, 22, heat up faster the 18, or 16gage. Less constriction of the current flow.

Time for a science project (or a call to Estes).

 

[Mad Rocketeer]

Thanks for all the good info.

This is good information on wire guages and what sources will fire each.

Currently, I use a 9v transistor radio cell Quest system for Micro-Maxx and a 12v 8-D-cell Alkeline cell system for everything else. My 12v D-cell system has external clips for attaching any other sort of battery, but the wires are about lamp-cord guage. Not bad for a system bought in the late 60s. I plan to build a 12-v gel cell relay system soon so I can fly clusters (like the Deuce's Wild and the Richter Recker I just bought) and composite motors with confidence.

I know that nickle cadmium batteries can put out more current by far than similar alkeline batteries, even the good ones, and they are less damaged than most alkeline cells by having a dead short applied across them. Lead-acid batteries and their gel-cell variants are the gold standard for pumping serious amps.

One thing I haven't see the answer to, though it must be available and fairly simple. How does one charge the gel cells? Do I use a charger like I'd buy at an auto parts store to charge car batteries, or is there a smaller cousin that I can get at the hobby shop or Radio Shack? Would the one I laready have for car batteries damage the smaller gel-cell?

Have one of you a chart matching wire diameters in inches to guages?

When I went launching, I noticed that the launch rod (wire) for my Micro-Maxx stuff is pretty loose in the launcher. The little sleeve thing holds the wire snugly, but the sleeve fits the launcher loosly. Do you usually wrap it in tape or something to get a good fit? None of my rockets tried to take the rod with them, but I could see it happening fairly easily.

What is Kapton tape, and what is is used for in rocketry??

Actually, the thicker the wire, the lower the resistance, all other factors being equal. [I'm a Middle-aged electrical engineer. A Rambling Wreck from Georgia Tech.]

wwattles: Great news on the job!

 

[shreadvector]

Kapton is used to insulate wire. Or at least it WAS used before a serious air disaster casued by worn kapton and exposed wires shorting (arcing) casuing a kapton fire. it apparently burns real good under the correct conditions.

https://www.resistancewire.com/mainpage.php?page=gaugechart

Oops, that website seems to be an insane resource for resistance wire. Better not let that fall into the wrong hands....

Originally posted by Mad Rocketeer
Thanks for all the good info.

This is good information on wire guages and what sources will fire each.

Currently, I use a 9v transistor radio cell Quest system for Micro-Maxx and a 12v 8-D-cell Alkeline cell system for everything else. My 12v D-cell system has external clips for attaching any other sort of battery, but the wires are about lamp-cord guage. Not bad for a system bought in the late 60s. I plan to build a 12-v gel cell relay system soon so I can fly clusters (like the Deuce's Wild and the Richter Recker I just bought) and composite motors with confidence.

I know that nickle cadmium batteries can put out more current by far than similar alkeline batteries, even the good ones, and they are less damaged than most alkeline cells by having a dead short applied across them. Lead-acid batteries and their gel-cell variants are the gold standard for pumping serious amps.

One thing I haven't see the answer to, though it must be available and fairly simple. How does one charge the gel cells? Do I use a charger like I'd buy at an auto parts store to charge car batteries, or is there a smaller cousin that I can get at the hobby shop or Radio Shack? Would the one I laready have for car batteries damage the smaller gel-cell?

Have one of you a chart matching wire diameters in inches to guages?

When I went launching, I noticed that the launch rod (wire) for my Micro-Maxx stuff is pretty loose in the launcher. The little sleeve thing holds the wire snugly, but the sleeve fits the launcher loosly. Do you usually wrap it in tape or something to get a good fit? None of my rockets tried to take the rod with them, but I could see it happening fairly easily.

What is Kapton tape, and what is is used for in rocketry??

Actually, the thicker the wire, the lower the resistance, all other factors being equal. [I'm a Middle-aged electrical engineer. A Rambling Wreck from Georgia Tech.]

wwattles: Great news on the job!

 

[Micromeister]

MR:
Radio shack and others sell a number of wall pack DC converters 120/12v, or you may have a 12v dc converter laying around the house left over from some electionic component. Any 12V voltarge converter can quickly and easily be changed into a Gel-Cell battery charger by simply snipping off the end plug, splitting the wire and attaching a pair of red/black alligator clips. Only critical thing is to be very sure you have identified the Pos/Neg lead properly. "nomally" there will be a white strip on one side of the dual wire jacket which is the positive lead. This should be checked with a meter before cannecting to your battery. I've been using RS 500ma and 1000ma (1amp) converters to charge my 7 and 26amp/hr Gel cells for a long time. smaller ma units will work but take longer to charge, I'd say try to say over 300ma. I've even used them to charge lead-acid wet cell RV, motor cycle and marine batterys for the club when we are using more batteries then we have standard auto 10amp chargers. Usual charging time is overnight (12-16hrs).
I recently saw a small Float charger on sale thru Harbor Freight www.harborfreight.com for about $8.00 that has worked well for us on Gel-Cells.
Hope this Helps

 

[Mad Rocketeer]

Thanks for the good info. The 12v DC power bricks probably have no provision for preventing overcharging batteries. No worries there?

 

[Justin]

I bought my 10 bird 50 motor set about two hours ago. I tried 5 times to fly, with two different ignitors to no avail.

It seems from this thread the easiest way to do this is launch with 1" of 30/32 guage nichrome wire with a piece of wadding seperating the leads and taped in? I'll have to order some wire and try it. My buddy has the older grey tube/pod launcher and kit, and he couldn't get it to work either. I was excited about this kit when he I called him tonight, and he say call him when it worked....

I have an electron beam controller converted to clip to a 12 volt latern battery, or car battery. I take it it would be better to use this instedd of the quest controller? Or if I get the thin wire and make igniters, the quest 9 volt will be fine?

I can tell already from my attempts tonight, that I agree with whoever said they were going to make a seperate boom on or next to their pad to hold the igniter leads. The weight of the clips pulls them all over the place.

I think these little guys are cool, and I want to make them work. And then maybe bulid something really cool like Micromiester does all the time.

 

[Daedalus]

Originally posted by Micromeister
You must be flying the little plastic Bricks I've have closed track minimum dia. models with closed tracks to 255 feet. My micro interceptor will get over 100' every time I fly it. The hardest part is getting them to slow down far enough not to break the 50-70lb kevlar shock lines

WOW, that looks a fantastic model. Do you have plans for it that you would be willing to share?

 

[shreadvector]

The Quest controller with a fresh 9 volt alkaline battery is one of the best on the market. We need more detailed info to troubleshoot it with you.

Did it beep when the clips were connected to the igniter and the safety key was inserted?

If it beeped, did the igniter glow red hot when the launch button was pushed?

If it did not beep, sheck the connections, the wires=, the battery connector, the battery and that the key is inserted properly.

If the igniter glowed red hot, then you simply need to make sure it is inserted properly - that means it is all the way into the motor. The motor should rest completely all-the-way-down onto the igniter. When connecting the leads BE CAREFUL not to pull the igniter wires down because they can slip inside the plastic igniter shell. if they pull down, they pull away from the propellant inside the motor. Push them up if necessary. I suggest snapping the tiny plastic tabs off the bottom of the igniter (the ones that the ends of the igntier wires are curved around). This allows you to push the wires up and still have a good amount of wire to connect the clips.

Good luck and let us know what you found while troubleshooting and tracking down the exact root cause of the problem.

Originally posted by Justin
I bought my 10 bird 50 motor set about two hours ago. I tried 5 times to fly, with two different ignitors to no avail.

It seems from this thread the easiest way to do this is launch with 1" of 30/32 guage nichrome wire with a piece of wadding seperating the leads and taped in? I'll have to order some wire and try it. My buddy has the older grey tube/pod launcher and kit, and he couldn't get it to work either. I was excited about this kit when he I called him tonight, and he say call him when it worked....

I have an electron beam controller converted to clip to a 12 volt latern battery, or car battery. I take it it would be better to use this instedd of the quest controller? Or if I get the thin wire and make igniters, the quest 9 volt will be fine?

I can tell already from my attempts tonight, that I agree with whoever said they were going to make a seperate boom on or next to their pad to hold the igniter leads. The weight of the clips pulls them all over the place.

I think these little guys are cool, and I want to make them work. And then maybe bulid something really cool like Micromiester does all the time.

 

[Micromeister]

Originally posted by Daedalus
WOW, that looks a fantastic model. Do you have plans for it that you would be willing to share?

Daedalus:
Yeap I sure do: in the file section of the MicroMaxRockets yahoo group I have pdf one page plans for 64 different Micro models. more coming all the time The plan for the micro missile toe is also there. I think the file is McCoy's Micro onepage plans or something like that it's kind of hard to miss

 

[Justin]

The light and beep did work. The igniter did not however get redhot. I have never used MMX, so I didn't know what it supposed to look like. Was the battery I bought dead? I will get another battery today. That would be great if my problem was a silly thing like a low battery. I'll let you all know later.
Thanks-Justin