Need cluster motor ignition tips

Could use some advise on cluster ignition. This is my first cluster kit, I've done multi-stage but not multiple-motors together instantly. The kit is LOC ViperIV I'm building now. Probably using 4 "E" motors, stock igniters wired in sieres maybe? Should I solder one leg to next and so on, or use multiple clips pig-tailed to main launch cables? Also I've been using a 6V Lantern style batt ignition on 10AWG wiring that made myself, (Is that enough power for 4 E's) Any help would be appriciated.

Parallel wiring, not series.
Tie one leg of each ignitor together, then the other side together.

Get rid of the lantern battery. It cannot provide enough current to do clusters.

There will be plenty of people on here that will explain exactly why, but the bottom line in is, get a better battery

Any 12V system will do, a car starter, a motorcycle/ATV/lawn tractor, similar rechargeable battery pack used for tools or RC planes, cars, or boats.

4 E's = high power due to total propellent weight. I suggest using Quest ignitors. What I have done is solder lengths of phone wire to the leads so that the microclips aren't suspended under the exhaust nozzles. Twist all of one side of the ignitors together and then the other side so you don't have to worry about clip whips.

skyspike1 said:

Could use some advise on cluster ignition. This is my first cluster kit, I've done multi-stage but not multiple-motors together instantly. The kit is LOC ViperIV I'm building now. Probably using 4 "E" motors, stock igniters wired in sieres maybe? Should I solder one leg to next and so on, or use multiple clips pig-tailed to main launch cables? Also I've been using a 6V Lantern style batt ignition on 10AWG wiring that made myself, (Is that enough power for 4 E's) Any help would be appriciated.

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The 10 gauge wires are a waste as a 6 volt lantern battery won't put out enough current to matter.

You need at least 2 amps per igniter to make the Estes igniters light, and should allow for at least 5 amps per igniter to assure similtaneous ignition. A 6 volt lantern battery will not deliver this current. Eventually the igniters will light, but it will not be simultaneous, and you would likely ignite lees than all 4 motors, creating an underpowered flight.

It becomes a non-issue if you use Quest low current igniters, however you cannot use an Estes launcher as the continuity check current will fire the igniters.

A 12 volt sealed lead acid gel cell is a much better choice than a lantern battery for clusters of 4 or more motors, and is rechargable. https://www.allelectronics.com/make-a-store/item/GC-125/12-VOLT-5-AH-GEL-CEL-BATTERY//1.html or any similar battery over 2 Amp Hours is ok. On a short you get ~30-50 C current per amp-hour. (2 AH x 30 = 60 amps to 2 AH x 50 = 100 amps for the short time when you fire your igniter.) Using a 12 volt battery instead of a 6 volt battery allows you can use 18 gauge zipcord wiring instead of 12 volts because the extra voltage overcomes the resistance of the wire. 30' x 2 of 18 gauge wire has a voltage drop of ~ 7.5 volts so you still have 13-7.5= 5.5 volts across the clips at 20 amps. Since 1.6 volts delivers 2 amps through an Estes igniter, 4 volts will drive 5 amps through an igniter, and you will get simultaneous ignition.

Please note that (4) Estes E motors in a rocket makes it a FAA Class 2 rocket. This is a high power rocket so you need high power certification and an FAA waiver to launch the rocket because each E motor contains 35.8 grams of propellant which in total is 143.2 grams, exceeding the FAA Class 1 propellant weight limit of 125 grams total installed propellant weight.

Bob

I've had good success using a wire-wrap tool to add ~8" 30 ga. wire-wrap extensions to Estes igniters. These have worked 100% reliably for me, in clusters up to 5 motors, hooked up in parallel and fired with a 12 volt car battery. Being sure to remember all the usual cautions about selecting only the best igniters with no cracks in the pyrogen and 1-2 ohms resistance, inserting them carefully to ensure they touch the propellant, avoiding shorts, etc. I pre-make them at home when there's no rush, so they're ready to go at the field.

Been clustering motors for some time. Quick match is the easiest way of making sure every motor ignites, use about 2 inch of quick match per motor, tape/straw everything up and one igniter to light the lot. so far this has never failed, wherea i have had failures using 12v batteries with estes ignitors ans with cluster whips.

The most effective way to cluster BP motors is to use flashbulbs in conjunction with a pinch of BP in each of the nozzles. You pour just enough BP to fill the nozzle, then place & tape a flashbulb on top of each nozzle end. Wire all of your leads from the flashbulbs so that you have 2 sets of wires.

Word of WARNING: Flashbulbs are not safe to use with Estes style launch controller. They WILL IGNITE soon as you insert the safety key.


JD

skyspike1 said:

Could use some advise on cluster ignition. This is my first cluster kit, I've done multi-stage but not multiple-motors together instantly. The kit is LOC ViperIV I'm building now. Probably using 4 "E" motors, stock igniters wired in sieres maybe? Should I solder one leg to next and so on, or use multiple clips pig-tailed to main launch cables? Also I've been using a 6V Lantern style batt ignition on 10AWG wiring that made myself, (Is that enough power for 4 E's) Any help would be appriciated.

Click to expand...

First I'd take bob's post to heart 4 E's will require a wavier.

But for clustering 2,3 & 4 motor clusters of 13, 18 & 24mm motors the new Q2g2 igniters are PERFECT.
I still recommend clustering with a Relay Ignition system which moves the battery power from the controller side to the launcher but these low current igniters make it a lot easier then it used to be with Estes good old Solar igniters.

Might I also suggest a little visit to the www.narhams.org website library. download Tech-Tip-006 Clustering BP motors. it's loaded with lots of good info that may be useful in your cluster flying pleasure
Hope this helps.

Gillard said:

Quick match is the easiest way of making sure every motor ignites,

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I understand that Americans need an explosives licence for quickmatch, so it's not much used. We don't.

spacecadet said:

I understand that Americans need an explosives licence for quickmatch, so it's not much used. We don't.

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Thanks, i did not know that.

- at last one thing in the UK where we have an advantage over the USA!

Thanks for all the advise,I'm building this rocket for upcoming L1 HPR Cert. at next months NAR launch. I am trying to prepare for everything ahead of time, to not have any problems at attempt.They have official launch equipment there, but I'd like to "Bench Test" my cluster ignition setups first. Maybe use lower power motors in test tube setup clamped down on cradle I built for static (Non-flight) test firing. All your tips and advise were very helpful, through these plus some research, I'm eliminating lots of problems already.

skyspike1 said:

Thanks for all the advise,I'm building this rocket for upcoming L1 HPR Cert. at next months NAR launch. I am trying to prepare for everything ahead of time, to not have any problems at attempt.They have official launch equipment there, but I'd like to "Bench Test" my cluster ignition setups first. Maybe use lower power motors in test tube setup clamped down on cradle I built for static (Non-flight) test firing. All your tips and advise were very helpful, through these plus some research, I'm eliminating lots of problems already.

Click to expand...

Hmmm... When I did my L1 you couldn't do clusters. Haven't checked the rules in ages, but if I were you I'd take a look.

dixontj93060 said:

Hmmm... When I did my L1 you couldn't do clusters. Haven't checked the rules in ages, but if I were you I'd take a look.

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You still can't - but you need to have one to launch them. That's why I'm building a cert model for H128W. Of course, once I DO have that cert...

My choice of ViperIV for L1 cert.seems to annoy a lot of people? Maybe one of my other kits would be better suited for attempt. However, I felt I was compliant with rule 4.4 of NAR level 1 certification process and documentation. It can be done with clusters(not 4 E's though). A limit of 640 newt. sec. T.I. if using at least 1 H or I motor. This rocket is a poor choice for this attempt,(probably will be another.) but it IS possible. I have researched the process and NAR rules and see nothing to prevent it except common sense. However thanks for the ignition tips from those willing, nothing easy is worthwhile! Saftey First, but why not push it a little.....

The L1 cert procedure outlined at NAR's website clearly states that clusters can be used for certification flights, but one of the motors in the cluster must be either an H or an I motor. The total installed impulse cannot exceed 640 Newtons, which is the upper limit of an I motor. If you put an H motor, as required, in one of the Viper IV's motor tubes, what are you going to use in the other three? You cannot put H motors in all four, because you will exceed the maximum installed impulse limit, and you cannot put anything less than H motors in them, because then you won't meet the requirement. And then there is the issue of motor diameter; the four motor tubes in the Viper IV are all 24mm in diameter. Where are you going to find a certified H motor that is 24mm in diameter?

So do you see the problem now?

MarkII said:

The L1 cert procedure outlined at NAR's website clearly states that clusters can be used for certification flights, but one of the motors in the cluster must be either an H or an I motor. The total installed impulse cannot exceed 640 Newtons, which is the upper limit of an I motor. If you put an H motor, as required, in one of the Viper IV's motor tubes, what are you going to use in the other three? You cannot put H motors in all four, because you will exceed the maximum installed impulse limit, and you cannot put anything less than H motors in them, because then you won't meet the requirement. And then there is the issue of motor diameter; the four motor tubes in the Viper IV are all 24mm in diameter. Where are you going to find a certified H motor that is 24mm in diameter?

So do you see the problem now?

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Mark, I think you almost have it right. You have to use at least one H or I motor, but I don't believe any of the rest have to be H or I motors. You could fly a central H and three E motors around it.

Back to what you said, where are you going to get a certified 24mm H motor? Even if you did find one, if I were the RSO, I wouldn't approve of a rocket with an H and 3 E motors unless the H was a central motor, and the E's were around it and air started, considering the difference in ignition time between them.

Handeman said:

Mark, I think you almost have it right. You have to use at least one H or I motor, but I don't believe any of the rest have to be H or I motors. You could fly a central H and three E motors around it.

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Take a look at the graphic below, which was taken from LOC's catalog. Note the arrangement of the motor tubes. If you were determined to use this rocket for a Level 1 certification flight, which tube would you put the H into?

spacecadet said:

I understand that Americans need an explosives licence for quickmatch, so it's not much used. We don't.

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You are correct,
but it's America...there's always a way around it.


[YOUTUBE]hwTcJeohoiM[/YOUTUBE]

I suppose that you could use a matched pair of Kosden 24 mm H motors. Not sure the motor mounts would be long enough. One of the issues would be setting the best delay time since it depends on if both motors light or not. Electronics would be a better choice but adds another layer of complexity.

Assuming they are still certified:

https://performancehobbies.com/secure/store.aspx?groupid=57

terryg said:

I suppose that you could use a matched pair of Kosden 24 mm H motors. Not sure the motor mounts would be long enough. One of the issues would be setting the best delay time since it depends on if both motors light or not. Electronics would be a better choice but adds another layer of complexity.

Assuming they are still certified:

https://performancehobbies.com/secure/store.aspx?groupid=57

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I doubt it. I don't think that any of the 1" reloads are certified. The problem is that there is no list of which Kosdon TRM motors are certified now (TMT has never made that list public), but the 1" reloads weren't certified previously, either. The Viper IV is 47.5" long, 2.63" in diameter and weighs 18 oz. without motors. How high do you think it would it go on a pair of Kosdon H200s, and would it even survive the flight? The largest motors that LOC recommends for it are Fs.

Addendum: Also each one of the TRM 1.0-250 cases is just over 15" long. Put a pair of them in a rocket like the Viper IV, and nailing the main deployment won't be your biggest problem.

Boy, I sure did make alot of you think hard about this subject. Looks like I'll be using a different rocket for L1 cert. All your advise has been pretty clear, and I appreciate all the comments. I'll post photos tommorrow of construction, I'm super ampped to launch...but it looks like I'll have to wait.(Official answer..) I'm looking into another for L1 cert. any suggestions? Thinking about LOC Vulcanite, Hi-Tech or maybe several Aerotech kits. I have until late March until attempt. I'm a carpenter by trade,(25yrs.)and have been building rockets and shaping custom surfboards since the 80's. I have a complete shop here, and "The devil's in the details" mindset. I hope to see some suggestions posted.Thanks for all your interest...I sure made you all think though.....

A good L1 rocket is the Binder Design Thug in 38mm.

Thanks...any more info

skyspike1 said:

Thanks for all the advise,I'm building this rocket for upcoming L1 HPR Cert. at next months NAR launch. I am trying to prepare for everything ahead of time, to not have any problems at attempt.They have official launch equipment there, but I'd like to "Bench Test" my cluster ignition setups first. Maybe use lower power motors in test tube setup clamped down on cradle I built for static (Non-flight) test firing. All your tips and advise were very helpful, through these plus some research, I'm eliminating lots of problems already.

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Skyspike,

Just use Quest ignitors and you need not worry. I did a cluster of 4-E9 and 10-D12 and all 14 motors kicked. They also come in a 8" lead.

Adding more bp to a motor is, I believe, an illegal modification and dangerous.

I like Loc cluster kits, but if you want to certify, one of the motors must be H or I. To do so, I would recommend their Tri Star or even better their 429SS, both of which are 29mm mounts which would accommodate Cesaroni H
motors.

If you have questions, drop a line. All the best on your cert flight!

Tsolo Dann, L2
"My first rocket was a scratch built"
NAR 82124
TRA 10359

A couple of very popular rockets for Level 1 certification are the LOC IV and the LOC Bullet. The Vulcanite and Hi-Tech would work, too, but slimmer diameter rockets like these carry the risk of complicating your recovery and consequently, the success of your certification flight. With the higher altitudes that they will achieve there is the risk of a long drift on the apogee-deployed parachute. If your rocket drifts beyond the boundaries of your launch field you will most likely fail the cert. even if everything else went perfectly. It can be done, though; people do cert. with those rockets. My under-construction scratch L1 cert. rocket is only 2.34" in diameter, so I'm going to have to find ways to mitigate this issue myself. Careful motor selection, running lots of sims and performing some test flights of the rocket on G motors will probably increase the chances of success. One reason why the LOC IV and Bullet are popular for L1 could be that they are both 4" diameter kits, and the larger frontal area gives them lower flights. Keeping the altitude low (under, say, 1,500 feet) is one bit of strategy to use in a cert. flight because it all but guarantees that the entire flight and landing will be easily observed by the certification team. As I mentioned, though, I'll be using a slimmer rocket for my L1 flight too, so even I don't think that doing so is necessarily a bad idea. I just wanted to make you aware of this factor (excessive recovery drift from a high flight), which is increased when you use a slimmer, higher performing rocket for your cert. flight.

MarkII said:

The L1 cert procedure outlined at NAR's website clearly states that clusters can be used for certification flights, but one of the motors in the cluster must be either an H or an I motor. The total installed impulse cannot exceed 640 Newtons, which is the upper limit of an I motor. If you put an H motor, as required, in one of the Viper IV's motor tubes, what are you going to use in the other three? You cannot put H motors in all four, because you will exceed the maximum installed impulse limit, and you cannot put anything less than H motors in them, because then you won't meet the requirement. And then there is the issue of motor diameter; the four motor tubes in the Viper IV are all 24mm in diameter. Where are you going to find a certified H motor that is 24mm in diameter?

So do you see the problem now?

Click to expand...

You know that you don't have to fill all the holes. 2 Hs would keep you below 640 and the thrust would be balanced. you just have to plug the other 2 mmts.

Tsolo Dann, L2
NAR 82124
TRA 10359

Thanks for reopening my thoughts on using Viper IV, I 'm still open to the idea of 2 H motor in opposite,(diagonally)corners.Only because of the work I'm putting in on this one. I do like the concept of a larger diameter,(maybe shorter)rocket for cert attempt.Although it almost seems like cheating...but if it makes it easier for Range Officer to track entire flight, it would be less complicated with one shot at it than clusters. Then I can experiment with different ignition setups with less at stake if all goes well during L1 cert. But practicing 2 motor setups first with lower powered motors could be harmful to this heavy of a rocket,(I think?) unless clamped down for static flight. Less power in this beast just seems wrong! Like ordering a new Corvette...with a V-6..Anyway I appreciate all the input, I'm posting pics of build of my Viper IV taken today on Gallery section.

Skyspike1, (BTW, hello Stuart! I have family there) you still have the problem of the motor diameter that the Viper IV can take. The four tubes are all 24mm, and there are no certified H motors in that diameter. The four tubes also form the lower half of the airframe, so you can't even rip them out and replace them with a single 29mm tube. And you also can't replace the four tubes (or even a pair of them) with 29mm dia. tubes because they won't fit. (You'd need at least a 2.6" upper tube for that.) I hate to be the bearer of bad news, but the plain fact is that the Viper IV simply cannot be used for a Level 1 certification flight given the motors that are currently available.

You asked about AeroTech kits. They are mainly geared toward mid-power launching, but I believe that the Sumo and the G Force are two that can be used for high power certification.

I apologize for getting so involved in your thread, but I did because I identify with your plight. I'm at about the same place and am preparing to certify for high power too. Not so long ago I went through the rocket selection process myself, so it's all still quite fresh in my mind. And don't get me wrong, I like the Viper IV, and plan on getting one for myself. But here's one more thing to consider: it can be really helpful to bring a back-up rocket to your cert. launch. So if you want, you can try pushing the envelope with one rocket, and if that doesn't work out and you fail the cert. flight, you can then turn right around and try again with your back-up. That way you don't waste the trip. If your first rocket is a bit daring, use a safe, proven and "easy" design for the back-up.

The goal of your cert. attempt is to make a successful flight. Period. Once you have earned the ability to purchase H and I motors, then you can be more adventurous without risking your status every time you put a rocket on the pad.

Good luck! I'm pulling for you.

Thanks for your involvement; it's been quite helpful. I'm looking into other options, but not delaying my build of viper IV(too much momentum at this point) I look forward to when I can launch "the beast" with full-on F21-8 X 4 POWER! Anyway, I'm launching in the morning some of my others; C.C.Express W/D12's, magician on E-9's, Quest AGM-84 on C7-5's, plus my 10 yr old nephews rockets( If he hasn't lost/broken them as usual). Should be clear, no wind, 80 deg. The "fringe benefit" of working for Martin Co. School District Maintenance Dept. (Carpenter) is having weekend access to all district properties for launches....5..4..3..2..1..gotta go!