Cluster Ignition

[David Schwantz]

What are some of your ways to ignite a cluster. Both BP and composite. Trying to do 3 motor cluster.

 

[jimzcatz]

Reloads or SU? BC? I assume you mean BP. And I use small electric matches. Composite I put a Pyrodex pellet in the top grain and light them with standard ematches like CTI loads.

 

[David Schwantz]

Actually all 3. I am guessing this rocket will be BP due to the limited space for 3 motors. Is there a battery min, for the pad? The composites I would use will be Q jets, is there room for a pellet up there? I think 18mm will be the largest I can fit.

 

[GalantVR41062]

I looked on MJG's page and they say a 9v battery can do 5 Ematches in parallel.

So our club uses 12v batteries, and I assume the plastic box with the continuity check LED's at the pads have a couple automive style relays that the control board trigger.

Apogee says under the Twiggy motor starters that up to 3 could be wired in parallel with club style 12v launch systems.

~John

 

[Rocketjunkie]

I looked on MJG's page and they say a 9v battery can do 5 Ematches in parallel.

NOT the new Duracells. I wouldn't trust the new ones with more than 1. The new ones only put out 2A while the old ones put out 5.5A. If I use the new Duracell to fire one of my tiny starters, I get only 1 use out of the battery. It will not fire a second one. However, the old Duracells would fire at least 30 of the same starters. This redesign occurred without even acknowledging that it had been done. I will not use Duracells in any of my devices any more. I also had Duracells leak in my Walston receiver even though it was still working. One must have been weaker than the rest and reversed voltage. For 9V, I will use Energizer Ultimate Lithium (they put out 5A and will perform like the old Duracells.) but they are more expensive than a small 2S LiPo so I might as well throw away a LiPo. I have not had luck with rechargeable lithium batteries in a use then keep charged and *maybe* use them again within a year.
Old New

 

[Rocketjunkie]

Use the new BP starters from MJG. They are small ematches and will fit 18 mm and larger BP motors. They will not fit a Q-Jet. I've used my tiny starters for Q-Jets that failed to light with the supplied starter.

 

[heada]

With a 2S 300 mAh LiPo taking up about the same space as a typical 9V alkaline, why not switch to lipo? They can source 10s of amps vs less than 5 from modern 9V. And for ground controllers, a 4S 6000 mAh 100C lipo can be had for ~$50 and will light 10+ starters at once and last the whole launch season on a single charge. Lighter than a SLA or motorcycle battery too.

 

[Five]

I just bought the full boost handheld launch system from pratt hobbies. It’s supposed to put out 12v from 8 AA alkaline batteries but I tested 4 Estes starters using a 4 motor clip whip and barely got the starters to smoke. I was thinking about putting in some Duracell’s in it but not after what I just read.

 

[David Schwantz]

Hi John, how's the Viking? One of the reasons I was asking about batteries was the fact that at times, the club fails to light even one starter. If only one or even two light on this, pretty sure she a'int gonna fly so straight
What type of ignition harness and clips are used for clusters?
Rocketjunkie, When you say "your"tiny starters, what are they? Thanks, Dave.

 

[Rocketjunkie]

Rocketjunkie, When you say "your"tiny starters, what are they? Thanks, Dave.

I make them. The leads are 30 gauge Kynar wire wrap wire. The bridge is 50u (.002") tungsten. Pyrogen is Quickburst ProCast. I do have a set of pictures showing construction. They have been posted in the 18 mm Motors thread in the Research forum. I can repost some here if you don't have research access.
Here's one with a Quest B4 motor.

 

[waltr]

Those are nearly the same as ones I make for the small nozzle motors.
30ga WW wire with 40ga nichrome dipped in Procast. Never have these failed to light a motor.

I make ones with 24ga shooter wire and 40ga nichrome & Procast for electronic airstarts. work great off a 2S LiPo (8V).

 

[David Schwantz]

Junkie, found the 18mm thread. But did not see any how to's on the igniters, just on 18mm motors.

 

[Rocketjunkie]

Junkie, found the 18mm thread. But did not see any how to's on the igniters, just on 18mm motors.

Fixed. Also posting it here.

I guess it didn't get posted.
Making the starters for the 18 mm motors.
Original Quickburst needs pyrogen painted on the top of the grain. These are D grain motors with only about 1/16
Motors for new Quickburst beta test. 7 5", 40 N-s E13 and a 3", 24 N-s E8. View attachment 511647

Tungsten wire on top of lead wire spool. This wire is 51um (.002", diameter of hair, gold plated). View attachment 511648

Lead wire, 30 gauge Kynar twisted pair wire wrap wire. View attachment 511649

Side view of tungsten wire spool. View attachment 511650

10 leads cut about 25" long. View attachment 511651

Strippers, purchased from McMaster.com. View attachment 511652

Leads stripped. View attachment 511653

Close up of motor end and a second pic. View attachment 511654

Bridge wire wound on. View attachment 511655

All 10 ready to dip. View attachment 511656
Original pyrogen requires painted on grain pyrogen as well as a dipped starter.
Received sample pyrogen today. There was only about 1 ml of binder in the bottle and it made a dry, crumbly mix. Added 2 ml acetone and it is now dippable.
Dipped in new Quickburst pyrogen. Will use to static test motors with no painted on pyrogen.
They worked but it looks like they lit the delay grain which then lit the propellant.

Dipped the above starters. View attachment 511657 Using ProCast and it works the best of any that I've tried.

 

[Grog6]

I wish you could still get the 9v lithium batteries at radio shack.
Not only did they last for 10 years, they would kill your tastebuds for a month if you forgot and gave it the tounge test for 9v batteries, lol.

 

[dpower]

Use a 12v system, preferably a relay system - just about any small SLA (Sealed Lead Acid) battery will do. If you don't want to make your own starters, for BP clusters, use MJG BP starters. For Q-Jet clusters, or CTI clusters, use the supplied starters. I don't have experience with clusters of AT motors.

 

[David Schwantz]

It will be a cluster of 3 Econjet F44W. Will be going out today to launch a Mercury Atlas. Will be using a 6S 5300 lipo on an AT controller.
How can a person use the club controller and add the lipo at the pad?

 

[Dugway]

It will be a cluster of 3 Econjet F44W. Will be going out today to launch a Mercury Atlas. Will be using a 6S 5300 lipo on an AT controller.
How can a person use the club controller and add the lipo at the pad?

With a cluster box: https://bpasa.com/Cluster-box.htm

 

[dpower]

It will be a cluster of 3 Econjet F44W. Will be going out today to launch a Mercury Atlas. Will be using a 6S 5300 lipo on an AT controller.
How can a person use the club controller and add the lipo at the pad?

Your club controllers are not a 12v relay design? Brave flier you are, clustering F44 motors, I've had 2 of those CATO - case split open.

 

[David Schwantz]

Great

 

[bad_idea]

For black powder, I use MJG starters. I have not had a single failure of the MJG starters, and my only failure to light a motor was when I allowed a starter to pull clear of its designated motor. At the time, I was trying to tape the starters in place. Since I've started using poster putty to hold the starters in place, I've had no further trouble.

After a few hits and misses with a relay starter I still need to disassemble and diagnose, I decided it was worth the cost of simply testing a full set of MJGs on each new suite of launch equipment I encountered, for however many motors I planned to fire.

Here is my test on the DARS equipment prior to launching my 7x18 cluster there for the first time:



As the club VP says, they blowed up real good!

 

[Five]

For black powder, I use MJG starters. I have not had a single failure of the MJG starters, and my only failure to light a motor was when I allowed a starter to pull clear of its designated motor. At the time, I was trying to tape the starters in place. Since I've started using poster putty to hold the starters in place, I've had no further trouble.

After a few hits and misses with a relay starter I still need to disassemble and diagnose, I decided it was worth the cost of simply testing a full set of MJGs on each new suite of launch equipment I encountered, for however many motors I planned to fire.

Here is my test on the DARS equipment prior to launching my 7x18 cluster there for the first time:



As the club VP says, they blowed up real good!

Not to handy with a camera

 

[Five]

For black powder, I use MJG starters. I have not had a single failure of the MJG starters, and my only failure to light a motor was when I allowed a starter to pull clear of its designated motor. At the time, I was trying to tape the starters in place. Since I've started using poster putty to hold the starters in place, I've had no further trouble.

After a few hits and misses with a relay starter I still need to disassemble and diagnose, I decided it was worth the cost of simply testing a full set of MJGs on each new suite of launch equipment I encountered, for however many motors I planned to fire.

Here is my test on the DARS equipment prior to launching my 7x18 cluster there for the first time:



As the club VP says, they blowed up real good!

I hope your MJG igniters do the job. I ordered a six pack of the mini’s and a six pack of the regular size. Im anxious for it to arrive. I want to try them out. C6 3x18 mm. I bought a the full boost launch system from pratt hobbies thinking it would ignite it but it barely got each igniter to smoke. Wired parallel. Once Im able to do the cluster of 3 then its on to my 4-29SS.
Look at her, don’t she look pretty?

 

[Hobie1dog]

NOT the new Duracells. I wouldn't trust the new ones with more than 1. The new ones only put out 2A while the old ones put out 5.5A. If I use the new Duracell to fire one of my tiny starters, I get only 1 use out of the battery. It will not fire a second one. However, the old Duracells would fire at least 30 of the same starters. This redesign occurred without even acknowledging that it had been done. I will not use Duracells in any of my devices any more. I also had Duracells leak in my Walston receiver even though it was still working. One must have been weaker than the rest and reversed voltage. For 9V, I will use Energizer Ultimate Lithium (they put out 5A and will perform like the old Duracells.) but they are more expensive than a small 2S LiPo so I might as well throw away a LiPo. I have not had luck with rechargeable lithium batteries in a use then keep charged and *maybe* use them again within a year.

You single-handedly destroyed all my confidence in Duracell batteries.

 

[Zbench]

Another +1 for MJG black powder igniters. We built a Flis Tres over the winter and wanted to test them out before hand. The video is 3 A8-3s, two from one lot, the third from an ancient source, complete with disintegrating clay nozzle. They were glued together and then to a piece of scrap plywood.
View attachment trim.19195BDF-405F-4963-B32A-70CB1C9FB518.MOV