Launchers Single vs Multi

[poke44]

Well as many of you know or dont i am a teacher at a small country school in Arkansas... the closest rocket group i know of is in Tulsa, OK. I was thinking of getting a 12v pratt hobbies 6 launcher system for around 120 vs getting a single 12v launch system for around 40-45. I have to get one or other as the TARC team needs to ignite RMS loads.

Reasons for multi
pro
1. have school launch with elementary
2. start rocket club in area when i get NRA number in (still waiting)
3. Cool factor

possible cons
1. ease of use
2. cost
3. trasport and storage (no idea on size though dont think its too much bigger)
4. Provides as much juice to ignite motors (probably not an issue but need to ask)

any other things people can think of please comment upon them

 

[JAL3]

I asked somebody about this very controller a few days ago and this is the reply I got:

"I still have the 6 pack launch controller and it was working the last time used it. I wouldn't recommend it however. It uses 24 gauge wire for the internal wiring including the high current paths for the igniters. "


I guess it comes down to how much current you want to reliably send through the system.

 

[AKPilot]

I'll take a different approach and definitely recommend Doug's controllers!!! They're perfectly fine and great for any LPR/MPR launching; the key is having a good 12v battery hooked up to it.

Here's the thread on the, 8-position, one I had Doug make up for me.

Pratt, 8-Position, Launch Controller

I store the launch controller, the 12v battery, all cords, blast deflectors, and clothes pins in a rolling tote. Makes it super easy for launches.

 

[Micromeister]

Poke44:
As you may or may not know I build all the Launchers and controllers and range equipement for myself and our Club Narhams, in Maryland. Doug Pratt is one of Our memebers as well. I know and have Used just about every Launcher/controller type Doug has put out.
I can only second the things AKpilot aready said.

Every single piece of Pratt Hobbies Launch equipemnt I've ever seen has always been first rate, and up to the job they are designed for.
If your not going to build your system yourself, I'd Strongly recommend Pratts 6-pack system or Go-Pack single system for you and a Tarc team. Along with the purchase of a good 12volt rechargable Gel-Cell Hi crank amp battery. For a regular Class size or Tarc team type launch requirements a battery in the 26 amp/hr or higher range will do the job all day long with plenty of reserve power. I've been using a 26amp/hr gel-cell for over 15 years for all our cluster, Mid and HPR motor launches without any power or ignition problems what so ever.

Heres a couple views of my "personal" 17 pad satellite system controller, with on-board auto 10sec countdown/launch sequencer and and remote gantry controls. When I begin this project I knew NOTHING about building a system! it's really not that difficult, You Can build your own if you want
If not Pratts Are the next best thing.
Hope this helps a little.

 

[SCE to AUX]

The Pratt unit looks pretty nice, but the electrician in me questions the use of standard 120V receptacles and plugs for this type of low voltage application.

Yes, they are easily available, more than capable of handling the current levels, and relatively cheap. But in an environment where 120VAC power is available (like a generator powering lighting and PA systems at a large launch event), using the same connectors for low voltage creates the possibility of someone accidentally connecting the launchpad cables to line voltage, creating a serious shock hazard to anyone at the pads.

For safety, I would recommend a different connector type, such as the Anderson "power poles" or similar. To eliminate the "rats nest" of cables between the controller and the pads, a multiconductor cable with a single plug for all 8 pads would speed setup and make things a lot neater.

 

[Starcommander]

I asked somebody about this very controller a few days ago and this is the reply I got:

"I still have the 6 pack launch controller and it was working the last time used it. I wouldn't recommend it however. It uses 24 gauge wire for the internal wiring including the high current paths for the igniters. "


I guess it comes down to how much current you want to reliably send through the system.

Don't know where this guy is coming from, but Doug's systems are tough to beat, for quality and reliability, as well as price. I have an older single SureFire11 that will fire any ignitor out there. I'd love to get my hands on one of his multi pad controllers.

BTW, has anyone heard from Doug? Last I knew he was sick. No answers to emails.

 

[Micromeister]

The Pratt unit looks pretty nice, but the electrician in me questions the use of standard 120V receptacles and plugs for this type of low voltage application.

Yes, they are easily available, more than capable of handling the current levels, and relatively cheap. But in an environment where 120VAC power is available (like a generator powering lighting and PA systems at a large launch event), using the same connectors for low voltage creates the possibility of someone accidentally connecting the launchpad cables to line voltage, creating a serious shock hazard to anyone at the pads.

For safety, I would recommend a different connector type, such as the Anderson "power poles" or similar. To eliminate the "rats nest" of cables between the controller and the pads, a multiconductor cable with a single plug for all 8 pads would speed setup and make things a lot neater.

Let me say first; Multiple lead to various pads is not a safety issue.

That "rats nest" as you call it is and has been, a staple of the Satellite system that''s been in use for almost as long as model rocketry has been around.
Multi-conductor cables are fine for Rack systems but leave much to be desired for Satellite or away pad systems.
That's what perimeter barrier ropes are for. May be hard to see, in these to models of the two systems but BOTH are by design to have barriers keeping folks away from the wire paths. Range safety is MORE then just multi conductor cables.

While there are Tons of different approaches to connections, standard plugs and receptacles used in the Pratt system are more then sufficent for a 12v DC system, while keeping the cost down i might add.

 

[SCE to AUX]

Let me say first; Multiple lead to various pads is not a safety issue.

Never said that they were a *safety* issue. But they take longer to lay out, and a tangle of separate cables can make troubleshooting harder. A single cable terminated in a "breakout box" is easier to set up, and reduces the possibility of cables getting switched between various pads. THAT scenario could conceivably create a safety issue.

While there are Tons of different approaches to connections, standard plugs and receptacles used in the Pratt system are more then sufficent for a 12v DC system, while keeping the cost down i might add.

Yes, as I said before, NEMA 5-15s are more than capable of handling 12V service from an electrical standpoint. The problem is the possibility of interconnection with 120V power systems where the 5-15 is the industry standard. Use of a different connector type eliminates this latent safety issue.

 

[poke44]

Welp I have had a little bit of electronic training as far as that goes... built some chemical testing circuits for chemistry degree. I teach 4 different subjects and time is always a premium. I HAVE to have some 12v launcher type asap to launch the TARC rocket so was figuring 40 for go box and was it worth to invest in the extra 80 to get the 6 pack.

This is all personal funds as the school has a spending freeze, though they did spend 4k on fixing the girls lockerroom to try and get the district tourney... go figure. Just trying to get things now to save money in future is what i was thinking.

Thanks for advice

 

[Micromeister]

Welp I have had a little bit of electronic training as far as that goes... built some chemical testing circuits for chemistry degree. I teach 4 different subjects and time is always a premium. I HAVE to have some 12v launcher type asap to launch the TARC rocket so was figuring 40 for go box and was it worth to invest in the extra 80 to get the 6 pack.

This is all personal funds as the school has a spending freeze, though they did spend 4k on fixing the girls lockerroom to try and get the district tourney... go figure. Just trying to get things now to save money in future is what i was thinking.

Thanks for advice

If your going to be doing class launches with lots of models, then go with the 6 pack, if your mainly lookng at Tarc flights I'd suggest the Go-Box as it will handle clusters easily also. either way you won't be disappointed with your purchase
Hope this helps.

 

[Randy K]

Mercury Engineering also makes a single launcher that is about the same design as the Pratt Go Box launcher.

https://www.mercury-rockets.com/Igliter.html

 

[ghost]

2. start rocket club in area when i get NRA number in (still waiting)

I know why you're still waiting! You joined the National Rifle Association (NRA)! You wanted the National Association of Rocketry (NAR)!!!
:rotflol:
:rotflol:

 

[skip_dye]

Did you ever consider making one yourself?

Or better yet, let the TARC team design and build. Parts are very inexpensive for a basic controller.

Alan

 

[poke44]

welp ordered a 6 pack...

i am thinking of having my TARC team work on a locater beacon... so to start another thread on that kit

 

[AKPilot]

welp ordered a 6 pack...

i am thinking of having my TARC team work on a locater beacon... so to start another thread on that kit

You won't be disappointed in the 6-pack.

As for the locator beacon, you may drop the hint to them that they can pick up a personal alarm (pull pin & it shrills) at ACE hardware or somewhere for $6 or so.