Multi Launch Controller Plans

IMO, the wiring diagram is the easy part -- basically take your single pad controller and replicate it as many times as you need in one box. For such a project, VernK has a fantastic writeup with schematics on his website.

The larger challenge is figuring out your range setup and committing to cabling it, and finding associated conductors to use with those cables. I've used systems with all-in-one connectors (ask any Lucerne flyer about the infamous "grey cables") and broken out ones (like Neutrik NL-8s for each bank). They can be incredibly difficult to service and maintain, not to mention expensive.

How many pads are you looking to serve? If it's any number over eight or so, you may want to look into a digitally multiplexed solution like Wilson F/X. When our club wanted to upgrade our launch system, I priced out building a new one from scratch with quality components and it ended up being nearly the same price as the Wilson solution, except without the super-simple setup afforded by the use of a single extension cord to hook up the entire range.

daveyfire said:

...... The larger challenge is figuring out your range setup and committing to cabling it, and finding associated conductors to use with those cables. .

Click to expand...

The solution is no cables.

Area66 said:

The solution is no cables.

Click to expand...

So then you're back to digitally muxing the output for transmission over wireless. Getting reliable, secure, and safe connections to the pad boxes is a non-trivial task. But it's definitely a nice solution; we use that for our away cell setup.

Green Jello said:

Hello all,

I'm looking into building a multi launch controller for my new club in Reno. I've seen many great designs on here for single setups. Does anyone know of good plans and wiring diagrams to build one for a small club? I am capable of all the building and soldering needed as seen here, but I'm no electrician.

Thanks so much

Click to expand...

Dave: You don't have to be an electrician. I've been building and flying from homemade Controllers and Launcher since almost the beginning of the mod-Roc era back in the early 60's. I've build more then a dozen different multi launcher systems for Our Club and two or three other groups over the years.

Below are two wiring diagrams for a 2 rack or 12 pad system and a 3 rack or 18 pad system. Both have been in use by our club. Narhams Section 139 since 1965. I have recently up-Graded some of the original components but the basic controllers are pretty simple.

If you need further info or higher res pics just drop me an e-mail to [email protected] I'll try to get you guys up and flying ASAP.

View attachment Narhams Sys-2-c_Controller Upgrade (2 Rack)_08-25-12.pdf





View attachment System-1-c_Controller 3-RackWiring Diagram_05-25-96.pdf

How far are you launching? If you are only doing LPR or MPR out to 100ft or less, then cabling will probably work fine. If you are going to run pads at 100, 200, 300, & 500 ft. then the cost of cabling can get very high! You might be better off just purchasing wireless units.

Even if you use relays at the pad and use 22 ga signal cable from the box to the pad, if you need 8, 10, or 12+ conductors, the cable get very expensive very quickly. If you're talking $2 per foot for pads 200 ft. away, that's $400 just in cable. That make wireless much more attractive. Even a phone wire out to an away cell at 500 ft can get expensive. It also has durability issues that aren't there with wireless.

Besides, if you set up and break down each day, wireless is so much easier.

I understand that it can seem cheaper to build your own units, but don't do that until you compare all the costs and issues of buying vs. building.

^ In referencing above

As an alternative point of view, we use relays at the pad, and transistors to drive the relays. The cabling is Cat 5; the system is reliable at 1000' of Cat 5.


Schematics for a transistor-driven launch controller



All the best, James

Fdog said:

^ In referencing above

As an alternative point of view, we use relays at the pad, and transistors to drive the relays. The cabling is Cat 5; the system is reliable at 1000' of Cat 5.


Schematics for a transistor-driven launch controller



All the best, James

Click to expand...

Relay systems are great allowing smaller diameter "Stranded" wires in cables to be used.

That Said Cat 5 cable is a real problem that WILL cause trouble very quickly after fabrication. Cat5 cables are made up of solid wire not intended to be coiled and recoils over and over with very little time these solid wire Will fracture and brake. Any Stranded wire cable is preferred over solid wire for launch systems. More expensive Yes, but trouble free for decades.

Micromeister said:

Relay systems are great allowing smaller diameter "Stranded" wires in cables to be used.

That Said Cat 5 cable is a real problem that WILL cause trouble very quickly after fabrication. Cat5 cables are made up of solid wire not intended to be coiled and recoils over and over with very little time these solid wire Will fracture and brake. Any Stranded wire cable is preferred over solid wire for launch systems. More expensive Yes, but trouble free for decades.

Click to expand...

Yes, that is an excellent point, thanks for bringing it up.

As a data point, we have a roll of 330' of Cat5e stranded that we've used for launches, this is it's third year. No problems yet. I've tested it a couple of times with a Fluke and it's always passed insertion loss with flying colors. We use a cheap little orange reel for extension cords that makes it easy to deploy and retrieve.





All the best, James

Cat5 cables come in two flavors, solid and stranded. Stranded is used for patch cables, or wall panel to computer, while solid is used for installed wiring, i.e. the wall panel to the central patch panel where the switches are located.

Just make sure to pick the stranded cable and it's all good.

Fdog said:

^ In referencing above

As an alternative point of view, we use relays at the pad, and transistors to drive the relays. The cabling is Cat 5; the system is reliable at 1000' of Cat 5.


Schematics for a transistor-driven launch controller



All the best, James

Click to expand...

This schematic seems to be for a single pad. Green Jello was asking about multi-pad controllers. Do you have schematics for a setup that could control multiple pad? Would you have to run one cable for each pad, or use a cable with more conductors?

Nope, don't have one for multiple pads. When we're launching without a club, it's just us and a couple of friends, so we're only launching one rail at a time.

This controller was designed for our own use and to be absolutely reliable. So far it's held to those design goals. I referenced it to point out that cables do work reliably at distances beyond 100'.

It's been my experience that most launch problems stem from two sources:

• The batteries
• The link

As a member of TRA Reno, I am pleased to help out whenever I can.


All the best, James

John Brohm and I had worked on a new multicontroller relay circuit last year. It was novel because it supported 6 pads using a single cat-5 (or other 8 wire conductor) and had to-the-controller continuity check. I have prototyped a single relay sample circuit and it has worked fabuously. Since there are a number of discrete components, I have worked up PCB plans for the 6 pad relay board. I'll try to dig up the schematics if anybody is interested.

Kevin

I'll try to dig up the schematics if anybody is interested

Click to expand...

I'm interested.

Steve G

We really need a company who will sell Wireless Launch Controller Stuff ....wait may be....

I'm afraid it's difficult to read because I only cobbled it together to get a PCB layout for OSHPark. I'll try to walk you through it.

Missing completely from the schematic are 6 automotive 12v relays. Pad power +12v goes to the igniter then to one tab on the relay switch and the connectors on the left (J1). The other tab on the relay is switched to pad power -. When there is continuity through the igniter, J1-1 (for the first pad) will be high, then to the pn2222 transistor which turns on the pad continuity led (cont1-1 connector), and also turns on the led in the ps2502 opto-isolator.

The connector across the top goes through the cat5 back to the controller circuit. J2-1 is +12 from the controller (and powers the control side of the relay), J2-2 is - from the controller, and J2-3 is the control signal for pad 1, etc. The eventual plan here is to have the controller power tap off to switch some alarm circuit like a buzzer or strobe so when it is selected from the controller, people know it's hot.

J2-3 is the control & continuity signal for pad 1. When there is continuity, there is a completed circuit from +12 through a voltage divider to J2-3. J2-3 is then presented with about 7v. When J2-3 is pulled to ground, the MIC4467 (MIC1_1) gate will trigger +12 to the RLY1-2 connector (which is of course connected to the coil of pad 1's relay).

The MIC4467/8/9 is a pretty neat chip. It's basically a CMOS buffered MOSFET. The MIC4467 used here has a CMOS inverter on it (hence why it's drawn like that). Since it's CMOS it has a high logic threshold and allows an intermediate voltage state to be used to signal continuity to the controller.

What's completely missing here is the controller circuit. I'm using a ULN2004 darlington inverter to drive the continuity lamps (LEDs) at the controller, and simple interlock and switch to ground to control the launch.

I have built a single channel version of this controller to test the circuit out and it seems to work like a champ. I'm struggling to pull the trigger on ordering boards from OSHPark because, well, I'm a wimp and think I might have something wrong.

Kevin

sghioto said:

I'm interested.

Steve G

Click to expand...

View attachment relay4.pdf

Kevin,

First off the J2 connector is labeled J7 on the schematic.

If I understand the schematic correctly there is a separate momentary launch button for each pad through a single interlock switch. Is this right and can you post the controller schematic?

Steve G

J7, J2 whatever - failing eyesight. I also don't know if all the resistor values are present - there are a few which are particularly important (the voltage divider around the mic4467 in particular).

I'll caress the controller schematic but right now it's rather confused - since it includes a rotary and digital selector logic for one of 6 pad units (to support 36 pads) along with continuity circuit, etc. What it doesn't have on it are the switched

Here's a brief rundown for the controller switches - you can pretty much do whatever you want as long as firing pulls the control line to ground. I am planning on having a bank of selector swtiches (DPST) one for each control line (6). One pole will turn on an led to show that pad is selected, the other will connect the control line to the master fire switch (interlock). There is a single master fire switch (momentary NO) which connects all the pad selector switches to ground.

For the switched interlock safety, I plan on having a key rotary which either switches +12 or - from the controller to the pad relay unit.

There's a whole lot of flexibility on the controller side. You want three sets with 18way drag races - you can do it it just requires a lot of switches!

Kevin

sghioto said:

Kevin,

First off the J2 connector is labeled J7 on the schematic.

If I understand the schematic correctly there is a separate momentary launch button for each pad through a single interlock switch. Is this right and can you post the controller schematic?

Steve G

Click to expand...

I forgot to mention, I sketched this up in Eagle 6.5 and would happily send that to you for a serious look. The current board layout is 3x4 inches two-layer and costs $60 for a set of 3 boards through OSHPark. This is a reasonable price but I don't want three - so if you want to split it...

I also cobbled together a 2 pad version which requires 4 lines from the controller. Since it is smaller OSHPark charges $30 for three.

Kevin

Kevin,

I'm not planning on building one but was curious about the design. No need to post the the controller schematic as I understand how all this works. And must admit I like the way you think! Excellent job!

Steve G

Area66 said:

We really need a company who will sell Wireless Launch Controller Stuff ....wait may be....

Click to expand...

This times the number of pads plus one (pad relays plus starter solenoid driver relay):

5V 30A 1-Channel Relay Module with Optocoupler H/L Level Triger ($3.25 ea)

https://www.ebay.com/itm/5V-30A-1-C...561?pt=LH_DefaultDomain_0&hash=item1c40d74ef1

One of these (starter solenoid for master arm):

F492 Starter Solenoid ($13.20)

https://www.amazon.com/dp/B003X0Z64O/?tag=skimlinks_replacement-20

Two of these:

Hot Pro Mini atmega328 5V/16M MWC avr328P Development Board Module For Arduino ($4.03 ea)

https://www.ebay.com/itm/Hot-Pro-Mi...353?pt=LH_DefaultDomain_0&hash=item43c8f61d29

One set of these:

3DR Radio 915Mhz Module for Telemetry ($27.67)

https://www.ebay.com/itm/3DR-Radio-...003?pt=LH_DefaultDomain_0&hash=item4181814943

EDIT: Or a set of these which I forgot. Much cheaper, but much shorter range and not spread spectrum:

433Mhz RF transmitter receiver link kit for Arduino ($0.99)

https://www.ebay.com/itm/433Mhz-RF-...919?pt=LH_DefaultDomain_0&hash=item19e430292f

EDIT 2: Or a set of these, much better that the cheap board immediately above. I stupidly forgot to include this type in this list even though I've already got a pair of these on order and not the above $0.99 type:

SI4432 470MHz 1000m Wireless Module 470M 433mhz Wireless Communication Module

https://www.ebay.com/itm/SI4432-470...z-Wireless-Communication-Module-/200932667345

One of these at the launcher end:

ZIPPY Flightmax 5000mAh 11.1V 3S1P 20C ($22.07)

https://www.hobbyking.com/hobbyking...lightmax_5000mAh_3S1P_20C_USA_Warehouse_.html

A much lower capacity 7.4V lipo in the controller.

Two of these:

5V USB DC 7V-24V to 5V 3A Step Down Buck ($2.24 ea)

https://www.ebay.com/itm/5V-USB-DC-...R33S-Module-Arduino-than-LM2596-/181008007744

Misc. enclosures, switches, cables, LEDs, etc. And some Arduino programming.

Or, if you don't want to DIY it for the fun of it, you could use one of these intended for fireworks. A red LED on the remote firing unit lights if there is no igniter/squib continuity on a firing channel.

Edit: Just discovered that these use only their special type of nichrome wire igniter. I have a question into them about the max current supplied by their igniter circuits. Regardless of their answer, these could easily be gutted, modified and re-cased inexpensively if necessary to fire any rocket igniter. The hard part they've done for you - the RF circuit with it's linked remote, possibly a rolling code device like a garage door opener.

Quantumfire™ QF-6LR (6 cue) Wireless Firing System - on sale for $59.00

https://www.firingsystems.us/Wireless-Firing-Systems-p/qf-6lr.htm

Quantumfire™ QF-2X6LR (12 cue) Wireless Firing System - on sale for $89.00

https://www.firingsystems.us/Wireless-Firing-Systems-p/qf-2x6lr.htm

Manual:

https://www.firingsystems.us/v/vspf...re QF-2X6LR Wireless Series Firing System.pdf