# Regular launcher from estes compared to the e launcher

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#### jpedersm

##### Member
What is the difference between these two? My friend just got a big kit with an E engine and wondering if we can launch it on the regualr launcher not the E. Is this possible?? If not can we use two regualar launchers? If not is there any way we can make one to launch this?

#### clreynolds

##### Well-Known Member
What is the difference between these two?
The only real difference is the length of the wires. Saftey code requires larger distances for personal safety. You can extend the length with lamp cord (sometimes called zip cord). Or if you are willing to sacrifice a second controller, just clip the wire from the 2nd, stip the ends where you cut it, and clip the leads from the 1st to the now exposed ends. No soldering required. Not the best connection, but it will work ok.

If you plan to launch composites, or clusters, the estes controller is mostly underpowered anyway.

#### accooper

##### Well-Known Member
The E launcher is heavier, and although you could launch an E from the lighter on, I would not just to be on the safe side. BTW you need to use a 3/16ths launch rod.

Andrew From Texas

#### jpedersm

##### Member
We got the e launch pad with the 3/16s rod just not the launcher. I have a couple of extra cords around the house so you so if I splice them and just make it longer it will work?

##### Well-Known Member

Anyway, the E pad is much sturdier and has a wider footprint and low center of gravity to help prevent the pad from tipping over with heavier rockets. It also accommodates the 3/16" diameter and 1/4" diameter launch rods, but does not accommodate a normal 1/8" diameter launch rod. The regular pad will work fine for models up to a pound, but you really want to add a weight on the 3 legs to prevent it from tipping over. Either a brick or a gallon jug filled with water. But remember the regular pad only accommodates 1/8" and 3/16" rods.

The E controller has the legally required 30 feet of wire so that you are far enough away from E motor flights per the NAR Model Rocket Safety Code. Since it is so long, and Estes is still using the 4 AA batteries, they made all the wire extra thick to lower the resistance and deliver more current to the igniter than the regular shorter controller with the ultra thin wires.

#### Handeman

##### Well-Known Member
TRF Supporter
As long as you have the 30 ft called for as the safe distance for the E motor, it should work fine. You will still be using the same igniter that you would use for an A - D motor.

Make sure you use fresh batteries. The only issue you may have is if the longer wire causes too much resistance. This shouldn't affect fresh batteries, but as they get used, they may stop working a little sooner then they would with only 15 ft of wire.

BTW, use at least the same or larger size stranded wire when you extend the wires you have.

#### luke strawwalker

##### Well-Known Member
What is the difference between these two? My friend just got a big kit with an E engine and wondering if we can launch it on the regualr launcher not the E. Is this possible?? If not can we use two regualar launchers? If not is there any way we can make one to launch this?
You can buy some extra speaker wire (or better yet lamp cord wire) at the Dollar store (usually in 10 foot rolls or so) or any length you want at Lowe's, Home Depot, or just about any hardware store. The thicker lamp cord type wire will have MUCH lower resistance than standard wire, which allows more of your battery power to reach the ignitor. As others said, the main difference in the controllers is the wire length-- standard Estes controller leads are about fifteen feet long, whereas the "E" controller leads are about 25-30 IIRC... You need to be back further from the bigger engines for safety.

Once you have your lamp cord, you can stop by Radio Shack and pick up a pack of micro clips (some hardware stores have them too, but I advise against the "gator clips" that are much more common in hardware stores-- the serrated jaws are much more problematic to get a good connection on an Estes ignitor than the flat style used on Estes controllers that are sold at Radio Shack). Split the two leads of the lamp cord apart at one end and pull them apart for about a foot length, strip the insulation off the last half-inch or so of the wires, twist the wire so the individual strands are smoothly spiralled together, and then push the strands through the hole of the microclip and fold over. If you have a soldering iron (they're like $6 at the dollar store or Walmart, or maybe a couple bucks higher at the hardware store, and a roll of rosin-core electrical solder) you can solder the clips to the wire, which is the best way to make electrical connections. Once you have the clips installed, split the other end of the lamp cord's leads apart about six inches or so and seperate the wires, and strip about a half inch or so of insulation off each wire. Clip your existing controller leads to these, make sure they don't short out against each other, and then hook the extended leads up to the rocket ignitor. OF course the BEST way to continue to use the Estes controller is to update it into something more capable. This project takes an afternoon, but it's not particularly difficult, and will make any Estes controller virtually as capable as any standard MPR controller out there that costs a LOT more money! The main thing is taking the case apart and removing the silly little thin 'bell wire' that Estes uses to make their controllers, because it is too small (too much resistance) and lowers the power available to launch your rockets. You can replace the 'bell wire' with 'lamp cord' from the controller to the clips and you'll REALLY improve the Estes controller with just that mod. Estes controllers are underpowered for igniting more than one engine, and they can really benefit from external battery power, which I modded mine for. I use a car jumper pack to provide 12 volt power with enough amps to launch anything I can hook up to it. Ditching the silly little AA batteries will REALLY give you plenty of power, though it does mean carrying an extra battery pack to launchers (you can also use cordless drill battery packs, motorcycle or lawnmower batteries, RC car battery packs, raise the hood and use your car battery, or stand-alone sealed lead-acid gel-cell batteries sold for things like deer feeders and stuff). The car jumper packs are nice because 1) they should be carried in the car trunk so they're handy, 2) they are easily recharged in either the car through the cigarette lighter, or most have a household wall-plug charger, and 3) they do double duty, handily starting your car if you leave the lights on or if the battery is flat on a cold morning, in addition to launching rockets. Another mod to the launcher that is VERY useful is to ditch the silly little flashlight bulb Estes uses for a 'continuity light' and replace it with an LED-- either a bulb-based LED bulb replacement (pinball machine LED bulb, LED flashlight bulb, etc) or wire in "LED indicator" units from Radio Shack-- you can even use regular LED's swiped from old electronics if you solder a resistor to them to reduce the current across the LED semiconductor bridge to prevent it from burning out. LED's GREATLY reduce the power drawn from the batteries during continuity tests and also make the controller safe for use with low-current ignitors like the Quest Q2G2's, which can be fired by installing the safety key on regular Estes controllers because the bulb allows too much power to flow to the ignitor, firing it. Here's a wiring diagram and an internal components diagram and a couple pictures of my modded Estes controllers. I also installed 110V cord ends (available at Home Depot, Lowe's, or any hardware store) so I can use a regular extension cord for launch leads, by plugging the extension cord into the controller at one end and the clip leads plugged into the other. It's not a terribly difficult conversion and it only takes about$15 bucks in parts, and a soldering iron. My modded Estes controllers can do anything an Interlock controller or Go Box controller (among others) can do without costing \$60 or more... and I have the satisfaction that "I did it myself". You can also build your own using switches from Radio Shack or the hardware store...

Enjoy and hope this helps... OL JR

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#### jpedersm

##### Member
so with this design will I be able to launch the aoratech motors to?

#### luke strawwalker

##### Well-Known Member
No reason why not...

The main thing is having enough battery power and wire large enough to pass enough amperage without too much resistance.

Battery power is largely a function of voltage-- voltage is the 'pressure' that pushes electricity through the circuit. In other words, more voltage is better (to a point anyway-- 12 volts is plenty in other words) The battery's internal resistance and capacity also plays a part-- that's why your car doesn't use a stack of 12 "D" flashlight batteries to get 12 volts, or a pair of 6 volt lantern batteries connected in series. Larger batteries like car batteries, motorcyle or lawnmower batteries, or car jumper packs can deliver a TON of amperage in very short order, whereas flashlight batteries cannot. Don't get me wrong-- the flashlight batteries are OK for single Estes ignitors, if you like counting to three after you push the launch button for the rocket motor to ignite-- but there are MUCH MUCH better power sources than flashlight batteries...

The other half of the equation is current (amperage). Larger wire can carry more current with less resistance. Lamp cord or extension cord is sufficient for the stuff we typically do in rocketry. Again, that dinky bell wire that Estes uses is fine for a single ignitor, if you like waiting to the count of three after pushing the launch button, but larger wire will ensure more than enough current gets to the ignitor(s) to do the job. More current means the ignitor heats up faster, igniting the motor faster, which is a good thing.

MPR ignitors typically need more current available than the standard Estes ignitor, which is why you really want a 12 volt power source, and wire large enough to pass more current (because of lower resistance). Of course there are SOME ignitors out there that are actually need LESS power than the Estes ignitors-- the Quest Q2G2's come to mind-- which will be fired by even the amount of current passed by the light bulb in the continuity check using an Estes controller-- that's why you want to switch to the LED bulbs or indicators: they will reduce the amount of current passed through the ignitor during a continuity check (LED's have MUCH higher resistance than bulbs, so use less power). Basically, you want to upgrade your controller to pass as much current with as little resistance as possible when you push the launch button, and to have as MUCH RESISTANCE as possible when you insert the safety key. That's why you want the bigger 12 volt battery, the larger lamp cord or extension cord wires, and the LED bulbs with their resistors for continuity checks. Basically, you want to provide the ignitor with as much power as you reasonably can, because it will only use as much as it needs anyway and no more-- BUT if you don't provide ENOUGH, THEN you start to get into trouble... If you fly a cluster, you're having to heat up two or more ignitors at once, which is why you need the larger wire and higher voltage. If you start getting into pretty big clusters, heating up 4-5 ignitors (or more) at once, you'll probably want to go to a relay launcher , which is a type of launcher in which the (usually large-ish 12 volt) battery is placed next to the launch pad, using heavy wires to connect the battery to the ignitors through a solenoid relay, which is basically just an electric switch which is activated from an external power source (like another launcher) from a safe distance. You push the button on your launcher, and the power closes the relay switch, which then dumps the battery power into the ignitors through short lengths of wire (typically 2-4 feet or so) which GREATLY reduces the resistance of the wire (longer wires have more resistance than shorter wires, just as larger wires have less resistance than smaller, thinner wires.) But this is really only necessary for larger clusters.

In short, yes, modding the controller for larger wires (and long enough per the safety code setbacks for MPR launches) and a better power source should make it more than sufficient to ignite MPR motors...

Good luck! OL JR

#### bobkrech

##### Well-Known Member
An expansion to the above.

Power is the product of the battery voltage multiplied by the delivered current.

P = I*V

Battery power is a function of both the battery voltage and it's internal resistance which determines the current it can deliver so it can also be expressed in terms of voltage and resistance or current and resistance.

P = I*V = (V^2)/R = (I^2)*R

The power consumed by the launcher circuit is P launcher = (V^2)/(R bat + R launcher+ R igniter). If any one of the 3 resistances are high then you won't get enough current to the igniter to activate it. A suitable 12 volt lead acid gel cell should have a resistance R bat < 0.1 ohms, and the resistance of the launcher wiring, R launcher < 1 ohm.

Current, not voltage, is required to activate an igniter. The power delivered to the igniter is P igniter = (I^2)*R igniter. The resistance of igniters vary greatly, but typically range from 0.5 < R igniter < 2 ohm with resistances > 1 ohm preferred.

Bob