Mock Nitrous in my Xmod!
 

Okay, so I haven't done this yet, and it sounds crazy but...

I was watching the Fast and the Furious, and then 2 Fast 2 Furious, and I saw Nitrous being used, which I had never seen before... I remembered I had a few A3-4T model rocket engines (about the size of a AAA, but with a bigger diameter) laying around, that I never used... I thought of putting them on my car, but then it would look stupid... Then I thought of rerouting the thrust using aluminum tubing bent and manipulated to look like exhaust :D I thought about it for a few minutes, and I couldn't do my homework because I couldn't stop thinking about the idea. I almost gave up when I couldn't figure out how to ignite them remotely, then I looked at my BCG...I figure, I'll hook up the pcb in parallel to the AAA's, and use forward for one boost, and backward for the next. I'll use two diodes hooked up to the igniters, so it only ignites one at a time... I can't wait to start...

I'm okay if you all think I'm crazy. It is a crazy idea. But just imagine the look of your opponent when they see (I forgot what came out of the model rocket engines, it's been a while! Smoke? Won't look like nitrous!) coming out of what they thought was a mock-exhaust...

Well, given that you are probably going to seriously screw-up your car, just pop a G40 or G80 in there, no one will notice:rolleyes: :D

besides the fact that your car will be melted into the concrete the second you ignite the rocket engine.. you may have something here....engine exhaust wrap and aluminum insulation *may* be sufficient... but the second thing, would be to make sure your engine is completely parallel to to your car. i hope you try it, or i may even try it.. if i knew how to ignite the engine.

It's done electrically, you get these igniters with the engines, and you hook them up to about 5-6 volts and they glow red while some kind of black coating on them burns off. I think the wire is called "nichrome", like what they use in toasters.

I still have to draw up my "exhaust" before any production can begin... I sure do hope that my car doesn't melt :( But if it does, hey, it was only $50 and there will probably be some parts left to salvage...

Or, instead of using a rocket motor, you could use a smoke bomb (4th of July leftovers). It doesn't get as hot so it won't melt up your car as bad.....

I think that you forgot about the small fact that they explode when they reach the end of the powder.

Rocket engines don't explode, per-se... They do let out exhaust towards the end of its reaction that pops the nose of the rocket and the parachute out to slow the fall.

Heatshielding will be interesting.

Thanks for pointing that out Bugman, I'm not going to use fireworks... About that ejection charge... Estes makes some larger engines without the reverse charge to pop out the chute for, I think the RC gliders? Or something else... I am hoping they also make them in 1/2 A size, like my A3-4T's.

Oh crap, no, they don't make them without the ejection charge :( I can always reroute it to maybe the bottom of the car... To make it look like it came out of the hood and the engine blew lol

I put two rocket engines, about the size F25/50 thing, on a 1:18 Corvette a few years ago. The ignition system was totally independent of the other circuitry, the whole deal was installed as a unit, and they both lit successfully on the first try. The car went about ten feet before the rockets gave out, and it probably didn't break 5mph. I don't know what kind of models those are engineered for, but rockets are typically a lighter than cars, and it showed in my experiment.

Despite the size difference, we lightened the Corvette, so it probably only weighed 50% more than an XMOD. And keep in mind, there were two rockets. But good luck! It'd be cool to see it work.

I am planning to use an independent ignition circuit as well, but I will use the rocket engines in conjunction with the motor. You know, like a boost to the car, not propelling it independently. I forgot to take into consideration the weight though! Oh well, if it doesn't add too much speed, or none at all, at least it'll look good:D I just need to go down to my local hobby store to get some tubing...

Actually, Estes does make several motors without ejection charges:

-A10-PT
-B6-0
-C6-0
-D12-0
-E9-P

Hrmm... b/c you plan on using a little exhaust-type setup, you might be able to make the thing pretty much fly! :D With the exhaust style setup, as long as you tune everything just right you could get it to work great ... rather than having the exhaust parallel to the ground at the end, have it pointing about 5 degrees up for some down force (it's an XMod, not an Airplane) and it might work good. Also, don't go to small on tubing, backpressure would make it explode (bye bye, poor XMod). I'd love to see how it turns out

Is that A10-PT in the mini size? Because that's the biggest I want to go... I'm assuming it's not:(

It's the same size as the A3 you have. The T stands for a 13mm [diameter] motor

would gold coated foil work to retard the heat or would it just catch fire and or interfere with the electronics? because I know nasa uses a type of foil similar to this, a better grade of course:D . just a thought. good luck!

The foil could cause a short if it connected the antenna with the motor can, metal heat sink, or any exposed hot wires.

Step one's out of the way... sort of:( I called my LHS and asked them if they had the A10-PT engines, the guy said no! He checked in his little catalog thingy, still none! Can you order these things online?

I asked if they had pinion pullers for slot car motors (really want to put my Tamiya mini4wd motors in this thing). No luck :(

But, the good news: They have aluminum tubing, and it's about the same diameter of the engines (half inch)! Foot long tubing, and only $2.75 per tube. I am so lucky :)

Well, they're fairly new (been out 2-3 months). This is a website you can get them from: http://www.discountrocketry.com/prod.itml/icOid/790

But can also get them from eHobbies.com, as well as other sites, but I can't think of them off the top of my head.

(BTW, discountrocketry.com can be trusted, a few of my friends have ordered from there)

Actually, you may want to get it at eHobbies, because they are in California near you. I'll look for the exact link and post it in this thread.

http://www.ehobbies.com/rk-est-1505.html

They're out of stock right now, but they have a better price and you'd get it faster since they are in California too

OMG lol, the description says A10-PT, but the pic shows 1/2A3-2T

Good news everyone! Well, for me at least. I went down to my local Walmart, and started browsing in my usual areas. I noticed the new Estes Rocket cars, and found that they also sell the rocket engines for the rocket cars, and they happen to use A10-PT's! This is great. 4 for $5. I bought a pack, and some purple paint (highlight my xmod :D ). Too bad I just ruined my BCG's PCB and my Xmods PCB as well :( It will be awhile until I get to test anything, but in the meantime, who says I can't make this car rocket-powered independently:D

am i the only one who sees how stupid this is? not to be mean but its not a good idea. first of all the bit charge cars pcb has a very limited range compared to the xmod so you would have to be close to your car. second you would have to have both rocket tubes comming out the middle because they would want to turn the car if they were on the sides. third the heat would probably melt the tubing or your PLASTIC car.

something about a flaming xmod makes me wanna say woo hooo

I'm planning to hook up all the four AAA cells (in parallel) to a cheap BCG clone's PCB, and then hook it up to the antenna on my xmod. For the controller, I will be using 3-4 cells as well as a telescoping antenna (If I don't use a clone with a telescoping antenna0. This should help to increase range, and if it doesn't extend it all that far, I'm only going to be using the boosters on a drag race, and I'll be standing like halfway between start and finish, which means I'll be plenty close when I ignite:D

I plan to have both the rocket tubes on either side of the car, and ignite them at the same time by hooking up the igniters in parallel (Yes, I realized the thrust-steer after thinking about how I would like one boost after the other.

As for the tubing, I will be using aluminum, and the exhaust gases should be diverted out the tubes so no heat build up will melt it. I will be sure to extend the tubing past the rear bumper so no hot gases will ever even touch the car. And hey, if it doesn't work, it's all in good fun;)

well its your car but if i were you i would make sure that the tubing can stand the heat. one way to do this would be to take a piece of it and ignight the rocket and point it right at the tube.

a bit char-g can have just the same range of an Xmod, all you have to do is put a longer antenna on it. I've stripped the top of my antenna on my BCG once, and I attached some thin-gauge copper wire (about 12"-14" of it) to it to experiment with range. I could control it from my room in the 2nd story of my house all the way to the basement...

OK, I'm just sitting here thinking again. Sawhit4, you are wrong about having the rockets side-by-side in the middle of the car b/c THAT is what would cause a spinout/Major Catastrophe (even a small wrong measurement would kill the car that way). However, EETOI is wrong about the aluminum tubing. Aluminum has an extremely low melting point (lower than the rockets will put out) so steel tubing with plenty of heatsink-fins (just like in the motor pack) would be much less likely to melt. Eetoi, you are on the right track about having the exhaust stick out a bit from the car, as well as having the rockets on the outer edges of the car. Hrrmmm..... Phsyics! :o Like I said in my last post, having the exhaust tubes pointed slightly upward (say 3 - 5 degrees above horizontal) would greatly help keep the car ON the ground, rather than OVER the ground (aka in the air). Having the exhaust perfectly level would cause the car to be the highest flying XMod ever if you hit a bump, or the most smashed up XMod ever if you hit a big enough "pothole". You would have to do lots of measuring to make sure that the exhaust is pointed exactly parallel to the line of the car, and that they are pointed upwards the exact same amount. All of this technical "garbage" will help you keep your XMod in a fully funtional (well, semi-functional since you already blew the PCB) condition. If you really don't want to do all this, slap on some motors, stick some exhuast tubes on the end, and blow that lil XMod apart ;) Haha... The best "experiment-not-measure" method would be to construct some time of "Faux" XMod ... something the same size, shape, and weight as an XMod, but made out of .... maybe metal for durability, or cardboard for cheapness, with weights added inside to mimick the XMod as closely as possible. I personally would go w/ full Metal chassis/body (unibody, perhaps?) with some lil model wheels or something attached to it for movement purposes. Now for Q&A/FAQ: Q)"Are you some technical genius or something?" A) "Yes. I have a very technical mind, which sometimes gets me into 'trouble' or 'hot water' because I tend to over-analyze and over-engineer things." Q) "Will you please stop posting your analyzations and engineering designs in this Forum?" A) "No, I'm afraid I cannot stop. If I do, I will not know what to do with what little spare time I have (between 2 jobs and Nite Classes for College), and fear that my mind may explode." Q&A/FAQ is now over, Thank You. BTW: Sorry for rambling on sooo long here, but it seems like Eetoi doesn't want his XMod to disentegrate, so I am just posting my related knowledge on the subject to help guide him along and give him ideas.

Come to think of it, I just came up for a great way to have the rockets in the center (for mass-centralization ... primarily a motorcycle thing) with the control of outer-mounted rockets, if you have time and skills. Think of a car exhaust system: (In a TRUE dual exhaust) It comes from a center-mounted engine, H-Pipes or X-Pipes together for equalization and keeping back-pressure the same, and then (typically) exits on opposite sides of the car (driver- and passenger-sides). ... How this system relates to the Rocket-Powered XMod idea ....

Have the rockets mounted together, they blow into an "exhaust system" (best to have a single cylinder surrounding them, preventing back-flow into the car)... The Collector shown below will help ensure equal pressure coming out of the dual exhaust (absolutely necessary if you want the XMod to live a healthy, long life). Here's a rough design to start your brain-gears:

EDIT: Removed due to errors of sorts with text, see image below instead. I made two different designs, mix & match as you wish. ;)

Just another nice, complicated method for you to ponder over ;)
EDIT: I just posted this, and the design came out all messed up, so I redid it as a JPG in Paint

Here's the JPG image for all y'all

well this is dangerous, insane and will mostly end with a broken xmod I LOVE IT.. just throwing out ideas but rather than addidng more wieght to your xmod (pcb, alothough not alot its stil added) you could wire the rockets to the motors brake function (not sure how) or seeing how this a soely drag racer, you could wire rockets to the seating control.. just make sure you lock the wheels up good.

and like many i wanna see a video of this, lol the look of your drag opponent's face should be priceless!

I AM INTO ROCKETS AND U NEED TO CONNECT WIRES TOTHE IGNITER ITS NOT REMOTE CONTROL.but on the other hand u could make it remote control if ur that smart.or buy a pack of ten remote control premade igniters that will drop you wallet around
50$$$$

but that would be sooooooo cool

o yeah dont blame me if im wrong im only 12 but im not stupid

Can you guys explain to me again why you would want the exauasts on either side, instead of in the middle?

I've had quite a bit of physics , and an adolescence and a half of blowing stuff up, and I would say to mount the exaust in the middle of the rear of the car. A slight misalignment of the motors will not cause any forces that you will be able to notice (They are pretty wieny motors on a pretty heavy car) I would also not fear the engines causing the car to fly. Your primary concern should be one engine lighting and one not. If this happens with your exausts far apart, the car will be much more likely to lose control. If only one fires and your outlets are close together, you will only notice a small pull, if anything.

I would also SERIOUSLY reccomend against using a X pipe or a H pipe to connect the two engines. This will only cause turbulence and heat, and ruin the performance of the engines. (sure it would equlize pressure, but it would slow exit velocity, and thats what a rocket is all about)

....hmmm, about that. It just dawned on me that if you are running the "exaust" thru a pipe system with bends in it that is larger than the smallest part of the nozzle on the engine, (I'm assuming your pipes were going to be as big as the enigne) then the gasses may just expand and slow in the first bend, and all you'll get from the exaust is some smoke and no power.

....man I keep thinking of more stuff... Have you noticed if you use a model rocket launching platform with a metal blast pad how the motors leave a scorch mark through the metal plate (can see it on both sides)? Make sure your piping can handle that kind of abuse

Good Luck! This can work :D

yeah i dont really get why you would want them on the side. if you put the on both sides then you will have to ignight both rockets at the same time so it doesnt push you to one side of the street or whatever you run it on. if they are in the middle you still need to hit them both at the same time but it wont make that much of a difference if you half a second off. or even better you would mount one of top of the other and then hit one and then hit the other. and i dont even see what the tubes are for why not just most the rockets on the back of the car. the tubes are just gonna slow you down and then might not work right (im gonna test this with my torch in a few minutes so i might be wrong.) anyway im only 13 and have never had a physics class but that doesnt mean im ignorant about things like this. as for remote ignighters heres how.........the ignighter is a switch right? that sends an electrical charge the the rocket motor. so you hook up a servo to a switch and hook the switch to the motors and a battery. you can check this out at http://www.geocities.com/cheeta_rc/index.html thats what i think you should do with the motors at the back of the car but not under it like he did

The reason for side exhausts is to keep the car straight (think of Pontiac's old slogan .... "Wider is better"). You would have to make sure that the bends are not too big, I hadn't thought of that part before. As for Xmods"man" (at 12 you say????) you can remotely ignite the rockets w/o buying expensive pre-mades. You simply hook up the igniter to an RX (receiver) board which is activated by the TX (transmitter) board through RF (radio frequency ... what the XMods and most other R/C's use). To Sawhit, I have no idea why you would have a servo hooked up to the system, a servo is a motor. All that needs to be done is hook up the igniter to some type of PCB/Board that would control when it fires. I'm thinking some type of Hi/Lo system by hooking it up to the headlight circuit maybe??

Basically, you would hook up the positive from the Headlights to the base of a NPN (Negative, Positive, Negative) transistor. For the NPN transistor, the wiring would (I think) be as follows:

Base (middle lead of NPN) would be hooked up-to the Positive for the headlights. Collector (first lead of NPN) would be hooked up DIRECTLY to the negative of the battery pack. Emitter (last lead of NPN) would be hooked up to one lead of igniters (make sure to wire igniters in parallel for "sure-fire").

For the other portion of the igniter PCB, you would use a PNP (Positive, Negative, Positive) transistor, the wiring would be just the opposite:

Base (middle lead of PNP) would be hooked up-to the Negative for the headlights. Collector (first lead of PNP) would be hooked up DIRECTLY to the positve end of the battery pack (opposite pack from before, you want as MUCH voltage going to the igniters as possible). Emitter (last lead of PNP) would be hooked up to the other leads of igniters (again making sure to wire igniters in parallel for "sure-fire").

All of this SHOULD ignite both igniters/rockets at the same time the very second that you pull the trigger for the car to move forward OR backward!! If you notice when you drive your XMod, the headlights go bright in both directions, but the taillights only go bright when you hit the brakes. BEFORE you do this, you will want to make sure to have the design checked out by someone that has plenty experience with electronics such as this.

WARNING!!! (have to have this) If you do not have experience with making the following electronics, be EXTREMELY careful or you will likely kill/maim yourself ;) The colors at the bottom are as standard ... red = positive, black = negative; the colors at the type end (the leads of transistors) are labeled in the JPG image.

Have fun ;)

Here is the graphic for it:

well i guess you didnt look at the link i put up cuz if you did you wouldnt ask that question. i shouldnt have said i was 13 cuz people think they have to talk down to me and explain things like servos. and the only pcb i can think of that would work that would be inexpesive would be a bit and i dont think it puts out enough voltage. but who knows ill probably be wrong on this one too.


EDIT: i probably wasnt clear enough in that post. if you use a servo or magnet actuator to activate a switch you dont have to worry about the pcb not haveing enough voltage to ignight it

if you think you can get the engines to light within a split second of each other, you obviously haven't used any estes model rocket engines and electronic igniters.

I would say that they vary from instantaneous to about 5 seconds. No tellin

This is dangerous, and that's why it's cool! If this isn't exactly right, you're gonna have an intimate chat with a curb or an airplane. You should just go JATO style, and mount this baby, sans body, on top of the car. This is about as risky as me putting 17 volts in an Xmod. Most likely, it'll be a bunch of parts at the end of this, but there's a small chance of sucess. I think the best bet would be to use a CO2 rocket. The worst case scenario is that you freeze something. I got a car about half of the weight of an X to 60 mph, so it should do somewhere around 30. The best thing is that it's compact, and has no chance of exploding, unless you drilled a hole in it. You just have to figure out how to pop the canister. This would also allow for aluminum exausts or even wood ones! I think that is the solution.

I've clustered motors in some of my rockets, and if you have enough voltage/current, they light reliably within 1/4 of a second

Exaran, I have used an Estes before (note that I did not say many) .... I had a nice lil rocket, flat black, about 2.5 feet long or so, orange streamer recovery system ... me and a buddy put a C class in it on a day that had about 400' ceiling (somewhere around there, anyway ... it was 4 yearz ago!) for a Physics/Chemistry project. Well, we lit it off w/ my lil ghetto rigging (7.2 battery from LHS designed for safety igniter, except that my safety igniter POS didn't work) and, needless to say, it went way above the clouds, and when we finally saw it again (on descent) ..... it was directly above a factory roof :( :mad:

So, I have used a couple Estes before (before the above rocket we used a Class .. B I think in my buddies rocket). MicroSpeed is more than likely right about using enough voltage, though.