Hybrid car... Black Phyonix

[kwik]

hi guys, im new as you could tell. im 16, from south east london, UK... (not sure how many brits are here)

anyway, im in the process of building my radio controlled hybrid powerd car...

i know what im doing, i think, its just the rocket part of it, and need some help with that, as i dont fancy dieing at 16...

im planning on modiffieing a RATTworks K240 and attaching my own NOS tank so i can control the throtal using a servo...

but firstly i odnt know how realistic it is, or what bottle to use....:confused2:

im hoping for some nice high speeds, and if i crash it, a spectacular explosion

hope you can help
chris

 

[billspad]

You might want to look at this before you find yourself reinventing the wheel.

 

[kwik]

yeah i know him, hes entering this year and i want to challenge him for next year....

what he did was design the whole rocket, wheas im keeping it simple by only doing half the rocket (the NOS tank, and leaving the hard bits for RATTworks....

so is it possible to modify the rocket so i can use my own nos tank?

 

[billspad]

yeah i know him, hes entering this year and i want to challenge him for next year....

what he did was design the whole rocket, wheas im keeping it simple by only doing half the rocket (the NOS tank, and leaving the hard bits for RATTworks....

so is it possible to modify the rocket so i can use my own nos tank?

It's possible but there's going to be some machining involved. You're not going to be able to just connect the tank to the RATT motor. You really need to know how a hybrid motor works before you start modifying anything. Trying looking at some of the stuff here.

 

[kwik]

i understand how mybrids work in general... but not specificly how the RATT works...

https://www.hawkfeather.com/rockets/hybrid_tutorial.html
i found this very usefull ^^

thanks again...

so what i should do is cut the tube behind where it flows in, then atach the valve and tank...

what material is the tank chamber bulkhead?... i might be able to drill and tap a whole so i can screw in the plumibing bits (valve and then valve to tank... this would work right?

thanks again
chris

 

[Grif Ingram]

Chris, first of all, it's great that you're interested in rockets and engineering - it makes me feel old to say it, but so few teenagers are! But I'd like to say (and it makes me feel even older to say this!) BE CAREFUL!! A device like this has the potential to cause a fair bit of damage if it comes to grief, so be careful where you test it, and design and build carefully, too! For example, a few years ago, a badly built and incompetently flown model aircraft, at the local model flying field where I used to fly rockets, smacked a young girl in the head, fatally, with the result that model flying on that site was banned. Have you flown many model rockets? Have you considered building a black-powder powered model first?
BTW, what part of South London are you in? I live in Bexley.
Grif

 

[kwik]

BTW, what part of South London are you in? I live in Bexley.
Grif

NO WAY!!! me to !!!

i live in bexleyheath inbetween nuxley village and the pantiles...

thats weird... was this plane club in theamsmead?.. anyway... back to rockets...

iv had 4 years experiance in RC... and 1 year designing and building one...

currently i have no cars and am selling up so i can build it, i understand the whole safety side of everything.. im not a normal teenager to be honest... i have a safety quallification in rock climbing, so safety is the most important thing in this project...

my friend who races motor x knows a place in essex (where he runs his bikes in) and he knows the owner well and said i can use the 1/4 mile of tarmac for testing etc...

as for building im not taking any risks, im getting the chassis lazer cut as i dont want to make the chassis unballanced... also im not letting my car be lighter than 10kg (as the rocket produces 22kg of thrust (on average) so i have control over it...

also, the rocket will be controlled (throttle) with the valve im planning to have, so i can shut off the NOS supply if i forsea danger, or if it goes out of radio range there will be a failsafe.. also im going to use braking to the wheel and a parachute (or airbrake) for after the run...

count yourself lucky im not going with my original design... that used a liquid rocket

i designd this car back in january/febuary time ( www.black-diamond-rc.blogspot.co.uk ) but my money tree stopped growing, and it only reached the design stages..

Black Phoenix (i can spell it now) is born from the failiers of the old design by simplifying everything... which means NOT designing my own rocket lol...

as for my knowlage of hybrids... i managed to design that one with a 12second burn and i think 10kg of thrust? cant remember off the top of my head.

the car side of it is easy for me.. just the rocket...

thanks
chris

 

[billspad]

so what i should do is cut the tube behind where it flows in, then atach the valve and tank...

what material is the tank chamber bulkhead?... i might be able to drill and tap a whole so i can screw in the plumibing bits (valve and then valve to tank... this would work right?

thanks again
chris

It's not quite that simple. The bulkhead is aluminum but the only thing that holds it in place is the pressure in the nitrous tank. You need something to hold it tight against the fuel grain. You also need to position your tank vertically so that only liquid goes into the motor.

 

[kwik]

It's not quite that simple. The bulkhead is aluminum but the only thing that holds it in place is the pressure in the nitrous tank. You need something to hold it tight against the fuel grain. You also need to position your tank vertically so that only liquid goes into the motor.

when i cut the tubing, i could cut about half an inch away from the bulkhead, so i can snip it and bend it over and maybe weld or braze a O ring to hold it on... would this work? iff not, i could make a piece from the chassis that is against the bulkhead (hmm... hard to explain) but i know what you mean....

as for the tank, it wont need to be vertical... theres 2 ways i could make it so it doesnt... the first being have an odd shaped tank where the nozel is right to one side (if stood on end) so when the nos is sitting in the tank, the level of it should cover the nozel (am now realising how hard it is to explain)... and once accelerating the G force will push the nos to the end of the nozel anyway...

another method (using a regular shaped tank, would be to have it at an angle of around 10-15 degrees (maybe less) so at standstill the nozel still has liquid nitrogen over it... and again once accelerating, the G force will push it towards the nozel

its 10 - 15 degrees because when you fit nos to a bike or car, thats how they have it for the same reason...

thanks
chris

p.s, sorry for my spelling, i know its awfull

 

[billspad]

when i cut the tubing, i could cut about half an inch away from the bulkhead, so i can snip it and bend it over and maybe weld or braze a O ring to hold it on... would this work? iff not, i could make a piece from the chassis that is against the bulkhead (hmm... hard to explain) but i know what you mean....

I hate to be negative but even though it could work I don't think it will. First of all the motor casing is aluminum so you won't be brazing it. Then there's the problem of sealing the fuel grain against the nozzle and bulkhead when the motors firing. The chamber pressure has got to be around 200-300 psi. If you don't have a seal that can hold that you're going to burn through the side of the casing.

as for the tank, it wont need to be vertical... theres 2 ways i could make it so it doesnt... the first being have an odd shaped tank where the nozel is right to one side (if stood on end) so when the nos is sitting in the tank, the level of it should cover the nozel (am now realising how hard it is to explain)... and once accelerating the G force will push the nos to the end of the nozel anyway...

another method (using a regular shaped tank, would be to have it at an angle of around 10-15 degrees (maybe less) so at standstill the nozel still has liquid nitrogen over it... and again once accelerating, the G force will push it towards the nozel

its 10 - 15 degrees because when you fit nos to a bike or car, thats how they have it for the same reason...

thanks
chris

p.s, sorry for my spelling, i know its awfull

I know what you're saying and again I think it could work but to do it right I think you're going to end up with a huge piece of hardware.

Take a good look at that thread on Rocketry Planet. The accumulator he built is really clever.

 

[kwik]

how about using a differnt system? like aerotech or skyripper

of is this problem for all 3? im not sure how the other 2 seystems go together...

 

[billspad]

how about using a differnt system? like aerotech or skyripper

of is this problem for all 3? im not sure how the other 2 seystems go together...

Skyripper works the same as RATT. Aerotech's hybrid is out of production. You might have a chance with Alpha or Hypertek.

 

[kwik]

the hyperteks look good....

the l200 looks like the right burn time aswell, hmm, the rockets im choosing are just getting more and more powerfull lol...

nothings set in stone yet, and it wont be until everythings in place..., so i do have the opotunity to have the chassis cut last minute if i so wish...

once iv drawn it on 3D software, it will be alot clearer for everyone... including myself...

thanks billspad for your time and knolage, its much apreciated
chris:eyepop:

 

[Grif Ingram]

Chris after asking permission from a friend of mine who has built a number of hybrids, take a lot at this:

https://www.aspirespace.org.uk/

Go to "Technical Papers", and have a look at the hybrid stuff. My friend points out that, with the tank horizontal, you will have vapour rather than liquid getting into the motor, which may cause "chugging". Hope all this helps!
Grif

 

[kwik]

thanks grif!!

though as i wrote in my previouse thread, i will have it at an angle, so the liquid will be where the nozzel is... this method is used in nitros boosters in cars or bikes so its nice and proven...

ill have a read though the site when i have time, thaks for the info grif
chris

 

[kwik]

i little update...

ebay auction will end in a few hours (so ill edit this post if i win it)
this will be probebly the hardest part if i cant get this car off ebay, as there so rare, and iv only ever seen 2 in the world

also, i have solidworks trial again for 90 days, so when im on my pc, im designing until i lose it again i took 5 minutes to show you the concept and what i mean...

the first one shows the angle im going to have on it (guestimate) so only liquid nos goes into the combustion chamber...

the size of the 2 rocket componants arnt to scale (as i used these 2 parts in my old design) and thats why theres no real work in fixing them or anything..

there only there to show you the layout... however, the length of the blue chassis is to scale (1500mm long) (4mm thick) alluminium, and where the arms come out to fix to the wheels will be around that size (IF i get this ebay item)

thanks
chris