Phun Rocket



Phun is a physics sandbox game where you can assemble objects and machines to see how they work in a perfect world. a simple project is a rocket.

Step 1: Wall

the first and most important step is the walls. it is important to note that the thickness of the walls will determine the likelihood of a fuel leak.
it is possible to decrease the mass of the walls to increase the height it travels, but this also destabilizes the trajectory. this can be done by entering options>geometry and then moving the slider marked as density.

Step 2: Cap

now any one know what went wrong there?
that's right the rocket didn't have anything holding it together. nor did it have any thing to direct the fuel downwards.
so we need to make a cap. the same rules about density and size apply to this that do to the walls.
next the cap must match the with of the walls exactly, and be perfectly centered. (this is more important the higher you go.)
we need to attach this to the walls using the fixate tool.

Step 3: Fuel

fuel is the first real choice of the designer. there are three main schools of thought on fuels.
1st is liquid pressure fuels.
2nt is solid object spring fuels.
3rd is solid object pressure fuels.

liquid rockets are arguably the easiest to fuel. all that is needed is to make several objects inside the rocket and liquefy them in options>geometry.

spring rockets work by attaching springs to the walls of the rocket and to the fuels objects. by decreasing the target length the object will be forced out faster.
the last is the one I shall demonstrate. solid object fuels provide some interesting options. first is shape. wile the majority are circular rectangular has its advantages to. with rectangular fuel it is possible to direct 100% of the pressure downwards because the overlapping objects try to separate as quickly as possible. IE the rectangles go towards the long side.
for this instuctable I'll be using circles or ball depending on you preference.
now the fueling process can be long or short depending on how you do it. the longest way is to make hundreds of shapes with one of the tools. I don't recommend this. not only do you get inconsistent thrust but it takes forever. next is to clone one object. this still takes a wile but is more reliable than drawing. next is copy paist. this is fairly quick and reliable. the last is to use a chain with low breaking strength. this last one I like the most. it is the fastest solid ball option and can be duplicated easily.

Step 4: Pressure Equilazation.

odds are if you build the rocket from the previous step it went a little wanky. and that's because the fuel wasn't evenly distributed. so how do you fix this. you let the fuel settle. "but won't it just shoot out the end" you ask. yes unless you cork it. and then in the options menu you set the destruction key for the cork.
hit the key and watch it fly.



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    14 Discussions


    10 years ago

    Hello, and welcome to the Instructables community! It's great that you've decided to tell the world about something you've made by publishing an Instructable. We just wanted to let you know that your project still needs a little more work if you want it to be well received on Instructables. Projects that don't include certain basic elements tend not to get the attention that they deserve, and so we'd love for you to check out the list below of what makes a successful Instructable. Successful projects on Instructables include: - clearly written details of a finished project with instruction - as many steps as are necessary to explain your project - clear images that you took of your project for most, if not all of your steps - an intro image - proper spelling and grammar - appropriate cautions or safety considerations I'll give you another opportunity to make any final changes to your project before we publish it. Once you're all set to go, please republish your project and send me a quick comment letting me know that you've made some changes. I'll give it a quick final check to make sure you're on the right path, and then remove this note. Thanks for your submission and we hope to see your project published soon!

    3 replies

    Reply 10 years ago on Introduction

    still a work in progress but I don't have the time to finish right now. bu 85% there.


    Reply 10 years ago on Introduction

    Interesting,you replied to admin with this comment and it shows under me.


    Reply 10 years ago on Introduction

    yes I could but then people would copy that and not make their own.


    Reply 10 years ago on Introduction

    nozzles tend to clog and or require smaller fuel. I have seen some people using nozzle for searing, but for the pressure it seems to be a little bit of improvement for a lot of work getting it buttoned down.


    10 years ago on Introduction

    I like to see peoplae making these Phun-ibles, I think Ill make one, nice instructable:)


    10 years ago on Introduction

    Thanks.Very nice intructable.What I did after doing the rocket,I made another,rotated it and fixed it to a car.Jet powered car!