/sci/ - Science & Math

Chain is length 'L'

1 hour is L/12 or L/24

RPM + radius of driving gear determine linear / angular velocity.

Simple

http://www.youtube.com/watch?v=uDpbFsfOFnk

>>4184596

Can we fit a reindeer tracking device so we're ready for next christmas?

Christmas is getting in the way of progress

>>4182362
Don't need a parachute for space

http://home.total.net/~launch/

Can buy plans for a liquid rocket motor for $21.95

Think they're worth it?

Gasoline

>practically finished budget for the week on christmas
>fuck

>>4181477


But srsly, a cone to survive leaving the atmosphere isn't a problem compared to everything else. It doesn't have to survive re-entry

>>4181414
>implying fucks given

>>4181414 What are you going to put on the front of it so it doesn't burn up leaving the atmosphere?

A condom

>>4180758
>>4180935

Lol, both sections aren't going to be fired at the same time. End one fires then drops off as the next one fires.

>>4180758
What if I'm certified to ASME standards for high pressure vessels?

>stabilize it and steer it into space
Create a closed loop feedback system featuring tilt sensors to automatically correct the actuators on the gimballed nozzle system (note that a gimballed system is also much easier with liquid!). In this system, program basic goals and expected parameters then hope it goes where you want.

Launch it over the ocean...

Can anyone get access to the NASA files on space technology? They only permit access to some stuff to official researchers

>>4180308 Sourcing resources

I can stock up on several ton of oxygen and propane much much easier than miscellaneous banned chemical powders

>>4180308 Not easier and not safer... this is pretty much building a small missle.

lol, because packing 100 tubes with solid propellant isn't a small missile either. Controlling the direction is a problem faced with both type of rocket, at least with a liquid rocket you have the option of adding an emergency stop to shut off the fuel.

>>4180315
What? Don't remove it yet. It will die when it dies. There is more progress to come!!!!

You are an absolute fuck if you remove it just for the sake of removing it.

>>4179615
Can anyone point me towards information about the compression of unconventional (not air) gases? Suppliers + info on pumps or generally everything to do with handling flammable gas.

I'm thinking retrofitting an air compressor setup will be sufficient but I'm also thinking the standard seals and ratios may not be up to the task of different gases.

Old refrigerator motors sound like they might be up to the task but right now I'm a little clueless

Was just thinking there that it's actually probably way easier and safer to just make a liquid engine. The entire rocket should be a LOT lighter than a bunch of tubes and the fuel will be way easier and cheaper to get. I can weld large tanks for oxygen and propane easily then just fill them with a few / whatever bottles. The plumbing and pumping will need to be housed in a section purged with nitrogen/argon/co2 and will need a reservoir for compressed gases.

Shit this is a way better idea.

An oxygen tank will be coming sometime after the christmas break following (hopefully) successful tests of a hybrid molded KNO3/Sugar motor using compressed air. Need to pick up a one way valve and a couple of other fittings before the motor can be tested

>>4178392

No where did I suggest this was at all safe but it's not impossible and there are a myriad of steps that can be taken to significantly reduce the risk.

>>4178074 It would require more than an infinite amount of energy...

You don't know what you're talking about

>>4176124
The chlorate will only be in contact with the steel immediately prior to launch. Liners will be used and all tubes will be etched and packaged before fueling. If Al proves to be beneficial to the motor characteristics the fuel will not be mixed to be stored for any length of time, investing in using perchlorates for a metal mix is considered. Stainless steel, aluminium or possibly some form of composite tubes will be considered too.

>>4177995
>implying longitudinal stresses aren't half of circumferential and can't be ignored

What's worse is I haven't even considered the inevitable heating of the walls. They're rough estimates for now and I'll be hiding in a makeshift bunker far away from the launch pad.

I think about 30 steel chlorate tubes for main engines with just as many KNO3 cardboard tubes will suffice to reach space.

Having so many separate engines will take refinement to reduce the weight and dissipate the heat if they're arranged in a crowded way.

:D

For 1m steel tube with an I.D of 60mm and wall thickness of 1.875mm

Mass = 2879.34 grams

Volume = 2827.433 cubic centimeters

Total fuel mass (ignoring core) = ~3541.36 grams

Assuming 10mm dia core = ~2513.3 grams fuel

Total mass = 6420.7 grams (Using no core but assuming this to cover nozzle and bits)

Approx density of pressed KClO3/Icing sugar fuel =

Weight / Vol
8.5g / pi*(0.6cm²) * 6cm

1.2525 g/cm³

http://www.nakka-rocketry.net/kdx002f.html
>To measure chamber pressure, the motor bulkhead was tapped with a pressure fitting which was connected to a 4" 0-2000 psi gauge. To prevent damage to the gauge by hot combustion gases, the connecting line was filled with oil (SAE 30).

Well shit this isn't a bad idea. The hydraulic load cell couldn't be simpler and connecting the pressure gauge with a hose filled with oil is genius.

His motor hits a max pressure of 1200psi so I'm going to say tripling that figure won't be a bad start to design around.

3600psi = ~25MPa

For a 60mm mild steel cylinder with a yield strength of 400MPa the wall thickness should be approx 1.875mm

2 wall thickness = pressure * diameter / yield stress

Also, I need ideas for getting estimates of the chamber pressure.

Once I get an idea of pressures involved I can finally make a start on doing some calculations for selecting the appropriate materials and wall thicknesses for the body instead of being way OTT.