I won't go into the great science of it but basically
A Rubens tube slows you to view a wave form using flames. This is done by a speaker driving a diaphragm to push the air for the tube.
In this Build we used 3 inch steel tube sealed one end of the steel pipe by welding steel plate on and ground off flush
Then a whoopy cushion Cut in half as a diaphragm.
The diaphragm can be made from anything we chose a strong latex material. stretched it round the end of the pipe and fastened it on with some gorilla tape or tough gaffer tape. We would have used a large Jubilee clip but we didn't have one
The steel tube is about 4 foot long and we drilled a 0.8 mm hole using a pillar drill about 40 mm apart leaving 100mm at the diaphragm end.
We then drilled a hole in the centre of the pipe for the gas feed and taped it allowing us to screw in the standard gas hose fitting see pictures!
And that's about it your done all that's left is to take any speaker we tried a surround sound sub but didn't work as well as hoped so tried a tiny surround sound front speaker and got much better results.
Bigger isn't always better.
Connect your gas hose using a jubilee clip on the hose fitting
Play some music and light the tube then have a play positioning the speaker and adjusting gas flow till your happy with the result.
DONT RUN IT WITH NO MUSIC IT WILL BURN YOUR DIAPHRAGM OUT
Please note for safety reasons I'm am not held responsible for any injuries. That said it is a very simple build and much like connecting a gas bbq.
Step 1: Short Video
as i used the tube for a patio heater at party's i played dance rock and pop through it but you will get a much more defined wave form with a tone generator easy to find on google and youtube