Funnily enough it was Fastways.

I recieved my cylinder today, the supplier was as good as her word and sent another one, and luckily this time Fastways managed to get it to me without breaking it! The supplier incidently told me that she had seen this thread, she must have googled fastways and cylinders or something!



I seem to recall PK mentioning BOC putting flow restrictors into the valves on their N2O bottles, and it seems that there is one in this CO2 bottle...



There seems to be what looks like an insert that can be removed with a 5mm hex key, and inside that there appears to be another restrictor with an orifice of <1mm that appears as though it can be removed with a flat blade screw driver. Does this look anything like the restrictors os N2O bottles?

I now need to think of something interesting to do with the CO2 in it rather than just venting it out... though i guess it would be a great way of chilling the bottle before filling it with N2O.

CO2 water rocket? im assuming its gas, not liquid

Thats them.

You can use it to test your fill valve setup..
PK

Good good, in that case it will shortly he making a one way trip to my bin.


Yeah, that's probably the best option.


Avachovy, the water rocket thing crossed my mind, but I dont have a regulator, so I would probably end up bursting more bottles than I launched!

Regulator? Go get your nails done!
Just use a real bottle!

PK

Here is one way to vent that pesky co2 cylinder. ....
http://www.youtube.com/watch?v=3cLrb7M7Mtw

.... now after watching that video ... I bet you are thinking, ... all it needs is a set of fins, a guide rail and a nice coat of paint .... am I right?

How much fun would that have been to do! The composite one looks as though it would fly quite well. I think PK has a point though, sodastream bottles with the valves removed, fins added and half filled with water would be excellent... I could see it upsetting a few people though.

Mmm, budha beer!

It looks good, but the taste is nothing special. I was a sucker for the packaging.

Things have slowed up here once again over the last couple of weeks as I had to make a second trip to the UK in as many months, but it is my intention to start wraping things up now and actually start using the thing. As I said at the beginning, it was always gonna be a fairly slow one.

Anyway, while I was back over in the UK again, I took the opportunity to purchase a few more bits that I needed for this, including some PCB making supplies (photo resist boards, developing & etching chemicals etc) so my next step is to attempt to produce a PCB for it. It should be interesting as it is something I have not done since I was at University. I will probably doccument my success/failure in the PCB thread. First thing I need to do is sort myself out with a suitable light for exposing the boards.

I'm happy to make them for you if that helps you get it built faster.

All I need is the artwork as a pdf.

CS

Thanks for the offer Craig. I'm keen to give it a go myself, as producing PCB is something I would like to get into the habit of being able to do. That said, if it turns out to be a total failure, I may take it up!

I had a go at producing the PCB today, and I have to say it was a lot easier than I remember. I had initially planned to construct a light box with UV lights for exposing photoresist boards, and then produce the board that way. But due to the simplicity of the board, I thought I would give the toner transfer method a go. If you are unfamiliar with this method, see this link: http://www.fullnet.com/~tomg/gooteepc.htm

The photo paper I used was cheap crappy stuff I bought in a $2 shop, and it worked a treat. I think the brand was called "Laser".



I printed two sheets of the PCB design, with four on each, as I figured it would probably take a few tries to get the hang of it. I just used my girlfriends iron to apply the heat and pressure required.

First attempt got very little of the toner onto the board. I was being cautious of how much pressure I was applying as I had read it could cause the toner to squidge out over the board, unfortunatly I didn't apply enough pressure to get the toner to stick to the board. I cleaned the toner off with acetone, cut another copy of the design from the sheet, and this time applied much more pressure.

I left the board soaking in water for as long as it took to walk to the bottle shop and back, and when I returned, the paper pealed off easily to reveal a perfect toner mask on the board.



I then just etched it as usual using sodium persulphate solution, and then after etching removed the toner with acetone to expose the copper.



To be honest I am stunned by how well this method worked, and the quality of the finished product. I was expecting a really scrappy board that would just about do the job.

Next step I plan to make a "piggyback" board, on which will be a solenoid saver circuit for the dump solenoid.

That's a great result Rocketstar !

Do you have a mini drill press/dremel or something for the hole drilling ?

I love the comment 'girlfriend's iron'

CS