The Vault Regulars

Wednesday, June 8, 2011

Lightweight gas cylinder inverter.

Following my modification on the Primus Express Spider support leg, i wanted to make inverting the remote gas cylinder better than just having the cylinder roll around on the valve head.
Today is a perfect day to have a go because the weather is appalling.

 I could of course go the whole hog and replace the existing valve for a flat head type with side regulator but that costs money and time and also you take a chance with your purchase that it will not be as good at regulating the gas flow as the original.

 So i decided the most cost effective method was to make a stand which would support the cylinder in the upright position and would allow easy use of the original regulator turn screw.

Do i make it out of aluminium or plastic or should i try and make it from wire?
All these thoughts were going through my mind about ease of manufacture, cheap, durable, simple to make, replaceable etc, etc.

I was holding the gas cylinder, the 125gr./225ml Go System and with it i had the Primus windshield that i used with the Optimus Crux last year.
I fitted the regulator from the Spider stove to the cylinder and then i fitted the Primus windshield. Once inverted it stood up quite well apart from the fact that i thought i could get it lighter and even more stable.

So this is where the impetus came from in coming up with this scenario below.

If you are like me, i tend to assess plastic food containers before throwing them in the bin because they are light weight and can be used for all sorts of ideas for backpacking, from bowls, cups, cereal storage and much more. (Sad really, i know).

Looking at the shape of the windshield and checking my pots i came across an old Prince’s hot pot container which is very similar shape.
(photo borrowed from Bob at Backpackinglight) hope he doesn’t mind.

The Weight of the Primus windshield is 60gr (Bob’s figure), and a nice piece of kit too. 

The weight of the Hot pot less the lid, wrapping, and contents obviously, is 31gr.

What i liked about the Hot pot, and a real benefit is that it has an alloy rim which gives good strength and stability.
I set about giving access to the interior and also the hole for the Cylinder lip. The side access holes are 60mm diameter and the hole in the base is 33mm.  They were cut using a hole saw.
The alloy rim also helped in maintaining the shape of the pot when putting the side holes in.

I had to slightly open out the small hole to make fitting the cylinder and removing it easy, but it was no more than 0.5mm and it’s now a slight interference fit which makes it self supporting.

Fitting the stove valve was no problem and it stood up very well.
Inverted cylinder in situ.

 Weight of finished inverter is 16gr. 
There is scope to get it a few grams lighter if you must, but for me i am pleased with the result.
It’s strong and stable.
 The pot is a perfect size to store the 125gr/225ml cylinder in.
It then fits neatly into my cup.
Which then fits neatly into my bowl. (I use a bowl for cereals, i know others don’t)

Well that’s about it, easy to make, does the job, takes up hardly any room and uses re-cycled parts so there is no cost. 
I’m pleased with the result. I hope you like it.
Thanks for reading.


  1. Clever chap simple design and even I could make that for my Spider!!

  2. Hi Mark,
    Anybody can make it. No excuses.
    Simple things are sometimes the best. Well so Sheila says! Ha.

    An everyday item and the original contents are not too bad either.

  3. Excellent MYOG! Love it. When winter sets in, I'll give it a go. Please - tell me you didn't eat the food within?? Alan, you need to come to Surrey for a BBQ if you enjoyed that stuff ;-)

  4. Hi Maz,
    It’s been like winter up here. Torrential rain and not fit to go out.
    Definitely a time for MYOG at the moment.
    Obviously we tried a couple of these and to be fair they are tasty but way too sweet for us. They must be loaded with sugar.
    We never bought them again.
    The pots are good. You can always bin the contents as they are cheap.
    You know i have never been to Surrey but thats where my family originated from pre Napoleonic war days.
    I must have a look which village we came from.
    Glad you liked my little idea though.

  5. That's excellent stuff. Are those pots aluminium? If so why not make one to go round the burner as a windshield ? i'm into caldera cones but I might try to make a wind shield, now you've inspired me,for my old Vargo gas stove.

  6. Hi Greg,
    Thanks for the comment.
    The pots are plastic.
    The spider is quite a difficult burner to make a windshield for that locates onto the stove like the Primus one in photo 2.
    I have had a couple of attempts but have not been happy with them. If i achieve something reasonable i will post it, but it probably won't be any time soon.
    I have been pleased with my MYOG cones they work well. The Caldera is a good system. Have you seen the Littlbug junior stove, it looks very interesting.

  7. Ingenious! What a clever chap.

  8. Cheers Robin,
    Its good when a MYOG idea works well. I'm very pleased with this one.(and the stove leg)


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