The Vault Regulars

Monday, June 6, 2011

Primus Express Spider modification

The Primus Express Spider is an excellent stove and especially so in colder weather. If i use gas in place of Meths then this is the stove i choose.
One of the 2 problems it has is that it is a little unbalanced on it’s legs. Unfortunately the designers decided for some reason not to put a supporting leg adjacent to where the tipping point is. That point is where the small bore rigid gas tube connects to the main body.

The other issue to be overcome is that the regulator is on top of the valve body which makes inverting the gas cylinder difficult.

I have now modified the stove to overcome the instability. I looked at taking the legs assembly apart and repositioning the stops but decided that would be too big a job.
It was far easier just to add an extra stabilising leg under the body but ensuring that it didn’t interfere with the folding of the legs for packing away or the subsequent storing in my pan and looked half decent.

Below are some photo’s of the simple job.

The leg started out life as a lightweight alloy tent peg. It had seen better days so after a bit of flattening, bending and cutting to length it was ideal to use it here. It was fixed to the body support with heat resistant Araldite.
Cost of mod, miniscule.
Time to do, about 30 minutes.

Could save you a lost pan of water or worse.
Cylinder inversion to follow.
Hope this helps.


markswalkingblog said...

Alan, I can see why you were/are an engineer, I would have never thought to redesign that way. Look forward to next post- I have a Spider and I hope you have come up with a mod that is easy to carry out!!

Mac E said...

Very neat Alan, look forward to seeing the regulator modification.

Unknown said...

Lovely neat mod! Looks like a big improvement for comparatively little effort and little weight.

AlanR said...

Hi Richard,
The regulator on this stove is excellent so i will try and come up with something lightweight which will allow inverting without changing it. Here’s hoping.

Hi Dave, Thanks, The extra weight is hardly worth a mention. The job it does is important in my book.

John J said...

Hi Alan,

A very neat mod!

I'm particularly interested in the heat-resistant Araldite (for another project), could you let me have details / source etc.



AlanR said...

Hi John,
I used this Araldite rapid which is heat resistant. I tested it on full power, with a heat shield for 7 minutes and it works fine in this situation. Have a look at the link here. Although its common to buy anywhere.

Its quite difficult to get something easy for above 140 deg C.
maybe this might help if you require higher temp rating..

JerungKampungJaya said...

wher to by this?

AlanR said...

What is it that you want to buy exactly?

Unknown said...

I have just used this stove over the weekend, and what a great stove it is too.
Now I have a question, if anyone can help me with please.
Once a light can I turn the gas cylinder upside down ?
On the user's sheet it says not to twist the tube.
So I am now wondering. ..
If any knows as too why I can't or advise not too or. .?
With thanks

AlanR said...

Hi Paul,
I have used it inverted without any probs. It does have a pre-heat tube and so the heat will vapourise the liquid gas.

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