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My fascination with bushwalking stoves has driven me to what is possibly a first for a hobby stovie, I have made myself a stove flame profiler which can do 1D and 2 D profiles of a backpacking stove flame.

Flame profiler rig

I have been planning this flame profiler for a few years now and I have been collecting bits and pieces since, I started to build the profiler about a 18 months ago but due to distractions the development stalled several times, the profiler project is still in its early days and as I am learning from it, I still have some development and improvements to do.

I wish to thank my friends Tony, Mike, Andrew and Mark (sadly no longer with us) for their help, but I would specially like to thank Peter for his top level programming skills, without the help and equipment gifts from these highly skilled people this flame profiler project would have never been possible.

The Flame profiler is an X-Y traversing system that can move a heat exchanger with a high temperature thermocouple temperature probe in the middle of the heat exchanger, the temperature data can be logged and recorded for analyzing with a 2D or 3D graphing program.

Heat exchanger

Details

The heart of the system is the X-Y traversing system, the traverser was started with being given some stepper motors and part from an old plotter which has about 600 mm travel, this has become the Y traversing system, it is driven by wire rope wrapped around a pulley and the propulsion is by a stepper motor. The X traversing system is made from an old linear bearing rail, for the X system I have made my own wire rope propulsion system, it is also driven by a stepper motor, the X system still needs some development but works OK for now.

Heat exchanger

The heat exchanger is made from an old saucepan which has a base diameter of 206mm, the base is 6mm thick and the temperature probe is located in the middle, the heat exchanger is filled with water which is conditioned with water pumped through some copper tubing which is coiled inside, conditioned water is pumped through the copper coil. I made the current heat exchanger system as a trial system as I was not sure what was needed and while this heat exchanger system while it works quite well, for some alcohol stoves the 206mm diameter is a bit small and the water conditioning system is a bit crude. I am planning a larger heat exchanger of around 400mm diameter with a direct flow through of the conditioning water but I am surprised how well the copper coil system works so I will doing some more thinking on the new heat exchanger design.

Stove platform

At the moment the stoves being tested sit on very crude adjustable height platform, the base of this system sits on an old computer case and an old car jack which gives me the ability of an easily adjustable height, while for now the system works, improvements to this setup will be high on my priorities to improve.

Temperature probe and signal conditioning

The temperature probe is home made from a K type thermocouple, the thermocouple wire is threaded through a piece of ceramic tube with two holes through it.

The thermocouple signal is conditioned through a modified Jaycar Electronics high temperature thermocouple kit, this kit converts the very small thermocouple voltage into a voltage that can be read by the data acquisition system, at the moment the maximum temp that I can read is 1043 degrees C.  I am not that happy with the thermocouples response time, I am going to try and improve this by making my own thermocouple with a smaller tip.

The conditioned data signal is then input into a National Instruments USB-6008, 12-Bit, 10 kS/s Low-Cost Multifunction DAQ A-D board, the voltage signal is then converted into temperature degrees ºC with a program written with Labview 7.

The Stepper motors are also controlled with a program written with labview through the parallel port, the profiler control program and data logging program are linked to the same timing.

The tests that I have done so far have been 1D and 2 D profiles, with the 1D profiles I ran the probe at 1mm per second and logged 1 sample every second

The 2D profiles, I ran the probe over in a matrix of 5mm x 5mm in a 100mm x 100mm square, the data was graphed in 3D using Mathmatica, I am new to this program and need do some more learning to make the graphs look better.

Why have I made a flame profiler? I am interested in understanding stove design and I think the profiler will help in this endeavor.

Some result so far

Below is a 2D graph of  a 1D pass over a JetBoil stove with the probe protruding 4mm, 2mm and the tip flush with the bottom of the heat exchanger, note the large difference in temperatures.

profile of Jetboil stove with different tip protrusion lenghts

Below is a 3D graph of the flame pattern of a JetBoil stove, what confused me here is the high and low temperature pattern in a cross, after some thought I pulled the burner head apart and as can be seen from the photo below the baffle inside has four support legs, even though the legs are relatively small it can be seen from the graph they have a reasonable large influence on the flame pattern.

JetBoil flame pattern

I still have to fully understand what is going on with the information that the profiler is giving me, but I hope that will come. I will post more results for different stoves on my blog soon.

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My new multi use sleep system arrived yesterday, it consists of a Western Mountaineering Summerlite sleeping bag, a Western Mountaineering Down Hooded Flash Jacket and a pair of Western mountaineering Flash Down Pants. The bag and clothes appear to manufactured to a high quality.

The idea of the down jacket and pants is to use the down clothing around camp and then on cold nights be able to wear the clothing inside the sleeping bag to increase the rating of the sleeping bag.

Western Mountaineering Sleeping bag

The Sleeping bag in storage bag weighs in at 600.9g, without the storage bag 574.4g, the manufacturers average weight for the 180cm Summerlite is stated at 525g. this sleeping bag is rated at 0ºC and is filled with 275g of 850+ rated loft down, the bag is made in the US.

Down Jacket Western Mountaineering Down Hooded Flash Jacket

The Down Hooded Flash Jacket weighs in at 310.2g, there was no storage bag and the manufacturers average weight is stated at 311.8g, the jacket is filled with 85g of 850+ rated loft down, the jacket is made in Canada.

Down Pants Western Mountaineering Flash Down pants

The Western Mountaineering Flash Down pants weigh in at 214.5g, the also was no storage bag, the manufacturers average is stated at 180g, the pants are filled 57g of 850 +loft  down and the pants are made in Canada

Total weight 1125.6 g

The manufacturers average stated weights add up to 1016.8g which is 108.8g lighter than actually measured, as a lightweight gear freak I am a bit disappointed by the amount (10%) of the difference.

I am planning to use the sleeping bag and down clothing on a trip up Hannels Spur to the Main Range in Australian Alps at the end of November.

I would like to add that I purchased my Western Mountaineering gear from Backcountry gear The service that I recieved form this company was first class and I thought it was worth a metion.

The Castle

The Castle walk inthe Budawangs National Park, New South Wales, in my opinion it is one of the best day walks around, it has just about every thing that one could want in a walk with some climbing, some scrambling through a cave, walking along a narrow ledge with a big drop and brilliant views, the day we did the Castle we had a clear sky and there was not a breath of wind

Start of the climbing

some more climbing

The view from the Castle, Pidgeon House Mountain in the distanceThe view from the Castle is one of the best around, the peak in the distance is Pidgeon House Mountain and recieved this name from Captain Cook in 1770, the walk up Pidgeon House is an interesting walk also.

With a bit of rope

 A few meters behind me we had to walk over a ledge with a slope on it, with no hand grips and a very large drop, it was quite scary for a non climber.

Aluminium cooking pots vs Titanium cooking pots .

Five years ago when I first started to get into lightweight bushwalking I replaced my super heavy MSR Alpine Stainless Steel pots (741.5g) with a two lighter Titanium Snow Peak pots (316.7g), this was a saving of 424.8g, after several years of faithful use, on one trip I wanted to cook a gourmet meal where I needed some slightly larger pots. I therefore went through my collection of pots, carefully weighing each one to work out which combination of two pots gave me the volume that I needed with the lightest combination, the combination that I ended up with was two cheap aluminium pots which I had purchased from my local camping shop. While the Ti pots are very tough, Ti is a very poor conductor of heat and whenever I tried to reheat a meal like a curry the food got burnt where the stove flame had contact with the bottom of the pot and was very hard to clean. After using the cheap Al pots I have never gone back to the Ti as the food does not burn in the Al pots and after several years of use the Al pots are still in good condition.

 Moving on a couple of years, to complete a series of tests on pots for a BPL article, I borrowed a set of lightweight MSR Titan pots, this kit includes pots of 1l and 1.5l volume, this set retails in Australia for A$189. The two MSR Titan pots came with one lid with a total weight of 306.6 grams, this includes the pot grabber or the storage bag.

My two cheap Al pots that I normally take use, a 1.5l pot and a 1.75l pot with one lid come to total weight of 243.6 grams, and have a cost of A$24.00 (these pots have had the wire handle removed and some of the lugs that the wire handle attached to removed).

If I use some Al pots with the same volume as the Titan pots a 1l pot and a 1.5l pot with one lid the total weight is 219.6 grams, this is a saving of over 30 grams just for the pots, the two Al pots with pot grabber and storage bag from the Snow peak Ti pots, the saving is even greater at 255.2g this is a saving of 51.4 g over the 306.6g Titan pot set, the 1l pot cost A$8 and the 1.5l pot costs A$10 so this twp pot set comes to A$18 .

Now are Ti pots more efficient than Al pots, from my tests Ti pots appear to be slightly more efficient that Al pots but this is very small. As Ti is a much poorer conductor than Al, why are Ti pots not less efficient than Al pots, I am not quite sure but I do have some thoughts and it has something to do with the emissivity of the pot surfaces, the Ti pots have a darker and slightly rougher surface than the Aluminum pots.

With my Al pots, instead of the wire handles which I have removed I use a lightened pot gripper that I purchased from the same shop as the pots, gripper cost the A$7, the pot gripper that came with the MSR titan kit weighs 28.1g and my modified gripper weighs 28.5g.

 Now for the big question “are Ti pots really worth the money” as far as I am concerned NO, for a given volume they are no lighter, they may or may not be a little more efficient, it is very easy to burn food in Ti pots and they cost much more.

 For now I am going to stick to my cheap aluminium pots.

The MSR Titan pots et left and my cheap Aluminium pot set on right

MSR Titan 2 pot set

My two well used 1.5l and 1.75l aluminium pots

The lighter 1.5l and 1l aluminium pots

This is the results of some test that I did to compare Alcohol, Petrol (White gas or Shellite) and Gas (Canister) stoves.

I tested a Trangia 27-1, a MSR Whistperlite and MSR Pocket Rocket all of them are considered to be classic stoves and are available in most countries of the world.

I tested them through a range of adjustment settings from the fastest to the slowest that I could get the stoves to operate with in reason. I used a 1l Snowpeak Titanium pot 150 mm diameter with a specially made Stainless Steel lid with a hole in the middle so I could place my temperature measurement probe into the water.

In all test I raised 1liter of water 80C, the ambient temperature was about 20C.

Adjustment

With the Trangia I used the simmering ring to choke the flame down to produce the slower heating rates, the fastest heating rate used was with no simmer ring.

The Whisperlite was the hardest to adjust, I did this by pumping different number of pumps into the fuel tank from a few pumps at a time to about 40 pumps and the valve was opened fully in all tests.

With the Pocket Rocket, this was simple I adjusted the heating rate by adjusting the valve from very fast to very slow, if the valve was opened too much lift off of the flame was experienced

Petrol vs Alcohol vs canister gas

Results

The results show the amount of fuel used in each test in grams vs time.

Trangia

Note that no matter how slow I adjusted the heating rate it used the same amount of fuel from 12 minutes to 30 minutes. 23-24 grams, Note the Trangia used nearly twice as much fuel as the correctly adjusted Pocket Rocket.

Whisperlite

The Whisperlite showed great improvement in efficiency 25% with slowing down the heating rate, this stove is not design to simmer and is very inefficient at the normal setting, though it has the advantage of working in very cold conditions.

Pocket Rocket

The Pocket Rocket also benefited from slowing down the heating rate a 25% improvement was seen. Note as can be seen from the curve (yellow line) that using the Pocket Rocket at too high a heating rate is a waste of energy, a time of around 12 minutes seems to be the optimum and heating rate faster was a waste of fuel and slower was a waste of time. Please note the most efficient fuel/time point 12 minutes coincides with the fastest heating rate from the Trangia 12 minutes, I am not sure if this means anything though but I found it an interesting point. Upright canister stoves have problems working in cold conditions but they can still work in the cold if used correctly

I hope this information is of some help to stove users and prospective stove buyers.

I made this little stove in 2007, it is a SUL low profile side feed remote canister stove that is designed so it can be used with a windshield or the pot supports can be removed so it can fit under a Caldera cone.

The stove is still in its early development and is a concept that I have been working on for a few months the stove still needs some tuning.

The canister is a small Butane canister that fits into the Firelite 550 pot along with the stove. The total weight of the stove, canister (empty), windshield (end2end Trail Supply) and pot+bag is currently 136.8g (4.825oz), the canister can hold up to 30g (1.058oz) of fuel, which can boil 3liters of water. The pot sits 36mm (1.417”) off the ground on pot supports that are at 25mm (0.984”) radius and. The stove feet fold under the mixing tube so it can be packed away into a small bag.

The stove and valve with pot supports weigh in at 42.5g (1.5oz) and without the pot supports 39.4g (1.39oz).

Low profile stove

Stove and small canister

The flame

All packed up

Morning sun through dead trees and mist near Broken Dam Hut August 2010