Every time I travel 'under my own power', I try to learn and become more efficient - which translates to 'carry less weight'. You can do this by taking less, doing without, combining functions and/or getting lighter weight gear. This saves energy so you can go farther, longer and/or faster.
In this day an age of lightweight backpacking, many hikers are turning to alcohol stoves because they are super-lightweight, inexpensive, simple to use, and alcohol can be shipped in bounce boxes along the the trail. Since most commercial backpacking stoves have an integral pot stand, someone who uses an alcohol stove needs to provide one. But the same criteria for choosing the alcohol stove in the first place must also apply to the pot stand-windscreen too.
Most manufactured pot stands and/or windscreens are designed to fit a variety of pots and stoves, making them versatile at the expense of stove efficiency. But most lightweight backpackers use one pot and one stove. Having a stand that elevates the pot to an optimum level above the stove, and a close fitting windscreen that provides adequate air flow while blocking wind and limiting heat loss, reduces cooking time and more importantly, reduces fuel consumption. This translates in less fuel weight to carry.
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Step 1: My Requirements for a Pot Stand-windscreen
My requirements for a pot stand-windscreen are:
1) lightweight and inexpensive
2) sturdy, stable, and functional
3) sized correctly but collapsible
4) ease of construction
1-Lightweight and inexpensive: Aluminum roof flashing is cheap and readily available at most hardware stores. Aluminum angle is also available at larger hardware/lumber stores. I had thought of using galvanized flashing but decided that aluminum would still be strong enough, saving weight. Various designs had me bending the flashing to provide pot support but I decided against it because of the difficulty in cutting and bending correctly.
2-sturdy, stable and functional: The pot stand uses a very stable 3-point leg design. The aluminum angles provide superior strength while the flashing helps with alignment. There is enough clearance to allow for optimum air flow while also protecting the flame from the wind.
3-sized correctly but collapsible: I only wanted a 1/4 inch gap around the pot to keep heat loss at a minimum. But I also wanted the pot stand to collapse small enough to insert inside the the pot for transportation.
4-ease of construction: Several of my early concepts were one-piece designs that filled all the requirements except ease of construction because they utilized too many cuts and bends in the aluminum flashing. Using the aluminum angle increases the weight, but also increases strength and ease of construction, an acceptable alternative.
Step 2: My Parts and Tools
Aluminum flashing: 15.75" x 2.5"
aluminum angle 1/16"x1/2"x3/4" length 2.5" (x3)
items to attach legs to screen: see "Attaching Legs"
scissors / tin snips = to cut aluminum flashing
ruler / tape measure = to determine measurements
marking pen = to mark cuts
nail / center punch = to make starter holes for drill bits
drill & drill bits = to drill holes
screw driver = to attach legs to flashing
hack saw = to cut aluminum angle
file = to remove burr edges
utility knife = to cut slots
[Working with metal can be dangerous. Cutting, drilling, grinding, and assembling metal can produce sharp edges, flying metal bits, and metal dust. Use proper eye wear, mask and gloves to protect against injury. Knowledge of the proper use of tools is also protection against injury. The following instructions is only to provide a demonstration of how I constructed my pot stand-windscreen. Your results may vary.]
Step 3: Outline of Instructions
Outline of Instructions:
a) calculate needed aluminum flashing:
measure diameter of pot + 1/4" + 1/4" = pot stand diameter
pot stand diameter x 3.145 = pot stand circumference
pot stand circumference + width of angle (>1/2" or more) = aluminum flashing length
b) calculate optimum pot stand height depending on stove.
c) calculate windscreen height & cut
windscreen height to be equal or greater than pot stand height
windscreen height + 1/4" able to fit inside pot for packing
windscreen height must allow for pot handle (or needs a cut out)
d) cut aluminum angle (pot stand height)
file edges smooth or round
e) calculate pot leg location
pot stand circumference / 3 = distance between legs
f) drill holes for leg screws in flashing
use a nail and template to mark holes
drill holes in flashing at each leg location
g) drill holes in legs and attach to flashing
use a nail and template to mark holes
drill pilot hole using a smaller bit
drill hole for screws
h) complete assembly and test
i) determine final aluminum flashing length
remove one end of flashing from assembly
collapse flashing into a smaller diameter and insert inside pot
mark where flashing overlaps & cut
j) make binding post slots
use a nail and template to mark holes
drill holes in flashing
cut flashing to connect holes making a slot
k) reassemble and test
l) GO COOK SOMETHING! [smile]
Step 4: Calculate Needed Aluminum Flashing
a) calculate needed aluminum flashing = remember to "measure twice, cut once" [smile] For this step I wanted a 1/4" clearance all around the windscreen from the pot, which means to add 1/2" to the diameter. That leaves 1/2" of each angle under the pot edge. If you have a limited amount of flashing, try making a paperboard trial piece first.
Step 5: Calculate Pot Stand Height
b) calculate pot stand height depending on stove = When I bought my stove, it came with a pot stand. I assumed that this was the best height for this stove as determined by the designer. If you are not sure, experiment and see what height is the most efficient for your stove.
Step 6: Calculate Windscreen Height & Cut
c) calculate windscreen height & cut = I added 1/4" lip above the leg support to hug the bottom edge of the pot. Adding more would increase the efficiency, but you must take into consideration how low the handle is on the pot sides and the total height must be smaller than the pot depth if you want to place the pot stand-windscreen inside the pot for transportation. Cutting the flashing with a scissors worked pretty well.
Step 7: Cut Aluminum Angle
d) cut aluminum angle (pot stand height) = You can cut the aluminum angle with a hacksaw, making sure your angles are square. Once you have all three cut out, compare and use a file to straighten cuts, even lengths and smooth edges. They don't have to be exact but it helps if they are pretty close. Remember when choosing angle, the end must be long enough to support the pot edge while still allowing for at least 1/4" for air flow (for example, my angle edge was 3/4", putting 1/2" under the pot edge).
Step 8: Calculate Pot Leg Location
e) calculate pot leg location = Basically, just the circumference divided by 3
Step 9: Drill Holes for Leg Screws in Flashing
f) drill holes for leg screws in flashing = Using a template (piece of cardboard) and a nail, mark holes 1/2" from the bottom of the flashing and 1/2" from the top of the legs for each of the leg positions. Save the template for the legs. Choose the smallest drill bit that will still make a hole in which the screw with slide through. Drilling through the flashing into a piece of scrap wood underneath makes for a neat hole.
Step 10: Drill Holes in Legs and Attach to Flashing
g) drill holes in legs and attach to flashing = Using the template and a nail, mark holes 1/2" from the top of the leg, and 3/4" from the bottom. First use a smaller drill bit to make a pilot hole, then use the correct size drill bit to finish. This all prevents the drill bit from migrating during the initial drilling. Assemble two legs in the middle of the flashing, and overlap the flashing for the third leg to attach, completing the circle.
Step 11: Attaching the Legs
There are several ways to attach the legs (angle) to the windscreen (flashing):
a) binding posts & screws: made of aluminum, lightweight but increased costs.
3/16" is long enough but be sure to get the longer screws.
Can be bought at hardware stores and some office supply stores.
post & screw = $0.53, weight = <0.1 oz
b) machine bolts & nuts: strong but heavier, use a washer to prevent tear out.
I recommend #10x1/2".
bolt, washer, nut = $0.15, weight = 0.1 oz
c) rivets: very inexpensive, lightweight, but requires rivet tool.
rivet ~$0.00, weight = ~0.0 oz
Step 12: Test
h) test = The pot stand-windscreen is now functional. Place it on a sturdy flat surface, then put your pot on top. Test to make sure there is a clearance gap around the top edge of windscreen to allow for air flow. Make sure the windscreen doesn't interfere with the pot handle. Make sure that enough of the aluminum angle is under the pot to help with stability.
Step 13: Determine Final Flashing Length
i) determine final aluminum flashing length = Remove the leg at the flashing overlap, and place the windscreen inside your pot. Push to limits around the complete circumference of the inside and mark the overlap. And cut off excess.
Step 14: Make Binding Post Slots
j) make binding post slots = Place back inside pot, pushing to the limits around the complete circumference inside the pot. Using the holes for the leg posts, mark a second set of holes for the leg posts. Now, join the two adjacent holes making a slot using a utility knife. This is the most difficult of part of the project. Begin by lightly scoring the flashing with the utility knife. Keep scoring with moderate pressure until it cuts through. Be careful not to cut past the drilled holes. These slots must be equal distance apart and at least wide enough for the screw to pass freely to allow the screen to collapse for packing inside the pot.
Step 15: Reattach Binding Posts & Leg
k) reattach binding posts & leg = Now, reassemble that 3rd leg. The overlap should be between the leg and the outside flashing (see top view). Test to make sure that binding posts slide through slots increasing/decreasing diameter of pot stand-windscreen. Test to make sure it can fit inside the pot, and also expanding to hold up pot. If, even with the screws loosened, the screen still won't collapse, disassemble and use a file to widen the slots.
Step 16: Go Cook Something!!!
l) GO COOK SOMETHING! [smile] = Don't wait till you're out in the woods to use this for the first time. Try using it at home to make sure all the design parameters work to 'actually' cook something. Congratulations!
Step 17: Design Review - Lightweight & Inexpensive?
Now, let's see if this new pot stand-windscreen met all the requirements:
1) lightweight and inexpensive = final weight using posts was 1.4 oz, compared with 1.6 oz for the pot stand and aluminum windscreen provided with the Atomic. Final cost using posts was $4.58. An alternative would be to use bolts with posts instead of the screw provided ($2.17 - 2.0 oz).
Step 18: Design Review - Sturdy, Stable & Functional?
2) sturdy, stable and functional = A three leg design gives us one of the most stable configurations out there and should work on almost any surface no matter how rough or uneven. To test strength, we placed 40 pounds on top of the pot stand and observed no instability or weakness. And stove worked as well as designed.
Step 19: Design Review - Sized Correctly But Collapsable
3) sized correctly but collapsable = Check to see if there is at least a 1/4" gap around the top of the screen to allow for air flow. And we already have a 1/4" gap at the bottom for fresh air flow. Check to see if windscreen will collapse to fit inside our pot. And in my case, I still had room to store the stove inside the pot with the stand-windscreen
Step 20: Design Review - Ease of Construction?
4) ease of construction = Materials were readily available at most hardware stores. Binding screws can be found at hardware stores or some office supply stores. Bolts & nuts can be used but are heavier and care must be taken to make sure windscreen can expand/collapse.
Step 21: Notes
Flashing (minimum 10') and aluminum angle (minimum 3') come in long lengths, so you will have enough to make several pot stand-windscreens. I ended up making one for each of my backpacking pots. Or you could invite over your hiking buddies and everyone could make their own out of the extra material.
Other tools can be used to make this project. I found out that cutting the flashing was actually easier with a scissors instead of a tin snips. A Dremmel tool definitely makes cutting the angle, smoothing edges and cutting the slots much, much easier. And if you have a rivet tool, rivets might make a good alternative to attaching the legs, but make sure you can still collapse/expand the flashing at the overlap leg.
Step 22: Conclusions
Actually this project turned out more complicated but simpler than I had planned. My early designs were lightweight and elegant but were too complicated to make well. Despite measuring everything out on paper, I ended up making several prototypes with slightly different measurements before it became what I had envisioned. Finally, it all boiled down to simple is better. The final design has all the features we were looking for. And I hope to use this same pot stand-windscreen for years to come.
For more of my 'projects' check out my website WanderingTheWorld.com