More tweaks for TreeHugger Mark-3 tent

I have been using SolveSpace to design TreeHugger 1P Mark-3 tent. Here is the previous blog post:

https://bkhome.org/news/202107/plans-for-treehugger-1p-tent-mark-3.html

While waiting for the 10D silnylon to arrive from China, I keep playing with the design. The latest iteration is have made the floor-width at the tail-end a bit wider, 70cm, up from 60cm. Just gives a little bit more foot room inside.

Also tweaked the catenary a little bit, and have put it directly onto the 2-dimensional plans. Here are the SolveSpace 3.0 files, gzipped:

mk3-2d-8.slvs.gz

mk3-3d-8.slvs.gz

Here are the cutout plans, the pink lines represent the usable fabric width of 151cm:

And the other side:

And as shown in the previous post, I have inverted one side so as to minimize the length of cloth required. In the latest design, as the foot-end is wider, the required length of fabric will be longer, about 5.22 metres.     

Tags: light

Plans for TreeHugger 1P tent Mark-3

The TreeHugger 1P tarp/tent Mark-1 project is documented here:

https://bkhome.org/light/treehugger-1p-tarp-weighs-only-178g.html

I started a Mark-2 design, with spreader-bar for head-space, but abandoned it:

https://bkhome.org/news/202106/treehugger-1p-tarp-mark-2.html

Thought about the design a lot more, and decided, rather than have a spreader-bar, will make the high-end higher. This means will do away with the constraint of using a carbon-fibre or trekking pole to hold up the high-end. The high-end will be held up by tying to a tree trunk or branch -- unless can use an extra-long pole.

With Mark-1, I first constructed a tarp, and then added end-panels to turn it into a tent,as shown here:

https://bkhome.org/news/202107/end-panels-for-treehugger-1p-mark-1-tarp.html

I was going to construct a built-in mesh bivvy for the Mark-1, but now jumping to Mark-3, based on Mark-1, with lessons learned, higher high-end, slightly longer, and end-panels included in the original cutout.

What I mean is, instead of adding the end-panels afterward, plan to include them in the fabric cutout. This will simplify construction. So, there won't be an intermediate tarp, the tent will be constructed directly.

Here are the SolveSpace 3.0 files, gzipped:

mk3-2d-5.slvs.gz
mk3-3d-5.slvs.gz
mk3-cut-5-cloth2.slvs.gz
mk3-cut-5.slvs.gz

SolveSpace is a "parametric 2D/3D CAD" application, for Linux, Windows and OSX, described here:

https://solvespace.com/index.pl

Here are the dimensions for each side. The outer lines include the hems and ridgeline overlap, the inner lines will be the actual dimensions after the hems are folded over and the ridgeline overlap glued together:

The other side includes the panel on the high-end:

Those 1.5cm measurements are hems, that will be folded over. The 2.0cm measurements are the ridgeline, and the two sides will be glued together at the ridgeline, by 2.0cm overlap.

Here are the two pieces put together, to show the length of fabric that will be required:

...based on the fabric having usable width of 1.51 metres, and the length required is 5.75 metres.

If we want to go for a deep catenary cut, as I did for the mark-1, here is a possibility:

...the left side is the high-end of the tent. Measure down 90cm and draw a line to the ridgeline on the low-end. Then plot the points as shown. This will be slightly less deeper than the Mark-1.

So, after cutting out the two sides, cut the ridgelines as per the above curve. Then join them, with 2cm overlap.

I am keen to get going on this, however, currently only have 20D fabric, and really want to use 10D, as aiming for lightest possible weight. Have placed an order for 10D, but it is coming by China Post, and my experience is will have to wait about 2 months. Aaargh! Will have to find something else to do in the meantime.

EDIT:
According to SolveSpace, the area of the two pieces is 2.537 plus 3.540, which is 6.077 metre squared. If the 10D silnylon is 31gsm, the weight of the fabric will be 186 grams. A bit less than that if there is a catenary cut.

EDIT 2021-07-21:
I discovered that the panel at the high-end actually requires the fabric roll to be wider than it is. My 10D silnylon has a usable width of 1.51 metres, same for the 20D silnylon. However, found by careful rotation of the cutout, can get the cutout width to be 1.518 metres, that is, 151.8cm.

Also, the two pieces can be cut out so as to use less fabric length, 5.112 metres, compared with 5.75 metres above:

...the brown lines represent the usable fabric width. The first piece is flipped vertically, so ridgeline is on the bottom. The second piece, on the right of the above drawing, is rotated slightly, to minimize the cutout going over the usable width. Even so, the bottom hem-line of the high-end panel is about 0.8cm over the usable width, going into the edge of the fabric that is not silicone-impregnated.

I can live with that. The bottom hem-line of the high-end panel will be folded over by 1.5cm, and the little 0.8cm un-impregnated will end up impregnated when the hem is glued.

Sure have designed this to the limit, maximum height that can be achieved at the high-end. Sitting inside, the height at the peak point will be just on 1.51 metres, but of course this drops rapidly on each side. That 1.51m is based on about 2.5cm air gap at the bottom of the tent. Then, as planning to construct an inner mesh bivvy, the final peak height will be lower. 

EDIT 2021-07-21:
I have played with the dimensions, now the second piece fits nicely within the 151cm usable width of the fabric, and without having to rotate it. Here are the updated SolveSpace 3.0 files, gzipped:

mk3-2d-6.slvs.gz
mk3-3d-6.slvs.gz
mk3-cut-6-cloth.slvs.gz
mk3-cut-6.slvs.gz

And here are the dimensions for cutting the pieces out of the fabric:

...required length of fabric now just a tad over 5.07 metres. 

EDIT 2021-07-25:
I think that when construct the Mark-3 tent, will reduce the depth of the catenary cut a little bit:

...same thing, measure down 80cm from the top-peak of the high-end of the piece. having cut the catenary on one piece, suggest use that as a template for the second piece. Depth measurement is 18.07cm from the straight-cut ridgeline, compared with 20.9cm for the previous "90cm" catenary cut shown higher on this page. Not much different, but the ridgeline will rise from the foot-end at a slightly steeper angle, which I prefer. 

EDIT 2021-07-31:
The plans for Mark-3 have been tweaked again, see later post:

https://bkhome.org/news/202107/more-tweaks-for-treehugger-mark-3-tent.html     

Tags: light

Testing mk1 tent and wood stove

The ultralight (242g) TreeHugger 1P mark-1 tent is described in an earlier post:

https://bkhome.org/news/202107/end-panels-for-treehugger-1p-mark-1-tarp.html

The ultralight (55g) wood stove is described here:

https://bkhome.org/news/202107/wood-burning-stove-weighs-only-55g.html

Firstly, the stove. As reported in the above link, there is a review on Amazon, quoting:

The first burn was only 1/3 full of cedar twigs (not hotter burning hardwood), and before I could put on a small pot the inner supports warped and collapsed into the fire and the outer frame warped into an oval. The outer frame and inner supports are made from very thin titanium, almost identical to what I use for a windscreen with my micro alcohol stoves. The design is quite similar to the small Little Bug stove, which weighs 9 1/2 ounces. This one weighs just under 2 ounces (without the control slider) and is just too fragile to be a usable stove.

Yesterday, I tested it. Here it is, loaded with twigs, ready to go:

Ha ha, I can also confirm, it wasn't long before the pot-rest collapsed! And I didn't even have a pot on top. The titanium just warped and collapsed.

The two side-pieces were still OK. Looking at it today, yes, warped, but still usable. Something stronger is needed for the pot-rest, and something that will help the side-pieces to retain their shape.

Anyway, I boiled water by placing the pot directly onto the wood:

...that smoke is because the wood is damp. Made it hard to start the fire, but once going, OK, except got lots of smoke when added more twigs. The water boiled fast, had soup for lunch.

The tent, well, not much to say, easy to erect, just needed a convenient tree to tie it up in "tree hugger" mode:

And of course, one of the big features is the side entry:

Erection was straightforward -- staked out the four corners, then tied up the high-end to the tree, then inserted the short pole and staked it. Five stakes, but then a sixth for the side -- that sixth stake not essential.

Thinking about the height of the high-end, that was set by the length of my carbon-fibre pole, if it is to be erected without a tree. However, if that constraint was removed, no pole, then the high-end could be higher, which would give more head room inside. Will think about that.

You can see in the above photo, the usefulness of the tree as a back rest while inside the tent. Yes, that was the idea. Or, it could be a wall in a shelter.  

Tags: light

End panels for TreeHugger 1P Mark-1 tarp

Continuing the TH1P Mark-1 tarp construction project, this is the previous post:

https://bkhome.org/news/202107/treehugger-1p-mark-1-tarp-deep-catenary-cut.html

By adding end-panels, it has now become a tent:

I won't post the dimensions, as it depends on a user's choice of pole height. It is easy to figure out -- just a triangle, well, almost.

At the front, one side of the triangle is glued to the tarp (left side of above photo) and the other two sides have glued hems, with a tie-out at the bottom corner. The tie-out is just like the others, with an o-ring attached.

The front panel is not quite a triangle, because I cut a bit extra so that the tarp will overlap, to minimize ingress of rain. However, you can see at the bottom, there is still a gap between panel and tarp -- if I had built the inner mesh bivvy, the intention was that would pull-in the front panel slightly, so that gap would disappear.

The tarp has a small hook on the tie-out, so can unhook from the o-ring and fold back over the ridgeline;

In the first photo, you can see an o-ring and a nylon hook beside it. That hook was the one originally attached to the tarp tie-out, however, today replaced it with a smaller one. The o-ring will have a tent stake through it -- I am using triangle-section stakes, so there are gaps for the hook to hook onto the o-ring, but it is better with a smaller hook.

I am intending to take this as it is, and just use one of my ready-made inner mesh bivvies on the next hike. Probably will not construct the Mark-1 tent any further.

The tail-end of the tent has just a simple triangle panel, glued to the tarp on both sides, hem along the bottom.

I have learned a lot from constructing the Mark-1. The tent as you see in the above photo weighs 242g (8.64oz) (not including poles), quite light, but I reckon, from lessons learned, could make it again with less weight, fairly close to 200g. So, rather than take Mark-1 to completion, with inbuilt mesh bivvy, will use it as-is.

I think also, might make the next one a little bit longer, maybe another 100mm, and a little bit wider at the front. The ridgeline has 25mm overlap, but it is such a strong bond, intend to reduce that to 20mm. The successor to Mark-1 will probably be named Mark-3.

Next step, use it on a hike, one or two nights.

EDIT 2021-07-12:
Here is the Mark-1 tent rolled up:

That's great, really small! Dimensions are about 175mm long and 80mm diameter.   

Tags: light

Wonderful quilt from undercling-mike

I posted about sleeping bags versus quilts for camping and hiking, back on March 20, 2021:

https://bkhome.org/news/202103/sleeping-bag-versus-quilt.html

Here is a photo from that post:

In that post, I didn't reveal who makes them. Will do so now. His name is Michael, known as "undercling-mike" on the Aussie Bushwalking forum. This is the thread where you can find out all about them:

http://bushwalk.com/forum/viewtopic.php?f=27&t=24995

Mike started making these in 2017, I think as a hobby, presume that he has a day job. Unfortunately for Mike, news got around how nice these quilts are, and the orders flooded in. The manufacturing delay got longer, then in December 2020, Mike declared a hiatus, he wanted to rest awhile.

But people still kept requesting them, myself included. I placed my order on March 11, and received it just over 3 and half months later. Despite the hiatus, Mike has kept making them, just very slowly. In his last communication with me, he indicated that he probably won't accept any more orders for awhile.

Anyway, what I have is this:

-8 degrees C rating, regular-length, wide-width, 950 HyperDRY down (ethically sourced), 10D burnt-orange taffetta fabric inner and outer, straps and 5L stuff sack.

Weight, in the stuff sack and including the straps, is 633g.

Dori is a lass who lives here in Western Australia, and she acquired her quilt from Mike in November 2020, and has posted a video:

https://www.youtube.com/watch?v=PtA7wT56ppQ

Hers is a little bit heavier, as she went for the 850-loft down and 15D fabric.

Mine would have been 594g if had also chosen regular-width, but was enticed by the possibilities of that little bit extra width. In the above photo, you can see the gap underneath. The wide-width fills that gap, which makes it, I think, more usable without straps, saving about 20g -- so, my pack weight will be 613g.

Here is a photo of a wide-width, you can see how the gap has been filled:

When mine arrived, I threw all the blankets off the bed and slept under the quilt. Lovely! So light and warm.
And so beautifully made -- as a beginner sewer, I marvel at the perfect stitching.
One thing I like about the burnt-orange 10D taffetta fabric is that it is translucent, and I can see how the down is distributed -- yep, it is spread everywhere.

If you are a camper/hiker and are drooling over these photos, unfortunately you cannot currently place an order. I have had feedback from a couple of people that Mike has not responded to their inquiry. That's because, as I stated above, he has taken a break from making them. He will of course complete the ones that he has accepted an order for, but be patient. He indicated to me that he will do a reset and resume making them, so probably best to just wait until he announces that on the forum.   

Tags: light

Wood burning stove weighs only 55g

I posted about tiny wood-burning stoves for hiking and camping a few days ago:

https://bkhome.org/news/202106/ultralight-wood-burning-stove-for-hiking.html

Had one on order, it arrived today, this one:

https://www.aliexpress.com/item/4000556939038.html

Weight is advertised as 100g, very interesting design, though puzzling. Packs flat, which is what I want:

...26x12.7mm, a good size that will fit in my lumbar pack.

What you see in the above photo is 4 pieces, titanium, weighing 55g, but it also has something else, called a "dampener", thicker titanium, that weighs 44g:

This dampener and the size and placement of holes is perplexing. It seems from this photo that the fire is above the dampener:

...but, there isn't much room for a wood fire above the dampener.

I saw on a YouTube video, a guy stating that a Lixada folding stove is a cheap Chinese knock-off of a USA-made stove. Which got me wondering about this one. I came across this very concerning review on Amazon:

"It collapsed 5 minutes into the first burn"
https://www.amazon.com/gp/customer-reviews/R1ISBTNKDTUIC5/ref=cm_cr_dp_d_rvw_ttl

That review mentioned that the Lixada stove is a copy of this one, made in the USA:

https://littlbug.com/littlbug-junior-stove/, and

https://www.raymears.com/Bushcraft_Product/1091-Littlbug-Junior-Camping-Stove/

...weighs 145g and made of stainless steel, lots of good reviews. Note, doesn't have that dampener. Of course, a lot more expensive. Ah, there is a video review of the Littlebug Junior:

Part 1: https://www.youtube.com/watch?v=DDasLCTBWg8

Part 2: https://www.youtube.com/watch?v=UOhpVkkknE8

Part 3: https://www.youtube.com/watch?v=ysSfOmE_KnY

So, the Lixada stove is a cheap knock-off, and apparently not a good one. There is that mysterious dampener, and a report that it collapses. Cannot find any more reviews. Ha, I see that the Littlebug design is patented, which may be why Lixada added that dampener thing, and an extra cutout at the top to feed in wood, to make it different. The review posted on Amazon doesn't bode well, but will take it on the next hike and attempt to use it.

EDIT:
I found an early video, made in 2015:

https://www.youtube.com/watch?v=qywFv8RRzx8

...and the original design does have that dampener. Interesting that they did away with it in the latest version.

EDIT 20210718:
This stove has its first test, report here:

https://bkhome.org/news/202107/testing-mk1-tent-and-wood-stove.html

...so, apart from the collapsing pot stand, it is usable. That will be an interesting project, to design an alternative pot stand that will not collapse and will assist the side pieces to stay circular and not warp.   

Tags: light

TreeHugger 1P Mark-1 tarp deep catenary cut

On June 5, 2021, I posted instructions for a glued tarp, straight-cut, that weighs only 178g:

https://bkhome.org/light/treehugger-1p-tarp-weighs-only-178g.html

After that, I speculated about a catenary-cut on the ridgeline, to try and get rid of looseness of the fabric along the ridgeline:

https://bkhome.org/news/202106/catenary-cut-for-tarp-ridgeline.html

...and cut a minimal catenary curve along the ridgeline.

However, the fabric along the ridgeline was still very floppy, so decided to experiment with a much more aggressive catenary cut.

To this end, I thought about what the curve shape should look like. It seemed to me that the curve of a boat mooring line looks "good", as calculated here:

http://abc-moorings.weebly.com/catenary-calculator.html

I can't say that this is the mathematically best shape for the deep-cut ridgeline, but it intuitively looks "right". I downloaded the spreadsheet file, and gzipped it, uploaded here:

Catenary-Mooring-Line-Shape-Tool.xlsx.gz

Here is a table that I got from that spreadsheet:

...you enter "77" for the "d" parameter, and "205" for the "X" parameter. "X" is whatever the actual horizontal distance is, as shown in the sketch. Transfer the table to the fabric, gives the green line.

This will be done on both pieces of fabric (the first can be used as a template to mark out the second), and when the two ridgelines are brought together, to be glued, there will be an overlap of 2.5cm, and it is necessary to mark a line on the fabric that will be underneath the overlap.

The ridgelines are now curved, and have to be pulled straight, so as to be glued. I did that by placing them overlapped and held down at each end with concrete blocks:

...so, in theory, I can run adhesive along the underneath fabric, and the top piece should just about flop back into the correct overlap position. The main problem with this plan, is couldn't lift the fabric at the ends, because of the blocks, so had to start further in. But that is OK, glued the ends afterward.

In the above photo you can see newspaper underneath. One layer of newspaper, with cling-wrap over that. The cling-wrap is important, because silicone adhesive does not stick to it. When I ran the seam roller over the overlap, a tiny bit of sealant bleeded out underneath, which is OK -- it will simply be flattened by the roller and won't stick to the cling-wrap.

I have posted about this before, but reiterating here, this is the roller I use:

https://www.bunnings.com.au/uni-pro-30mm-seam-roller_p1662302

Glueing worked reasonably well. I used the 25.4x25.4x1.6mm spreader tool that I discussed in an earlier post:

https://bkhome.org/news/202106/refinements-to-glueing-tarp.html

...that worked really well. Using the applicator gun, ejected the silicone adhesive in a zig-zag pattern, fairly generously as the spreader tool will catch any excess glue -- it just piles up inside.

Here is the ridgeline after glueing, with one side pulled out flat, so you can see the curve:

...and as you can see in the photo, the tie-out webbing has been sewn on. It is best to wait several days after glueing, before sewing, to avoid gunking up the sewing machine. Here is close-up of the short end:

And here is close-up of the high end:

In the original straight-cut ridgeline, I experimented with "sockets" to hold the carbon-fibre poles. What I have done as shown above is very simple, just silicone end-caps glued to the webbing. These, 7.7cm ID:

https://www.aliexpress.com/item/1005001609758449.html

I have experimented with this, and found it to be very strong. Silicone adhesive bonds to the silicone end-caps very strongly -- so strong, that it can't be separated. The weak point is the bond with the webbing -- I used the applicator gun pressed firmly onto the webbing and forced silicone adhesive as much into the webbing fibres as possible. Then used my finger (wearing disposable gloves) to press the adhesive firmly to try and force it into the fibres even more.

The end-cap is glued right on top of where the webbing loop is sewn together, so it is, I think, a pretty strong end-result.

I have mentioned in an earlier post, reiterating here, I now use a mini-applicator gun, that takes 150g tubes of silicone sealant:

https://www.bunnings.com.au/monarch-mini-compact-caulking-gun_p1662108

...I find this easier to wield while glueing hems and ridgeline, and also, unlike the full-size gun, the flow stops immediately I take my fingers off the lever -- I like that very precise control.

The black webbing is this, nylon 12mm wide, and 1mm thick:

https://www.aliexpress.com/item/4000126877988.html

The blue webbing at the high end is for when want to erect the tarp in "tree hugger" mode, tied around a tree trunk. That is much lighter, nylon 10mm wide, 0.5mm thick:

https://www.aliexpress.com/item/1005001666741572.html

Oh, and that cord-tensioner on the black webbing is from here:

https://www.aliexpress.com/item/1005002198346631.html

Here is the final weight of the Mark-1 deep-cut tarp: 183g (6.46oz)

Photo erected:

...yes, very good, the sides are fairly taut.

Of course, you do lose head-height, but it still looks OK. When erected in "tree hugger" mode, I will be sitting at the very end, leaning against the tree trunk (or wall inside a shelter), so my head will be at the highest point of the tarp. And yes, there will need to be rain protection to make that feasible, will get onto that stage of construction soon.

Actually, the weight is a little bit higher than it could have been. I cut the ridgeline open twice, going from a straight-cut, to a slight catenary curve, then a deep-cut curve. This resulted in a mess at the ends of the ridgeline and had to glue extra layers of reinforcing fabric to rejoin the ends of the ridgeline. Even so, 183g is pretty good.

Next instalment coming soon!     

Tags: light

Ultralight wood-burning stove for hiking

Years ago, I bought a few different metholated-spirits-burning stoves, aiming for extreme light weight. I was reminded of this today, reading this post:

http://bushwalk.com/forum/viewtopic.php?f=53&t=36046

...forum member 'crollsurf' has a really light setup, stove and windshield:

https://www.ebay.com.au/itm/324185702933

https://www.ebay.com.au/itm/144062317171

...total 42g. But may also need a metal disk under the stove, to insulate from the ground. And of course a small pot.

I also have this kind of gear. Of course, meths has to be carried, lets say a 100ml bottle for a multi-day hike. So, at least another 100g, and the bottle has to be carried such that it doesn't leak.

lately, I have been exploring the option of a wood-burning stove. It certainly does appeal -- just using fuel from the forest floor, no need to carry fuel. Even in the most arid wilderness, there are going to be leaves and twigs lying around on the ground.

These little wood-burning stoves are in a grey area, in places where open fires are banned. Here in Western Australia, many hiking trails allow fires within designated fire-pits, and in some places even on open ground, but usually only over Autumn - Winter - Spring. In the hot dry season, only a gas or meths stove may be allowed.

It is an interesting question, whether any tiny wood stove could have its combustible material so constrained as to be considered equivalent to a gas or meths stove.

Anyway, here is a comparison of many of the choices:

https://www.youtube.com/watch?v=ajPCW41YWOU

...some fantastic wood stoves!

But, are any of those suitable for the ultralight hiker? Like, under 100g? Yes, he reviews one, the Emberlit Fireant:

https://emberlit.com/products/fireant-titanium-multifuel-ultralight-backpacking-stove

...weighs 85g (3oz).

There are plenty of others like this on Aliexpress, Amazon and eBay, but not this light. If you want to research what is out there, go to these sites and search for "wood stove folding ultralight" ...or similar words... cast the net a bit wider: "wood stove hiking".

The Emberlit Fireant can also hold a meths burner.

Thinking about burning wood, it is not really constrained. You would insert twigs in the side, so there is always the possibility of burning wood to fall outside of the stove body.

The Emberlit is fascinating, but I have ordered a different kind of wood-burning stove, that weighs 100g (and much cheaper). It is also titanium and folds flat for easy carrying. Will post a report after it arrives and have tested it.

EDIT:
Here is another interesting comparison of wood-burning stoves for hiking:

https://www.youtube.com/watch?v=P28PK5m4Gjw

And if you would like to see something really creative, here is a no-drill gasifier tomato-juice-can wood stove:

https://www.youtube.com/watch?v=8he7txE6uLw 

EDIT 2021-0630:
I received an email from ally, with links to very light stoves. For an alcohol-fuel stove, you can't get any lighter than this spill-proof stove and folding frame:

https://speedsterstoves.co.uk/20ml-spill-proof-mehs/alcohol-burner.html

https://speedsterstoves.co.uk/utralight-mini-pot-stand-for-cups-mugs.html

...8g plus 4g, great for making a quick coffee on the trail!

He also posted a link to a tiny ultralight titanium wood-burning stove, Firebox Nano, 4oz (113g):

https://www.fireboxstove.com/folding-firebox?product_id=337

...including its case, weight is 6oz.    

  

Tags: light