A Simple Sling chair

[Hog On Ice]

A couple years ago I started playing with variations on the classic tripod based bushcraft chair - the basic idea was to replace the tripod part with an attachment to a tree in much the same way as a hammock is attached to a tree and then to tie relatively short sticks (props) to the front stick to push the fabric sling away from the tree. Anyways after a fair bit of playing around I came up with a chair that is rather comfortable and is somewhat easy to adjust for different settings of the chair back incline.

I am not planning on selling or trading this chair but if someone wants to make it as a DIY project I am willing to help as best as I can over the net. Personally I think the chair is simple enough that anyone who can do a bit of sewing can make one or even as seen with some of the other adaptations of the tripod based chair just use the same sort of fabric seat that it uses.

The first pic shows the fabric seat and the cut sticks that will make up the bulk of the chair - the fabric seat is a piece of ripstop nylon cut size 55 inches by 26 inches with a half inch rolled hem all the way around with a 5 inch channel on the front/bottom edge and a fan folded gathered and constrictor tied end for the top/back edge. There is one fairly strong stick, 25 inch, for the front channel, two prop sticks about 30 inch, and two stakes for the antislip lines:

The second pic shows the various lines that are used to attach the pieces together arranged in rough order of how they are used - note I use UCRs for the primary support to the tree strap and for the cross ties between the front prop sticks - this is not a requirement ordinary lines can be used for these purposes - its just that it is easier to have adjustable lines in these locations IMO. The lines are all DynaGlide - on top is the tree strap and attached UCR for the primary support, crossed in the middle is the two UCRs for the cross ties, beside the ends of the front stick are the adjustable loops I use for fast attachement of the prop sticks to the front stick and along the sides are the antislip lines used to keep the prop sticks from slipping backward under load:

The third pic shows the cross ties and adjustable loops attaching the prop sticks and the front stick - the adjustable loops are put on the front stick then given a full twist before inserting the prop sticks - note the fork on the prop sticks are to prevent the adjustable loops from slipping down the prop sticks. Adjustable loops are just a sliding larks head tied back onto itself forming a loop - the sliding larks head is locked into place after tightening with a bow knot. The cross ties have a small loop on each end and these small loops are used to larks head the cross ties to the prop sticks. Also attached to the prop sticks are the two antislip lines larks headed onto the bottom of the prop sticks

The fourth pic shows the tree strap and primary support UCR attached to the tree. The small bottom loop of the UCR will be used to larks head the gathered end of the fabric seat.

The fifth pic shows the chair side view after it has been larks headed to the tree. The antislip lines have been attached to the stakes driven in slightly to the front and to the outside of the ground end of the prop sticks. Note the angle of the prop sticks to the ground is less than 45 deg. - this is important to get a good push of the prop sticks pushing the chair away from the tree - when one sits in the chair the angle of these sticks will increase and if they start out too vertical then the chair folds into the tree and the user hits the ground - a quick fix for this issue is to lengthen the primary support UCR or to lower the tree strap on the tree - this will allow the prop sticks to have a lower angle.

The last pic shows me sitting in my chair.

Other notes - it is important to have the same tension on each side of the fabric seat - otherwise the user will feel as if the chair is collapsing to low tension side and possibly dumping the user on the ground. It is also important the the fabric looks taught and not sagging when chair is not in use.

To change the chair back angle change the placement of the prop sticks - more upright move sticks closer to the tree, more inclined move sticks aways from the tree and adjust the primary support line for the new position. After moving the prop sticks the antislip lines and stakes must also be placed in the new positions.

I will be showing other variations in following posts.

 

[Hog On Ice]

This second configuration is actually the original implementation - I wanted a chair I could setup quickly while backpacking so I carried a front "stick" that was a 3/4 inch PVC pipe that I also used to gather water and might have been useful for blowing on a fire to get it started (I rarely have a fire while backpacking so this is untried). The antislip stakes were a couple gutter nails and the prop sticks were the trekking poles collapsed to minimal length. The setup is basically the same but the tips and handles of the trekking poles made the attachment of lines easier.

The first pic shows the fabric seat with the PVC front stick, trekking poles, and gutter nails. Note the ends of the PVC pipe are wrapped with friction tape to prevent the adjustable loops from slipping. Also note that in this example the trekking poles are collapsed to their shortest position and locked into that position - it is not required to do this step but if done _and_ if the ground is good and firm enough then the antislip lines are probably not needed. If the ground is too hard or too soft however then the antislip lines are needed because the tips of the poles would not be able to be stuck in the ground or the tips will just dig a deep hole. Note if non-collapsible poles are used then the antislip lines are necessary because the angle to the ground is too acute for the pole tips to hold.

The second pic shows the chair assembled in the same way as the previous example but with the substitution of the PVC pipe and the tekking poles plus the gutter nails for components that would have been created on site with the previous example. This is how the chair looks after I sat in it for a while. Note the chair was put up faster than the previous configuration because I did not have to cut the sticks. The cost is the extra 9 ounces of weight carried in the pack for the PVC pipe and the extra two gutter nails.

The third pic shows the back of the chair showing the lines looped on the tips of the trekking poles instead of being larksheaded onto the poles as in the stick prop configuration. Also you can see the antislip lines going to the white headed gutter nails located in front of and slightly to the outside of the trekking poles. Note the cross ties are attached to the upper part of the handle to give them better leverage in keeping the chair stable.

The advantage of this approach is the speed of setup - nothing to gather and I know that the front stick won't break. The disadvantage of this approach is the weight - a small saw weights less than this PVC pipe and is more useful. This tradeoff is the reason this is not the primary configuration for the chair.

 

[Hog On Ice]

Recently I went over to the county park to try a few different things. Mule tape seems to have some good features for use with the chair - knots are easy to tie and hold well - in this test case I replaced the primary suspension UCR with mule tape. To simulate a case where there were no trees to tie onto I setup a ground anchor and bipod using the mule tape. I also tried moving the bipod so as to show a couple of different seat back positions. The first position is comfortable for when sitting up and talking to people. The second position is good for taking a nap or star watching. The mule tape was larks headed to the fabric seat which was generally a good idea but some care needs to be taken so that the unloaded end is on top of the line leading up to the bipod or tree so that it is held pinched in the knot. One time I did have the larks head slip but in that case the unloaded end was loose below the tensioned line. The primary adjustment point for this approach is the mule tape larks head at the fabric seat - mule tape is relatively easy to untie and adjusting the larks head so as to shorten or lengthen the primary support line is easy. One of the setups was to just have the mule tape tied to a tree using a round turn and two half hitches - this worked well. About the only issue I saw with using the mule tape is the it tends to snag when wrapping it around the tree making it a little more difficult to adjust the round turn before adding the two half hitches. Note larks heading the antislip line onto the bottom loop of the cross tie UCR is _not_ a good idea when using sticks for the props - what happens is that as the antislip line tightens up the loop on the bottom of the prop stick opens up slightly and the prop stick slides through the loop dropping me out of the chair.

Anyways the pictures as follows:

The first pic shows the chair back slope set for reasonable upright - conversational mode. The bipod attachment height was 61 inches, the chair front height was 12 inches, the chair front edge distance from the bipod was 41 inches giving a calculate seat back angle of 50 degrees - I suspect the effective angle is actually larger because of the seat shape after sitting in the chair

The second pic shows the ground anchor used - The Claw see http://www.theclaw.com/ for more details. Note the ground anchor could have been a distant tree, large rock, strong bush etc.

Here is a long shot showing the whole setup of the ground anchor to bipod to chair - the mule tape is the white line seen in the pics. Also note the line between the legs of the bipod is a DynaGLide UCR.

The next pic shows the chair back slope set for reasonable laid back resting position. The bipod attachment was 61 inches, the chair front height was 15 inches, the chair front edge distance from the bipod was 63 inches - calculated seat back angle was 36 degrees . Note the change from the first position was to move the bipod back somewhat.

The fifth pic shows the chair is tied to a real tree with mule tape using a round turn and two half hitches - worked well once I rearranged the larks head to have the loose end positioned above the tensioned line.

Note mule tape is normally used to pull wires through conduit - it is rated to about 1500 lbs max load and has been used for hammock suspensions. To use mule tape for camping purposes it has to be washed to remove the grease that is normally used to ease the wires through the conduit.

 

[decorum]

Like this a lot , I've seen a couple of tripod versions but not bi- and mono-pod like these. Thanks for sharing.

 

[fishfish]

great thread thanks mate.

 

[Hog On Ice]

Trying an odd configuration today I set up two long props and figured out how to adjust the chair for comfort in this case. Basically I used the adjustable loops to attach the front stick to the long poles and with each pole on opposite sides of the tree and strapped the poles together at the base of the tree - I used a 4 foot tree strap with a single wrap on each pole and tied the two end loops together with an adjustable loop - the adjustable loop allowed me to get the strap reasonably tight. One item I think was important was to make sure that the butt ends of the two poles do not extend significantly past the tree - this is so that when the chair is raised up from the primary suspension UCR the butt ends do not hit the ground and mess up the chair side to side tensioning. Anyways after getting the chair up to sitting height I found as before that the tension was not equal on each side of the chair - the adjustment that I did was to loosen up the adjustable loop on the front stick that is on the "tight" side and slip the front stick back a little bit toward the tree on that side then tighten the adjustable loop to hold the front stick in the new location on that side. This seems to work and the chair felt better for sitting after I made this adjustment. I am still rating this configuration as somewhat of a novelty and not something I would normally setup in the field but it is nice enough once setup for sitting and the limited side to side motion is sort of nice when changing the direction of interest. The chair however doesn't "rock" as well as the other configurations - the long poles cause it to pivot at the base of the tree instead at the closer ground point of the props in the other configurations. Its sometimes nice to have a bit of a rocking chair but its not a big deal either way.

The pics I took today are nothing special

The first pic is a sort of a front view of the chair showing the long poles going back to the base of the tree.

The scond pic is a closer view of the strap between the poles at the base of the tree.

The last pic is a close view of the butt ends of the poles showing that they are not hitting the ground and thus not interfering with the leveling of the chair.

 

[Hog On Ice]

Here is a video SGT Rock made for me of the setup of the chair:

[video=youtube;TXOFR1DjRRw]http://www.youtube.com/watch?v=TXOFR1DjRRw[/video]

 

[Elines]

Yes this is impressive, and a good video - what is a 'UCR' though?

 

[crosslandkelly]

Neat ideas.

 

[Hog On Ice]

A UCR aka Utility Constrictor Rope, is an adjustable length line similar to a whoopie sling except the big loop that the WS has is opened up and the constriction section is terminated with a prussic or similar taught line hitch - see pic for an example: http://www.outdoortrailgear.com/wp-content/uploads/2012/11/ridgeline-002.jpeg The constriction section is twice as long as with a whoopie sling due to the differrences in how the outer part of the constriction section is tensioned.

 

[Hog On Ice]

Well I thought I would put together a few random notes about the chair:

1.) if using a found stick for the front stick you want a stick that is 24 inches or longer, smooth or can be made smooth so it doesn't damage the fabric, and can't be broken across your knee - I have found this last item to work for me anyways - I hold the stick with hands about 24 inches apart, lift my knee and then try to break the stick with my knee - if I can't its strong enough

2.) if using found sticks for the props it helps to have a fork or knob where the adjustable loop is to go so that the adjustable loop does not slip down the prop stick - if the is nothing in the right spot then cut a small notch in the prop so as to hold the loop in place

3.) its OK to larks head the antislip line to the lower loop of the cross tie IFF you are using trekking poles with baskets for the props but do not connect the antislip line to the cross tie if using found sticks or trekking poles without baskets for props because it will interfere with the cross tie's ability to hold its place on the prop stick

4.) the lightest fabric I ever used for the seat fabric was approximately 1.1 ounce/yd ripstop nylon - if you choose to use this type of fabric be aware that it will wear out probably faster than expected and you should inspect the fabric often for wear - typically the stitching for the front channel pushes the threads in the fabric together creating a weak point

5.) using a polyester fabric is also a possibility if you want to limit the UV degradation of the fabric - nylon tends to degrade with prolonged UV exposure much more than polyester does

6.) if not using DynaGlide lines for the chair then the following are possible substitutions - for the cross ties and adjustable loops the Spyder Line 1.8 mm line will work nicely - the cross ties would no longer be adjustable however so they would have to be tied to a specific length - not a problem if using a specific model of trekking poles but might require retying if the model was changed; for the primary support line the Spyder Line 2.8 mm can be used or mule tape can be used - the Sypder Line would be typically tied to the tree strap with a double sheet bend and larks headed on the gathered end of the fabric seat - mule tape can be tied directly to the tree without a separate tree strap typically with a round turn and two half hitches, second hitch slipped - mule tape would be larks headed to the gathered end of the fabric seat with some care so it does not slip - put the free end of the knot in a position where it is above the tensioned end or add a slipped hitch of the free end onto the tensioned line

7.) as mentioned in the video one of the issues with the setup of the chair is to get the tension on each side of the chair to be approximately equal otherwise the user may feel twisted to one side or even have the chair collapse to that side; another somewhat common issue is when the prop sticks are too close to vertical - here the user will feel that the chair is collapsing backward - a quick fix is to increase the length of the primary support line to allow the prop sticks to tilt forward more - another fix is to move the prop sticks and antislip stakes closer to the tree (or whatever the chair is tied to).

8.) there are a few ways that the slope of the back of the chair can be increased so as to sit more reclined - as seen in the video the primary support line can be lengthened with the consequence that the chair height is reduced - if the user wants to maintain the same chair height then the user can lower the attachment point of the primary support line to the tree and shorten up the primary support line - this allows the chair to remain in place and with the same chair height - alternatively the primary support line can be lengthened and the chair is moved away from the tree along with the antislip stakes and lines; to decrease the slope of the back of the chair (to sit more upright) then just reverse the above operations

9.) when increasing the slope of the back of the chair be aware that like a hammock the force on the supports increases the closer the chair gets to having a horizontal back - when the force gets too high the antislip stakes will probably pull up and the user lands on the ground - as a general rule of thumb it is probably best is the chair back angle does not go below 30 degrees for the same reason that 30 degrees in a magic number for hammocks - any lower and the force on the supports goes up above the weight of the person sitting in the chair

10.) the function of the cross ties is to limit the side to side motion of the seat - it is not necessary to have these lines completely tight but the tighter they are the less the side to side motion will be felt when changing position on the chair - once in the chair you will always find that only one of the two cross ties is really tight and the other may feel quite loose - this is expected and generally not an issue unless there is excessive side to side motion as the user leans to one side or the other

11.) inspect the lines and fabric often - recommended every time you set up the chair and if a line is showing excessive wear then it should be replaced before it breaks

 

[Hog On Ice]

I've added a new thread in the DIY forum for how to make the chair - if interested see http://www.bushcraftuk.com/forum/showthread.php?t=101233