Sep 1, 2008 at 8:26 pm #1230966
External Fame and Cuben Pack Bag – New as of 1 Sept 2008
Ever so often when I think a might get out for a hike I gather all my previous MYOG- External Frames to see if I want to use one of them or make a new one.
I have made a bunch of frames over the last few years but have never really got one like I want it.
I got the new Shirt and Pants BPL.com just started selling and I have been wearing them in our South Texas heat. The temperatures have been from 96 to about 102 – direct sun – for most of my test hikes with them. I have decided that when it is that hot the only time any clothes are cool is when you jump into a cool body of water wearing them.
Then if you put the typical backpack on you find out real fast that hot just got hotter. That is unless you have a pack with a window between your back and the pack bag.
That is the type of External Frame, Pack Bag combination I have been working toward for the last 4 years or so.
I have made frames that do this really well but they have all been heavier than I want one to be.
This new frame is an improvement and is one of my lightest frames to give me a decent size "window" so far.
The shoulder straps are from an older test frame and will be much lighter when I make a new set to go with this frame.
The Pack Bag is the "Cuben – Snowshoe Bag" I made last year. It weighs 2.5 ounces and is a good size for the max weight I might want to carry. Here is a link to that thread:
New External Frame w / Pack Bag
1. The white perforated things are what I am calling my "Air Pillows".
3. "Wing" things – idea from an old Jansport Pack I have. My "Wing" things are lighter than the ones that came on the Jansport pack.
I have been carrying this Frame setup for the last 2 days. I carried it 3 times for 2 miles each time today. The first time today without the air pillows on the frame. Hot.
Then I put the air pillows on and went back for another 2 miles. What I nice difference. With only a slight breeze I was able to feel the air blowing between the frame and my pack bag.
The load in the bag pack today was about 13 pounds. I will add weight to the pack every few days till I see what the top limit might be.Sep 1, 2008 at 8:56 pm #1449571
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
Interesting. The wings – I haven't even thought about doing something like that. I wonder how long they will last?
If I may, can I suggest covering the blue foam with fabric. The downside is that you get reduced grip, but the upside is that the foam will last a lot longer and not get sweaty/gungy. Well, I think.
RogerSep 1, 2008 at 10:09 pm #1449578
@tbeasleyLocale: Pigeon House Mt from the Castle
Great work, nice to see you are feeling better and are back doing MYOG.
One question, what does the frame weigh in at.
TonySep 1, 2008 at 10:30 pm #1449580
The wings are strong and should last long enough. I will take some pictures so you can see how they are mounted. Sort of like door hinges.
I have thought about covering the blue foam at some point. I would like to be able to say it is screwed on so I can take it off at night and use it to sleep on. It is easy to change if necessary and some kind of covering adds weight.
I carried the frame / pack bag a couple times without any foam padding. I would like to get back to no padding if I can. When I go back to a lighter load I will play "no foam" again and see at what point I start to think I need padding.
Right now the whole frame is a Prototype and subject to some changes. On my last hike I added some more weight and found a place I need to add a small brace to keep something from pushing into my back.Sep 1, 2008 at 11:02 pm #1449582
Thanks, I am up to 6 miles plus walking a day and it seems like the more I walk the better I feel.
See all that all that empty space on the table? That is my sewing table, it is 4' by 8' long and had been piled up with junk that I have put away where it belonged or dumped it.
I have a few things I need to sew and when I get the new frame under control I will get on the sewing.
The frame without the pack bag weighs 32.66 ounces. The Thermoplastic "air pillows" are a bit heavy. I have tried to make them lighter but the lighter ones don't hold up the weight very well. The Cuben pack bag weighs 2.54 ounces.
The frame as you see it with the bag empty comes to a total of 35.20 ounces. 2 pounds plus but I hope to reduce that to below 2 pounds before I am finished with it. It carries nice and is cool on my back.Sep 2, 2008 at 2:36 am #1449591
well done bill
it really looks like Jack Stephenson' jack pack which had been made circa late 1950s.:)Sep 2, 2008 at 6:14 am #1449601
Hi qiu tian,
You are sort of correct, this thread is a follow-up to this one:
I found the old Jansport pack before I had a picture of the old Stephenson's pack. Same idea.
I can't get or bend that small aluminum tubing.
Ultra-Light External Frame PackSep 2, 2008 at 2:12 pm #1449654
Guessing the alum. tubes on your design are pretty light ?
If not, do you want to try and add some superlight carbon tubes to try and reduce the weight ?
Guessing the wings might be the heaviest part of this design?
I have a 3 year old daypack that I use for mountain biking that has movable wings on the hips and then uses a "net" that pushes the pack off my back. Superlight and lets all the air flow over my back. Netting would conform to your back and be lighter then the foam pads … something to think about.Sep 2, 2008 at 3:27 pm #1449669
Thanks for the comments and suggestions.
I have/had Fibraplex carbon Fiber tubes inside the aluminum tubes. The aluminum tubes are acting as spacers between the cross pieces. As the pack bag weight went up the spacers caused a stress point and one of my Carbon Fiber tubes cracked at the joint. I have taken the frame apart to rebuild it.
While it is apart I will weigh the main parts and post how much the "wing things" weigh.Sep 3, 2008 at 3:41 pm #1449827
Yesterday I rebuilt the upper part of my new frame. I got rid of all the tubing and have replaced it with aluminum angle material. I also added a couple of braces.
I have carried it three times now and it seems to carry a bit better than it did. You may see that I have also changed the size of the blue foam in the hip belt area. I expect to make additional changes as the amount of weigh I have in the pack increase.
When I was about to put the "air pillows" back on I connected them at the top of the frame. This made a really big improvement in the amount of air that can now move between my back and the pack bag. I have walked twice today so far. It is around 96 or so. When my back gets a little damp and the air blows over it – it is almost like standing in front of an AC unit.
The weigh in the pack today is about 15 pounds and I will add more weight in a couple of days.
This frame / pack bag are being used as a training pack to get me used to carrying about 25 pounds of weight. You might say this is a conditioning exercise to get my body used to more and more weight.Sep 4, 2008 at 11:40 am #1449979
Any chance we might be able to see a picture taken with you wearing the pack? Maybe a side view? I would like to see how far it sits off your back and how the wings work with the straps.
KevinSep 4, 2008 at 12:33 pm #1449986
are the shoulder straps attached to bar at all or free to slide around? seems like if they were free they could slip off or require constant adjusting…Sep 10, 2008 at 4:13 pm #1450791
I have always used and really like the oldere Go-lites and now only use the G.G. packs. No frame and just two light carbon poles to support the frame structure.
Tell me what advatage you have in using the side wings ?
If they really contribute to to something that I cant figure out … I have a intersting idea using carbon fiber to build a complete one piece back stay / side wing frame that you could R & D. Light and strong …. Give me your thoughts.
KevinSep 10, 2008 at 9:36 pm #1450824
Hi Kevin and Derek,
I guess I didn't notice the other two messages.
Kevin – I will try and take a few side pictures of me wearing the new frame/pack bag tomorrow. I never owned a Go-Lite pack but did look at them from time to time. My first Cuben Fiber Pack was a bit like the one Ray showed how to make in one of his books.
I own two GG – G6's and really like them. One stock pack and one highly modified pack. I am working on my modified one as I type this. I have more or less taken the modified one apart again and will make a few more changes and sew it back together. It is very well made and the only real way you can say that is if you take one apart. I have a thread here someplace about the modified G6 and will add the new modifications to it when I am finished.
On a big – high volume and high weigh load – External Frame Pack you need a really thick / wide hip belt or someway to help stabilize the hip belt. The "wing things" helped stabilize the hip belt with less weight.
On a smaller external frame pack carrying lighter weight I have been able to use the "wing things" without any padding. I have blue foam pads on this frame as I missed a bit on my dimensions and the hinge point hit my hip bone. That will get changed on the final version. I was carrying this frame with less weight but as I added weight I discovered the hinge point problem. With a very light load and wanting a frame that would push the frame and pack bag away from my back the "wing things" seem serve a useful function.
A year or so ago I was going to try carbon composites but the stuff was hard to get. I have thought for a long time that composites were the key to a really light frame.
Derek – The sholder straps are on that cross piece and attached to the frame sides and can not come off. Once the frame is on me I can adjust or slide the straps a bit for a better fit. Then the pack weight and my head keep the shoulder straps from being able to slide very much.Sep 11, 2008 at 8:59 am #1450861
"On a big – high volume and high weigh load – External Frame Pack you need a really thick / wide hip belt or someway to help stabilize the hip belt. The "wing things" helped stabilize the hip belt with less weight."
I now understand your thought process. I guess I always just assumed you had the "lightest of the lightest" loads when you are hiking after reading all your posts. What do you anticipate the high volumn and high weight load you will want to carry on this type of pack? 30+ pounds? At first I just assumed you were trying to get as much airflow as possible over your back ?
"On a smaller external frame pack carrying lighter weight I have been able to use the "wing things" without any padding. I have blue foam pads on this frame as I missed a bit on my dimensions and the hinge point hit my hip bone. That will get changed on the final version. I was carrying this frame with less weight but as I added weight I discovered the hinge point problem. With a very light load and wanting a frame that would push the frame and pack bag away from my back the "wing things" seem serve a useful function."
I ordered up some casting supplies yesterday and plan on building up some new tooling to try and make a new composite frame with some small flexable wings all in one piece. I have some crazy ideas going though my head that YOU always seem to inspire Bill !!! If I get anything that looks like it might be worth testing I will send you some photos and we can see if I can get you something to play with. A side photo showing how you might want the pack offest away from your back would be very helpfull.
KevinSep 11, 2008 at 11:29 am #1450879
"On a big – high volume and high weigh load – External Frame Pack……."
For the last couple of years I have been doing a lot of thinking and planning and re-planning something where it would be necessary to carry a heavy pack. Not a lot of heavy gear but a lot of food, like for 25 to 30 days worth. The gear for a hike like this would be in the Super Ultra Light (SUL) weight range. The high end pack weight I am looking for is about 40 pounds on day one. That assumes that I can hike with a pack that heavy. I am slowly working on the physical aspect of this task.
I have other large packs that can carry that weight but those packs are really heavy.
I am trying to get the new External Frame / Pack Bag at or really close to 2 pounds empty. The Cuben pack bag that I am using on this frame now weighs about 2.5 ounces.
"lightest of the lightest"
My hiking philosophy is to reduce each piece of hiking gear to the lowest safe level, use each piece of gear for more than one thing when ever possible, and to test my gear before going to the woods.
I have been trying to make a very light External Frame with some type "air pillow" system for years. I have several good prototypes but they are still not as light as a want them. I am still working on a really light External Frame but my Cuben Packs or my GG-G6 are used for most all my Sub 2 – 3 – to 5 pound gear lists.
I am thinking about trying my new External Frame for some of my Oct Hike if the hike happens. My gear list for that hike using the External Frame should still be below Sub 5.
It will be very interesting to see what you come up with.
What you refer to as "crazy ideas" are just the first step in how great designs happen.Sep 11, 2008 at 12:27 pm #1450888
@retropumpLocale: The Antipodes of La Coruna
Bill, as always your creations are inspirational. Although I have contemplated something similar using a Vaude AeroFlex system I finally realised there was no reason for me to re-invent the wheel. I have a LuxuryLite frame/hipbelt combo which ventilates better than anything I've ever used. I have been using it with a cut-down GoLite Gust, but now I think I'll just make a cuben sack to replace the gust and be satisfied. This frame combo carries heavy loads with extreme ease IMHO. But a lot of MYOG projects stem from the fact that everyone is different, and what suits me may not suit someone else. Not to mention the satisfaction of making it yourself!Sep 11, 2008 at 3:36 pm #1450915
Bill, Thanks for the photo and follow-up on the questions. I'm so used to doing the 100 to 225 mile hikes always with resupply points that I didn't even think that you might be carrying all that extra weight in food.
That photo really helps me see what you might need in the way of a carbon frame sheet. Two questions for you:
1) I was thinking that I would make the frame sheet contour more along the shape of a back. Was thinking you might be able to use some small strips of foam to push it off your back to give you something comfortable with some air flow. If the shape matched the contour of your back I think you might be able to get by using some smaller and lighter foam pieces as you wouldn't maybe have as many pressure points? Or, you might only need the foam in the upper areas of the back and lower areas of the back, nothing in the middle? What do you think? Or, would you rather have the framesheet curved away from the center of your back?
2) What do you see as the length of the frame if make this as a single frame spine, going from maybe as inch or two below your hips to maybe 5.0" above your shoulders ?
3) the bottom of the spine is at the same horizontal plane as the waist belt so this should make it pretty easy to try and incorporate the wings into the design.
o.k… no more questions after you answer these. I'm just going to play with some carbon and see what I can come up with.Sep 11, 2008 at 6:07 pm #1450928
I have made a couple of frame changes and have gone back to no padding in the hip belt area. I will go for a 2 mile walk in a few minutes and see how that works. I went back to 12 pounds in the pack and will add more weight if removing the padding works out. If I decide to use this pack in Oct I may only carry 3 to 4 pounds of gear. I also should never have to carry more than 3 to 5 days worth of food. I may use the new frame for all my hiking in Oct to give it a good work out and see if anything breaks.
This picture shows what the hip belt area looks like without padding. You need to try and make your frame with a curved hip belt area if you can.
This picture is my modified Harrier Pack Frame. I am working towards a hip belt like the new frame and the upper part from the Harrier.
I will answer your questions when I return.Sep 11, 2008 at 8:44 pm #1450936
The curved hip area was exactly what I was going after and I can make that section strong, light, and exactly form fitting without any screws, bolts, or sharp edges. That part should be pretty easy.
It is the frame portion that I'm trying to figure out what design might be best. Flat, curved to match the shape of your back, or like the modified Harrier pack that you just posted that arcs away from your back (guessing for improved air flow?) ?? Sounds like you are going after the last route, curved away from your back. Supplies should be in on Monday to start the new tooling concept. Should be a fun project!Sep 11, 2008 at 10:10 pm #1450939
A – 1. I have found that if I make an "air-pillow" that is attached an inch or so from the outer edge and goes from the top to the bottom of the frame the comfort level is good and I get air flow between my back and the pack bag. The "air pillow" is most comfortable if if is a bit smaller at the bottom and tapers larger toward the top. I agree that your "frame sheet" should be more comfortable if it is contoured to fit the back.
A – 2. Look at the picture of the modified Harrier Frame. Notice the wooden – brown – pointed things on the top outer edge of each upright. The pack bag is made to slip over the pointed things to hold the bag on the frame. Their are pieces of webbing on the bottom of the pack bag that attach to the bottom of the frame. These are pulled tight and that pressure holds the bag on the frame.
From the top of the hip belt to the top of the brown things it is 21.5 inches. I can adjust that distance with a spacer. You can see the space ( brown also) just above the blue foam hip pad.
Friday or Saturday I should have some time to work on a few ideas I have to mate the wing things to my Harrier frame.Sep 15, 2008 at 12:07 am #1451156
I made a few changes to my new frame this past weekend. I combined parts of my modified Harrier frame with the "Wing Things" frame.
I put the stock Harrier pack bag on it and loaded it with 26 pounds of stuff. I then took it for a walk. The frame carries the weight OK. I tweaked the frame a bit and backed off the weight some and carried it two more times. I don't know the last time I carried a pack with 26 pounds in it. The heaviest pack I have hiked with in years has been about 16 pounds and that was with a lot of food and water.
I have a great window for air to blow between my back and the pack bag. I have two of my "Air-Pillows" on the frame at this time but I think I might be able to remove them. I will try that on Monday and see what happens.Sep 15, 2008 at 4:09 pm #1451199
Looks good Bill. I'm still waiting for the tooling supplies to come in. Figure it will take me about a week to try and make the tooling before being able to try and make the first R & D part. Thinking I'm going to have to make two tools to really make the structure that would be best. Looking forward to hearing some feedback from you soon!Sep 15, 2008 at 5:47 pm #1451217
@mad777Locale: South Florida
Bill, this thing is beginning to look like a European sports car! Keep up the good work!Sep 15, 2008 at 6:10 pm #1451222
Hi Kevin and Michael,
Thanks for the comments.
I took the "air pillows" off and went for another 2 mile walk. Just got back. I am getting breeze where the "air pillows" were so I may leave then off.
I want to try them on the hip belt but I think this set may be to big. I also am going to put the shoulder straps from the other frame on this one and see how that works.
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