Pack design assistance request

[Bill P]

Hi all, looking for some advice please.

My 750g Golite Jam pack is now nearing its end of life. I intend to MYOG its replacement - im keen on an external framed roll top- something like an zpacks arc haul with a sub 700g weight.

Most packs seem to be fabricated from multiple panels , even when the main body is fully rectangular.

I'm proposing to cut my whole bag from a single piece of fabric as per attached sketch. This would reduce seams , simplify the build and improve waterproofness.

Ive not seen this done before and it seems to be a good idea- especially as the throat and main body are the same fabric. Is there something I'm overlooking in attempting this simplistic type of construction?

Regards
Bill

[Moondog55]

One of the reasons is that the seams add strength and shape, also they are a handy place to put compression straps etc but it also aids construction when they are made in a factory
Never tried sewing a one piece pack so I can't comment further but I don't see any technical hurdles

[andrewa]

I've thought about it, but the most important aspect of pack design for me is for it to carry what I need to carry - fishing stuff, packrafting stuff, skiing stuff, and for this I need side straps/pockets etc. So, I've given up on designing with minimal seams, and just design for my needs.

My large rucksack which is still going well 5 yrs later...

viewtopic.php?f=53&t=8363

And a cuben finer one, which I really haven't used that much

viewtopic.php?f=53&t=19792

A

[Bill P]

Thanks for the advice Moondog and Andrew. The cuben one you made Andrew looks beaut. Love the weight.

Where did you get that red fabric from ,please Andrew? It looks good.

Also im intending to use grosgrain in lieu of webbing whereever possible for weight savings.

I have heard of slippage with ladderlocks though .

Regards

Bill P

[andrewa]

Red fabric was from Dimension - Polyant. Forgotten which particular fabric it was, coz I bought it about 10 yrs ago with a whole lot of other fabrics. I was surprised at the time that a big company would sell fabrics in small volumes to a DIY gear maker - at the time, they had lots of ends of rolls of fabric, and I had plenty of choice.

As to Grossgrain, I've not used it, but I imagine that ladder locks will slip on it. They can even slip on webbing , most noted on shoulder straps, where the ladder locks really need to be the ones that have little teeth. On reflection, there isn't really anywhere on either rucksack that I would use Grossgrain.

Have fun.

A

[Moondog55]

there isn't really anywhere on either rucksack that I would use Grossgrain.

Have fun.

A

I think it has function to bind the edges of canvas or LW ripstop to stop them fraying, in that place it also acts as a reinforcing. Pack straps really need thicker webbing but if you can find 20mm that is more than strong enough and a bit lighter

[Strider]

Andrew Skurka gives an example in his book of "stupid light" where he replaced webbing on a perfectly good pack with grosgrain and it made the pack unusable. Leave something else at home instead.

Sent from my SM-G930F using Tapatalk

[andrewa]

Moondog, I don't normally bind seams on rucksacks, nor overlock them. I've never had a problem with seam fraying with the fabrics I have used - may just be lucky. I agree that 20mm webbing is strong enough

Strider - I agree.

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