I've been toying with the idea of making one of these for a few years, mainly due to the staggering cost (although I appreciate why).
There are various DIY offerings out there, DIY packraft and iron raft are a good resource, however I couldn't find anyone willing to send plans, which is fair enough really considering the amount of design development required and ease of copying, so I've developed my own plans.
It took quite a bit of messing about with Autocad and paper models before coming up with a template that seems to work (at least on paper..)
Progress so far:
Development of various designs:

1:5 scale model of final design enabling final tweaks:




1:1 paper template

Template transfer to material:

Will update as it progresses, probably slowly..
Wow, cool! Looking forward to watching it progress.
Top Work fella!
I've had an Alpackaraft for a few years now, been some great expeditions on it, Bike-rafting and pack/fishing-rafting.
Its awesome, but when on open water I do always get the fear that its deflating (it never is, just the colder water decreasing the air volume slightly).
Not sure my stress levels could handle the thought of my own ham-fistedness having built the actual raft itself - so 'chapeau!'
WOW
That is fantastic - following!
Awesome, watching with interest 😀
have you costed it and compared to the cost of the alpkit and PX ones??
£200 off our packrafts because we're too far ahead of the curve.
https://www.planetx.co.uk/c/q/outdoor/packrafts?deal=toosoon200
This looked interesting btw - https://www.indiegogo.com/projects/uncharted-rapid-raft-world-s-lightest-pack-raft#/
but our supplier said:-
If make similar type like uncharted rapid raft , very thin materail and no any equipments, But it is too weak and too high risk , we will have too many complaints to solve
the alpkit … ones
What, Alpkit selling packrafts - that's worth a look - sadly, I think that was an autocorrect for Alpaca?
Alpacka ~ £800+
Planet X ~ £500 with discount
Second hand ~ £400+
DIY ~ £120 materials
However, even though I said cost was a factor in making one, if they were cheaper I'd probably still try and make one... you either get it or you don't when it comes to making stuff that probably costs as much and doesn't perform as well in the end.
Progress Update:
Shapes cut out:

Temperature test - 180 degrees no good, 200 and 220 material is inseperable

All shapes joined to centre, double layer bottom which will be inflatable on its own

Sealing the curved parts to together, hardest part so far with each seam taking around 45mins (10 in total)

8 curved seams complete so far, next step is to aquasure/glue them internally to ensure they are air tight

Time taken so far: 2hrs tracing and cutting, 10hrs seam sealing
Getting there now:
Valves for inflatable floor - armband valves, 1 c/w 1 way valve the other one has the 1 way valve removed for ease of deflation. Not really a critical part of the packraft so the extra failure point isn't really an issue.

It works! jump test confirmed it's airtight and not going to pop

95% complete, the Boston valve hasn't arrived yet, fingers crossed it'll arrive today. The last front and rear seams were very awkward and took ages, hopefully I've heat sealed them enough to get a good bond.

Time to start thinking about a paddle, tempted to cut an existing one into 4 at the moment but have seen some nice homemade carbon creations, however, material costs alone would be ~£50
STW members never fail to impress with their creativity. Awesome work
This is bonkers!
you either get it or you don’t when it comes to making stuff that probably costs as much and doesn’t perform as well in the end.
I totally get this. I've made a fair bit of my own gear over the years. I enjoy making them, take pride using them and know how to fix them. That said, if they fail, I won't sink!
We'll done, really impressed with this.
How easy was it to use the seam sealer and how expensive was it? Would you be able to use it to make bags? How heavy is the material?
Keep up the good work
Impressed!
I believe one of the "build your own" companies mentioned are basically an Alpacka clone (being careful with exact wording here!).
Comparing costs Stateside with here for Alpacka rafts and you've the usual dollar-pound numerical equivalence though with the pound going the way it has that might not be any fiscal difference at all in the near future! Looking at Alpacka rafts there's quite a few variations from "expedition" to "white water", no idea what the design differences are but there's obviously work gone into that which will be built into the pricing.
Good timing as well - we are off on a packrafting "taster"/gettogether this weekend. I'll try and get some shots and post a trip report next week.
Brilliant. Can't wait to see it float 🚣
I am eagerly awaiting a photo of the raft on the water. Amazingly impressed by this build!
I trust the children won't miss their armbands the next time they go to the pool...
How easy was it to use the seam sealer and how expensive was it? Would you be able to use it to make bags? How heavy is the material?
Seam sealer is a modified RC model film iron, was about £18 IIRC.
Fabric is approx 265g per sqm, packraft weighs in at approx 1400g so far (without valve)
Definitely suitable for bag or outdoor kit fabrication, I believe it’s used for life jackets and other safety gear.
I trust the children won’t miss their armbands the next time they go to the pool…
It’s ok, I only used one arm band
She's alive!
Bow view

Stern view

Underside - notice the tubes being pulled "in" slightly, this is due to the inflatable floor.


Great effort! Very impressed, looking forward to seeing photos of its maiden voyage.
.
Awesome self build - inspirational!!!
Brant – is that the best price you can do on the spray deck boat? Nearly £250 notes more than the open boat
Pricing follows Fibonacci numbers so best I can do.
Brant – is that the best price you can do on the spray deck boat? Nearly £250 notes more than the open boat
Wow. I know I reply quickly but how have I replied before your post 🤔
Mindreader 👍
Shame, in cold UK water I think the spaydeck model is the only option but still out of my budget as I’d need 2
Drop me a DM.
The packrafting meetup at Llyn Tegid (Lake Bala) at the weekend had glorious sunshine on Saturday. There were a few packraft companies there - this lot of boats were from Anfibio

There were various courses, we took the packrafting 101 having paddled kayaks a total of about half a dozen times over twenty years ago. This covered the basics of inflating & deflating the raft, ingress and egress along with basic safety practices.

In the afternoon we'd booked on the "open water wizard" course which covered the effects of wind and terrain on the water, simple rescue techniques, maintaining position on the water (not as easy as it sounds), maintaining a course when there's cross winds and currents.

I tried a different raft for each session and even to a complete novice like myself it was obvious just how different they were to manoeuvre and having a raft that "fits" is pretty important to being able to paddle efficiently. We were using "generic" rafts not those aimed at white water.
Interesting but it's not something for me, I'm not a watersports person.
Wow, looks like this has turned into a marketing campaign for on-one 😉 DM me to arrange my commission - a paddle will do 🙂
Looks great Whitestone, maybe I should have done something like that before starting my design.. I thought it would handle like a tractor inner tube compared to a traditional boat so just cracked on.
I knew this stage would have to be done, but I was kinda hoping I had been thorough with the heat sealing and aqua-sealing: Leak finding: a couple of holes found by sound, but had to do the old water test to find the rest:


This thread is ace, top work mikeyd.
When does the naming competition start? 😉
RM.
One thing I notice with your design that's different to the commercial offerings is the floor - the commercial rafts have a simple fabric bottom not an inflatable one, it also seems to be a slightly heavier material. Presumably this is for protection as the rafts are single chamber so if you puncture the floor then everything starts to deflate.
For "comfort" there was a separate inflatable seat and back rest.
Nice work OP, can I ask where you got the material?
Brant Brant Brant - STW instant messaged you last night.
OP - still amazing work btw wish I had the talent and time
Brant Brant Brant – STW instant messaged you last night.
I've just gone through pricing and looking at cost, how few we have left, and what we have available, I can't go any lower.
T-Zip ones are same price as SprayDeck only ones, and paddles are v cheap.
So no movement sorry. Certainly the best price for this quality anywhere.
Plans to make a paddle were scuppered by Planet-X's bargain paddle - DIY materials were going to be around £40 and their Carbon/Nylon offering was £55. At just over 1kg, it's lighter than a few of the big name 4-piece paddles and has been designed so each piece is the same length which is great.
A bargain compared to something like this, similar weight, 6x the price and the pieces are different lengths.. http://wernerpaddles.com/paddles/packraft/pack-tour-m

Total weight of the setup including paddle and mini USB air pump 2925g.the commercial offerings come in around 3-4kg for the packraft alone.

Possible sea trials tomorrow as long as the weather isn't too bad..
How much does the Life jacket weigh?
has anyone notified the coastguard?, last post was 3 days ago!
Sorry, I'm alive, didn't have time last week for the testing..
Managed to get out for it's maiden voyage today, thought a bit of surf, off shore wind and no lifeguard cover would be a good test...


Vid:
Fairly terrifying/super fun in the surf, not so much of case of catching a wave, more the wave catching you!
Paddling position is a little odd in that you are very low in the water and have to make sure the paddle goes in very close to the raft as it turns on a dime, will be great fun on river whitewater.
Lack of spray-deck is a bit of an issue in the surf, fills up quickly which needs to be emptied after each big wave. All in, pretty pleased!
To answer a couple of questions I missed:
can I ask where you got the material?
https://www.rivertex.com/en/
HT200 fabric
how much does the life jacket weight?
Cheapo 50N Helly Hansen jacket is around 500g, better white water style is a bit more but has some decent pockets/features.
👍
Great thread. If only to realise planet x do cheap 4 part paddles