I'm wishing to make a DIY subnotebook, if possible.
You are going to run into a few problems here...
Do a requirements specification
o What functionality do you require
---- whiteboard 3 levels -- ideal (dream on), realistic, minimum
o What do you have to spend
---- whiteboard 3 levels -- worst, best, middle
o What is the likely basic component cost
---- whiteboard 3 levels -- worst, best, middle
---- include R&D -- prototyping defines over-budget
Do a feasibility study.
o Display -- your biggest problem
---- TTL desktop -- smallest is MOBI 15", 2kg, conventional 3.8kg+
---- LVDS laptop -- requires LVDS EPIA m/b, £199 for 15", 1kg
o Display mounting -- friction hinges
---- RS do a small & a large - £8 small, £14 large
--------- if you need these, let me know I have some new
---- NO friction hinge will hold a desktop TFT at its edge
--------- rotational moment is huge re 1/2-ht * weight
o Keyboard type -- small & lightweight
---- Cherry G84 with Trackball
---- IBM Travel Keyboard with Trackpad & Trackpoint
---- both are 22mm high, compact
o Battery -- LI-Ion possible, also Lead Acid
---- weight vs power draw is an issue
o Vibration/Shock -- basic knockable
---- this gets ugly on cost, complexity, capability
o Packaging -- your biggest problem
---- custom - alloy angle, honeycomb PP, latches, corners, edging - 10lb
-------- customisable but design LAST re internal space
---- Pelican case - flange mount case for keyboard, TFT in lid - 10lb
-------- gives you a sealed box, use flying cables to panel mount skts
Components exist to make it work - at a price.
Problem in reality is the weight - it adds up very fast.
Whatever you do, you have a chain of dependencies...
o Keep the design open as long as possible
---- packaging should be the last thing
---- making it fit a package can be making a rod for your own back
o Identify those dependencies re Change-A = Change-B-C-D
---- eg, TFT size/type changes case size, m/b spec, layout
---- eg, PSU size/type changes case size, PC spec
o Identify those areas which COULD change in future
---- eg, battery/PSU tech changes requiring different form factor
---- so create a degree of contingency in the design for such
---- common for a design to be obsolete before it is in use
o Identify each option at each stage
---- whiteboard the various options of doing *anything*
---- keep a record, and go back over it
Pilot on paper or ideally 2D CAD package - plenty of cheap ones.
The problems are...
o You want a sub-notebook -- packaging problem
---- custom cases are limited by extrusions for edges & top/bottom
-------- ex - Z-edging is 22-27mm, corner-edging is 22-27mm
------------ that means 44-54mm for EACH of top & bottom = 88-108mm
------------ you have form-factor height on cooling fan & connectors
---- off the shelf cases are limited in range & similarly sizing
-------- ex - Pelican 1470 is slim, but what can you fit in it
------------ you still have form-factor height on cooling fan & connectors
o You want a screen hinging down over a keyboard
---- that requires something to a) limit the angle b) provide adjustment
---- which is known as a friction hinge, which Pelican don't offer
---- laptop TFTs are super-light, extra-thin (0.9mm glass), limited bracing
Key problem often ignored - look at your laptop, the keyboard sits in a
pool of material which doesn't impinge on the wrists. Either a Pelican case
or flight case solution will have a Z-edging or U-edging which will press
against the wrists, and be very uncomfortable. Ok, so you could stick a
gel pad in the way to provide cushioning, the lid then clamshells down.
There is a product which does exactly what you want...
o Around 27% of the rugged market is still 1.4-2.7B$ these days
---- it isn't laptops (Toughbook, Dolch briefcase jobbie)
---- it is Luggables - Lunchbox PCs
o You could realistically create a Luggable
---- PC + TFT in a box, lid comes off, floating standard or slim keyboard
The only way you can realistically create a sub-notebook is...
o Tiny 10.4"-TFT LVDS display in the lid of a case
o IBM Travelsaver or Cherry G84 super-light super-slim 22mm keyboard
o VIA C3 in ideally non-fan version (533Mhz) or AMD Geode etc
---- Mini-ITX or EBC or SBC --
www.bvm-store.com for ideas
---- ensuring you get a LVDS version, and cable & bits n bobs
o DC-2-DC convertor board re ATX - or - a m/b with onboard convertor
---- some boards have 1 voltage input, eg, Mobile Celeron needs 5V etc
o Battery -- price is key here
---- big $ -- LI-Ion generic & charger - someone on uk.adverts.computer
---- small $ -- lead acid gel type - deep cycle discharge type, quite heavy
You are still going to find it heavy due to the casing:
o Flight case
---- parts --
www.penn-fabrication.com
-------- they do the h/w you need from latches to Z-edging & angle
-------- you will want to use 5mm sheet section stuff re weight
---- case sheeting -- forget ply, you want a) honeycomb or b) PP
-------- solid PP sheet from bayplastics, still heavy, leathergrain (PC monitor)
-------- honeycomb PP does exist in 5mm, most commonly 7mm (Astroboard)
o Pelican case
---- even small ones are still the same 1/4"-PP which has weight
---- it's going to be about 5-6lbs for small but usable
More likely you create a luggable...
o Any size TFT monitor - lightweight MOBI 15" or standard desktop 15"
---- use the VESA mount on the latter, creativity on the former (MOBI)
---- the MOBI is actually a laptop panel with LVDS input
---- you need a TFT with 12V input (external power brick), power off PC PSU
---- realise a desktop TFT = 30W due to backlight = ~2.5-3A at 12V
o IBM / Cherry keyboard
o 1U PSU or DC-2-DC convertor etc
o Motherboard from super-low power Geode to Dual Xeon
o Battery or very long mains lead
o Build PC, stick TFT to PC, stick whole lot in the flight case
---- ideally on rubber stud mounts --
www.rswww.com
---- eg, Paulstra Diabolo, Radiaflex, gives a bit of shock mounting
---- shock mounts must only be in compression/shear, not tension
o Fit keyboard by velcro retainer belt into the front lift-off-lid
o Fit 4 feet, use panel mount connectors on the flight case
---- or go cheap and have m/b connectors thro to the case side
Astronomers to Tropical Forest researchers have used various forms.
One wanted a Peli 1610 (big such that council tax is payable) with a very
low power CPU, huge SLA for ease of replacement, lots of 2.5" disks. It
was used for radio telemetry logging in some place they didn't want him
back from, ever, like they didn't even offer a map for him to even find it.
So it comes down to is it practical - or economic - for what you want.
If you want a customisable laptop, stripped down, try Asus.
If you want a rugged low power laptop, try a CF-27 ToughBook.
Whiteboard (even on paper) all the ideas, possibilities - don't discount any
at first as they often give insight into other solutions (or where they fail).
I use a luggable server...
o I needed -- Rugged + Multi-PCI slots + Easily Repaired + Upgradeable LT
---- basically I have a laptop, but needed a very flexible server
---- able to take anything, be shipped, wheeled, yet very cheap
---- no external connectors physically linked to internal re damage
o Chassis cost ~£180, sub 18lb, stainless, alloy & PP
---- takes 17" or 15" VESA mount TFT (not that you could tell)
---- integral wheels, shock mounted to about 3ft (shake table tested)
---- takes off the shelf PC parts, beats £4-8k luggables
---- Bulgin panel mount RJ45 to USB & cable link to m/b
It was however a pilot for a commercial unit for video production people,
and one currently having the daylights beaten out of it around Brazil. Asset
is 1) power 2) ruggedness 3) commodity upgradeable 4) super low cost.
So define what you need carefully.
You will struggle to get a sub-notebook size solution of similar fnality.
You can even recycle a notebook - but TFTs are tied to onboard graphics,
and there are a couple of variations of LVDS (making laptop TFT re-use hard).
Biggest problem is laptop size = custom enclosure = custom wallet.
Separating the TFT from computer makes life easier:
o Easy to create/buy a micro-PC - EBC, SBC board or full Micro-PCs
o Then take a TTL TFT - 8", 10.4" mini-monitors exist quite cheaply
o Stick the two in a simple flight case or nylon camera case etc
If you run an EPIA off a 12V SLA...
o Really you need a car-battery DC-2-DC convertor
o This monitors the voltage re protecting the battery
o Do a google for Mini-ITX - Car PCs & Embedded Alarm/X10 apps
Have fun
