[NTLK] AA battery trays

[Jeff Sheldon]

Tony,

Thanks for posting these links.  I had forgotten all about this and
boy does that look good, thin or not.  Here's the GitHub location for
the STL file.  It would be great to see this on Thingiverse.com for
more exposure and paid-print options, but anyone with a 3D printer can
use that STL file.

https://github.com/davisr/Newton-MP2x00-AA-Battery-Tray

I think people are missing an opportunity here.  Why use 4x AA
Alkaline batteries?  What about a tray with the same outer dimensions
and form, but different battery source and charging circuit
internally?

Some MP100 specs pulled from the web (characteristics which mostly
apply throughout all 4-cell MessagePads):

"Uses 6V AAA alkaline batteries which last 14 hours, and a 4.8V NiCd
battery which lasts 4 hours."

So at peak, 4.8-6 VDC to power a MessagePad through the battery port.

The power circuit is also so touchy with poorly regulated power
supplies that one could make a rechargeable Li-Ion power battery pack
and isolate the charging circuitry to a micro-USB socket on the side
which could become the "new" power port.  Then we could use the
multitude of USB-based charger cables and devices while keeping the
batteries topped off.

Davis' battery tray design is the perfect for starting point.



-Jeff


On Tue, Jan 30, 2018 at 9:58 PM, Tony Morrow <gizmo1482 at gmail.com> wrote:
> Found the thread: https://marc.info/?t=136362910100003&r=1&w=2 <https://marc.info/?t=136362910100003&r=1&w=2>
> Davis’ comment about printing: http://lists.newtontalk.net/pipermail/newtontalk/2013-March/010246.html <http://lists.newtontalk.net/pipermail/newtontalk/2013-March/010246.html>
>
> -Tony Morrow
> https://lookanotherblog.com
>
>> On Jan 30, 2018, at 10:49 PM, Tony Morrow <gizmo1482 at gmail.com> wrote:
>>
>> I remember that being part of the discussion, although I can’t find the specific message. Someone suggested printing the tray vertically might allow the walls to be thin enough to hold batteries and still slide into the chassis.
>>
>> -Tony Morrow
>> https://lookanotherblog.com
>>
>>> On Jan 30, 2018, at 10:03 PM, <tonykan at xtra.co.nz> <tonykan at xtra.co.nz> wrote:
>>>
>>> Hi Folks
>>>
>>> From memory the thinness of the plastic required to build a tray; and the
>>> imprecision of 3D printing at the time meant it wasn't practical to
>>> continue.
>>>
>>> Cheers
>>>
>>> Tony Kan
>>> Christchurch
>>> New Zealand 8245
>>>
>>
>
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-- 
-Jeff