[OpenTRV-dev] 3D OpenTRV case design

[Bo Herrmannsen]

see lines with >>>>>

-----Oprindelig meddelelse----- 
From: Damon Hart-Davis
Sent: Saturday, October 12, 2013 5:23 PM
To: Closed list for developer discussions
Cc: Damon Hart-Davis
Subject: 3D OpenTRV case design

Hi,

Bruno came round today and we worked on the case design: initially something 
for DD1 given that I want to have some eye-candy this coming Friday for the 
Dynamic Demand Challenge Hackathon, but actually to think about a 
standardised OpenTRV design.

Given the work that Bo has done to make the OpenTRV REV1 board match the 
footprint of the DD1 board, the aim is that what we have done today should 
cover a whole family of OpenTRV (and DD1) boards with a standardised base 
and lid and only a collar above and below the board needing adjustment for 
each board revision for positioning of connector cutouts and so on.

Basic layered design from top might be:

>>>>> for 3d printing, could we make one parameter in openscad whatever to 
>>>>> print in layers or the whole buttom part of the box in one go? but 
>>>>> still with nut cuntersunk in buttom part and bolt inserted through lid 
>>>>> etc?

1) Lid with holes for buttons, sensors, etc.

>>>> maybe some of the holes on the sides, but in like a punch out config 
>>>> where there is 0.5mm matrial thickness and you just jam a screwdriver 
>>>> through to remove the matrial and then a scissor to sharpen up the hole

holes could also be a paramenter in the openscad file so we just select 
board and it makes the holes... loads of ways.... a sub parameter could be 
where to place the buttons?

2) Spacer collar (~3cm).

>>>> by this you mean layers that makes the box 3 cm high?

3) Thin upper collar for cutouts above the PCB.

>>>>> cut outs?

4) Base and under-collar for cutouts below the PCB.  Includes screw slots 
for wall mounting if desired.  This could be two layers.

>>>> screw slots for wall mount great idea... will it be an parameter so its 
>>>> an option?

Collars/cutouts can be selected by board revision, eg V0.2-REV1 would flick 
various switches to customise the basic design in OpenSCAD and then the STL 
goes to the 3D printing process as usual.

(I think that much of this should be immediately convertible to 
injection-moulding were we to want to go beyond a run of say 100, eg top two 
layers as one half and bottom two as the other.)

I'll post a link when I've put up the STL, SCAD and some photos; just 
letting the spacer collar print run at the moment...

Also, given constraints of our thinking and printing time, etc, I propose 
that we have this housing enclose only the OpenTRV (/DD1) board itself, with 
separate battery packs for the first run, on flying leads, and containment 
for the SSR for boiler control units.  Bruno suggests that we could make 
these mechanically mate in some way, though be separate items.

>>>> yes, if he does not get an smart idea before time runs out that would 
>>>> make the space for SSR / Battery an parameter....

Possibly Bo could do the SSR containment boxes separately via his mechanism 
and send them to me: we'll only need a small number and it would be good to 
make use of the time he has already put in on that side.

>>>> yes... the box design i have can very easy be changed... basic i just 
>>>> need make it smaller again so it only houses battery or SSR.... a 2 AA 
>>>> holder i have... but should i make big enough for 3AA's ?

        how much space needed for an SSR?

       i picture 2 holes in the box... one for mains if we fit a SSR.... and 
one for battery leads



Rgds

Damon