I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

I'd like as light-weight, but strong material as possible.

My one thought was to recycle PET soda bottles and develop a home-made
pour/compression mold, but I'm not certain that's the practical way.

Or, perhaps using a pourable resin (polyester or epoxy?)

Finally, I've considered a shop-build vacuum forming table, but I'm
concerned about forming the support ribs on the inside of the bottom
case half.

Any suggestions would be welcome.

tillius wrote:

I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

I'd like as light-weight, but strong material as possible.

then its ali, carbon fibre / kevlar reinforced

Seriously, youre just not giving enough info. No info re plastic vs
metal, application, what issues matter and what dont, budget,
appearance requirements, etc etc.

My one thought was to recycle PET soda bottles and develop a home-made
pour/compression mold, but I'm not certain that's the practical way.

Or, perhaps using a pourable resin (polyester or epoxy?)

Finally, I've considered a shop-build vacuum forming table, but I'm
concerned about forming the support ribs on the inside of the bottom
case half.

Any suggestions would be welcome.

Give us a lot more info


NT

tillius wrote:

I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

I'd like as light-weight, but strong material as possible.

My one thought was to recycle PET soda bottles and develop a home-made
pour/compression mold, but I'm not certain that's the practical way.

Or, perhaps using a pourable resin (polyester or epoxy?)

You want Sylgard, a pourable silicone resin, comes clear and can be used
to encase electronics. The only problem with it is it helps to degass it
after you mix in the activator, you can rig up decent vacuum with
Vernouli type device attached to a tap. It is very thermally resistant
and has excellent shock absorption properties. Might not be good for
airflow though.

Peter
--
Add my middle initial to email me. It has become attached to a country
www.the-brights.net

On May 19, 12:17 pm, tillius wrote:
I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

I'd like as light-weight, but strong material as possible.

My one thought was to recycle PET soda bottles and develop a home-made
pour/compression mold, but I'm not certain that's the practical way.

Or, perhaps using a pourable resin (polyester or epoxy?)

Finally, I've considered a shop-build vacuum forming table, but I'm
concerned about forming the support ribs on the inside of the bottom
case half.

Why not just get an old desktop computer and gut it? A Dell P1 or
early P II might do.

On 19 May 2007 04:17:45 -0700, tillius
wrote:

I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

Can't say I've ever had this problem.

Can anyone suggest a good way of racking vast piles of discarded
cabinets from old electronic equipment? These days the only bit that's
wroth recycling is the case and the power switch. I (and every other
electronics geek I've known) have truckloads of old cases just waiting
for projects that will never get built.

tillius wrote:
I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

I'd like as light-weight, but strong material as possible.

My one thought was to recycle PET soda bottles and develop a home-made
pour/compression mold, but I'm not certain that's the practical way.

Or, perhaps using a pourable resin (polyester or epoxy?)

Finally, I've considered a shop-build vacuum forming table, but I'm
concerned about forming the support ribs on the inside of the bottom
case half.

Any suggestions would be welcome.

A lot depends what it is for - if it is as some form of technology
demonstrator to convince people to invest in it / buy it / support it
for manufacture, go to RS or Farnell and buy a case. A secondhand case
or home built case won't give the right impression. And please don't use
Dymo tape for any labels - professionally produced labels or engraving
are not that expensive and make a BIG difference to the first impression.

If you get a green light beyond this stage, look at something like thin
RIM moulding:

http://www.martello.co.uk/

It is a very cost effective method for producing one offs and small
production runs (I don't have any connection to them other than as a
customer).

Finally remember that your time has value. Work out what your time is
worth and how long it will take you to make a decent case, then see if
it still the best option to make your own rather than staying focussed
on the electronics.

Cheers

Chris

--
Cut along the dotted line to reply

On 19 May, 14:59, Andy Dingley wrote:
On 19 May 2007 04:17:45 -0700, tillius
wrote:

I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

Can't say I've ever had this problem.

Can anyone suggest a good way of racking vast piles of discarded
cabinets from old electronic equipment? These days the only bit that's
wroth recycling is the case and the power switch. I (and every other
electronics geek I've known) have truckloads of old cases just waiting
for projects that will never get built.

What specifically do you mean by 'good'? 2x2 uprights & chip shelves
are a simple option.

Another option that can fly in places with low ceilings is a long
shelf 6" below the ceiling, onto which various kit is placed, with the
leads coming down to working height. Good where space is needed and
access to kit is only needed here and there. Eg power supplies,
servers, desktop PCs, UPS, pattern gens, etc


NT

In article . com,
tillius wrote:
I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

That sounds like a near standard rack mounting size. Have you looked at
the suppliers of such things?

--
*If God had wanted me to touch my toes, he would have put them on my knees

Dave Plowman London SW
To e-mail, change noise into sound.

On May 19, 7:56 am, wrote:

Seriously, youre just not giving enough info. No info re plastic vs
metal, application, what issues matter and what dont, budget,
appearance requirements, etc etc.

Give us a lot more info

NT

Sorry. I'm looking for a plastic case.

I don't think I'll be able to find a case off-the-shelf that will work
for this.

It is designed to lay flat (the 3" being the height) and has several
controls on the top sides with a large (15") LCD screen mounted in the
middle of the top.
The inside also needs to have ribs to support/segregate the various
electronic components and to provide clearance for shielding to
prevent certain components from interfering with certain other
components.

The edges of the case also need to be eased and wide side to wide side
it is a slightly wedged shape, with the thickness (height) at one of
the wide sides being 2.75" and the thickness at the other wide side
being 3.25". The wedge shape being integral to it's functionality.

On May 19, 8:01 am, (Peter Ashby) wrote:
You want Sylgard, a pourable silicone resin, comes clear and can be used
to encase electronics. The only problem with it is it helps to degass it
after you mix in the activator, you can rig up decent vacuum with
Vernouli type device attached to a tap. It is very thermally resistant
and has excellent shock absorption properties. Might not be good for
airflow though.

Peter
--
Add my middle initial to email me. It has become attached to a countrywww.the-brights.net

Thank you. I will check sylgard out.

On May 19, 1:21 pm, "Dave Plowman (News)"
wrote:
In article . com,
tillius wrote:

I'm building a prototype electronic device and need to construct a
case for the prototype. The approximated dimensions are 13" x 19" x
3", and it needs to have cooling slots in the bottom for fan driven
airflow.

That sounds like a near standard rack mounting size. Have you looked at
the suppliers of such things?

--
*If God had wanted me to touch my toes, he would have put them on my knees

Dave Plowman London SW
To e-mail, change noise into sound.

Thanks, the rack mounted cases are better designed for rack mounted
devices and I don't believe they would work well for my application.
See my previous responses listing additional requirements.

Thanks for all your replies.

On 19 May, 22:26, tillius wrote:
On May 19, 7:56 am, wrote:

Seriously, youre just not giving enough info. No info re plastic vs
metal, application, what issues matter and what dont, budget,
appearance requirements, etc etc.

Give us a lot more info

NT

Sorry. I'm looking for a plastic case.

I don't think I'll be able to find a case off-the-shelf that will work
for this.

It is designed to lay flat (the 3" being the height) and has several
controls on the top sides with a large (15") LCD screen mounted in the
middle of the top.
The inside also needs to have ribs to support/segregate the various
electronic components and to provide clearance for shielding to
prevent certain components from interfering with certain other
components.

The edges of the case also need to be eased and wide side to wide side
it is a slightly wedged shape, with the thickness (height) at one of
the wide sides being 2.75" and the thickness at the other wide side
being 3.25". The wedge shape being integral to it's functionality.

well, thats the first fraction of the information


NT