The way to build a chassis

[Johnny2Bad]

I remember the night I was hanging lights for a dinner theater production, scraping the asbestos off of I-beams above a suspended ceiling to make good places to attach beam clamps.

I was covered in the stuff when someone came up to me with a newspaper and showed me the article about asbestosis and carcinogenic properties.

That must have been 25 years ago. So far, so good. It seems however that if its gonna happen, Im about due.

It's safe unless disturbed, and it's not really the stuff you could see on your clothes that you have to worry about anyway. It breaks into microscopic fibres that suspend for a fairly long time in the air; if you breath that, it embeds in the lungs. Everyone who attended the theatre that night got a dose, as did anyone who laundered those clothes.

But, since it was in virtually every public building, every schoolhouse, hospital, etc for a long time, and W R Grace used to sell zonalite insulation for three decades that they knew was contaminated with asbestos, everyone over 60 has had a dose guaranteed, most people over 40 have some exposure. Long term exposure is bad, short term, probably nothing to lose sleep over; everyone is in the same boat as you.

 

[WagBoss]

How are you finding all the aluminum pieces? What is a surplus store? I am near Toronto, what one did you go to?

 

[Speedskater]

Now, a decade later, I doubt that any stock remains.

 

[mortron]

So what screw size is recommended for building a chassis? I saw 6mm mentioned... is that the size of the thread or length? i assume not length. I have a chassis I am building for a gainclone and am curious if I can get away with only using one screw size for building the enclosure and fastening the chips to the heatsinks.

As well, is 3/16" considered adequate thickness for top and bottom plates on an amp? I have rather large sinks, but the plates only need to be about 11" square.

 

[palstanturhin]

I myself do not use much else than just M3 screws for the enclosures. Although I do use stainless steel screws which are a bit stronger than the ordinary 8.8 steel or what ever...

Here is also a tip how to mount the front panel if one does not want visible screw heads on the panel and do not have suitable aluminium glue.

Use atleast 4mm thick aluminium for the panel. When you get used to, you can do this even with a 3mm aluminium.

Drill the mounting holes from the back side of the panel. Use 2.5mm drill with M3 screws.
Do not drill through the whole plate! As little as only 2mm is adequate depth. 3mm will fasten the panel so hard that the screws will break before they loose their grip.

Use a small drop of oil when you screw the screw into the hole. The screw will then self thread the hole.

Nice screwless panels and enclosures...
Been there done that...