Plain Jane chassis

I've been working on a design for a chip amp enclosure for a while, mkI is finally built so it's time to show it.

The ideas behind the design are as follows:

Clean lines, no screws on show.
Suitable for a group buy.
Minimum of parts.
Reasonable heatsinking.
Requiring little metalworking skill for a good finish.

I'll show the picture now, then explain why I'm thinking about a group buy. If everyone hates the design I won't need to continue

The group buy idea is to get a decent quantity of the side panels made up (standard size, finished and anodised) from 15mm aluminum. Hopefully for a price which compares well to a regular heatsink.

Then the skin is stainless steel which doesn't need finishing. It is hard to to make holes in, but I should be able to offer custom widths with a range of punched holes for sockets.

The inner structure is wood, so the DIY skills needed are cutting/ glueing/drilling wood. And tapping aluminium. Any mistakes should remain hidden inside.

I wouldn't rule it out but it may not work for outside UK/EU because of postage costs and because you may be able to get it made cheaper locally.

In the UK there is a lack of affordable heatsinks/enclosures. In fact there is a lack of most things at reasonable prices.

I was thinking about offering finished chassis but this is more of a half DIY approach.

The DIYer would still have to build the wood part. The insides of this amp can be seen here:
http://www.diyaudio.com/forums/showthread.php?postid=878343#post878343

This one has a wood rear with the stainless lid screwed to it. So it meets the criteria 'no screws on show from front/top/side'.

For a group buy, I would expect people to want the stainless wrapped around the rear as well. This requires a bit more forethought on assembly but it has some other advantages as well. I'll post a rear picture of this model as soon as I've cut some more aluminum sides (which I find difficult).

What sort of price would get people interested?

I'm thinking of something like £20 for the stainless (front/top/rear/bottom, with socket holes), and £40 for the aluminium (2 sides, anodised, tapped). Remember you don't need to buy heatsinks.

300x100x15mm linished Al plate costs about £10 each from http://www.metalfast.co.uk and I'm guessing about another £10 each for finishing the edges, tapping the holes, and anodising. If anyone can suggest somewhere that might do this for a good price let me know and I'll get a quote.

I've removed the requirement for the DIYer to tap any holes, so just basic woodworking remains. I think that will be more acceptable.


I would also offer all the little things that eat up time and money > RCAs, Fused IECs, Binding posts, switches, heatsink paste, pcb standoffs, hookup wire, heatshrink tubing,

I_Forgot said:

Have you considered the possibility of using other means to assemble parts? Epoxy can be used to join aluminum to aluminum, wood to aluminum, etc. No tools required other than simple jigs to ensure accurate alignment.

Click to expand...

I haven't up to now, but I will.

My efforts with glueing speakers are always quite traumatic, maybe this has led me to not associate glue with precision work.

I'm thinking there might be lots of speakers builders that are happy working wood but not metal. Also it's not that easy to find aluminum sheet/plate in small quantities. Then you might have to purchase tap sets, etc.

I've not been brave enough to try my wood router bits on Al yet, but the Al blade I bought for my table saw was a waste of money. Maybe my fault for scrimping on both the blade and table saw.

Wood is good for inside an amp, you can screw your pcbs into it without the need to tap or use nuts.

The proposed design for the group buy has a one-piece front/top/rear. This means no joins or screws on show. And it removes all fit and finish problems.