My first attempt to make a chassis

[S.C]

My bad ideaMy Old Ugly IGC Plastic Box
A Better idea The Fake Amp - 2 Chassis
After I read Peter's Chassis kit for like a week, I decided to make a chassis for the following NIGC that I will build with Brian's PCB because horizontal chassis is too popular now. I wanted something different. And Peter's Kit tread provided many information that I needed to start my project. However, there was something that I'm unsure of. Plz input some comment/ tips.

"Materials" are pretty expensive, so I don't want to make mistake on this:
Dimensons: Thickness X Width X Height ("=inch)
Aluminum 6061-T6 Bare Plate 1 (Left/Right)
0.375" x 7.88" x 6.3"
Aluminum 6061-T6 Bare Plate 2 (Front/ Back)
0.375" x 3.35" x 6.3"
Aluminum 6061-T6 Bare Plate 3 (Top/bottom)
0.375" x 3.35" x 8.66"
Aluminum 6061-T6 Bare Extruded Square
0.75" x 2.56"
Copper 110 Plate
1" x 2.56" x 5.51"

Transformer : Avel Y236750 330VA 25+25V
Dimensons: Diameter 4.8", Height 2.1"

Questions:
1. After I installed the Transformer, I will have enough space to add a stepped attenuator. I think it has space. Do you guys think I should add it, or leave the front panel a lone and build a preamp? ( I hope I can afford Passive Pre.....)
2. I will arrange all the Binding Post, RCA Jacks, AC Inlet, Switch on the back panel. The fuse will be on the bottom. Do you think this is a good idea?
3. how do you guys cut AC inlet hole on Aluminum? Should I change the back panel to a thinner palte? Will it still support the whole standing structure?
4. What kind of screw are you using (Peter)?

plz help

[Nuuk]

S.C. - it is nearly impossible for anybody to answer your questions. Without being with you, with the exact same components in front of us, we cannot say what will work and what will not.

Even making my own cases, I can never guarantee success, especially when I try and make a case compact. Even with access to CAD (which I don't have) the odd mistake can creep in.

All I can suggest to give you the best possible chance of completing your case successfully is don't make it too small, in other words allow for something needing more room than it appears to; remember to allow for fixing components, ie how will you get a screwdriver or spanner to it; and probably most important, mock up the case using MDF or plywood first.

As regards your choice of materials, they should be plenty strong enough and whether you can cut the aluminium for the sockets will depend on what tools you have access to but it is not a difficult metal to work with.

[Ropie]

mock up the case using MDF or plywood first.

Mock up? Some of my best cases have been finished in plywood . The case I made from tropical hardwood and teak soon found its way to the skip. IMHO plywood is one of the best materials for a case, particularly as it's very forgiving to work with! For rfi rejection just line it with nice thick aluminium foil from your kitchen.

The point about leaving enough room for everything is important; unless you are very well practised, nothing less than an over-sized case will work, trust me.

Lots of people seem to use use nylon screws.

[Nuuk]

Mock up? Some of my best cases have been finished in plywood .

I saw you lurking here and knew that would be the next best way to wake you up (next to your boss giving you something to do ).

Yes, I have nothing against wood or plywood either.

[Ropie]

>> Yes, I have nothing against wood or plywood either.

I know you are a carpenter at heart (atleast as far as case design goes) but I am looking forward to the next Decibel Dungeon amp in an aluminium (pillaged from a laboratory skip) case, cut with a sharp bread knife and nicely finished with a brillo pad gaffer-taped to the end of a drill (or something like that)

[Nuuk]

I know you are a carpenter at heart (atleast as far as case design goes) but I am looking forward to the next Decibel Dungeon amp in an aluminium (pillaged from a laboratory skip) case, cut with a sharp bread knife and nicely finished with a brillo pad gaffer-taped to the end of a drill (or something like that)

All the local factories working with metal use those horrid closed skips so I can't get my hands on any offcuts

I have a design for a brushed aluminium case if only I can get my hands on the materials.

[Magura]

Originally posted by S.C
"Materials" are pretty expensive, so I don't want to make mistake on this:
Dimensons: Thickness X Width X Height ("=inch)
Aluminum 6061-T6 Bare Plate 1 (Left/Right)
0.375" x 7.88" x 6.3"
Aluminum 6061-T6 Bare Plate 2 (Front/ Back)
0.375" x 3.35" x 6.3"
Aluminum 6061-T6 Bare Plate 3 (Top/bottom)
0.375" x 3.35" x 8.66"
Aluminum 6061-T6 Bare Extruded Square
0.75" x 2.56"
Copper 110 Plate
1" x 2.56" x 5.51"

You have to get 7075T6 if you want to use aluminium still. Its much easier to get a reasonable result with and not as prone to bruises as 6061T6.

Besides that you should make sure you get electrlytically clean copper, anything else will most likely contain something the aluminium dosnt like and cause corrosion.

Magura

[Peter Daniel]

You might check this thread as weel. It provides additional info on tapping drilling, finishing and even the srews Useful tools and techniques

I usually like Allen type screws as they loog more professional. I also bore recess for the head, so the screw is flush with the panel (it's explained in the other thread how to do it easily).

You might try to go with ready made extruded bars, so you will have less cutting and finishing to do. But those extrusions come in standard widths with 1/2" variations.

As to the alloy, get whatever is available and cheap. I didn't have any problems with using 6061-T6 as this is the most popular alloy and usually regular stock with most suppliers.

[h_andree]

Thickness.

You could with less thick panels. I'm using a 5"
aluminum channel for sides and 0.1" plates
for bottom and top and back.
The front is 0.25" which is already pretty thick.

If you use 0.375" thick panels it will be nice and
heavy and strong but also a lot of work of drilling
and it'll cost way more money.

Check
www.onlinemetals.com
for materials (Small quantities available).

Harry

[elizard]

I found it that most of these stores are quite expensive, including online metals.

The shop I got my aluminum from is called speedymetals
just as an illustration of the price, one 9"x3.5" 1/8" (6061-t651) plate cost me $3.78 ..
no minimum orders, no charges for cutting

sadly, no website, but if you email them at speedymtls AT aol DOT com they'll give you a quote (btw, i did the email like that so i don't cause them griefs w/ spam)