ANSWERS : Workshop

I need to make a custom enclosure for a project, but I don't know how to machine it. I made a quick 3d model of one half to help explain. It will be made from two blocks of aluminum, with the edges and corners rounded (see first picture) and the inside hollowed out, except for 4 protrusions for screws to go in to connect the two halves (see second picture). Then, a few holes will be drilled, and somehow a rectangular slot will be made (see third picture). I don't have access to a CNC Mill, so how would I make this by hand with high precison?

Comments

[orksecurity]

"High precision" either requires skill and time, or spending money to get someone to do it for you, or finding something available off-the-shelf, or some combination of the above.

If you want something with those nice rounded edges, on hobbyist budget -- make it out of wood, make it out of some kind of modelling compound (sculpy?), or buy it.

Mounting posts aren't absolutely necessary; there are other ways to mount the electronics, including just gluing in stand-offs.

[Ethanal]

The mounting posts are actually to connect the top and bottom halves of the enclosure, but I could still use stand-offs I think. I have decided to make the enclosure out of wood then cast a copy out of some type of plastic or make it out of a block of plastic. I can use a table router to round the edges of the enclosure, but how can I hollow out the center by hand?

[Ethanal]

On second thought, now that steveastrouk showed me that website, I think I will just buy the enclosure. Thanks anyway.

[orksecurity]

Hollowing the center could probably be done most quickly via template routing, followed by a bit of clean-up work. Some materials other than wood can be routed, given a suitable router, suitable bits, the right speed, and gradual enough progression of cut depth. I have no idea whether that kind of "hand machining" would be practical for this particular task.

[Ethanal]

How does that work? As far as I know, template routing is for routing around the outside of a shape until it matches the template. How do you template rout the inside of a block of wood?

[orksecurity]

You create a template which has a cutout, and use that cutout to guide/limit the bit's travel. Any book of basic router techniques should have a section on this.

[nicelly]

They are now accessible to the fans and can be easily obtained at any of the leading apparel store These jerseys are made from thinner fabrics so won't last as well as the more expensive authentic Cheap Ralph Lauren Polo jerseys, but Ralph Lauren shoes are much cheaper This is due to the fact that on acquiring an authentic jersey, one feels better polo ralph lauren shirts sale and more confident Fans can support their teams at homecoming by wearing the team's jerseys.
http://www.italianralphlaurenpolo.com/polo-ralph-lauren-donna-c-11.html

[Ethanal]

How would I make a good quality part out of plastic (colored) without a milling machine? Would it be durable and aesthetically pleasing? Could I polish it to make it shiny?

[steveastrouk]

Why don't you just BUY a suitable box !

[Ethanal]

Where?

[steveastrouk]

Where are you in the world ?

[Ethanal]

US

[steveastrouk]

http://www.okw.co.uk/enclosures/handheld_enclosures.htm?gclid=CKL3m-KG5KMCFYeY2AodTkVq-g

[Ethanal]

That's an awesome website! Thanks!

[steveastrouk]

Some really nice gear there isn't there ?

[Ethanal]

Yeah, I especially like the intermediate rings and the free samples. Also, they have a great selection, unlike some other companies. Nice find!

[steveastrouk]

You can see now why I wouldn't make one, even though I could.

Steve

[Ethanal]

Do they (or other companies) make aluminum enclosures that aren't boxy?

[kelseymh]

There's another really cool Web site you should learn about; it's called "Google". It hasn't been around very long, so lots of people (especially people who post questions on Instructables) haven't heard about it.

Apparently, they do nothing but answer questions for you! In particular, if you're trying to find something on the Web, they can look for it and give you a whole list of Web pages with the information you want. And they have so many people working at this, you don't have to wait for someone specific to reply to you.

I haven't used this Googlething very much, but it seems pretty useful.

[Ethanal]

Yes, I have googled it quite extensively, but all I could find is thin boxy aluminum enclosures. I was just wondering if I was overlooking something.

[kelseymh]

I've seen some very nice rounded enclosures, along the lines of what you've been looking for. But yeah, mostly they are the boxy aluminum or plastic things, or worse, NEMA electrical boxes.

Hmmm....I know that some of the big electronics suppliers (DigiKey, etc.) have their own internal search layer, such that their complete results aren't echoed to Google. Let's try some exploration...I tried "iphone enclosure", "ipod enclosure", and so on, but came up either with "wow they look cool" reviews, or protective sleeves.

What's your budget? Have you tried contacting some of the custom prototyping companies, like ProtoCase, which show up in Google search results?

[Ethanal]

That's probably way out of my budget (sub $50) - I'll probably end up casting an enclosure out of plastic or buying a plastic one unless I can find an rounded aluminum enclosure like you are talking about. Do you know generally where you saw one?

[kelseymh]

In our group's electronics shop at my work (SLAC National Accelerator Lab). One possibility might be to use a pair of lids from higher-quality "boxy" enclosures, and small bolt-nut pairs to hold them together at the corner posts.

[kelseymh]

With plastic, you could injection mold or cast it. With thin aluminum, you can stamp it as suggested elsewhere. You can certainly polish and seal polycarbonate.

[Ethanal]

How would I go about stamping the aluminum? What tools would I need?

[kelseymh]

Did you read Steve's answer to the same question?

[Ethanal]

Yeah, but I was wondering if I could modify the design so I could make it at home.

[kelseymh]

Have you looked up "metal stamping" or "metal forming" anywhere? You will get much more information, and it will be much more organized, than a series of questions and answers.

[jeff-o]

On a commercial scale, a shape like that would probably be forged from a mold. Then, the hole for the screw would be tapped and some other details might be machined. Does it have to be made of aluminum? Or would plastic be OK? That might be easier to make on a homebrew CNC machine.

[Ethanal]

Just out of interest, how are iPod Shuffles made, because they are anodized aluminum and a similar shape?

[steveastrouk]

They are pressed from sheet and punched, probably simultaneously. The act of pressing stiffens the metal considerably

[Ethanal]

Is there a way to use that process at home without a huge investment in equipment?

[steveastrouk]

None at all I'm afraid. There is serious money involved, in the many thousands of dollars. How big is it ? Does it have to be metal ? I could mill it on my machines, but it would daunt me a bit to be honest, for a one off.

[Ethanal]

I was thinking of maybe anodizing it, which can't be done easily with forged aluminum. No, it doesn't have to be made out of aluminum, but I like the look and it is more durable than plastic and it is a relatively cheap metal for it's quality. Is there a way I could modify my design so I could make it without a milling machine?

[steveastrouk]

You can anodise forged aluminium, you can't anodise CAST aluminium very well

[kelseymh]

I must be missing something. What you've described and pictured looks almost identical to a perfectly normal, commercially available project enclosure. Does your project have some weird unique dimensions that are unavailable?

Or are you just exploring how these boxes are actually made? In that case, Jeff-o's response is correct. These things are never milled from scratch. First, creating a large, deep box from a solic ingot is horribly wasteful of material, of time, and of energy. Second, milling deep narrow posts without much clearance around them is difficult, and may be impossible depending on the precise dimensions.

[steveastrouk]

Answer: you can't. You can get the outside something like, but you won't be able to do the internal posts like that.

[Ethanal]

How would I do the outside?

[Ethanal]

Then, assuming I had unlimited resources, how would I do it?

[steveastrouk]

CNC mill would make mincemeat of it. A ball ended mill for the inside rad, and either generate the outside curve with a ball-ended, or use a form cutter.

Take a blank, epoxy it to a surface you can clamp too. machine outside edges.

Heat to 100C, remove from epoxy

Turnover, epoxy to machining surface, turn over, mill inside and your slot.

Heat again. Done.

[Ethanal]

Or can this be done on a normal milling machine by hand?

[steveastrouk]

You'd get the outside on a normal machine, you could pocket the inside by hand with an endmill, and follow it up with ballended mill and a lot of patience and skill, or you could put a couple of steps in the edge. .

[Ethanal]

Can I have this done by someone for relatively cheap? Or are there any really cheap CNC solutions?

[NachoMahma]

. Cheap? Not unless you can find an (very) advanced hobbyist who will do it just because he/she likes you. If you have to take it to a pro, it's not gonna be cheap.
.
.  It takes just as long to set up the machines to make one as it does to make a million. Good machinists to setup the machine don't come cheap.
.  A high-precision CNC machine is not cheap, even if you build it yourself. Then there is the cost of bits/lubricants/cutting fluid/&c. If you can spread the cost over 10000+ units, the cost per unit isn't too bad. When you're only making one...
.
.  You _can_ find custom machining shops that will do the job without forcing you to mortgage the ranch, but you may have to wait a year to get that new computer.

[steveastrouk]

DIY metal cutting CNC mills tend to be a bit expensive to put together for a one off.