Modifying project enclosures - Page 1
Forum section: electronics / projects

author: fsleeman
author_rank: Regular Contributor
timestamp: April 16, 2010, 06:13:03 pm
content: Is there a standard or recommended way creating non-circular holes in project enclosures (plastic, metal, or wood)? I know corner punches can be used for 90 degree angles, but can they be used for anything else? Are there any good Dremel attachments for making these holes? A jigsaw does a good job on rectangular holes but usually is much too large for small switches or buttons.

author: MTron
author_rank: Regular Contributor
timestamp: April 16, 2010, 06:49:48 pm
content: To make smaller sized non round holes in an enclosure i find the easiest (for me anyways) is a good rotary tool and a variety of sizes of cutting discsI personally use the Foredom SR flexshaft kit with the H.30 Handpiece which has a small jacobs chuck at the end....awesome toolWith a steady hand you can cut some very nice slots or rectangular holes for switches, displays, header/plug boards, gauges, etc etcI use the standard dremel type cut-off discs, and i keep the worn out ones to make smaller more precise cuts. Also the small burrs and reamers make cleaning up corners very easy.

author: saturation
author_rank: Super Contributor
timestamp: April 16, 2010, 07:02:53 pm
content: I find a versatile tool for modifying sheet metal or plastic enclosures is a nibbler; its not the fastest but it will always work and get the job done. What nice about it is you can custom make a hole in most any container. You can make a pilot hole with a hand drill and take it from there. If you have many uses for a dremel type tool, that would be better.

author: Waifian
author_rank: Regular Contributor
timestamp: April 16, 2010, 09:07:17 pm
content: Nibbler?

author: MTron
author_rank: Regular Contributor
timestamp: April 16, 2010, 09:21:29 pm
content: Quote from: Waifian on April 16, 2010, 09:07:17 pmYea, a nibbler....It makes small cuts, or nibbles, in sheet metal or other materials. Its handy, but it can be slowIve tried them, but i prefer the rotary tool method myself. You can find an extraordinary amount of accessories for a good rotary tool. For cutting plastics i have a miniature saw blade that makes a very quick a clean cut into plastic, for harder materials i use small diamond discs that make a very clean cut, and there is always the general purpose fiberglass reinforces cut-off wheels

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 17, 2010, 01:24:18 am
content: Usually , I do small drill holes in line , the next step are to work the drill bit side ways, like connecting the small holes together .It takes time , but its cheaper than laser cut ..

author: DJPhil
author_rank: Frequent Contributor
timestamp: April 17, 2010, 02:08:53 am
content: Quote from: Waifian on April 16, 2010, 09:07:17 pmI'm so glad that show's coming back on this summer.I tend to work with plastic more than anything, so most of what I know is plastic. I usually use a drill to start a hole and whittle away with a boxcutter or tile knife until I have the shape right. If you work carefully and aren't working on small holes it can turn out very nicely with some practice. The hardest part was learning to work slowly enough to avoid stressing the plastic, which lightens the color of the dye in it and looks horrible. You have to be very careful applying heavy pressure with sharp stuff as well, it's easy to slip and slice up yourself or something nearby so always make sure it's safe 'downrange'. A good score line, carefully made with several passes, will snap off cleanly in one go or with a little bending, and the remaining fin can be sanded or shaved down.I wouldn't recommend it to anyone with better options, but it works if you're too poor for good tools.

author: EEVblog
author_rank: Unknown
timestamp: April 17, 2010, 09:10:57 am
content: Yep, I second the Nibbler, at least that's what they are called in Australia. Had one for maybe 25 years.The easiest and quickest way to cut irregular holes in a case IMO.Not ideal if the edges will be visible in a front panel, as it's hard to get them perfect.Dave.

author: Simon
author_rank: Unknown
timestamp: April 17, 2010, 12:54:02 pm
content: what about a router tool on a dremel ? you will need a stand for it though

author: saturation
author_rank: Super Contributor
timestamp: April 17, 2010, 03:08:36 pm
content: Quote from: EEVblog on April 17, 2010, 09:10:57 amSame here, but for 35 yearsIt has never failed me while a Dremel has, usually because the cutting tool needed replacement and I didn't buy a new one when I needed it.Also, per the title, for modifying holes, a nibbler is just right. A power tool tends to cut a bit too fast and much too, whereas with a nibbler you can go slow and sure.For edge issues, I cut holes slightly smaller than needed, then file the edges. Should have also added a file as a good companion tool with the nibbler.

author: Simon
author_rank: Unknown
timestamp: April 17, 2010, 03:19:29 pm
content: a dremel on a stand with a router bit should allow you to be accurate, the only issue is that at 10'000+ rpm which is their usual speed if you cut too fast it make the plastic melt and can be a bit messy, I learnt to use tricks so that it cut only a small amount of material at a time and did not plunge in and melt the plastic as that made life harder. I've not tried straight lines thought. of course the ultimate solution would be a desktop mill like the sable

author: MTron
author_rank: Regular Contributor
timestamp: April 17, 2010, 03:49:59 pm
content: Quote from: Simon on April 17, 2010, 03:19:29 pmSuch a situation is why i have and use the Foredom SR flexshaft. It has a foot pedal that allows continuously variable speed, from a few rpm up to the max 18000rpm...its super handy for making very neat, very precise cuts into plastic..no meltingYou can get variable speed on your dremel/rotary tool of choice as long as its a brushed universal motor....all you need is something like this to vary the voltage going to the unitIts listed as a router speed control, but it will work with any brushed (NOT induction) style motor, including the Foredom i have (which is brushed)But again, if your only doing ocasional work, then a Nibbler works great, i modify a lot of cases and enclosures (mainly computer modding) so i have the need for the Foredom and the variable speed control....but it is a bit of an investment that might not be worth it if you only use it 3 or 4 times a year

author: Simon
author_rank: Unknown
timestamp: April 17, 2010, 04:12:20 pm
content: a router bit will need high speed to work anyhow, I found that it worked better at 33'000 rpm than at 10'000 rpm for a clean cut and the melting was no worse, the trick is to make small cuts so that the material is removed before it melts, for example i had an 18 compartment box and wated to remove half of the dividers to make it into 9 larger compartments, if I just hacked my way into the plastic wall it soon left a load of melted plastic in its wake, the best thing was to hold the box very still and then operate the stand lever so that the dremel cut a small sliver of the wall away in a vertical movement, this made a clean cut despite the speed and cause not jamming when the plastic melted and the deremel was too far in to cope with the load

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 17, 2010, 10:13:42 pm
content: Everything is connected with the word " Production rate " , if you do just 20 panels per year,you can use common tools , and spend more time .If your needs are for higher production, then you can use services like " laser cut " ,you remove all the front panels from your boxes , so to be " drilled " ( laser cut ) or ( water jet cut ) .And what you do , are only the assembly .

author: Simon
author_rank: Unknown
timestamp: April 18, 2010, 06:50:37 am
content: If I were doing medium rate productions from home I'd use a desktop milling machine, at work we bought in standard metal boxes and then milled all the holes for the front panel on a CNC mill

author: fsleeman
author_rank: Regular Contributor
timestamp: April 18, 2010, 01:23:31 pm
content: Thanks for the advice, I think a nibbler might be just what I am looking for since I would be making very few devices and only for personal use. I do like the idea of the CNC milling machine and if I get more serious with this kind of stuff I might look at little closer into some of the projects I have seen online.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 18, 2010, 01:26:12 pm
content: In anything related to the " size " of the project , I had few pictures to demonstrate ..10 years back, I had work in a small project , making up those boxes, that was for use with communications equipment. ( Mil specs, so I can not say more about them) .Still , there was allot work on them , as they should be able , to be dissembled , and re assembled,so to be able, to be installed at tight fit places.We had to punch in, in every little or large hole, special steel nuts.(oh yes, all parts are aluminum)Happy times of my thirties , go for the red.

author: Simon
author_rank: Unknown
timestamp: April 18, 2010, 01:30:26 pm
content: that rings a bell with what my company do, we make all of our own metal work for aircon units and most of it is bolted together

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 18, 2010, 02:00:23 pm
content: And this is what I was doing 20 years back ... (1991)Oh by the way , I am the one man show corporation, never stopped to be a dreamer.Its an well made PSU , but do not try to lift it ..

author: Simon
author_rank: Unknown
timestamp: April 18, 2010, 02:11:45 pm
content: Quote from: Kiriakos-GR on April 18, 2010, 02:00:23 pmWhy will the cat scratch ?I'm thinking of going the same way as soon as i get me my first house (iminent) and has some room to work. (1 spare bedroom + 1 shed + 1 outhouse = should be enough)

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 18, 2010, 02:51:47 pm
content: Quote from: Simon on April 18, 2010, 02:11:45 pmYou can add this fear factor too,but the most important are the amount of kilos, of mixed steel and copper in it.Aka Transformer .. + two rails of heatsink' s ( 8 transistors like the 3055 ones but 7Amps its one )and the metal fan in the rear ( made in France)

author: saturation
author_rank: Super Contributor
timestamp: April 19, 2010, 05:26:02 pm
content: Great photos Kiriakos-GR! thanks for sharing.

author: fsleeman
author_rank: Regular Contributor
timestamp: May 12, 2010, 08:58:18 pm
content: As I did a little more research, I found another problem: where to actually get an enclosure? I was planning on using some RadioShack plastic project cases and pre-drilled boards until I realized they don't actually sell matching parts! The boards physically do not fit in the cases they sell, off by 1/4" and even if they fit the holes would be off too. Does anybody have a suggestion of a good place to get matching cases and boards? I know I can etch my own board to fit a custom case but some times it more trouble than its worth.

author: Unknown
author_rank: Unknown
timestamp: May 13, 2010, 08:52:21 am
content: If you don't want to etch (or order) a custom board, why not take a piece of veroboard/perfboard and cut/drill it to size? Getting a PCB to match the enclosure is usually easier than the other way around, unless you go for the typical hobbyist approach and take an enclosure that's way too big.