Cutting large square holes for LCD screens on metal enclosures

[TheWinterSnow]

I am trying to get a feeler for this one.  I am slowly in the process of making a DSP based pedal effect.  Since the DSP pedal realistically needs to have an LCD screen to navigate the program, a hole for a SD card drive and USB drive, I need a professional quick but cheap way to cut straight square holes.  I know the best solution would be a metal cutting CNC router but that is a little too expensive and I really don't have the room for even a small one.  It has to be professional looking and easy enough for production runs so no nibblers or dremels are out of the question.  What kind of tools are available?  I was looking at routers but I can't seem to think of a way to set up a jig that could make a hole accurate within a fraction of a millimeter.

Also, where is the best place to get an internal SD card reader that you see in rackmount units and keyboards?  Everything I am finding on the net are the 3.5in drives for PCs.

[Gus]

 The post reads like you might want to have it cut by an outside company if you don't want to buy the equipment.  There is no easy way to make the kind of cuts you want without a mill or waterjet etc cutters.

[Seljer]

î'd agree with the above, if you want actual production runs and professional results get a professional to do it

the DIY way is
drill pilot holes
cut it out with a jewelers saw
touch it up with a file

Aluminum is soft as cheese so it's not really that hard a process. I've had decent results when I used this for rectangular toggle switches

[TheWinterSnow]

Any cheap machine services that do one time and small runs?

[slacker]

The Tone God has a drilling service, I don't think he offers square holes as part of the service but you could try contacting them to see if it's something they can do. Your best bet is a local small engineering firm or something like a hacker space may have someone with a mill.

Doesn't seem like it would be too hard to do with a router or a drill press using a template though.

[alparent]

Look for a machine shop in your area.

[davent]

For ideas... a couple tutorials on creating templates to allow the use of a router to do a large cutout on an aluminum chassis and then an IEC cutout.

http://www.silvatone.bravepages.com/Tutorials/PT%20Cutout.htm

http://www.silvatone.bravepages.com/Tutorials/IEC%20Cutout.htm

dave

[gcme93]

http://www.youtube.com/watch?v=L5AzbDJ7KYI

called a reuleaux triangle drill, not sure how feasible it is...

http://www.mikesenese.com/DOIT/2011/10/drilling-square-holes-with-a-reuleaux-triangle/ (another source)

[kodiakklub]

a jigsaw with a metal blade would be cheapest. but the holes will only be as straight as you can cut them, but the bezel of the LCD should cover any small mistakes. we would use a pneumatic "airsaw" that had a great grip which made it a little easier. but you want lots of blades. they burn up kinda quick.

[phizone]

Also, where is the best place to get an internal SD card reader that you see in rackmount units and keyboards?  Everything I am finding on the net are the 3.5in drives for PCs.

Apologies in advance if I'm misunderstanding what you are looking for, but try searching for SD Card Connectors. Mouser lists them as memory card connectors or if you're looking for something a little easier to deal with, places like Sparkfun have them on a breakout board.

[chi_boy]

PPP is supposed to be able to cut square holes.   Personally, I love their work, and I hate drilling.   

For a prototype, they might be the way to go. 

George

[TheWinterSnow]

For ideas... a couple tutorials on creating templates to allow the use of a router to do a large cutout on an aluminum chassis and then an IEC cutout.

http://www.silvatone.bravepages.com/Tutorials/PT%20Cutout.htm

http://www.silvatone.bravepages.com/Tutorials/IEC%20Cutout.htm

dave

You know I just may go the router table route like this, I didn't know that there was equipment like that to do work in that regard.  It is more like what I wanted, I knew that routers would be the way, but handheld routers seemed like they would be a little inconsistent and difficult to work with when using jigs.  A table router with a flush trimming bit is the perfect solution.

[Jdansti]

Given the tools at my disposal, I would use either a Dremel cut off wheel or an electric jigsaw with a metal cutting blade. Either method would be followed with a file.

[totes]

Given the amount of effort and money you'd need to invest into tooling in order to cut out a square hole yourself, having an external company do the cut for you is infinitely better.
Waterjet cutting may cost a few dollars per minute, and such a cut on a thin metal enclosure won't take longer than 2 minutes, given you provide the file with the cutting pattern.
Total costs should be a maximum of $15 according to my experience.

[merlinb]

The other option to to find some sort of ready-made collar / frame that is the right size for the hole. You can then cut out the hole fairly roughly, then insert the collar to hide the edges and create a neat / stylish finish.

[defaced]

Look for a machine shop in your area.

+1000  I work with machine shops on a regular basis; it's way easier than it sounds.  Depending on the details of your requirements, you could get the job quoted in a few minutes with little more than a sketch, the part in question, and a quick conversation.  Generally (and this a broad swath statement), the smaller the shop, the more likely they will be to work with you for a reasonable price.  And don't discount retired or out of work guys making chips out of their garage.  For something like punching a few holes in a box, they'd be a great source.

You might also want to check out a sheet metal shop and see if you can have the box fabbed from flat cheaper than buying a production box and having the holes put in afterwards.  Here again, just a quick phone call or a stop by the shop can get you tons of info and help for getting the job done.  

And lastly, depending on how many of these you plan to turn out, you might want to look at dedicated tooling like a punch set and manual/hydraulic press.  These will not be inexpensive, but might be worth it long term.  The methods used to manufacture are directly related to output quantity, speed, quality and desired cost. 

[TheWinterSnow]

The other option to to find some sort of ready-made collar / frame that is the right size for the hole. You can then cut out the hole fairly roughly, then insert the collar to hide the edges and create a neat / stylish finish.

What would be the technical name for those?  I have been looking around at mouser and it seems they don't have anything of the sort, either they don't carry anything like that or I am looking in the wrong area becuase I don't know the name or category.  Right now I have been looking in screen modules and module accessories.

[amptramp]

The other option to to find some sort of ready-made collar / frame that is the right size for the hole. You can then cut out the hole fairly roughly, then insert the collar to hide the edges and create a neat / stylish finish.

What would be the technical name for those?  I have been looking around at mouser and it seems they don't have anything of the sort, either they don't carry anything like that or I am looking in the wrong area becuase I don't know the name or category.  Right now I have been looking in screen modules and module accessories.

You can get bezels as an accessory to digital panel meters.  They are usually in the same place in a catalog as the panel meters themselves.

[Jdansti]

^+1

Or purchase displays that either come with a separate bezel or the bezel is part of the display.

For example:
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_175951_-1

[TheWinterSnow]

I am lookling at something like this

http://www.mouser.com/ProductDetail/Newhaven-Display/NHD-12864WG-BTMI-VN/?qs=sGAEpiMZZMvkC18yXH9iIjqe6IqxYXYlA07cJbWSHaI%3d

I have been looking for hours now and can't find any bezel that would work.