neatly cutting square and rectangular holes for power IEC connectors and through-chassis transformers in alimunium sheet.
How do YOU do it?
How do YOU do it?
I use my Sylar finger
An externally hosted image should be here but it was not working when we last tested it.
Square holes
For a one off, I mark out the shape of the desired hole, drill a series of small holes (almost touching) around the inside of the mark, remove the centre and file to shape.
For a one off, I mark out the shape of the desired hole, drill a series of small holes (almost touching) around the inside of the mark, remove the centre and file to shape.
If the chassis hasn't been bent yet, a scroll saw with a 28TPI twist blade.
If it has, draw the IEC hole template needed, 1/8" drill each corner (4-6), then dremmel with cutoff wheel (the real thin ones that come 20 per package)
Cheers!)
If it has, draw the IEC hole template needed, 1/8" drill each corner (4-6), then dremmel with cutoff wheel (the real thin ones that come 20 per package)
Cheers!)
I sent the chassis pieces to Front Panel Express (frontpanelexpress.com) and got the IEC connector plus all the other holes and text engraving done in one go. Shipping would be a bit expensive from your hemisphere though. Maybe you can find a local machine shop that wants some after hours work. Otherwise, I have used all of the techniques already suggested (other than the rectangular drill bit, must be only available in Oz. ) Quality of results depends on your patience.
has anyone used the rectangular IEC chassis punches?
Agree with John about 16 gauge steel sheet - its a beeee-atch to cut! And fold...
Agree with John about 16 gauge steel sheet - its a beeee-atch to cut! And fold...
dremels with cutting discs cannot do small square holes (EDIT- am talking small holes, they can work with an IEC power inlet). The cutting disc is large and round and by the time you have gone through the metal vertically the disc has made a long transverse slit. So here are some tips-
-you should cut on the inside not the outside.
- save halfway worn out discs, they have a smaller diameter so will not provide as much overshoot.
- mount the IEC on the outside of the case so its flanges cover any imperfections.
Usually I make a full size layout and cutout on paper, using a knife or scissors and test it with the IEC, then trace this on the metal for dremel work.
-you should cut on the inside not the outside.
- save halfway worn out discs, they have a smaller diameter so will not provide as much overshoot.
- mount the IEC on the outside of the case so its flanges cover any imperfections.
Usually I make a full size layout and cutout on paper, using a knife or scissors and test it with the IEC, then trace this on the metal for dremel work.
Got $350 to casually drop on one? Because that's what Greenlee IEC's start at 😱
Cheers!
Rectangular drill bit is no good at all - too much faffing to get the hole square afterwards.
Curves of Constant Width and Reuleaux Polygons <-- that's better.
Curves of Constant Width and Reuleaux Polygons <-- that's better.
They're cheaper than than in the UK but still way expensive.
One problem not mentioned so far is panel distortion.
I use drills and dremmel under transformers where distortion is not visible but punches where the hole is on show.
Andy
Try using VERY sharp chisels to cut the shape exactly as you want. If you take your time and back up the work with a smooth piece of wood the holes will be perfect. It is the same basic principle as using a hole punch just in small increments. One nice thing about aluminum is how well it broachs on each cut. Most materials containing iron and nickel do not work out as well.
Another good item is using a small mill cutter in your drill press.
If you have a Harbor Freight store close buy you can buy the square chisels used in a plunge mortise machine quite cheap. Just remove the drill bit. They come in several convenient sizes and are real sharp. If you predrill a round hole the approximate size as the finished item you only have a small amount of material to broach off. Metalsmiths and blacksmiths did some nice work 500 years ago with no power tools in raw iron. Just remember to tape up the work to protect it while you are working. Small scratches really spoil the finished item. You can also brush finish in one direction with 400 grit paper and obtain a nice professional look. Ain't DIY fun.
Tad
Another good item is using a small mill cutter in your drill press.
If you have a Harbor Freight store close buy you can buy the square chisels used in a plunge mortise machine quite cheap. Just remove the drill bit. They come in several convenient sizes and are real sharp. If you predrill a round hole the approximate size as the finished item you only have a small amount of material to broach off. Metalsmiths and blacksmiths did some nice work 500 years ago with no power tools in raw iron. Just remember to tape up the work to protect it while you are working. Small scratches really spoil the finished item. You can also brush finish in one direction with 400 grit paper and obtain a nice professional look. Ain't DIY fun.
Tad
A Reuleaux drill set is pretty expensivo.
For thin plate, as in a few mm, it's ok to drill a round hole and punch out the corners by hand.
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