I've just bought a nice big 3U rackmount case to mount a pair of LM3886 monoblocks in & I need advice in how to make some holes in the case for sockets/switches/etc.
As far as I can tell the metal is 1mm thick steel. I have a set of 'high speed steel twist' drillbits & an old 350W 3100rpm power drill. This combination worked nicely for drilling the thick aluminium you see in the picture but I'm not certain how well it will work against steel, particularly so thin. Do I stand a chance or will the drill completely mess up the enclosure?
I also have a Dremel, which can't take thick enough bits but probably runs slower than 3100rpm at its lowest setting so might be useful for making pilot holes?
Any advice? I don't want to mess up a case I just spent £65 on...
As far as I can tell the metal is 1mm thick steel. I have a set of 'high speed steel twist' drillbits & an old 350W 3100rpm power drill. This combination worked nicely for drilling the thick aluminium you see in the picture but I'm not certain how well it will work against steel, particularly so thin. Do I stand a chance or will the drill completely mess up the enclosure?
I also have a Dremel, which can't take thick enough bits but probably runs slower than 3100rpm at its lowest setting so might be useful for making pilot holes?
Any advice? I don't want to mess up a case I just spent £65 on...
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This might sound strange,
I find standing above it helps use your feet to hold it..so you are drilling into a thick catalogue is better than it twisting in a vice..That said if you have a workmate that helps..
Large holes you can clamp it to scrap wood and drill the wood gives support..and your cutter will go through it!
Also probably assemble it mark out then strip it and drill..if it twists as you drill it can run off..
Variable speed drill helps..something with just one speed is a pain and will scrap your project..and burn cutters out (slow and steady)
I have done wonders with the budget argos £12.00 drill variable speed..
More about finesse not brute force..
Regards
M. Gregg
I find standing above it helps use your feet to hold it..so you are drilling into a thick catalogue is better than it twisting in a vice..That said if you have a workmate that helps..
Large holes you can clamp it to scrap wood and drill the wood gives support..and your cutter will go through it!
Also probably assemble it mark out then strip it and drill..if it twists as you drill it can run off..
Variable speed drill helps..something with just one speed is a pain and will scrap your project..and burn cutters out (slow and steady)
I have done wonders with the budget argos £12.00 drill variable speed..
More about finesse not brute force..
Regards
M. Gregg
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Large diameter twist drills have a tendency to either distort or rip the metal if it's too thin, and can also make funny, lobe-shaped holes when freehand drilling without a press. When using them, it's advisable to clamp the metal between a couple of blocks of wood for support. On chassis', not always practical.
A step drill is probably the best tool for drilling large holes in sheet metal, but they're expensive.
Up to about 6mm or somewhat larger, you should have no problem. I used to use a handheld taper reamer, which is a little bit of a pain, but they work just fine. Cheap, too, and should be pretty available.
With a Dremel, you have the option of drilling a series of small holes near the perimeter of the hole you're making, then cleaning the edges up with the Dremel. Get a small carbide burr (rotary file), and you'll be amazed by how much metal it can move. If you have holes larger than10 mm, this is the method I'd use with simple tools.
Of course, it's not exactly the tool for the job, but if you just have a few holes to drill then it's not worth spending a lot of money for more specialized tools.
M.Gregg was right on the drilling; keep the speed low and use some kind of lube, and keep some pressure on it. You don't want the bit spinning without cutting. Make sure your drills are sharp, too.
--Buckapound
A step drill is probably the best tool for drilling large holes in sheet metal, but they're expensive.
Up to about 6mm or somewhat larger, you should have no problem. I used to use a handheld taper reamer, which is a little bit of a pain, but they work just fine. Cheap, too, and should be pretty available.
With a Dremel, you have the option of drilling a series of small holes near the perimeter of the hole you're making, then cleaning the edges up with the Dremel. Get a small carbide burr (rotary file), and you'll be amazed by how much metal it can move. If you have holes larger than10 mm, this is the method I'd use with simple tools.
Of course, it's not exactly the tool for the job, but if you just have a few holes to drill then it's not worth spending a lot of money for more specialized tools.
M.Gregg was right on the drilling; keep the speed low and use some kind of lube, and keep some pressure on it. You don't want the bit spinning without cutting. Make sure your drills are sharp, too.
--Buckapound
I agree,
trouble is if its just one project it can get be expensive..Then again cutters (hole saw) are not cheap..
I would not try to cut more than 30mm by hand drill..
Yes how to drill a square hole with a round drill easy...LOL try 10mm in sheet metal...with no pilot hole even easier..
Regards
M. Gregg
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If the panel is removable, clamp on work bench with sacrificial scrap of wood and several padded clamps - this'll free up both hands to control the drill, as well as reduce nasty edges on rear side of cut out areas. Cut undersize and finish off with fine cut files - cheap sets are available with small profiles that can allow for more than simple round holes - I consider them to be essentially disposable.
sorta duplicate of buckapound's post
sorta duplicate of buckapound's post
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Thanks for all the advice guys. My power drill is very old (the chuck says 'Made in West Germany') so it only has 1 speed & isn't particularly useful for anything that doesn't want full speed (I end up 'pulsing' it on & off for certain materials). It was okay with the aluminium, drilling through a drop of water to keep the bit cool & stop the shavings from going everywhere.
I've asked my university's physics department if one of their workshop technicians would be willing to drill for me (health & safety won't let me use their equipment) but if they come back negative I think I'll look at getting a punch. Seems less likely to go wrong!
The case is completely dismantleable (it came flat-pack) so a good working position isn't an issue.
Yep, I was already planning on only using circular parts, even going so far as having a hardwired mains cable (with strain relief grommet etc.) rather than trying to make a rectangular hole for an IEC socket. I haven't come across sheet metal punches before, how easily will one go through 1mm SECC? If I do it right I can get away with just buying 1 size.
I've asked my university's physics department if one of their workshop technicians would be willing to drill for me (health & safety won't let me use their equipment) but if they come back negative I think I'll look at getting a punch. Seems less likely to go wrong!
The case is completely dismantleable (it came flat-pack) so a good working position isn't an issue.
Wow, a thread I can actually give advice on! As a newbie here, this is neat...
Anyway, I have drilled a lot of holes into a lot of different metals (sadly, not a hobby). Stainless steel sinks, aluminum plate (6061 T6), copper plate, sheet metal, and mild steel plate. And tubing and pipes.
The one thing that I learned early on is that even with a good punch, twist bits tend to "skate" all over the place (scratches = no good) and to make matters worse they "bounce" around in the hole giving you an oblong hole.
This is what you need.
Unibit Step Drills - Drill Bits - Tools - IRWIN TOOLS
Step drills. I bought a set of three on sale ($20 CND when it was 66% off) and bought one very good one for $27 for aluminum and copper. The steel tends to wear them fast. I have used them in a drill press on the odd occassion, but most of the time I use them in a portable drill driver. I also use cutting oil and go slowly to start, but never go full blast on it (wear on the bit). Slow like a 45 rpm record (yeah no kidding) actually works nicely. I still use a punch, but only to make a small dimple.
The great thing is that each step is a defined width listed on the flat side of the drill bit. I mark which one I want with a marker mark if I am do a lot of the same sized hole. Good practice is soft backing like solid styrofoam or scrap wood, clamping down good and hard with non marring clamps, and go to the races.
Trust me, this is the best round hole maker you can get with a drill. And you can try it on scrap.
Enjoy!
Then spend some more on good tools first.
Of the advice given so far, the step drill would be my favourite, esp. when limited to using a handheld drill. I use a taper drill for holes bigger than 10 mm.
But you will have to buy a drill with viarable speed first as these step or taper drills need to be used at low revs.
For rectangular holes: a fretsaw (with lots of spare fine teethed blades, these things break easily) and files. I use the fretsaw to roughly saw out the big part first and then file the rest down to get a reasonably rectangular shape. Doesn't need to be perfect as the bezel will cover it.
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