How To Make Holes In Aluminium
Feb 19, 2011 21:28:19 GMT
Post by jonclancy on Feb 19, 2011 21:28:19 GMT
Making Holes in Aluminium
Hi All,
I’m surprised that I’m writing this small HOWTO, as it has been the metalworking or box-making aspects of this hobby I have found most daunting. Despite having practised woodwork, metalwork (workshop, forge and foundry) and design at school for a few years, it’s a standing joke at home that anything I DIY will have nails bashed into it at odd angles.
I think that’s probably somewhat unfair, but the truth is in there, I suppose.
Anyway, this is really a case of passing on what I found works for me, and in summary:
“In regione caecorum rex est luscus” and “nanos gigantium humeris insidentes”.
While most of us are happy to sling solder around, following a stuffing plan, to create a perfectly functioning whateveritis, one of the downsides of DIYing is that is sometimes looks, well, DIYed! The old triangle of Cost, Quality and Time has never been truer here. If you have deep pockets, there are some high quality, CNC drilled, look-as-good-as-high-end-manufacturers', chassis available. Budget well over £100. You get what you pay for, it’s true, but you also do not benefit fro the economies of scale that the manufacturers enjoy. Besides, if you compare a mass-market amp chassis from the Eighties onwards, it seems biscuit tin factories were sub-contracted to make chassis lids. We want to avoid that look!
At the other end of the range, you can buy a folded, mild steel box for a few tens of pounds. Or even fashion your own from sheet aluminium and a metal frame. While fine for casing up a power supply that will be hidden behind an equipment rack, for instance, you might want a better finish if it is going to be on public view!! You could use an online machining service like Front Panel Express to design your own chassis fronts, but costs soon mount up with lots of holes to make for RCA sockets, binding posts etc. For engraving and finish, these online services might be a reasonable option for that special project, especially as you are able to send them your own front panel for machining.
In this HOWTO, I’ll list the equipment I use to punch and drill holes in medium-cost aluminium chassis that are available from eBay vendors. With care, you will be able to place near-perfect round and square holes in your preferred layout, giving a professional finish you will be proud to show off, at an affordable cost. While there is an initial outlay on equipment and tools, these will last you a lifetime and pay for themselves very quickly indeed!
Nearly all the items listed as essential or desirable are readily available on eBay. Paying a little more for a decent quality branded tool is a must – it will last longer and your results will be better that using a cheaper, poor quality substitute. While the brands (where listed) are items I have bought, there are other makes out there you could try, and you might get better results!
Essential Items
Superfine permanent marker (Lumocolor)
Accurate ruler
Low tack decorators’ masking tape (blue)
Automatic Centre-punch (I got mine from Sears – plenty on eBay)
Set of quality metric HSS drill bits
Lubysil BCO14 www.lubysil.co.uk/Public/Static.aspx?page=products
QMax metal punches (round and square). Datasheet from Farnell, but readily available from eBay vendors: www.farnell.com/datasheets/14928.pdf Square ones are pricey, but worth the money as they will last a lifetime!
Castrol LM grease (for keeping punch screw threads lubricated)
Selection of decent Allen/hex keys for use with QMax punches (cheaper than buying the QMax “keys”.)
Warding File set – eBay
Step-drills Metric and Imperial - eBay
Tap wrench and 3mm taps (starter, middle and end!!) - eBay
Electric Drill
Personal Safety Equipment (eye protection, face mask, gloves, chain mail etc)
A2 stainless steel nuts, bolts washers etc. From your local fastener supplier, or readily available for reasonable prices on eBay. My current favourite are button headed bolts. They still use a hex key to tighten, but are a lower profile than the socket cap items I’ve been using till recently – look less industrial!!
Threadlock - eBay
Desirable Items
Pillar drill (drill press)
Work bench (Workmate-a-like)
How To Make Holes
Design your layout on paper. Decide how you want power and signals to be separated (of course!). A DAC might have an IEC inlet on one side of the rear panel, and signals on the other. An Amp will probably be better with power coming in centrally and signals on each outer side of the rear panel.
Once you’re happy with the design and layout, take your panel and cover it with low-tack masking tape. This protects the panel surface and also minimises the chance of your drill bit skating around and causing damage. Using the superfine permanent marker, measure and draw horizontal and vertical centre-lines. These are your reference.
Mark out the centres for each hole to be drilled/punched. Take into account the diameters when you planned the layout, so the end result will be evenly spaced sockets etc. If you are making more than one chassis, take notes on the layout. This will allow you to very quickly mark out subsequent panels once the reference lines are drawn on.
Once you are happy with the marking out, centre-punch all centres. You will find that the spring-loaded punches will allow you to “move” a slightly off centre punch with further applications because the aluminium is so soft - just punch at an angle and the hole will move in the direction you want, while gettign deeper.
Once you are happy with the centre-punched marks, apply some BCO14 fluid to the drill bit and work piece and drill a small (around 2mm) pilot hole in each location. Just drill through the masking tape. If you are going to use a step-drill, then drill out the pilot hole to correspond to the smallest step-drill diameter (say, 4mm). This will allow you to position the step-drill in the work piece and then start the drill. It means you start drilling when perfectly centred. Make sure you clamp or hold the work piece tightly. Use plenty of BCO14, a light touch on the drill press (if you are using one) and a reasonable speed. I have my pillar drill set to the highest speed, which is around 3000 RPM).
If you are using a QMax punch, drill out the required clearance hole for the bolt (or use another QMax punch to make the hole) and follow instructions to effortlessly punch out a perfect hole. It is possible, with careful planning and clearance hole positioning, to use a square punch side by side to create a rectangular IEC socket mounting hole. Beware that IEC sockets come in various sizes. Check the datasheet for dimensions and plan accordingly. I use Furutech FI-10 IEC sockets, and these can be mounted using two punches with the square punch, and finishing the last mm or so with a flat warding file. Mount the IEC socket in the hole and use the mounting holes as a template with your Superfine to mark the centres for the mounting screws. If you are going to tap the mounting hole with a thread, then use a 2.5mm drill bit to give you some meat to cut the thread. If you are going to use a screw straight through, just drill a 3mm hole and use a nyloc nut and lock washer.
If you are going to tap a thread into a heat sink or panel, drill your clearance hole or the correct diameter.
www.engineering-supplies.com/info/15/tapping-drill-sizes/
Once you are ready to start, insert your first tap into the tap wrench. You will notice that the starter taps will have a tapered end and will not have any cutters to begin with. My set of three M3 taps (from eBay) are marked with a ring around the shank for the starter, two rings for the intermediate, and no markings, but full cutting length, for the final tap. This final tap will cut almost to the bottom of a blind hole. Use plenty of BCO14 and make sure you hold your tap wrench perpendicular to the hole. Once the tap has bitten, turn two revolutions forward (to cut deeper into the pilot hole), then once reverse to free the tap. Two forward, one back all the way till the tap either goes through the panel, or the tap nose hits the bottom of the blind hole. If you feel a strong resistance, STOP TURNING!! You do NOT want to break off a tap in the pilot hole, and it is possible to do this if you are too enthusiastic. If needs be, remove the tap completely and flush the hole with solvent. The re-apply BCO14 and start again. Once you have tapped the thread, flush the hole with spray solvent (Maplins etc). If you hold the work piece inverted, you will be amazed at how large the amount of aluminium bits that reappear!
Finally, remove your masking tape from the panel and wash in a mild washing-up solution. And carefully dry with a soft towel. Use thread lock on any critical fasteners (heat sinks to chassis etc.).
So there you have it – the first draft on how to make presentable holes in aluminium. Please feel free to ask questions, add further advice/comment, or equipment recommendations.
Cheers
Jon
Hi All,
I’m surprised that I’m writing this small HOWTO, as it has been the metalworking or box-making aspects of this hobby I have found most daunting. Despite having practised woodwork, metalwork (workshop, forge and foundry) and design at school for a few years, it’s a standing joke at home that anything I DIY will have nails bashed into it at odd angles.
I think that’s probably somewhat unfair, but the truth is in there, I suppose.
Anyway, this is really a case of passing on what I found works for me, and in summary:
“In regione caecorum rex est luscus” and “nanos gigantium humeris insidentes”.
While most of us are happy to sling solder around, following a stuffing plan, to create a perfectly functioning whateveritis, one of the downsides of DIYing is that is sometimes looks, well, DIYed! The old triangle of Cost, Quality and Time has never been truer here. If you have deep pockets, there are some high quality, CNC drilled, look-as-good-as-high-end-manufacturers', chassis available. Budget well over £100. You get what you pay for, it’s true, but you also do not benefit fro the economies of scale that the manufacturers enjoy. Besides, if you compare a mass-market amp chassis from the Eighties onwards, it seems biscuit tin factories were sub-contracted to make chassis lids. We want to avoid that look!
At the other end of the range, you can buy a folded, mild steel box for a few tens of pounds. Or even fashion your own from sheet aluminium and a metal frame. While fine for casing up a power supply that will be hidden behind an equipment rack, for instance, you might want a better finish if it is going to be on public view!! You could use an online machining service like Front Panel Express to design your own chassis fronts, but costs soon mount up with lots of holes to make for RCA sockets, binding posts etc. For engraving and finish, these online services might be a reasonable option for that special project, especially as you are able to send them your own front panel for machining.
In this HOWTO, I’ll list the equipment I use to punch and drill holes in medium-cost aluminium chassis that are available from eBay vendors. With care, you will be able to place near-perfect round and square holes in your preferred layout, giving a professional finish you will be proud to show off, at an affordable cost. While there is an initial outlay on equipment and tools, these will last you a lifetime and pay for themselves very quickly indeed!
Nearly all the items listed as essential or desirable are readily available on eBay. Paying a little more for a decent quality branded tool is a must – it will last longer and your results will be better that using a cheaper, poor quality substitute. While the brands (where listed) are items I have bought, there are other makes out there you could try, and you might get better results!
Essential Items
Superfine permanent marker (Lumocolor)
Accurate ruler
Low tack decorators’ masking tape (blue)
Automatic Centre-punch (I got mine from Sears – plenty on eBay)
Set of quality metric HSS drill bits
Lubysil BCO14 www.lubysil.co.uk/Public/Static.aspx?page=products
QMax metal punches (round and square). Datasheet from Farnell, but readily available from eBay vendors: www.farnell.com/datasheets/14928.pdf Square ones are pricey, but worth the money as they will last a lifetime!
Castrol LM grease (for keeping punch screw threads lubricated)
Selection of decent Allen/hex keys for use with QMax punches (cheaper than buying the QMax “keys”.)
Warding File set – eBay
Step-drills Metric and Imperial - eBay
Tap wrench and 3mm taps (starter, middle and end!!) - eBay
Electric Drill
Personal Safety Equipment (eye protection, face mask, gloves, chain mail etc)
A2 stainless steel nuts, bolts washers etc. From your local fastener supplier, or readily available for reasonable prices on eBay. My current favourite are button headed bolts. They still use a hex key to tighten, but are a lower profile than the socket cap items I’ve been using till recently – look less industrial!!
Threadlock - eBay
Desirable Items
Pillar drill (drill press)
Work bench (Workmate-a-like)
How To Make Holes
Design your layout on paper. Decide how you want power and signals to be separated (of course!). A DAC might have an IEC inlet on one side of the rear panel, and signals on the other. An Amp will probably be better with power coming in centrally and signals on each outer side of the rear panel.
Once you’re happy with the design and layout, take your panel and cover it with low-tack masking tape. This protects the panel surface and also minimises the chance of your drill bit skating around and causing damage. Using the superfine permanent marker, measure and draw horizontal and vertical centre-lines. These are your reference.
Mark out the centres for each hole to be drilled/punched. Take into account the diameters when you planned the layout, so the end result will be evenly spaced sockets etc. If you are making more than one chassis, take notes on the layout. This will allow you to very quickly mark out subsequent panels once the reference lines are drawn on.
Once you are happy with the marking out, centre-punch all centres. You will find that the spring-loaded punches will allow you to “move” a slightly off centre punch with further applications because the aluminium is so soft - just punch at an angle and the hole will move in the direction you want, while gettign deeper.
Once you are happy with the centre-punched marks, apply some BCO14 fluid to the drill bit and work piece and drill a small (around 2mm) pilot hole in each location. Just drill through the masking tape. If you are going to use a step-drill, then drill out the pilot hole to correspond to the smallest step-drill diameter (say, 4mm). This will allow you to position the step-drill in the work piece and then start the drill. It means you start drilling when perfectly centred. Make sure you clamp or hold the work piece tightly. Use plenty of BCO14, a light touch on the drill press (if you are using one) and a reasonable speed. I have my pillar drill set to the highest speed, which is around 3000 RPM).
If you are using a QMax punch, drill out the required clearance hole for the bolt (or use another QMax punch to make the hole) and follow instructions to effortlessly punch out a perfect hole. It is possible, with careful planning and clearance hole positioning, to use a square punch side by side to create a rectangular IEC socket mounting hole. Beware that IEC sockets come in various sizes. Check the datasheet for dimensions and plan accordingly. I use Furutech FI-10 IEC sockets, and these can be mounted using two punches with the square punch, and finishing the last mm or so with a flat warding file. Mount the IEC socket in the hole and use the mounting holes as a template with your Superfine to mark the centres for the mounting screws. If you are going to tap the mounting hole with a thread, then use a 2.5mm drill bit to give you some meat to cut the thread. If you are going to use a screw straight through, just drill a 3mm hole and use a nyloc nut and lock washer.
If you are going to tap a thread into a heat sink or panel, drill your clearance hole or the correct diameter.
www.engineering-supplies.com/info/15/tapping-drill-sizes/
Once you are ready to start, insert your first tap into the tap wrench. You will notice that the starter taps will have a tapered end and will not have any cutters to begin with. My set of three M3 taps (from eBay) are marked with a ring around the shank for the starter, two rings for the intermediate, and no markings, but full cutting length, for the final tap. This final tap will cut almost to the bottom of a blind hole. Use plenty of BCO14 and make sure you hold your tap wrench perpendicular to the hole. Once the tap has bitten, turn two revolutions forward (to cut deeper into the pilot hole), then once reverse to free the tap. Two forward, one back all the way till the tap either goes through the panel, or the tap nose hits the bottom of the blind hole. If you feel a strong resistance, STOP TURNING!! You do NOT want to break off a tap in the pilot hole, and it is possible to do this if you are too enthusiastic. If needs be, remove the tap completely and flush the hole with solvent. The re-apply BCO14 and start again. Once you have tapped the thread, flush the hole with spray solvent (Maplins etc). If you hold the work piece inverted, you will be amazed at how large the amount of aluminium bits that reappear!
Finally, remove your masking tape from the panel and wash in a mild washing-up solution. And carefully dry with a soft towel. Use thread lock on any critical fasteners (heat sinks to chassis etc.).
So there you have it – the first draft on how to make presentable holes in aluminium. Please feel free to ask questions, add further advice/comment, or equipment recommendations.
Cheers
Jon
) as practised in workshops.
