Allo, First time cutter here.... Just a quick one, wanting to cut 2 holes into a sheet of al. so 2x120mm fans can get proper airflow. I was going to mask the sheet as i have seen people do in mods on here but is that the side to cut through first or not? I was also going to use some circular cutters that attach to a standard drill, will these do the job ok? peace fatman
As long as you mark the tape itself where you want to cut the hole - obviously, then yes... cut the hole from the taped side. Dunno if you knew already, but a CD/DVD is exactly the right size for a 120mm fan hole template And again... yes... a variable-speed drill, with a suitable sized holesaw (114mm is the size you need for a 120mm hole) is the best way to do it
awesome, cheers fella. Great reply there, everything i needed to know and more, cheers dude. peace fatman
Make sure that the piece of metal that you are cutting is firmly clamped to a thick piece of wood, this is necessary for two reasons, first of all it will mean that as the holesaw starts to cut into the Al sheet it cannot spin in the opposite direction (Newtons 3rd law of motion - action gives equal and opposite reaction), secondly it will also mean that as the holesaw breaks through the Al sheet it will not dive through because of the cutting pressure you are applying suddenly meeting no resistance. It needs to be a thick bit of wood because the pilot drill for the holesaw usually sticks out past the edge of the saw teeth by about 10mm. Top tips for a trouble free cutting experience when using a holesaw and a hand held drill on Al sheet metal:- WEAR EYE PROTECTION. Use a cutting lubricant, something oily is best, don't use water, but if you use a light oil such as WD40 make sure you have plenty of ventilation as the heat will vapourise the oil and it isn't very good for you when you breath in the fumes over a prolonged period. Use a vari-speed drill and start slowly, if you don't have a vari-speed set the driil to its slowest speed if you can, use short bursts of power to the drill and don't run it at full speed for too long . Make sure you keep the drill vertical otherwise the holesaw can jam on the edges of the hole and stall the drill, the thicker the Al sheet the more noticable this problem will be. It will try to yank the drill out of your grip if it does stall so be prepared. You can use a drill that has a built in spirit level to help keep it straight but in my experience you spend more time looking at how well the holesaw is cutting rather than looking at the spirit level. Your best bet is to have someone else looking at the vertical alignment as you make the cut. If possible have a couple of test cuts on some scrap before you commit yourself to the real deal, just in case you have any problems. As an alternative to the drill, it is possible to buy sheet metal punches (all kinds of sizes are available and sometimes known as Q-Max cutters) which require a pilot hole to be drilled and then the punch splits in two with one half either side of the Al sheet connected by a bolt through the pilot hole. Then all you do is grip one part in a vice (it has flat edges for this) and then connect the other half with the sheet between them and tighten the bolt. You will then have a perfectly round hole - other shapes are available. The amount of effort required will depend on how thick the sheet is, I would say that for Al the thickest sheet you should use is about 3mm (1/8 of an inch in old money), you can use thicker (I've done it with 6mm sheet) but you run the risk of bending the sheet as it does take a fair bit of force to get through this kind of thickness. PS I really am serious about the eye protection
