Drill press for case work.

[mike_d]

Quote:

Originally Posted by bg4533 Can anyone recommend any good bits to use for drilling aluminum cases and heatsinks? Are certain brands better than others? What coating should I look for?

Plain high speed steel (HSS) bits are fine for drilling aluminum. Cheap too. I'll replace the most used bits in my index every year or so. Never had luck trying to resharpen them.

You might want to look into the stepped bits like the unibit. I have never used them but people seem to like them for working aluminum.

-mike

 

[The_Mac]

Something you might look into for bits would be if you have a friend or know someone that works in a machine shop or a factory, to ask if they can save worn carbide or diamond bits for you.

Drill bits that machine shops throw out for being worn out of tolerance are still GREAT for home work, are still much better at cutting than HSS, durable as all get-out, and best of all, free (if you ask nicely). You may not get all the sizes you like, but a carbide bit that's not quite up to production specs is still an excellent tool.

 

[mike_d]

Remember that solid carbide bits can be extremely fragile, carbide tipped bits are better. If your 'press has problems with runout (very common with cheaper machines), or the chuck is not centering the bit properly, they will break very quickly. I experienced this with my dremel drill press while using some carbide resharps to drill PCBs - I was breaking a bit every 3 holes or so. I switched from the crappy 3-jaw chuck back to the 1/8" collet and most of the problem went away. The proxxon press mentioned earlier looks like the perfect beast for this job.

-mike

 

[The_Mac]

Quote:

Originally Posted by mike_d Remember that solid carbide bits can be extremely fragile, carbide tipped bits are better. If your 'press has problems with runout (very common with cheaper machines), or the chuck is not centering the bit properly, they will break very quickly. I experienced this with my dremel drill press while using some carbide resharps to drill PCBs - I was breaking a bit every 3 holes or so. I switched from the crappy 3-jaw chuck back to the 1/8" collet and most of the problem went away. The proxxon press mentioned earlier looks like the perfect beast for this job. -mike

YEah, sorry. Meant to specify carbide (or diamond) tipped bits, rather than full-carbide.

 

[pburke]

slightly off topic - but what do you use for square cutouts? I have to put some big rectangular holes into 0.9mm sheet metal for a power on/off switch and was thinking to use a hack saw, or to use some sort of router attachment on a dremel. The hole I need this time is about 20x15mm in size and the switch edge will cover up slight imperfections.

Peter

 

[mike_d]

First, blacken the aluminum with a permanent marker and scribe the outline of the cutout. Work from the rear so any marks won't be on the money side of the panel. I'd drill out as much material as possible then use metal files to square it up.

If you can get a nibbler tool, go for it. It's a fast way to remove lots of material and much easier to control than a router. Nibble away metal up to the line, then clean up with files.

http://www.jdr.com/interact/item.asp?itemno=NIBBLER

-mike

 

[The_Mac]

Alternatly, put a small hole at each corner, and then take a cut-off wheel in the dremel and just cut along the outer lines. The corner-holes make it such that it's easier to stop at the appropriate place.

Then just finish-file the edges.

 

[bg4533]

So should I just head out to Harbor Freight and get myself a big set of bits or does anyone know any websites that have good deals on this kind of stuff? I had a 17pc bit set, but broke most of the small bits with my hand drill. I want a larger assortment of sizes too.

The_Macs suggestion for cutting square holes should work well. I also had decent experiences with side cutting bits for the dremel.