Drilling cases and PCBs
Nov 6, 2001 at 6:45 PM Post #16 of 25
hsnam:

First, make sure the "dimmer" you got can handle inductive loads, a lot of them are designed for standard lightbulbs that are purely ohmic. Not really sure what happens if it can't handle the load, actually, but i'm not sure i want to try...

I think the main difference between a standard light-dimmer and the pedal that Dremel sells, is that the dimmer will slow down the drill, but you will lose torque accordingly, whereas the Dremel-pedal will slow the drill while preserving it's torque even at lov revs. Low torque obviously means that you cannot drill very hard materials, so the pedal is probably your best investment.

/Uffe
 
Nov 6, 2001 at 9:10 PM Post #17 of 25
Quote:

Originally posted by Nisbeth
Re: Irregular holes in cases.
If you already have a Dremel, get a milling-bit for it (preferably tungsten-carbide). that'll cut through aluminum, steel and PCB's like hot butter and it should last reasonably long, provided you don't use it at full speed (a Dremel runs at 25-30 kRpm AFAICR). (BTW - if you want to have ANY fun out of the finished amp, wear ear-protection while working
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)
/Uffe


Milling bit? Cuts through STEEL like butter? Where can I get one? I've got a 1/16" steel case that needs some work...

As for speed, I've got a Dremel Pro with cool LCD RPM-o-meter and RPM +/- buttons
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And regarding ear protection, Etys rule man!
 
Nov 6, 2001 at 10:57 PM Post #18 of 25
Hey guys.
Here's a place where you can find ANYTHING! I work in a machine shop, and we order from there all the time. The actual printed catalog is over 4" thick.

http://www.mscdirect.com/

The people working there can often recommend the proper product if you let then know what you are working on.

If you are looking for a good, self starting drill that will not wander off on you, get a SPLIT POINT screw machine drill. Split point drills are sharpened so there is no, or very little web thickness at the point and will start into the metal with no center drill or punch mark.
Screw machine or jobber length drills are shorter than the typical drill, so if you are just drilling through thin metal it should be just fine. Of course you should always spot your hole with a center punch if possible.

Personally, in metal this thin I would rather use a punch of some sort. If you have to to drill thin metal, make sure you have the work secured in a vice or clamped to the bench. The drill will grab, suck up and spin your part around when it breaks through the other side if not held firmly. Believe me, and my cut fingers!

As far as tool life: If you're burning them up too quickly, SLOW DOWN! Lower RPM's never hurt anybody, and use some king of lubricant. Oil, WD40, even beeswax can work!

Another good place to buy stuff:
http://www.mcmaster.com/
 
Nov 6, 2001 at 11:20 PM Post #19 of 25
Quote:

provided you don't use it at full speed


Woops
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That must've been my problem when working with my steel case. I thought, "hey, this isn't getting anywhere, let's max out the RPMs" and put my Dremel at a full 30,000
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Those HSS bits sure wear out fast that way. I just got some new tungsten carbide bits from eBay, so I'll remember to use them properly on the next metal case I work on.
 
Nov 10, 2001 at 11:49 PM Post #20 of 25
Quote:

If you already have a Dremel, get a milling-bit for it (preferably tungsten-carbide). that'll cut through aluminum, steel and PCB's like hot butter


Eh? How does this happen? I spent an hour yesterday cutting a hole for an IEC power connector in a 2 mm thick aluminum endpanel using tungsten carbide bits at anywhere between 5000 and 10000 RPMs. If I held the Dremel steadily at those RPMs, it seemed like the bit wasn't even cutting through anything. However, if I let the Dremel go crazy and vibrate like it was out of control, the bit actually moved very quickly through the aluminum (quickly being visible motion compared to not moving at all). What is the proper technique to achieve this cutting speed, yet with the Dremel in control?

BTW, the good thing I see so far about tungsten carbide is that none of the 2 bits I was using was worn down at all.
 
Nov 11, 2001 at 2:26 AM Post #22 of 25
Nov 11, 2001 at 8:11 AM Post #24 of 25
eric, I dunno man it's a "multipurpose" and aluminum is soft... as metals go, anyway. This thing will ziiiip thru a 2.5mm faceplate... I could sign my name with it like a pen.

If you're talking steel it'll work but it's much slower and heats up real fast (as anything in a dremel does) Hey c'mon, steel? can anything you can use at home cut thru steel like butter? Uhm are plasma torches legal for home use?
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Anyway I cut out alu panel holes in seconds for non-round stuff like rectangle power switches and IEC jacks. It's a good bit, I use em alot for stupid stuff. WEAR SHADES because this thing makes an unfair amount of debris.
 
Nov 11, 2001 at 5:52 PM Post #25 of 25
Well, I always wanted one of those monster CO2 lasers... It takes around ~1 watt to burn paper IIRC, so a couple hundred watts should do the trick... Anyone have a spare laser I could take off their hands?
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