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RTPBurnsville
12-28-2009, 08:19 AM
Would these work to drill a few holes in a stainless (304 or 316) NEMA4 type enclosure? I need to to install a couple cable box connectors and the box is to large to fit in my mill. Thanks

www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96275

Black_Moons
12-28-2009, 08:22 AM
those work wonders in sheet metal, noisy as hell but works wonders. Never tryed in stainless but I don't see why not other then it might dull it quickly (But hey they look easy enough to sharpen, just hone along the flute)

thebigron
12-28-2009, 08:41 AM
Dont forget: SLOW RPM in the stainless. A lot of people, as the hole enlarges, fail to realize that the speed needs to drop accordingly. They start OK, then gradually become too fast. A bit of cutting oil could not hurt either.

Black_Moons
12-28-2009, 09:12 AM
Yea, slow, and plenty of force and torque. My favorate drill for large (>3/8" holes) in steel is a 500rpm airdrill that just matchs the output of my 5HP compressor. Usally feed hard enough on drills over 1/2" to nearly stall the drill. But then, im not happy unless my drills are spiting up large chunks of swaff. Thin (18awg) sheet metal with step bits requires much less force.

Im not sure about that stainless alloy, but stainless is typicaly considered abrasive and 'work hardening', meaning if you let your drill bit just rub without cutting it can harden the steel to near uncutable strength while simutaniously dulling your drill bit.

To avoid bending the enclosure with feed force, clamp some wood overhanging a bench, and hang the enclosure onto the block of wood so your drilling into the wood after you make it through the metal. The step bit won't enjoy wood but im sure it will drill it none the less.

John Stevenson
12-28-2009, 09:31 AM
I tend to squeeze the trigger of the drill, let it start to speed up then stop and do it again to keep the speed down.
Many of the modern drills have a far too higher speed or rely on electronics to control speed but they are worth squat on torque.

I much prefer the older metal two speed mechanical drills but mine are all starting to show signs of old age.

The last new one I bought has 2 speed mechanical 1,000 and 2,000 rpm which is still far too fast.

One thing I have found that's a good deal are these SDS hammer drills

http://www.screwfix.com/sfd/i/cat/35/p3248435_x.jpg

You get get these here new in 240 volts @ 1250 watts for about 30 to 50, secondhand with a broken hammer action you can pick them up for 10 to 20 for spares.

One here on Ebay for 6.00 http://cgi.ebay.co.uk/titan-6kg-sds-rotary-hammer-drill_W0QQitemZ220523584371
Another one, working, for 10.50 http://cgi.ebay.co.uk/SDS-HAMMER-DRILL_W0QQitemZ260519088990

The motors are unbreakable, all you need to do remove the hammer action and shaft and turn a new shaft up and weld the original drive dog on it and make it suit whatever you want.

I made mine with a MT3 taper so i can hole any Morse drills and also a chuck.
They have a fixed speed of 700 to 800 rpm depending on model and the motor has a clutched output so if you do jam a big drill in it just slips.

A really cheap way to get a big man eater of a drill.

.

Black_Moons
12-28-2009, 10:25 AM
Don't bother trying to get one drill that does everything. Get a low speed and a seperate high speed drill.
http://www.princessauto.com/tools/corded-power-tools/hand-held/8039521-1/2-d-handle-drill get one of these for your big holes :)

Or if you really must have one awsome drill, how about this:
http://www.princessauto.com/tools/corded-power-tools/hand-held/8171084-1/2-right-angle-drill
330rpm/1300rpm gearbox, so you know it has more torque then should be sanely held by a human. 1300rpm is plenty for most smaller drilling too, but IMO that thing is too unwieldy for small holes, get a small drill for small holes!
Also your smaller high speed drill will double for all your 2000rpm+ wire brushing and drum/flap sanding and whatever other weird accessorys you have for your drill.

you really want a <500~rpm drill for those big holes. running those faster drills at low RPM's and high torque kills them super fast because there is little airflow and way more then designed torque and often they don't have thermal shutdowns. iv seen 3000rpm drills *smoke* in seconds when used at 300rpms with big drills. 1000rpm drills won't take much longer!

Running those big drill bits at high RPM and low feed rate 'works' but also seems to dull the drill bits very fast and generate lots of heat. Low rpm and high feed cuts WAY faster. I know its strange that less RPM = faster cutting, but thats just how it seems to be (I could be wrong...) as the higher torque lets you use a much higher feed rate, and large drill bits love to be forced into the work, and heat is extracted with the chip as it should be

JoeFin
12-28-2009, 10:41 AM
From experience - might do 1 hole

Even the best quality Step-Drills (Lennox) have trouble is SS. All the advice has been good, "Low Speed, Oil, ect" but given Happy Fart quality issues I would say if you have more then 1 hole to do try Home Dippo for the Lennox Step Drill

gb25
12-28-2009, 10:53 AM
Used the same drill bits to drill four 7/8" holes in a hoffman stainless nema box. Worked great and the bits look the same as they did new. I did drill a small pilot hole to get them started though. The points weren't split very well, so I wasn't very confident in how well they would stay on center when starting.

gnm109
12-28-2009, 11:42 AM
I've been using a set of HF step drills for several years. they work very well in stainless steel sheet and everything else I've tried them on. A pilot hole is always a good idea when laying out your work.

RTPBurnsville
12-28-2009, 08:03 PM
Thanks for the help guys..... My enclosure is Hoffman as well so looks like there should be a good chance of creating a few holes in stainless. Looks like a trip to HF in the next day or two. I was at a friends house today and he had a Lenox step drill which made lots of noise and chatter in aluminum but the hole looked pretty good. Thanks again, Robert

RobbieKnobbie
12-28-2009, 08:23 PM
Even with low speed and cutting oil, I've had mediocre results with the HF step drills. It's not that they burst into flames or anything, they just need the corners toucher up more often than I like. (then again, look at the price...) I don't believe I've ever cut into stainless with them, but I have done a lot of holes in regular enclosures. If you have a number of holes to do, try a punch instead, HF also carries them in little kits in standard knock out sizes.

I use this drill... Milwaukee RA Drill (http://www.milwaukeetool.com/ProductDetail.aspx?ProductId=3107-6&CategoryName=SC%3a++Right+Angle+Drills). It goes plenty slow and has torque measured by the mile-ton.

gb25
12-28-2009, 09:09 PM
I used an older 14.4v cordless dewalt drill with a pretty weak battery (all I had at the time). No oil was used. I used speed two out of three, full speed. That worked fine till the battery got weak. Then I used low speed, which worked ok til the battery was dead.

I got about two holes per charge. Here's a pic of one of the holes, and the drill bit after all four holes were drilled. The back side of the hole raised a little burr, so I used the bit on the back side to remove it. Like I said, the cutting edges look pretty much the same as new.

edit: By the way, this was a Hoffman NEMA 4X stainless box.

http://lh3.ggpht.com/_-PoJwKJBpeI/SzlfV0vGkSI/AAAAAAAAACY/Qk3akrQHwj8/s800/IMG_0932.JPG

http://lh4.ggpht.com/_-PoJwKJBpeI/SzlfXAbaYYI/AAAAAAAAACg/ccUawTlyGyw/s800/IMG_0938.JPG

Black_Moons
12-28-2009, 10:08 PM
a 3 speed drill? never seen such a beast (assumeing thats a gearbox)

Yea, they do make AWFUL noise. seriously just awful noise, even with large support. I heard them using one in princess auto on an overhead fume hood and the entire store was covering there ears as it resonated the entire hood.

Its amazeing anything that makes that much noise could make nice holes, but they do.

gb25
12-28-2009, 11:06 PM
a 3 speed drill? never seen such a beast (assumeing thats a gearbox)

My drill is kind of like the drill at the link below. Quite a few dewalts have the three speeds. Variable trigger with low, medium, and high settings.

http://www.ultimatehandyman.co.uk/1cordlessdrill.htm

Paul Alciatore
12-28-2009, 11:38 PM
I love those step drills for sheet metal work. And as gb25 says, they are also great for cleaning up the burr. I just set the depth stop on my drill press for the right depth and do the hole. Then I turn the work over and get the burr in a second or two. Fast and easy.

I've done mostly aluminum and some mild steel with them, but it is nice to know they will also do stainless or at least some stainless.