Today I tried installing a PDC system in my rear bumper.

Sofar I weared out two drills in my rear bumper. It is much thicker steel then I expected.

The drills are special hole-drills.


for some reason I am doing something wrong. Because my drill starts smoking very quickly and turns blue.

please some advise for making 22mm holes for my PDC sensors.

 

If it's turning blue, it's heating up, try giving the bit a spray with water every two seconds, method for drilling through glass, you could probably use WD-40 also, just to add some lubrication, but I'd try water first, the WD-40 may affect the amount you're cutting into the metal.

 

Did you skimp on the quality of the hole saw? Spend the $15-20 for a quality tool and it'll work just fine. The cheaper ones will work for a few holes in wood and then give up the ghost.

 

thanks!

can you explain to me how WD-40 may affect the amount that the hole saw will cut?

 

It's an oil, I'm just thinking that with the extra lube the saw may not have the same abbrasive quality. If you catch my drift. It's mostly for temperature control... you could just hook up the garden hose with a steady stream of water, but I'd be careful not to get the drill wet, especially if it's plugged into a wall outlet lol ZAPPP!

 

another question. How should i finish the boreholes themselves? I mean to prevent rust? clear coat? or something else?

 

I would use paint on the bare metal, clear coat isn't as resiliant as paint. I would also try to moung the sensors in some sort of rubber, or if that isn't possible, just some clear silicone... but don't be too liberal with the silicone, it could end up looking like crap. (sorry about any typos, i'm on my smart touch phone)

 

Exact opposite of the truth. Coolant for cutting machines (mills, lathes, etc) has an oil in it. Cutting fluid for drills and taps also have oils in them. You _want_ the lubricating properties to help the chips evacuate from the hole, and to keep the drill bit from dragging on the workpiece. Having oil there will not affect the cutting operation at all in a negative way, and will actually help making the drill more effective by keeping it cool. Heat is the number one reason for drills to go dull, and running it dry is the quickest way to overheat it.

If your drill turns blue, you've WAY overheated it. My first thought is if you bought the cheap hole saw, most likely it's a carbon steel saw, intended only for soft materials like wood and plastic. What you want is the bi-metal saw, preferably with drilling fluid, but for the general home user/DIY type stuff, just about any type of lube will work. WD-40 is commonly recommended. Hell, I've even used engine oil in a pinch.

The biggest thing to keep in mind though is go slow. You're likely running the saw at too fast of an RPM, and pushing on it too hard. You only need light pressure on a properly sharpened bit, and for a 22mm saw, about 450rpm. If you're spinning a carbon steel saw at around 1500rpm, dry, and pushing hard on it, you'll strip the edge off the teeth in 2 or 3 seconds.