What drill bits for bus conversion?

[jjrbus]

 Some people are gifted with great eye and hand coordination if you are not. Drill Doctor, Drill doctor, Drill Doctor + Drill Chill, Drill Chill, Drill Chill or other suitable cutting fluid,you want cutting oil not lubricant!!!!! not WD40, not used motor oil. Cutting fluid is designed to help break down the metal, not lubricate. Decent drill bits, Grainger is a good source.
Think of a drill bit as a chisle wraped around a pole. With a sharp bit and the proper speed and pressure and cutting fluid the cuttings should be coming off in long thin strips. Just like if you are useing a chisle, whch you are, well sorta.
You dont have to use cutting fluid on wood       HTH Jim

[belfert]

When I drilled the 1,025 holes for rivets on my bus we actually drilled at the highest possible speed.  Drilling at low speed was taking forever and by accident I found that high speed seemed to work fine and was far faster.  We dipped the bits into used motor oil at least twice per hole.  We used about ten Cobalt drill bits from Grainger.

Enco looks like a good place to buy from.  I was considering Harbor Freight, but most of their tools are junk.

[Sojourner]

The most common metal drilling bits are HHS, Cobalt and Tungsten carbide. Depend on type of material to drill and bits, you must be using the correct speed to follow thorough or you will shorten its life.
Good sharpen bit with narrow web center point will drill thorough faster than wide center web. Otherwise, pre-drill with smaller bit just large enough to allow larger one stage web bit to drill with ease. Drill Doctor can do 2-stage sharpening. Only problem with Drill Doctor is that it made of plastic trying to hold true and precise. Also to index its drill bit is more flimsy to set-up correctly. A true sharpener machine will sharpen every time, but cost many times higher. However, Drill Doctor is fine if we take more time setting up index and light grinding.

Drill Bit Speed Chart:
http://www.ibiblio.org/twa/info/drillSpeedChart.pdf
Too fast will dull because bit's cutting edges to over heat. Too slow will cause too much of heavy metal cutting to breaks bit's cutting edges.

Use cutting fluid while drilling to keep bit's cutting edge from overheating to lose temper.
http://en.wikipedia.org/wiki/Cutting_fluid

Now days you can use better cutting fluid for aluminum as well another for steel.
These are my favorite and use at General Motor Tech Center.
For aluminum...   http://www.tapmagic.com/TMaluminum.htm
For steel...   http://www.tapmagic.com/TMepx.htm

There are several material types of drills as well version.
Soft low carbon steel bits are used only in wood. Usually at very low price.
High Carbon steel bits are made from high carbon steel and tempered
High speed steel (HSS) is a form of tool steel where the bits are much more resistant to the effect of heat. Cost more (about double), very common and usually their base line variety in most good retailer store.
Cobalt steel alloys are variations on high speed steel which have more cobalt in them. Their main advantage is that they hold their hardness at much higher temperatures, so they are used to drill stainless steel and other hard materials.
Tungsten carbide is extremely hard, and can drill in virtually all materials while holding an edge longer than other bits. However, due to its high cost and brittleness, it is more frequently used only in smaller pieces screwed. Only machine tool supply store carry these.
Coatings
Black oxide is an inexpensive black coating. A black oxide coating provides heat resistance and lubricity.
Titanium nitride (TiN) is a very hard ceramic material, and when used to coat a high-speed steel bit (usually twist bits), can extend the cutting life by three or more times. A titanium nitride bit cannot properly be sharpened
Titanium aluminum nitride (TiAN) is another coating frequently used. It is considered superior to TiN and can extend tool life five or more times.
Titanium carbon nitride (TiCN) is another coating and is also superior to TiN.
Diamond powder is used as an abrasive, most often for cutting tile, stone, and other very hard materials.
Zirconium nitride has also been used as a drill bit coating for some Craftsman tools.
For more detail of the above: http://en.wikipedia.org/wiki/Drill_bit
FWIW
Sojourn for Christ, Jerry

[muddog16]

One of the best tools that I have purchased while doing this bus, is "Drill Doctor"
I read the booklet that came with it, and honestly I might have well been written in Greek!  I left it alone for about a year and didn't use it, then i discovered in the box under the instructions........a video tape........on how to use "Drill Doctor", in 30 minutes I sharpened every drill bit I could find, and was disappointed that there were no more..............This thing in the right hands can save you money!

[belfert]

My Drill Doctor came with a DVD and I don't own a DVD player.  The videos are online, but I never watched them for some reason.

I did actually get one drill bit sharp with both edges even, but when we tried to drill with it, it just kinda skipped all over trying to start the hole.

[jjrbus]

Maybe watching the video would be a good place to start ?   Which model of the Drill Dr did you buy? From my experience they are paramedic proof!!!!

[boogiethecat]

The BEST drills I've ever used, hands down, and cheap, $39 for 115 piece set:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=528

These drills are made of harder steel than any American counterparts, and last much longer.  Don't waste your $ on TI coated... these are quite decent.
THe only hitch is that they are harder than most bits and if used improperly they tend to snap easier.  None of us misuse our bits though, right? 

Also taps and dies from Harbor tend to be MUCH better than most you can find from reputable dealers in the USA.  Harbor freight might have a lot of crappy stuff, but the metallurgy of the drills and taps from drillmaster is the tops!!

If you're drilling stainless, ABSOLUTELY get some of this stuff:

http://www.westlandproducts.com/

Using "westlube" when drilling stainless makes the experience much more like drilling aluminum.  It's AMAZING.  In my production line, westlube changed things from 1-2 holes per drill bit (dry) to hundreds of holes per bit.

[JackConrad]

Maybe watching the video would be a good place to start ?   Which model of the Drill Dr did you buy? From my experience they are paramedic proof!!!!

Hey!!  I resemble that remark!  Jack

[belfert]

I sold the Drill Doctor a few months after I bought it.  It was the DD750X I believe.  I mainly wanted it because I had to drill 1,000 holes to cover the windows.  I couldn't get the Drill Doctor to work so I ended up spending about $50 on bits from Grainger.

Other than the bus, I probably wouldn't buy enough drill bits in a decade or two to pay for a Drill Doctor.  Most drill bits I have purchased in the past are either broken or lost, not dull.

And the whole reason I never watched the video was the lack of a DVD player.  I guess I didn't want to take the time to drive across town to watch it a friend's house.

[jackhartjr]

I grew up on dairy farms, they taught me early how to sharpen them on a grinder.
(They also taught me to use safety glasses when using it.)  (I think I will start a new thread concerning the use of safety googles.)
Jack

[junkman42]

I wish I had been told that I could buy drill bits from dockside china junk supply inc instead of buying quality drill bits when I was manufacturing turbine components.  I would like to see a chinese drill bit drill punch a hole in one inch thick inconel 718.  Give Me a break.  Cobalt drills are probably the best bet for drilling the stainless sidding on most buses.  My old humble 2 centavos worth.  John

[DrivingMissLazy]

When I was manufacturing equipment we tried every type of cutting fluid available. For an overall fluid for drilling either aluminum of steel and that did not leave an oily mess, we utilized RapidTap. It was heads and shoulders above any product for drilling or tapping.

http://www.mytoolstore.com/relton/rapidtap.html

Try it. It is really great.

Richard

[JohnEd]

Belfert,

Using motor oil for drilling and taping is a big mistake.  The oldest and smartest machinist I know told me that motor oil would actually dull the bit.  Use rapid tap.  PS:  I used to use motor oil because it seemed to make such sense.  Too soon old!

I hope, and I mean "really hope", that you are picking up on the fact that you are the only one that can't get a Drill Dr. to work.  They work gang busters...really, that good.  You have to read the instructions real slow and ponder what each means and what it does.  Get inside the Dr.'s head.  I figured it out pretty quick but I have always had a knack.  You need that sucker so knuckle down.  Get a friend to walk you through.  I had only the book and after you get it down it just becomes that much more clear.

I don't own a Drill Dr. and probably never will.  I have a friend that has the full setup and has never been able to sharpen a single bit.  I sharpen his bits for him and in gratitude he lets me sharpen all of mine and also take the thing home for a couple weeks when I need it.  Just so he hassharp bits when he needs them.  I am very impressed with that thing and Bubbagal is right.

Yes it does have plastic parts.  They wear like iron.  I must have sharpened a thousand bits with that thing, some the very largest it will take(7/8?) and gobs of them.  It is still running flawlessly. 

If you need one get another.  Take it to the next gathering and there will be people pushing each other out of the way to take a turn showing off.  Not me though, I would come back late at night

Take care Belfert,

John

[H3Jim]

And another thing about drilling.  lower speed, higher pressure works well. If it smokes you are toasting your bit, and ruining the temper so it never will hold a good edge again.

I have found when working with stainless if I do busrts, it cuts faster than any other method.  Never go too high an RPM, start the drill, get to the RPM desired, then take my finger off the trigger and let it stop.  start it again etc.  Never will work harden that way.  It works for drilling larger holes with circle saws too.

and yes, use that Westlube. I got some free samples, three small bottles, that have lasted me for all the stainless holes I've needed to drill.

[kyle4501]

Belfert,
I hope, and I mean "really hope", that you are picking up on the fact that you are the only one that can't get a Drill Dr. to work.  They work gang busters...really, that good. 

I don't agree.
I have used them & while they may work well IF you get the right model & it ain't a dud . . . . It has always been easier for me to hand sharpen bits.
Besides, I buy the cobalt bits & don't need to sharpen them very often. 
I also can easily adjust the relief angle to suit the current needs.


Looks like one size doesn't fit all here.

To each their own. 

I guess it just depends on how your shop is equiped . . .