i need help drilling 1 inch holes

turbo36 · Feb 7, 2006

Daryl, we "throw" them carefully /forums/images/graemlins/wink.gif being a manually trained machinist as well as an Engineer it is interesting to see how this part could be approached with different methods. Manually, I would pilot drill , core drill and then ream to hold size and location; with CNC I would blast a clearance hole with an insert drill and then "mill/bore" with a carbide end mill.
By the way, my dad is a retired steel hauler that still has all his fingers /forums/images/graemlins/blush.gif

RobJ · Feb 7, 2006

WOW what a ton of replys in drilling holes. But like many other I agree a normal bench top drillis to fast. When I worked in a shop we had some old, old and heavy cast drill. Tranny in the machine that would turn the big bits about 60-100 rpm. Probably closer to 60rpm. No pilot holes and keep it cool. This old thing even had an auto feeder to just let it take over.

Oh and a real expensive bit helps.

moeh1 · Feb 7, 2006

I have an old Walker Turner drill press with the standard too fast minimum speed, but a keen desire to drill lots of big holes in metal /forums/images/graemlins/laugh.gif Ended up mounting a larger plate where the motor should go, and mounting both the motor and an intermediate jackshaft in pillar block bearings onto that plate. The motor ( mounted upside down) is belt driven to the jackshaft, and the top end of the shaft belt drives the drillpress. I only have 1/4 hp, but it drills well up to 1". One other trick I have seen used with some success ( admittedly a tool misuse, but it works) is to employ a single cutting edged countersink. The design of these limits the amount it tries to take off and although it produces alot of heat, they can drill a big hole at higher speeds like your little press probably has. Would love to find one of the big old gear drive cast iron devils like I used to have access to /forums/images/graemlins/grin.gif

markct · Feb 7, 2006

ct tree guy,

yea not my first choice of how to get it done, but the best way i had on hand. i have always wanted to make a hydraulic motor into a large slow drill, that way i could use the tractor hydraulics and have slow rpm but once i got this 3/4 milwaukee drill i realized that you wouldnt want anymore power than that in a hand held drill anyhow /forums/images/graemlins/grin.gif heck when we do fenceposts we use it with a 5 inch auger and two people one on each handle and its still caused a few uncontrolled moments

john_bud · Feb 9, 2006

Hi,

I just got sixteen 1" holes put into 1/2 steel plate the other day for a loader quick connect I am making. Where I bought the steel they have a little "iron worker" shear. It also has the punch attachment. I had my wooden prototype in the truck and chalked out the location of the holes on the plates and they poped the holes. At 50 cents each. They were apologizing about the cost and I was giggling with joy at it being so low and fast and easy.

I also used a hole saw to make some 2" holes in the 1/2 plate. Total of 8 holes done by hand with an old craftsman drill. The saw still looks good, but I broke 2 of the pilot bits. I really should pay more attention, but ....

jb

escavader · Feb 10, 2006

I went to home depot today,i couldnt find the rigid cutting tool oil,or a clerk with an actual brain[but thats another topic] I found gunk brand machine and cutting oil[dark],im gonna try it.I still havent seen hide nor hare of my craftsman drill press belts.I was looking at the bi metal hole saws,the bits were not bad ,but the mandrel was costly,so were the 1 inch drill bits,im gonna try again with my bit,it was working sweet before the belt broke ,and now i got some good oil.
ALAN

CT_Tree_Guy · Feb 10, 2006

I just got sixteen 1" holes put into 1/2 steel plate the other day ... they popped the holes ... At 50 cents each. They were apologizing about the cost ... 

I just hate it when people take advantage of you like that - how do they sleep at night??? /forums/images/graemlins/smile.gif

Nice to have the right tool, isn't it? (Although I agree with you that in a pinch, the lowly bi-metal hole saw has its place).

John

fuelburner · Feb 10, 2006

And the half inch drill motor and operator with good wrists.

Dan_574 · Feb 10, 2006

I havent read all the posts but I have used these cutters (see link below) and they are fantastic, no pilot hole, quick cut and are great. They are an aussie company, I spoke with the owner once and he regualrly go's over to the states, email him and there might be a distributor over there, if I remeber rightly there isnt any similar product that go in a normal drill.

http://www.drillmate.com.au/cutters.html

IslandTractor · Feb 11, 2006

( I went to home depot today,i couldnt find the rigid cutting tool oil,or a clerk with an actual brain[but thats another topic] I found gunk brand machine and cutting oil[dark],im gonna try it.I still havent seen hide nor hare of my craftsman drill press belts.I was looking at the bi metal hole saws,the bits were not bad ,but the mandrel was costly,so were the 1 inch drill bits,im gonna try again with my bit,it was working sweet before the belt broke ,and now i got some good oil.
ALAN )

I never knew there was special cutting oil. /forums/images/graemlins/blush.gif I've always used light machine oil and don't think I've ever had a problem. What advantage does the cutting oil have?

ronjhall · Feb 11, 2006

I use Tap Magic Pro Tap for most of my metal cutting projects. Works with a lot of different metals. Click Here
I suggested Rigid Thread Cutting Oil, because it more readily available.
It makes a difference on how easily metal can be cut. Try it, you will like it.

Farwell · Feb 11, 2006

Most ACE Hardware stores carry cutting oil. They are not the cheapest but the price is not out of line. Think I paid $13 for a gallon the last time I bought it.
Farwell

MadReferee · Feb 11, 2006

( I never knew there was special cutting oil. I've always used light machine oil and don't think I've ever had a problem. What advantage does the cutting oil have? )

5030 answered your question in a post on the first page of this thread.

Besides having properties that lubricate, cutting oil/fluid has excellent heat dissipation properties along with better ability to allow chips to flow away from the cutter thus allowing longer cutter life. In other words, cutting oil/fluid is more efficient at its job than simple light machine oil.

3RRL · Feb 22, 2006

Hi Alan,
I just finished drilling 4 holes on 2 brackets stacked together.
Drilled thru 1" thick.
-center drill
-Ø1/2" drill thru
-Ø1-1/8" drill thru

Less than 5 minutes including set-up and indicated.

2 HP Bridgeport mill, DRO, collets, clamp kit....$10,000 (then)
Interapid Indicator, Indicol, 1-2-3 blocks..........$250
Drills ............................................................$150
14" Custom made milling/grinding vise & clamps....150hrs+
2 beers...............................................................$2.50
Chance to share pics with TBN buddies....PRICELESS

Ha...and the holes are for clearance!!! /forums/images/graemlins/confused.gif

scott_vt · Feb 23, 2006

Gee Rob,
I could have sworn that I used those same 1-2-3- blocks yesterday /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

By the way, I like your blue print /forums/images/graemlins/grin.gif

scotty

3RRL · Feb 23, 2006

LOL, LOL,
Yea, you can see it's not to scale...

escavader · Feb 23, 2006

It Must be nice! Lesson learned...Its tough to drill big holes with a 1/2 hp mini drill press.I cheated,i got my boss to finish them at work one morning,while i covered for him.He didnt mind,it was cold out that morning ,and our planing mill isnt heated /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gifThumb project is all done now,works great! The holes were the hardest part.
You can tell when a bit is cutting good ,when it leaves them filings like you got there.Too bad your so far away /forums/images/graemlins/grin.gif
ALAN

RobJ · Feb 24, 2006

Ok second post on this but here is another poor mans way. I needed some 14mm holes in 3/4" bar for a spacer behind my bumper. Nothing seen when complete. I drilled a 1/4" pilot hole then used the oxy/acet to do the rest. This one was freehand and you can see where I moved on one side. I could have taken a little more time to make a wooden guide from wood. But this'll do. Only about 5 minutes for 4 holes. Not pretty but it'll work and I didn't have to buy an expensive bit. The pilot hole helps the torch to get started with a clean cut all the way through the material. And yes the hole is supposed to be off center. The upper bumper holes on the L2500 are closer to the sheet metal than the center of this 2" bar. /forums/images/graemlins/grin.gif

dfkrug · Feb 24, 2006

I know why there have been so many responses to this thread: drilling holes in thick metal is the biggest hassle of all for us amature fabricators. Now that said, I think all the methods I have used have been covered. Twist drills up to 1-inch, bi-metal hole saws (2-inch is my record in 1/2" A36 steel), plasma cutter with aluminum templates, milled holes (on a friend's Bridgeport mill), lathe with 4-jaw chuck (has that one been mentioned?), and my favorite: $1/hole on a
50T hydraulic punch at a machinist. My next tool may be a 40T ironworker....they can be had for $2500 new. Punches and dies are extra. Like others, my drill press is crappy, a 16.5" Delta floor model purchased new more than 25y ago. 250 RPM is slowest speed and the bearings complain big time when doing big holes. Is it time for a "good" drill press? BTW, if you ever get that plasma cutter (sweeeet), the oxy-acetylene torch will be relegated to the rare heating and brazing tasks.