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?