How to drill?

[benmychree]

When you feel the drill starting to advance more easily, ease up on the feed pressure; it works!

 

[P. Waller]

I have been pondering how to finish a through hole just before it breaks through. With a hand drill this is where it bites, and tries to wrap you around the object being drilled. On a press, or mill this is where the bit will spin in the chuck, now that I have nice Albrecht chucks what is the actual proper procedure/technique? I usually have mild steel to work with.

Do you want to know how to drill a through hole without drama when it passes through the far side using your existing equipment and methods?

Or do you want to know how to drill through holes using equipment and controls that you do not have the "proper way"?

By far the easiest method is to drill through the part into but not through a sacrificial material under the part, this will limit the uncontrolled feed.

The "proper way" is to control the feed.
Good Luck

 

[tjb]

What if you marked the drill bit with a sharpie, paint marker, lumber crayon etc just short of the depth to break through. That would give you some visual warning to use a little more care just before the drill breaks through.

I have a selection of colored sharpies that I will use to mark important spots on a piece of work when I'm working on the lathe.

That method works. I've used it successfully with green or yellow masking tape.

 

[Aukai]

Interesting point Mr. Waller, I was told/taught that during the operation one should look for a continuous coil of swarf to be an indicator of proper feed. I'm not sure if this is true, or if it is correct for all materials. Do you slow the feed as you get close to the through depth? My Z axis is powered for position, but not rate adjustable. Drilling is manual feed. Thank you all for the responses so far.
I will have to look into backing material more often.

 

[Bob Korves]

Which keyed chucks are good?

USA made Jacobs ball bearing Super chucks are the best keyed chucks I have seen anywhere. They are no longer made in the USA, and quality, while still good, has definitely diminished. Some intermediate ones say "USA" on the chuck, but are not actually made in the USA (it is part of the company address -- no deception intended???) You need to see the word "Hartford" on the chuck for it to actually be made in the USA. The others are not as good.
The part numbers are:
8-1/2N .250" maximum opening
11N .375
14N .500
16N .625
18N .750
20N 1.000
Again, look for the word "Hartford" to get a USA made one, and the words "Super Chuck" and "ball bearing" for it to be a ball bearing model. Some older Super Chucks only have the model number information stamped in small letters by the chuck key holes, and not on the sides of the arbor end of the shell. They still have all the correct words. They look like the cheaper Jacobs sleeve bearing chucks, so look closely at Jacobs chucks for the older ball bearing model. Many sellers do not catch what they are. They are at least the equal to later ones, and can be found for cheap sometimes.

 

[Superburban]

For hand drilling, I have turned to the step drills. I used to dismiss them as a joke, until I tried them. I used one to drill a ton of holes in my truck frame, when I converted an old 2wd, into 4wd. The drill faster, take forever to dull, and can be easily honed with a stone to freshen them up again. And do not grab when you punch through. I found it best to use a 1/8" or so drill first, then the step drill flys through the metal. For larger holes in sheet metal, there is nothing else that works as good. Even the cheap harbor freight ones work great. Spend the $10, and give them a shot.

 

[P. Waller]

Interesting point Mr. Waller, I was told/taught that during the operation one should look for a continuous coil of swarf to be an indicator of proper feed. I'm not sure if this is true, or if it is correct for all materials. Do you slow the feed as you get close to the through depth? My Z axis is powered for position, but not rate adjustable. Drilling is manual feed. Thank you all for the responses so far.
I will have to look into backing material more often.

This is true, however when you run out of material on the far side before the drill passes through how do you maintain the chip?

In other words you begin by drilling air and finish by drilling air. You can not maintain a consistent chip the entire time (-:

Remember that when a twist drill reaches the far side of the hole and pierces it will turn into a cork screw and advance itself if the feed is not under control, if you drill into a backing material the feed is under control.

I made this video a few months back, how to drill a hole with a lathe, I dislike the constant chatter that most ytube guru's employ so this is the basic idea.
Place stock in chuck, place drill in tail stock or turret, turn spindle on and power feed the drill until thru the part. You will notice that it is fairly silent until the drill begins to pass through the farside. 1 5/16" drill 3 1/2" thru in about 5 minutes each part with excellent chip formation for the most part.

Control the feed and most of your drilling problems will be solved.

 

[Aukai]

LOL, sometimes the obvious must be stated. I have a better feeling about it now.
I found I like step drills too, just sometimes the steps are too short for the material.

 

[Bob Korves]

This is true, however when you run out of material on the far side before the drill passes through how do you maintain the chip?

In other words you begin by drilling air and finish by drilling air. You can not maintain a consistent chip the entire time (-:

Remember that when a twist drill reaches the far side of the hole and pierces it will turn into a cork screw and advance itself if the feed is not under control, if you drill into a backing material the feed is under control.

I made this video a few months back, how to drill a hole with a lathe, I dislike the constant chatter that most ytube guru's employ so this is the basic idea.
Place stock in chuck, place drill in tail stock or turret, turn spindle on and power feed the drill until thru the part. You will notice that it is fairly silent until the drill begins to pass through the farside. 1 5/16" drill 3 1/2" thru in about 5 minutes each part with excellent chip formation for the most part.

Control the feed and most of your drilling problems will be solved.

Wow! You get to sit down on the job? Amazing...

 

[P. Waller]

This was one of the first parts so I remained long enough to make sure it wasn't going to blow up the drill or push the parts through the chuck, I left to place the first part in a CNC lathe for finishing, these operations took way longer then the rough drilling op.
So I got to sit for 25 minutes per part for 35 parts when finishing, standing and looking at them run does not make the cycle any faster (-:
I have 1 stool for each machine that I run but can only sit in one at a time.