where to educate myself about drilling?

[tarbellb]

so after reading what i can about drill bit types, feed rates, coolant, etc... is there a recommended, qualified piece of literature i can buff up on to educate myself on the particulars?

i would really like to see something that isnt completely boring, long, or overly complicated (engineer cryptic language). does this exist? in particular, what kind of bits (hss, cobalt, etc) for what kinds of metals. uses, practices. ie what does a proper drill shaving look like in mild steel, how does stainless react to _____ type of bit.

i am relatively knowledgeable on general practices, but still consider myself young and new to fabrication.

thanks in advance. pics for clicks

 

[tweety652]

the machinery hand book is good but experience is better...harder metals require lower speeds and lots of coolant....get good bits and practice.

 

[diesel research]

I find most technical writeups involve workpieces mounted rigidly in a drill press with coolant, precise feedrates, and precise rpm control available. Drilling vertically.

Basically, the instructions are for an "ideal world" and seem semi useless in a lot of "portable" applications. If you will end up doing a lot of hand drilling, I haven't found the specifics to be of much use.

Quite a while ago in machining school I learned to rely on all kinds of charts pasted near various presses. These days I rarely ever have the luxuary of using a press and just have to go by "guess". Guess being the the presence/amount of smoke, noise, vibration, and chips.

Go to harryepsteins.com buy a handful of each of the kinds of bits they have in a specific size, procure some blocks of stainless and mild steel, and proceed to burn them up/break bits with your hand drill until you figure it out.

 

[kissmeimgerman]

Can you afford to take a machining class at a local community college?

 

[Outlawmws]

I think advice given so far shows we need more info. Do you have or plan for a drill press? using hand drill in portable apps? wood plastic or metals?

A Machine class and Machinery's hand book as already mentioned are good starting places.

You might try used book stores or a college book store for used copies. A college text boko on machine shop practices can also be good, especially the older ones that focused on practical rather than theoretical machining.

 

[Regnar]

Here is a video of the Basics from MIT. http://techtv.mit.edu/collections/ehs-videos/videos/130-machine-shop-2


+1 for the Machinery Handbook.

 

[Hurricane_Whisperer]

A few quick tips.

300 series (autenitic) stainless steels are a ***** due the the ridiculously tenacious chips they produce. The 300 series (304, 316, etc) are very "stringy" and it is difficult to get the chip to break when doing lathe work. In drilling, you can interrupt the cut once the chip get's big enough to clear the work. It also work hardens, so you don't want to dwell without feeding. You need to press hard enough to get the drill to plunge rather than just sit on the surface and hardening the hell out of it. The 300 series stainless also galls and can grab the bit and break it. If you did a lot of drilling of 300 series, like in a production setting, you might want to try TiN coated bits.

400 series stainless are tough but don't have the notorious chip problem that the austenitic 300 series do.

Cobalt is often used to drill stainless, but HSS will work fine in the 300 and 400 series under the kind of drilling a machine shop might do that isn't doing long production runs and trying to extract the ultimate in speed.

HSS will work fine for most things provided you stay within the tools capability.

118 degree tip angles are most common and will drill most things. Really soft materials like aluminum or brass can use a drill with a pointer tip (less than 118 degree), but 118 will work fine. 118 degree will work in materials from soft aluminum and brass to steel to stainless to cast iron. 135 is also good for steels and stainless.

Fancy features like different helix angles may be helpful is some real particular situations, but if you are drilling a few holes now and then, it wouldn't be worth fussing over if takes you awhile to find them in your tool box.

Get a chart out of machinery's handbook like some have suggested.

First, set your speed slow enough so you don't burn the bit up too fast, but as fast as practical in the speed range given by the handbook. If you are drilling steel, with coolant in a cnc machine or heavy duty drill press you can adjust the speed so that you are just shy of having the chip turn blue. If it turns blue, slow the speed down. This is for a machine shop environment, so don't try to push it so fast if you just want to get decent results drill at home. But, if you see chips starting to turn blue on what you are working with you probably ought to cut back on the speed.

Feed is about plunging fast enough to make a nice chip come out but not so fast that you break the drill or bend the drill or end up with a terrible surface finish as you crowd the drill. As chips come out of the hole in ductile materials like stainless and mild steels, you have to interrupt the feed long enough to eject the chip. The chips will come out and be stringy and you don't want them to get very long at all, lest they grab onto something while you are drilling. Chips can be very dangerous and sometimes they stick to the bit.

 

[Yojinbo]

Everything depends on what you are drilling. For small scale metalwork I suggest Rudy:

Rudy Kouhoupt was America's machine shop teacher in many ways.

http://www.craftsmanshipmuseum.com/kouhoupt.htm

http://www.amazon.com/dp/B003E1VEG6/?tag=atomicindus08-20

http://smartflix.com/store/author/23/Rudy-Kouhoupt

 

[tarbellb]

thanks guys, this isnt a bad start. im wondering if there really is anything out there that educates and informs the real world fabricator? meaning, someone who does not have the luxury of using a drill press, and ideal positioning.

it is such a large scope of information that i asked for, it would be difficult to have a single source for a answer.

the type of work i do is: mostly custom furniture, architectural pieces (handrails, stairs), and pretty much anything that comes my way.

materials i work with: mostly mild steel, some stainless, titanium (rarely), hardwoods, softwoods, plastics, fiber/resin, concrete, glass

maybe i can narrow down the field of questions i have:

1) a reference for what drill bit type, and material for specific metals
(does not have to be micro specific like 304 ss vs 400 ss etc.)

2) are lubricants the same? im using a water based lube, should i?

3) whats the difference in tip angles? 118, 135, ?

i will look into the books mentioned, a class would be great but not likely.

 

[Greatbear]

i would really like to see something that isnt completely boring...

When learning about drilling, boring comes with the territory.