knowing ones limits

I just became disolusioned when after drilling some holes in a case, i realised they didn't line up as i had hoped so had to file the holes a little, i was annoyed with myself as i expected better results, then i thought the way large companies do there metal bashing is machines, i am sitting at the bench drilling holes with one hand whilst holding the case in the other, now i'm wondering if it makes sense to buy a drill press with the relevent clamps or just accept i am not going to achieve professional results with my current methods and file (botch) it till it fits

Neil.

A decent drill press is a REALLY good investment. They don't cost much these days and last practially forever. You can get quite a large heavy duty one for $150 or so, but even a $69 cheapy is MUCH better than trying to use a handdrill.

Hi,

To botch or not to botch, that is not the question

It's botch and rebotch until it looks right anyway. Hobby stuff doesnt have to be perfect, but it helps to use imagination when it doesnt work out on the first try.
Made one end of a rectangular hole a little wider than the other end? No problem, just make the other end a little wider too and suddenly it looks like you planned it that way.
Cant do that or dont want to do that? Add a little tasteful trim around the edges to square it all up again. Make a nice label on your printer.
Lots of ideas just waiting to be thought up.

I did a switched USB hub a while back, where i needed to have four ports sticking out the front. Rather than cut out each individual port hole (which really had to be rectangular) i just cut one longer hole across the whole front. In the end it looks nice. I could have also drilled larger holes then filled the top and bottom with some strips on the inside to make the holes look semi rectangular again, but i didnt feel like it needed that much attention. I could have also glued some strips vertically but it looked just fine with one long hole.

So it's not whether or not we're going to botch it, it's how we are going to cover it up and make it look as though we thought it all out that counts

Ahh yeah, I have yet to perfect the art of drilling by hand. Sometimes it works out nicely...but mostly... MrAl, put I beautifully though 'rebotch until it looks ok' - as long as you haven't drilled away half the material.

Whether or not a press is an invertment, I'm a utilitarian so the question is, how often do you think you'll need to drill holes with any accuracy? Or even non accurate holes - by hand, after 10, I quickly regret starting the entire project. A drill press would make life much easier, as well as 'neater'. Plus, you could always sell it when you no longer use it, they really do last.

I think you can achieve (semi)professional results with basic tools. Goes back to time, money and effort (and experience). I seem to have got a lot better over the years, and its not just planning things, maybe its just judgement/experience, but I do spend much of my life hacking away at things - a situation where a professional powered tool would save time, tears, and blisters.

lol.....thanks guys, actually i was using a power drill while holding the panel in the other hand but i still managed to mess it up.

off to the hardware store tomorrow to price up a drill press.

Neil.

If you're drilling metal, do yourself a favor and get a spring-loaded center punch. Layout the pattern with a scrawl, and then punch each location before drilling. If you're drilling big holes, start out with a small bit and work your way up. Even is you're using a drill press, this the the best method I've found for accurate machining. I think you'll be amazed at the results.

A center punch helps but my little Harbor Freight 8" drill press, cheap as it is, has improved my accuracy to the point where my ability to measure and mark where I need to put the holes is a bigger limitation than my ability to hit the marks I make. Maybe someday I'll spring for a mini-mill.

I've never had luck using a center punch.
When I need accuracy, I'll sketch it up in a cad program and print it out 1:1, then tape it to the piece I'm drilling.
This was a box for controlling my Tesla Coil. Final project for school, so I wanted it to look nice. I had the machine shop at school cut the rectangular opening for the LCD.
**broken link removed**


**broken link removed**

Was a bit time consuming, but I was pleased with the results.

Hi,

What Brownout has said is very informative and very useful and works very well too because that's the way i do it too when i have to drill holes and so i know it works well first hand.

Creating a layout pattern on paper helps to get the positions correct too as i think you illustrated, but there is one more little tiny detail that makes it near perfect.

That is, you have to create your own precision center punch. The ones you get at Home Depot and the like are not nearly good enough for small electronic and front panel work.

To make your own, first get a box of 10 penny hard steel nails. This are not the soft steel common type nails but are made of hard steel and have ridges in the sides that follow the length of the nail twisting slightly around the body for the most part. These are also NOT the rectangular body type nails either used for hardwood flooring. The kind of nail i am talking about is usually used for concrete.

The simple idea is to grind the tip of the nail down to a fine point first with a bench grinder and then with a Dremel with a cutoff wheel or grinding wheel.
You can do this by hand pretty quickly even just using only the Dremel. It works a little better though if you chuck the head side of the nail into a 3/8 inch regular drill, and while running the regular drill at some nominal speed not too fast but not too slow either, you apply the Dremel to the tip of the nail on an angle and the combination of both spins creates a needle like point on the tip of the nail. The angle of the point should not be too sharp, but somewhat blunt (say 40 degrees from the axial body). You dont want it too steep or you'll get a deep narrow hole from the punch when you really want a wider shallow hole to match the soon to come bit tip better.

To make the pattern template, use good quality graph paper. Try to get hole spots aligned with crossing grid lines. After you tape the template to the front panel of your project (or pc board or whatever) tip the new center punch slightly to the side and place the needle point at the cross lines intersection, then press it in slightly as you rotate the angle back to 90 degrees from the surface. You then give the center punch a quick tap with a small ball peen hammer using the flat side of the hammer head not the curved side. You can get small hammers like this which work nicely at various places.
After you've done all the grid points, you take off the paper and using a very small bit like #66 for example go and drill all the holes with that first. Note a 1/16 inch bit works too but the smaller #66 works better as the 1/16 inch bit can still drift a little. With the tiny center punch mark you need a very small bit to get it perfect.
After you do all the holes with the very small bit, you can then go back over them with a slightly larger diameter bit, then work your way up to the final bit diameter for each hole.
The rule of thumb is to increase the diameter by 2 bit sizes for every pass, but it really varies depending on the type of material being drilled.

Using the above procedure with the new center punch you can get some VERY accurate hole placement. I once made a 40 position switch where i had to drill 80 tiny holes to accommodate small pins with tiny springs on each pin, all within a diameter of about 1.5 inches. It worked almost perfectly.

Mmmm... making swarf!
My other favourite passtime!

Drill presses.
Most of the ones in hardware shops are made in Asia, and made down to a price.
They have their limitations, but will certainly be better that a hand drill held in one hand while holding the workpiece in the other.
I have an Asian drill press in my workshop and over the years have learned most of its shortcomings and foibles.
If I found an old British or American drill press which had not been abused over the years for a good price, I would buy it to replace the cheap one.

Drills
Only buy good quality ones made from high speed steel, which have been sharpened correctly.
A badly sharpened drill point or one which has gone blunt will never cut a decent hole.

It may be worth buying a centre drill (sometimes known as a Slocombe drill), these are usually used in conjunction with a lathe, but they are short and rigid and when used in the drill press make it much easier to start the hole in the correct place. Ordinary drills are quite bendy (up to the point where they snap!) and can wander off the centre mark when starting the hole.

Marking out
On something which is visible when finished, I prefer to mark out with a pencil rather than a scriber.
The pencil must of course be sharp, otherwise you get quite a thick line.
When you have marked the hole positions, use a centre punch, it gives the drill a place to start, otherwise it will wander if you are not using a centre drill to start the hole.
When it comes to centre punches, I think the automatic ones are just an expensive gimick for the average hobby machinist.
There is a lot of stuff I would buy before an automatic center punch.
The good old manual ones are more versatile, you can just tap them to start with and the check that the mark is in the correct place. If not you can hold the punch at an angle and drift the pop mark into position, and then give it a heavier blow to make the final mark.

There is lots of other stuff which could go on about, but I think that is enough for now.

JimB

whole heartedly agree with you Jim about manual center punch, once that auto punch strikes, you are somewhat commited.

Neil.

Another handy thing to do is learn about drill bit sharpening. If you know the hows and whys of the different point angles and configurations it is also very helpful when drilling holes being that not all materials drill the same or require the same bit points and angles.

I have a few buddy's that think I am some sort of hole making god when they quickly dull a bit on a hard piece of material and then I go and resharpen their bit, changing the angles of course, and it all of a sudden now drills hard steel like its going through hard wood!

Another real neat trick once you get good with bit sharpening is to reshape the masonry drilling design of a carbide tipped bit to that of a steel drilling bit. Nothing stops them regardless of how hard, rusty, or difficult the material is! Sharpening and shaping one is slow though.

BrownOut said:

If you're drilling metal, do yourself a favor and get a spring-loaded center punch. Layout the pattern with a scrawl, and then punch each location before drilling. If you're drilling big holes, start out with a small bit and work your way up. Even is you're using a drill press, this the the best method I've found for accurate machining. I think you'll be amazed at the results.

Click to expand...

I second Brownout! After decades of working at this, I use a centerpunch, a drill press, and a 1/16 drill bit first. Bigger bits will wander due to their large chisel shaped tip. Also, use a piece of sacrificial aluminum or wood underneath the work. Otherwise you'll be using a really big drill to scrape off bits of metal sticking to the bottom rim of the hole.

Make sure the work piece is secured tight. Drill downward slowly or the bit might catch at the bottom and the work will spin around.

I was in a hurry drilling a hole in an electrical box and was holding the box in my left hand. The drill was a half-inch high torque type. When the bit caught and siezed in the hole, it nearly tore my right wrist off. We learn best the hard way!

Really!! I'm shocked. .... Grown up guys discussing "how to drill a hole".

Bob Scott said:

Really!! I'm shocked. .... Grown up guys discussing "how to drill a hole".

Click to expand...

Machine tools, boats and pretty women are the only things a grown man needs to talk about.

I'll put my two cents in, as I've drilled a few holes...

For most shop work, you can use simple hand tools to do layout. This means scratching fine layout lines on things to locate a hole. I use various tools to do layout. If applicable, I use my dial calipers, as they can be set to the desired dimension and then scribe a line with respect to an edge. If I can't use those for some reason, then I'll try to use either hermaphrodite calipers or machinist dividers. For most work, however, a machinist rule is adequate. Draw lines or arcs to locate the centers of the holes you want. I keep a blue Sharpie marker in my shop apron to mark where the scribed lines will go to make them easier to see.

Then you want to put a center punch mark at the intersection of those lines. I've got a number of automatic center punches (bought 30-40 years ago), but I virtually never use them. Instead, I use a Starrett toolmaker's hammer and a prick punch. The toolmaker's hammer has a good magnifying lens built in, so I can see that the tip of the center punch is at the intersection of the lines. Then I just barely tap the prick punch with the hammer. I inspect the mark made with the magnifier and move it if necessary. Once it's where I want it, I give it a deeper mark with a center punch.

Then you use your drill and drill bit to start drilling. But the secret is to start drilling and just make a mark with the drill bit's tip. Inspect the mark with respect to the layout lines and, if it's not centered, you can correct it with a diamond or cape chisel (see any basic shop book written in the last 100 years about how to do this). Once it's where you want it, finish drilling the hole.

For fussy work, I like to start a hole using a center drill (as someone else mentioned). If you don't have one of those, you can also get a small (say, 1/4" diameter) screw machine drill that can work as a substitute. These drills are more rigid than the typical jobber's length drills.

Of course, as others have stated, it helps quite a bit to do this drilling on the drill press rather than free-hand. If you've properly center-punched the work, the spinning drill bit will pull the work to be centered under the drill bit when you lower it into the center-punched hole. If the material is hard to hold, you'll want to center it under the drill bit without the spindle turning, then clamp things to the table. You'll only get your hands mashed up once or twice before you get pretty good at knowing what needs to be secured and what doesn't.

Buy good HSS drills. Forget cobalt drills or titanium nitride coated, etc. Regular HSS drills will be fine for most shop work and, with care, should outlast you. My drill sets are near or over 50 years old and they'll be passed onto my descendants. If I had more discretionary cash, I'd buy a set of screw-machine length drills, as I find them useful for lots of my drilling tasks (these are basically shorter styles of drills used on automated machines).

You can learn to hand-sharpen drills (any machinist can show you how to do it in short order), but unless you do it regularly, you're probably better off buying something like a Drill Doctor. General Hardware made a simple die-cast drill sharpener that also works pretty well (I bought mine in the 60's for about $10). Starrett makes a drill-grinding gauge, although the industrial suppliers often give such things away.

You'll also need to countersink the holes you drill. This can be done with larger center drills (as I do often on my lathe), but a better tool is the Weldon-style countersink. These are countersinks with a hole through them and work the best of all the different countersink styles I've tried (i.e., chatter the least). I often just use a machinist's hand-held deburring tool instead; in fact, I mostly use a machinist's scraper for single holes. You can make such a thing from an old triangular file.

You'll find that careful layout and center-punching will serve for most of your drilling needs. I have a milling machine sitting next to my drill press, but 99% of the holes I drill are done on the drill press, as it's the most convenient tool and is adequate for most tasks.

One thing that struck me reading through this thread is how many men does it take to drill a hole? lol

Three. One to set up the machine, one to chill the beer and one to tell how back in his day, there weren't fancy 'electrical' tools, just a hand-crank and a screw bit

I may have missed it, but I am surprised no one mentioned a small vice to hold the work. Beats mangling your hands.

I have used an eggbeater drill. Does that count?

https://en.wikipedia.org/wiki/Drill

Drilling is an art unto its self!

QuietMan said:

I may have missed it, but I am surprised no one mentioned a small vice to hold the work. Beats mangling your hands.

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Good point. Its one thing to keep the drill bit steady, straight, and true, but thats meaningless if the piece is simply placed on a surface where it can be fired at a nearby wall/colleague if the bit catches it.

I must say, I rarely do any work on pieces larger than a pack of cigarettes, simply because most portable ultra-low-power electronics is all about that. But for some clients where I do on-site work at the workshops, they get me to do odd-jobs and I use anything they can provide. They have a huge array of clamps, vices, and G-clamps around their main pillar drills, as well as scraps of wood and metal with crude labels scratched into them. Theres one vice which I cannot lift by myself, its about the size of two housebricks.

I'm pleased that this thread has developed. Yes, its just about drilling holes. But theres always more to something 'practical' that an exchange of experiences can help us less 'mechanical' guys do a better job. From the half-arsed 'drill in one hand, piece in the other, after 6 beers' to the 'spend 25 minutes getting the centre punch right and using 15 different tools' the spectrum of methods provides some good clues as to what to do, and when.