Saturday, August 27, 2011

V2.19 - Drill Press know-how

I thought that for this week, I would just go over some of the little tidbits of information that I like to call ‘Tips & Techniques’. Since we have been discussing Drill Presses the past 2 weeks, we might as well stay on topic.

One of the areas that folks need some assistance with is that of choosing the correct bit speed for their particular project. The main rule of thumb is: ‘The harder the material, the slower the bit needs to turn.’ Right behind that comes this: ‘The bigger the bit, the slower it needs to turn’. How that plays out is like this. If you’re drilling the same size hole in wood and metal, the speed will need to be slowed down for drilling into metal because it is a harder material. By the same token, if you’re drilling into pine wood and making a ¼” hole and a 2-1/4” hole, slow it down for the 2-1/4” hole. It may be that not much speed change is needed between these two, but the idea is that you don’t usually want a 2-1/4” cutter turning as fast as a small ¼” bit.

Now, let’s talk safety. First and foremost, dress appropriately when using a Drill Press. Wear your safety glasses, roll up your long sleeves and pull your hair back out of the way (IF your hair is that long). I once saw a training film that showed what happened when a lady got her long hair tangled in the Drill Press she was operating. It was not a pretty sight. She reminded me of what Custer’s men must have looked like after being scalped.

After you have all those bases covered, here’s another ‘first and foremost’- ALWAYS clamp your work. I cannot over-emphasize this. Yes, it’s a pain and not always convenient but it IS necessary. I have a nice 2” long scar on my left wrist that is a constant reminder of the need to clamp your work. The very afternoon that I was going to drive my dirt track racecar for the first time, I was making an accelerator bracket and need to drill a hole in it. The bracket was just 8” long, ¾” flat stock, with one end bent at a 45 and that was where I needed the hole. So I go to my DP and hold the long part and place the bent area on the table under the bit. I started drilling the hole and OOPS…it grabbed and swung around 360 degrees and in the blink of an eye it made a few revolutions before I could get it shut off. Unfortunately, on that first swing, the top end of the stock sliced my wrist open and I wear that reminder to this day. It looks like I tried to commit suicide. So, I tell everyone - clamp your stock.

Send your questions or comments to: and we’ll see what we can do to help you.

Tuesday, August 23, 2011

V2.18 - Drill Presses and their chucks: part 2

Last week we talked about putting your drill chuck on your Drill Press. I ran out of room to fully explore the subject, so here we are again.

We were at the point of what steps to take when the chuck won’t stay on the taper… it keeps falling off when you try to use it, or maybe it won’t even stay on when you try to put it on. So, we said, the first thing to do is to check and clean VERY THOUROUGHLY the taper on the DP and the chuck’s taper.

NOTE: while you are checking/cleaning those tapers, this is a good time to inspect the surface of the tapers closely. The tapers need to be smooth and free from any galling. ‘Galling’ is a machinists term that refers to the tendency of metals, when scrubbing together under force, to grind and scar each other. If your chuck has been loose on the spindle nose (unknown to you) for a while, the two parts may have galled their surfaces. IF they have, it is usually useless to try to get them to properly seat again. (The prescription is to replace both parts and start fresh.)

Ok, let’s say that you’ve checked for galling and found both the chuck and the spindle nose taper to be smooth and in good shape. Now, you’ve cleaned them again and they are absolutely oil-free and dry as a bone. Take the chuck and ram it sharply onto the spindle nose.
Now, it’s time for the 2x4 and small sledge hammer again. Swing the table out of the way so that you can get a pretty decent swing with your sledge. Retract the chuck jaws to prevent them from getting bent and put your 2x4 under the chuck. Hold the 2x4 with your ‘weak’ hand and use your dominant hand to swing that sledge upward and SMACK the 2x4 (which is against the chuck) very hard.

As I said last week, Tapers seat best with a shock to them. A good 3lb sledge and a 2x4 block will allow you to deliver that shock to the chuck without risking damage to your chuck or Drill Press.

If you continue to have your chuck fall off, there may be a misfit between the two parts, or you may be asking the Drill Press to do something it was not designed to do (like milling, or using an out of balance item in the chuck) and the design of the chuck/spindle taper was not intended to account for that.

Send your questions or comments to: and we’ll see what we can do to help you.

Friday, August 12, 2011

V2.17 - Drill Press - Chucks ‘n Stuff

Drill presses are usually found in almost every shop. I was one of those ‘poor folks’ who didn’t have a drill press during my ‘learning how to work on stuff’ years and let me tell you what, by the time I got older and realized what I had been missing…hoo-boy, was life in the shop so much easier with one around.

Most of today’s ‘home/hobbyist’ drill presses use a taper to hold the chuck onto the spindle. Some manufacturers have the chuck already installed, while others ask the buyer to do it. In any event, the following information will come in handy.

Drill Press Tapers & Chucks usually fall into one of two categories: A spindle with a male taper and the chuck having a female taper; or a spindle with a female taper, a chuck with a female taper and an adapter with a male taper on each end that goes between the chuck and spindle. Each style has their place, with the adaptor style being used more on the bigger Presses.

Alright, there’s your ‘taper background’, now let’s get specific. Drill Press tapers engage (‘seat’) best with a shock. I know some manufacturers will tell you to just push them together, but that’s not the best way. Let’s say that you have a Drill Press with a female tapered chuck and the spindle has the male taper sticking down. First, clean the tapers completely to remove any oil, grease or coating that could prevent metal on metal contact. My favorite solution to this is an old rag saturated with acetone (NOTE: if you use acetone, be aware that it is highly combustible). Next, once you have the tapers cleaned, turn the chuck so as to retract the chuck jaws. Next, Place the chuck onto the spindle taper by hand. Finally comes the ‘shock’ part. Put a small 2X4 underneath the chuck jaw opening and use a small mallet (I have a 3lb sledge for this) to hit upward on the 2X4 (chuck bottom). One good sharp whack ought to do it. Once the tapers are seated properly, they will usually remain engaged unless something too large or out of balance is put into the chuck.
Let’s say that you get the chuck installed and all appears to be well. But then, one day, you turn your DP on and the chuck falls off of the spindle nose. Now, what to do?
Well first, you’d want to make sure that the inside of the chuck taper is clean and free from any oil or contaminants. Once you’ve checked and cleaned the chuck, check and clean the spindle nose also. We’ll continue here next time.

Send your questions or comments to: and we’ll see what we can do to help you.

Saturday, August 6, 2011

V2.16 - Collecting dust from all over

I got a question past week that might be good to pass along to my readers. Here’s the issue: “Samples are being cut from defective units. Once the employee rough trims the pieces to approximate sizes with a circular saw they use a tile saw to finish trim them and a belt sander to clean up the edges. The samples are made from Gel-Coat, resin, wood and ½” X 1” metal bar stock. What would be the best dust collection system for this?”
In his email, he gave 3 separate issues. #1-wood, #2- not wood, #3- metal. Each of these need separate consideration. The easiest is wood. Both Delta, Jet and many others make wood dust collectors. Most units are now the single-stage style- meaning the incoming material travels right thru, and impacts, the wheel. Steel is more resistant to the material’s impact and steel wheels are what is found in the single-stage units.
With that in mind, let’s look at each: wood would be fine with single-stage units and standard bags- no issues, however, with ‘not wood’, you’d need to be concerned about the bags themselves. At its most basic, wood is a porous material- meaning if the airflow was hard enough, *some* air could pass thru it. Not so with ‘not wood’. If the inside of the bag was coated with Gel-coat or resin, the airflow would stop and either it just wouldn’t work, or the pressure would build up and cause a bag seam to rupture. Your best bet here is to just collect it in a two-stage system like Cincinnati Fan has. This was the company that Delta used to get their 50-180-series units from. You’d want your dust to just drop into the barrel and not get to the bag to clog it up. Now for metal; metal is a whole different ballgame. If you are collecting wood and metal at the same time and using a single-stage, STEEL wheel, once the wood dust got to the critical ‘lower explosion level’ of 40 grams per cubic meter of air, and a metal spark was injected into the mix, a dust explosion is a real possibility. It would be safer to use the Cincinnati Fan style, two-stage collector as they use cast aluminum radial wheels so sparking is not as much of a concern; however, if you have a pile of wood dust in the bottom of the barrel and a grinding spark of metal made it thru to that pile, you could have a smoldering fire occur. Mixing metal and combustible material is never a good thing. Metal dust collection is best handled by a dedicated unit such as Delta’s old 49-826. (for those who’ve read this far and might need a good ferrous metal dust collector, I happen to have a brand new one- never used- $4000.00 value for only $1500.00) But it will not do the multi-material collecting either. It’s not good for anything but ferrous metals.

Send your questions or comments to: and we’ll see what we can do to help you.