Saturday, June 29, 2013

V4.26 - Drill Press: Speeds and Capacities

My, my. We’re just moving right along with our information about Drill Presses.

At some point we’re going to get into ‘what to look for when buying a DP’. I’m sure that will help anyone who is contemplating adding a new machine to their shop.

For now, let’s get back to our rundown.

Where’d we leave off? Oh yes, we were at the chuck and the next nearest thing to talk about is the spindle. The ‘spindle’ is usually driven by a stepped-cone pulley or pulleys that are connected by a v-belt to a similar pulley on a motor. The ‘motor’ is bolted to a plate that is located at the rear of the head casting at the rear of the column. The average range of speeds of the typical DP is 250rpm to about 3000rpm. Delta used to manufacturer a ‘super hi-speed’ Drill Press. It was so named because the bit speed was around 10,000rpm. The motor only turned at 3450rpm, but because of the belt ratio, it could really turn ‘n burn. It seems that jewelers loved it. Since the motor shaft stands vertically, a sealed ball bearing motor is best suited for a Drill Press. For average work, a one-quarter or three-quarter horsepower motor usually meets most requirements.

The capacity, or ‘size’ of a Drill Press is determined by the distance from the center of the drill bit to the front of the column - then doubled. For instance, a 12-inch Drill Press can drill to the center of a 12-inch diameter circle, but the distance from the center of the bit to the front of the column is only 6 inches. This is how all Drill Presses are measured. One of the most versatile Drill Presses was the “Ram Radial” Drill Press. This was an industrial Drill Press that was used a lot, during the Second World War, in airplane factories. The head had a long appendage fastened to its back and that casting rolled inside a ball bearing track. What this allowed was that the head could be moved backwards and forwards almost 3 feet. I’m working off memory but as I recall this press could drill to the center of a 72-inch circle, or down to about an 8-inch circle…and any and all points in between. It was such a popular concept, but one that most home shop guys could not afford, that back in the 1970’s, Rockwell International created a home shop version that could drill to the center of a 32-inch circle. It could also slide in and out, just like its bigger brother, which enabled it to be just as versatile.

Next week we’ll outline a few tips to keep in mind when you’re out shopping for your new Drill Press.
Send your questions or comments to: and we’ll see what we can do to help you.

Friday, June 21, 2013

V4.25 - Drilling, etc…

Ok, where were we? Lost in Space? In the Twilight Zone? Maybe in a Galaxy Far, Far Away? Nah, we were just playing around in the shop talking about Drill Presses.

Back we go… A conventional DP consists of the following main parts: the base, the column, the table and the head. The ‘base’ supports the machine. Usually it has pre-drilled holes that are for fastening the DP to the floor, a work table or a bench. Some bases have a machined surface that is used to hold a workpiece that might be too large to fit on the regular DP table. The ‘column’, usually made of steel, holds the table and the head and is fastened to the base. Actually the length of this hollow column determines whether the DP is a bench model (it mounts on a work bench) or a floor model (it stands on the floor). Floor DP’s range in height from 66 to 75 inches tall and bench-mounted models range in height from 23 to 48 inches tall. The ‘table’ is clamped to the column approximately midway between the head and the base. It can usually be moved up and down the column, so as to fit odd-sized objects inside the drilling range. The table may have slots and/or clamping ledges in it to aid in clamping and holding fixtures or workpieces. Most tables have a centered locator hole through them and some tables can be tilted, left or right, while some tables have a fixed position only. Some tables have a ready-made “dummy table” which can be easily attached to the table for certain sanding operations.

The term ‘head’ is used to designate the entire working mechanism that is attached to top of the column. The most important part of the head is the spindle. The spindle revolves in a vertical position and has bearings at both ends and is housed inside a moveable sleeve, called the quill. The quill, and therefore the spindle it houses, is moved downward by means of simple rack-and-pinion gearing, worked by the feed lever. When the feed handle is released, the quill is returned to its normal up position by means of a spring. Adjustments are provided for locking the quill and for presetting the depth to which the quill can travel. The quill usually has a stroke (travel length) of 2 to 3 and one-quarter inches on most home shop models. Industrial, or heavy-duty, DP’s usually have a stroke of 6 inches.

An average DP comes equipped with a one-half inch capacity geared chuck with key. This chuck offers the best grip for the most work.

We’ll wrap up this week here and be back with you next week.

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

Sunday, June 16, 2013

V4.24 - My friend, The Drill Press

So… last year I got to thinking (yes, my wife was shocked at that, too), I write about tools and I’m sure that some readers see what I write and think, “What the dickens is he talking about?”… because they have never heard of a wood shaper or a drill press or a bandsaw. So, I thought that I would introduce you to the tools.

Our next few weeks will be about what’s likely, my favorite shop tool, the Drill Press. I’ve done a few columns about the chuck and stuff, but not any about DP’s in general. I call this my favorite tool because it’s the only one that’s ever tried to seriously maim me…and it was MY fault. The story is that I was getting ready to race my dirt track stock car for the very first time and I needed to make an accelerator bracket. So I had this piece of flat steel that I had bent on one end and I needed to drill a hole in that end. I was “in a hurry” and set the bent end flat on the Drill Press table, which left the other end sticking up at an angle…and I thought ‘oh, I can just hold it and it will be fine’… yea, right. I held it, started drilling the hole and BAM! before I could move, the bit grabbed the metal and swung it around so fast…and I looked down at my arm and all of a sudden I had this huge slice in it…started bleeding like a stuck pig and all because I was in too big of a hurry to clamp my work or put it in a vise. To this very day, I have a scar on my left wrist that looks like I tried to commit suicide. Seriously.

Anyway, back to our lesson…the Drill Press (hereafter referred to as a DP) was originally designed for the metalworking trades; however, with the availability of woodworking techniques and of cutting tools, jigs and attachments, the DP is now one of the most versatile tools in the shop. It not only drills in metal, it bores in wood and performs other woodworking operations such as mortising and sanding. In fact, after the table saw, the DP can easily become the second most important piece of equipment in the average home shop. Notice one technical distinction: it “DRILLS” in metal and “BORES” in wood. Since I am a tech-guy, such nuances are important. They really are. We’ll talk more about DP’s next time.

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

Friday, June 7, 2013

V4.23 - 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.