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Homeowners, Machine Tools and Good Advice.

So, all the kids moved out and now there's room in the garage. So what? Yeah, wait 'till the wife sees my new drill press and table saw!

Among the tools bought by homeowners these two are the most dangerous. A few thoughts and some calm and thoughtful planning will keep you from breaking ribs and will keep your finger count at ten -- provided you started out with ten.

So, before you even build a stand for that drill press go back to the store and buy eye protection, the best drill press vise in the store, a three pound shop hammer, at least three large "C" clamps and a gallon of cutting oil. Next take your drill press vise to a machine shop and have them cut and grind a piece of steel 1 in. by 8 in. and about two inches longer than the width of your drill press table. NOTE do not let them "true" the faces or you'll be in divorce court! Have them tap and harden four SAE course thread holes so the vise can be centered 90 degrees right and left. When you mount the vise use a torque wrench to torque to 65. Now, whatever you drill on should be mounted in this vise and "C" clamped onto the table using at least three "C" clamps. Tighten things up a bit and put a "center" into the drill press chuck. Use the shop hammer to move the vise around a bit by tapping the mounting plate. When you're "dead on balls accurate" (...after "Balls" Tomei, a famous American machinist) tighten each "C" clamp by a fraction of a turn. Tighten them at random until they are all dead tight. Pound them dead tight with the shop hammer. Check your center. If you are out of tolerance repeat the above.

No Smoking

When center is proved within tolerance insert the drill and drill slowly and use a lot of oil. If you are precision drilling a large hole like 2 in. drill a ½ in. pilot hole first. This preserves the edge and the life of large drills. If you routinely drill precision holes then make some kind of oil recovery pan underneath the drill press table. This can feed into a five gallon can of cutting oil. Make sure a tube delivers the hot oil to the bottom of the can and put some strong magnets down there. Install a vertical baffle in the container from the bottom of the can to about two inches below the oil level. Draw cutting oil from the bottom of the other side. Additionally put some strong magnets next to the draw tube as well. Use oil liberally. Whatever you do you absolutely don't want to see smoke when cutting.

Drill Press as a Milling Machine??

It is possible but not recommended to use a drill press as a milling machine. If you elect to do so work very slowly. Think of a milling machine as the rabbit and the drill press as the tortoise. Apply much less pressure and run the mill or cutter at 50% speed. Use a lot of oil.

If it needs to be square, then learn to use a square or "jo-block." If it needs to be at an angle learn to use a protractor and a scriber and how to securely mount at that angle. Also buy a book on drill press operation and importantly learn and obey the rules of drill speed. A machinist considers his cutting tools to be jewels, these jewels are used on a work piece to create a thing of art and utility. When a tool is stressed it can quickly go out of specifications. Do not stress your tools under any circumstances whatsoever. The fact that you use twist bits with a hand drill and no oil running at a gazillion RPM to cut a hole in some metal thing does not form the standard of operation for a precision drill press.

If you have a drill press vise with calibrations in three dimensions, you may cast the odd piece in Plaster of Paris which has been richly mixed with chopped up steel wool. A pint milk carton is good for this.

If it is slightly irregular you can cut up bits of Oak into wedge shaped strips and using them mount the odd piece in the vise. Make sure this "lash-up" is secure. If you're drilling into any odd piece drill slowly and use a lot of oil. Take your time. By the way, it is always a good idea to keep a can of light oil or cutting oil handy and use oil whenever you drill, be it aluminum, brass, cast iron or steel. It's a lot less costly to clean a piece than it is to throw away something you've burned up and start from the beginning. More importantly you don't want to foul up your tools.

Most of these precautions are intended to keep you from ruining a piece of work or your tool. However if you're holding onto and drilling a piece of 3 in. angle iron and it galls you can have broken ribs really quick. So at the least use some "C" clamps. NOTE: If you must hold the work piece free never absolutely never stand in the way of rotation!

Count your Fingers

Now on the table saw. Count your fingers. Take a piece of poster board and using a really big RED magic marker write that number on it. Mount the poster board securely so you can see the number when you're standing in front of the saw and looking at the blade. I think this is the most important rule of table saw safety. The second is of course to keep fingers away from the blade. To assist in this avoid removing the blade guard. If you must remove the blade guard use a notched piece of wood to push the work piece through. Always keep the blade as low as possible. If you are cutting a ¾ in. piece of plywood the total height of the blade should not exceed one inch above the table. Let it be a shop rule, the blade rides ¼ in. above the work piece. If you must make many cuts which are identical. Make jigs which ride the grooves on your table saw so the work piece can be clamped down and positioned automatically. Admittedly, this takes some planning and skill. Then all you have to do is to grab the handles well away from the saw blade and make the cut. This is especially useful when cutting panels for doors, dental molding or panels for wainscoting. A set of jigs is highly recommended if you're working on a big project or working in exotic woods or veneers such as Walnut, Cherry, Teak, Bird's Eye Maple etc. When I paneled my library I designed the plan. Then I prepared the surfaces and installed lath. Then I made exact measurements and determined the degree off square. I built eight jigs for the panels & slats and five for the book cases, crown and dental moldings, two for chair rails. A router and router table were used as well. Once proved, it took three days to cut the components and label them, one day to perfect custom cuts, six days to finish to 0000 steel wool and apply an initial oil treatment, then 4.5 days to assemble. As I was very careful the maximum cumulative error on the long wall 18 ft. was less than ¼ in. Now I'm thinking about the ceiling.

The Rules

When you are using a machine tool these are things to do.

1. Think about the job be totally focused.

2. Plan what you are going to do make the plan and take your time.

3. Draw a plan and check off what you're going to do and label each component.

4. If you make a change draw it, prove it and then make the cut and check it off. If the cut is proved put it into the plan and then review the plan. If the new cut solves a problem and does not create other problems accept this amendment.

5. You must always know exactly where you are in the job, what you are doing and why and what the next step is.

6. Vision in your mind how your hands will move in each cut otherwise a drill will go through you or a saw will cut you.

7. MOST CRITICALLY SPEAKING -- when you do the job do not allow any distractions of any kind whatsoever! Do understand this may involve some confrontation and compromise with WIFE (working infrastructure facilitator and expediter) Clarity here is critical.

Remember what the doctor said

If you are tired do not operate a machine tool. If you've had a couple of beers do not operate a machine tool. If you've been rattled by the wife, the kids, relatives or other events do not operate a machine tool. Just remember what the doctor said during a news conference after he reattached a certain anatomical part of John Wayne Bobbit, "When you cut it off for whatever reason it is very difficult to reattach it in the first place and very very chancy to get it to work properly."

So, for all do-it-yourself types, weekend carpenters, weekend engineers, and just ordinary folk who prowl about doing home improvements: I salute you! Please be careful, plan ahead, draw your plans, prove them, test them and then do a great job!

Happy Thoughts -- Bill McCaslin -- 25 Jun 2003

 

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