Using a Bench and Pillar Drill Safely
When you want to drill a piece of metal with a bench drill or a drill press, just what things do you need to watch out for?
Firstly, for safety’s sake, the vice you are holding your work with will need to be secure, otherwise the work and vice may spin round as the drill bit suddenly gets to grips with the metal. This happens frequently with the softer metal like copper. brass and aluminium, and it is more often than not as the drill tip is just about to exit the work.
Generally this can also happen when you are using a large drill bit at a low speed in tougher materials like steel.
This securing can be achieved in a couple of ways; you could bolt the vice down, or alternatively for lighter work you could use the vice handle as a stop against the column. This all depends on the speed of your drill and the size of the work you are drilling.
Larger diameter drills need to be run at low speeds, which in turn means lots of torque (a twisting force) being exerted, and in this situation it is better to secure your drilling vice properly.
A hand drill can be used as a bench drill providing the drill is mounted in an inexpensive drill stand to help keep it upright (much like the one to the right),
whereas a purpose-built, but more expensive pillar drill has its own
column, as in the picture above, especially for this purpose.
Next we come to the depth of the hole to be drilled.
For thin sheet drilling it is best to have the sheet sat on top of a softer material (timber is fine) as this allows the drill to exit your work in a much safer manner, making the snatching as the drill exits almost non-existant - plus you have the benefit of your work not bending from the pressure applied by the drill.
This drill pressure can be a problem in a few ways. Firstly, if the column of your drill is narrow, it can flex as the pressure is applied, and in the same way the drilling table, despite the fact that it may well be cast iron, can flex downwards as well, causing your work to be drilled out of plumb.
For shallow holes in sheet metal, or say up to ¼ inch deep, then a hole can be relatively true, but when you come to drilling deeper than this, there may well be a problem with accuracy if the table dips.
I found the first bench drill I bought from a local department store had the above problems although nothing was obvious at first - it was relatively cheap and looked the part, so what could go wrong? I found also that when any pressure was exerted on my work, the table would slide down the column despite me using a ring spanner for leverage to tighten the clamp. In the end the clamp broke - cast iron again, and the whole lot was deposited in the scrap bin.
I now have a much sturdier drill press (shown to the right) I purchased from Amazon with a stiffer column and wind up and down, more solid bedplate to make life much easier and can use it without the drill penetrating way off square to the work.
Many times I tried to drill squarely with my cheap bench drill in my formative model engineering years, making small brass models with columns between the base which carried the crankshaft and the cylinder above which should have been sitting square, only to find the columns were all over the show.
Obviously, if these aren’t something like square, these little steam engines will never run because of the excessive friction, and that cheap drill caused that to happen to me a few times before I realised what was wrong, and that was almost the end of my model engineering enterprise.
that false economy just doesn't pay in the long run...
I also use the drill press to start any tapping that's needed before completing it in the vice, unless the work is already set up in the lathe, along with any die work started in the lathe.
How to Use a Pillar Drill Safely
A pillar drill is very similar to a bench drill except it is sat at the top of a taller column and stands on the floor. Both machines are used to create holes in various materials, and while you can fix the bench drill to a tabletop or bench, the pillar drill is larger, and it needs to be operated in a standing position on the floor.
speaking, the pillar drill is used for larger work, using bigger drill
bits like the blacksmith drills,
usually having a half inch shank for entry into the chuck, but with a
bigger cutting shaft going into various sizes, and these need to be
used at a very slow speed otherwise they'll chatter and go blunt very
Normally these machines come with some safety devices already attached and you can add more to suit the work you are doing.
Using a drill of any sort is relatively easy to do but requires you to be aware of others around you and to take precaution to do no harm to yourself, others and anything else around you.
Pillar Drill Safety Rules
If this is your first attempt at using a drill, make yourself aware of any instructions available to you. It is wisest to wear work gloves and safety goggles as small fragments of metal are thrown off from the drill tip and they can travel a good distance as well as being very hot.
Make sure you are using the right drill bits to suit your machine (there are various sorts) and that you are using a suitable drill for the material you are working on.
Before you begin drilling make a mental note of exactly where the emergency stop button is as this may be needed.
Make a point of removing the chuck key after tightening the drill in place - assuming you have used a chuck key rather than the more modern twist grips. A chuck key flying out of the chuck on start-up can do some serious damage to anyone in the vicinity.
Make sure the drill guard is in place before work begins - they can be a pain sometimes, but they do protect the local area from hot swarf and chips.
Wearing safety goggles is a must with a drill as you only have one pair of eyes in your lifetime and they are like jelly, showing very little resistance to hot flying metal. Do not work without them!
Do not force the drill into the work - allowing the bit to do its job in a more natural manner will prolong the life and sharpness of your drill bit as well as being more accurate.
Adjust the pulleys (or select the right gearing) on the drill to give you the correct speed needed for the drill bits you are using. The smaller the drill, the higher the speed. This stops chatter with larger drills which bluntens them very quickly.
Make a point of wearing work gloves as the material you are drilling may be sharp, along with removing the drill bit in a hot state could easily burn your hands.
Finally, once your work is done, make a point of unplugging the drill just in case some child comes along while you are not there and hurts themself. Also, once the drill is cool, make a point of cleaning off the swarf and make it clean and ready for the next drilling session to come.
Hope this helps you out.
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