Although the professionals (and I include the esteemed John Stevenson in that category) are moving into an ever-more computer-controlled world, most of we amateurs are still using manual techniques that were well-established before
1950.
However, there is one way in which electrickery could be employed to increase safety in the workshop, and that is by placing a couple of microswitches behind the lathe's tool board such that the lathe (via its contactor) will not start unless both the chuck keys (3-jaw, 4-jaw) are firmly pushed into their relevant holes on the tool-board
Just visited a lawn mower repair shop that had a small lathe on the bench. Where was the chuck key - in the chuck of course waiting to be flung at the operator !!!!!
It's very easily bypassed by fabricating something that looks like a lathe chuck key. Then you can leave the chuck leys where they belong, in the suds tray for the one you are using, and in the hole in the middle of the chuck that is stored on the shelf.
The easiest way to remember to remove the chuck key is to stand in line with the key in the chuck and switch the lathe on. The sharp crack on the head and accompanying cut will knock that information securely into your memory banks, with the added advantage that should you forget you can repeat the process to top up your memory bank. No need for complex interlocks after that. Regards Alan
Micro switches are liable to be shorted by swarf, so I suggest a time delay and relay connected to the start switch could be used to electrically operate a hammer aimed at the operators head while a voice recording of "Take the ****ing chuck key out, you plonker!" is bellowed 5 seconds before the motor runs
I well remember the dull "THUD" as a metalwork teacher at my school flicked a lathe on with the key in place. The key ricocheted neatly straight into his balls.
I cannot believe how often I see keys left in chucks both on the lathe and the drill. As first year apprentices we received a hefty clout round the ear if our hands were ever seen to be off the key when it was in the chuck. As second years we received no physical abuse but were just addressed as "Mr" and asked if we had our hands were empty for some sort of "self abuse"? More senior years just got "the look". I have a block of wood in the drip tray which is drilled for the chuck key, if it is in the chuck my hand stays on it, if I move my hand the key comes out - every time - and the key is dropped into the wood block. I don't use those spring loaded keys but the theory is the same. Even now if I am tempted to leave the key in place, particularly with the 4 jaw, while I do something else I remember the sore ear or the fun everyone else had at my expense during the tea break. Once you had acquired the "self abuse" nickname you kept it until some other unfortunate won it from you. I don't suppose for one minute that this type of "training" is legal these days but it was certainly effective and produced a "lifetime" memory. It is really surprising how difficult it is to break a habit once established - just make sure that habits are safe and sensible before they become programmed.
I painted mine bright yellow. It really stands out against the drab colours of my lathe. Works a treat. A couple of times now the colour caught my eye as I went to switch the lathe on.
Also told my kids to slap me as hard as they can if they ever see the key resting in the chuck. Trust me, they cant wait to spot a key in chuck.
Unfortunately you can't get away with giving them a clip round the earhole anymore. I did that at the last place to an apprentice and got hauled in on assault. It was only the apprentice stepping in that got it all dropped. This was in company BTW not plod but it could have got me sacked.
It's only practice and habit that gets you safe. One lathe has a set of holes drilled in a ledge on the satnd to hold 4 or 5 keys for various chuck. The other lathe has an eye bolt screwed into one of the screwcutting gearbox studs to hold the current key in use.
John Hi, yes I totally agree it is the habit that needs to be developed for safety. One thing I have learnt recently, and it is not entirely age related, is that I do not get as "focused" on jobs as I used to, so the habit doesn't always happen automatically. With my mind very easily diverted these days (I even hear when the workshop door is opened nowadays) I do not feel that the habits of a lifetime offer the same protection they once did. I have moved my drilled wooden block to just above the on/off switch to try and help but I do worry that I am not as naturally safe as I once was. I can even waste several minutes these days looking for the chuck key when it is in my other hand !!!!!!!!
The first year of our apprenticeship was at a local Tech College and the 97 (yes 97 engineers starting each year in a small college - different now?) of us were split into 3 or 4 groups. There were two girls in one of the groups and during the first couple of introduction days they were asked how they wished to be treated by the others in the group. I can't, on a public forum, quote their answer but to paraphrase it they wanted to be treated like any other apprentice. I know that many say it about women in a (then) mans world but they were two superb engineers.
The apprentice that stepped in on your behalf must have liked you. Much later in life I had the tricky situation where a team had made a formal complaint against their foreman (he was a bit of an a**hole) for swearing at them. His defence was that another foreman (good guy this one) was always swearing and they never complained. While he was right he got some "advice" on dealing appropriately with team members and was sent on a team leading course, nowadays it would be "counselling and retraining" I guess.
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