Two workshop mysteries.

[ccdjg]

While working on my current project, a couple of very irritating mysteries cropped up in the workshop. Luckily for my sanity I eventually found the answers, but I wonder if anyone here can work out what the hell was going on?

First there was the case of the blunting drill bits. I came into the workshop one morning with the intention of drilling two holes in a block of mild steel, as a follow on from some drilling I had done the day before. I selected the appropriate drill bit from my favourite set and using my trusty old Myford lathe I set about drilling the hole. To my surprise the drill made hardly any impression on the steel. I wondered if I had picked up a piece of hardened tool steel by mistake, so tried again with a scrap of definitely mild steel, only to find the same problem. I presumed then that it must be the drill bit that was the problem and I must have seriously blunted it the day before. So I then took a drill bit of the same same size from a new pack and this also refused to drill. Something seemed to have taken the edge off all my drill bits overnight. I tried few other drill bits and none were any good. Any thoughts?


The second mystery was the case of the kamikaze bluebottles. During one of the recent hot spells every 10 minutes or so a bluebottle would fly into the workshop and drive me nuts with its incessant buzzing and crashing into the lathe and the windows. It go so annoying that I had to keep a can of fly spray at hand and waste a lot of valuable time chasing the beggars around. I couldn't understand why they would come into a sterile workshop, having to fly through a narrow gap in the outer garage door, cross a large floor space and find a narrow gap through the workshop door. I suppose I could have completely closed the two doors but it was too hot to do this for very long. It took me a while to figure the problem out and get it sorted. Any suggestions?

[RichardH]

Reverse the rotation

Can’t help with the flies

[Garvin]

I suspect Richard has nailed the drill blunting problem. Was there some food around or something attracting the flies? They have an almost uncanny knack of locating eg. a bit of dropped sandwich in my experience...

[RichardH]

I suspect Richard has nailed the drill blunting problem....

Been there

[I. J.]

Can’t help with the flies

Spray them with hair spray.
It doesn't kill them - they just have to glide everywhere.

HTH
Ian

[Benelli B76]

I am forever sharpening drill bits, its difficult to find good quality ones today. I was one of the best at sharpening them during my apprenticeship, but I hated the tiny ones. Any suggestions where to buy good quality ? RPM speed is also a big factor in easy drilling, depending on diameter.


Baz

[trajectory]

If you were drilling in the lathe & it was spinning in the right direction but all the bits were "blunt" was the tailstock properly locked on the bed?

[rovercoupe]

Any scale on the block of steel?

[edbear2]

I am forever sharpening drill bits, its difficult to find good quality ones today. I was one of the best at sharpening them during my apprenticeship, but I hated the tiny ones. Any suggestions where to buy good quality ? RPM speed is also a big factor in easy drilling, depending on diameter.


Baz

Hi Baz,

Buy colbalt ones, but they are not cheap;

https://www.orbitalfasteners.co.uk/e...balt-bits-a777

Unfortunately the general public (ie. non trade who have no idea what proper engineering costs are) think that B+Q or Screwfix gold drills are actually what an engineering firm might use

Also look on the bay for used older sets, over the last few years I have acquired full sets of British made metric / imperial / letter and number drills, all for a fraction of their value by being patient. Well looked after or little used sets often pop up on there.

ATB, Ed

[ccdjg]

Hi Baz,

Buy colbalt ones, but they are not cheap;

https://www.orbitalfasteners.co.uk/e...balt-bits-a777

Unfortunately the general public (ie. non trade who have no idea what proper engineering costs are) think that B+Q or Screwfix gold drills are actually what an engineering firm might use

Couldn't agree more Ed. I came into hobby machining very late and have acquired various sets of drill bits over time, some bought without much serious thought, and I find myself again and again going to the cobalt ones in preference to all the others.

[Benelli B76]

Hi Baz,

Buy colbalt ones, but they are not cheap;

https://www.orbitalfasteners.co.uk/e...balt-bits-a777

Unfortunately the general public (ie. non trade who have no idea what proper engineering costs are) think that B+Q or Screwfix gold drills are actually what an engineering firm might use

Also look on the bay for used older sets, over the last few years I have acquired full sets of British made metric / imperial / letter and number drills, all for a fraction of their value by being patient. Well looked after or little used sets often pop up on there.

ATB, Ed

Gonna get me a complete set, thanks. Fed up with bits made of toffee.

[ccdjg]

Reverse the rotation

Can’t help with the flies

Spot on Richard! The old Dewhurst switch on the lathe had come loose inside and somehow I had put the lathe into reverse. As I had never used the reverse setting before (why do they have the option when Myford tell you never to use it in case the chuck unwinds?) it was not something that came immediately to mind. So there's a golden nugget of information for you all - drills don't work very well in reverse. You don't get these sort of tips in the text books!

As to the bluebottles, Danny more or less has it. No food of any sort in the workshop, but I did begin to notice a smell of something like cat crap. Searching behind all the cupboards etc, in case a moggy had crept in and left a deposit proved fruitless, as did a close inspection of the soles of my shoes. Eventually the penny dropped and I realised it was a sheet of emery cloth made in China I had recently got out of the drawer and left on the bench. It sure did stink. God knows what they use as the adhesive but I hope they never get round to using it on envelopes. I know recycling is all the rage, but cat crap should stay as cat crap however cheap it might be.

The fly spray was pretty effective but I thought it was a bit cruel, so I used spray varnish instead. They took a bit longer to die but they did have a lovely finish.