Geplaatst: 06-09-2016 13:20
Ik weet wel waar je dat gezien hebt.
Todays tip
how to sharpen your own butterfly drill
Remember this is what you are trying to acheive
So start with an 8mm drill, it must be a good quality HSS drill
Then with the bench grinder
Grind the end flat, keep twisting the drill when you are doing this to get it nice and even
Then back into the bench grinder at this sort of angle on the edge of the stone
You need to twist it slightly as you go, then twist it round and do the other side
The idea is to have both sides equal and the same and both cutting points level, with a raised nipple section in the middle, the nipple must be as central as possible or else it will wander as you try to drill, you could centre punch the spot weld if you need to, and by keeping the nipple only 1mm tall, it wont drill right through the underskin either
The important thing is that the trailing edges are lower than the cutting edges, otherwise it will just skid ontop of the steel and not cut in
If you use the following dimensions as a guide you should not go too wrong. Again, plenty of practice helps
The good thing about this type of drill, is that it wont bite as it goes into thin steel, so it wont twist the metal or twist itself out of your hand, and you don't need a pilot hole first either, they are great for drilling big holes in thin steel, you can easily sharpen a 13mm drill like this and drill straight through 1mm steel without snagging
Todays tip
how to sharpen your own butterfly drill
Remember this is what you are trying to acheive
So start with an 8mm drill, it must be a good quality HSS drill
Then with the bench grinder
Grind the end flat, keep twisting the drill when you are doing this to get it nice and even
Then back into the bench grinder at this sort of angle on the edge of the stone
You need to twist it slightly as you go, then twist it round and do the other side
The idea is to have both sides equal and the same and both cutting points level, with a raised nipple section in the middle, the nipple must be as central as possible or else it will wander as you try to drill, you could centre punch the spot weld if you need to, and by keeping the nipple only 1mm tall, it wont drill right through the underskin either
The important thing is that the trailing edges are lower than the cutting edges, otherwise it will just skid ontop of the steel and not cut in
If you use the following dimensions as a guide you should not go too wrong. Again, plenty of practice helps
The good thing about this type of drill, is that it wont bite as it goes into thin steel, so it wont twist the metal or twist itself out of your hand, and you don't need a pilot hole first either, they are great for drilling big holes in thin steel, you can easily sharpen a 13mm drill like this and drill straight through 1mm steel without snagging