Thread: A Basic (DUMB) question

i drill mine about 400 - 600 rpm
maybe you need to invest in a new drill bit ?

Kev,

Sometimes it depends on the timber especially burls. But the other thing has the quill on the drill got any play in it which would cause the drill to wander.

In fact this morning I drilled a burl blank that caused the drill bit to wander.

One other thing I do is I always centre punch the blank by marking across the blanks to get the centre.

Troy, thanks.. The drill bit is relatively new

Barry, I will check it out by rolling it over my table saw table to see if it has a "bend" in it. The off center is occouring at the bottom of the hole, the top is in the center.

Kev

Maybe there is a little play in the chuck ? I know mine has a little in it so lately I have chose to drill them out on my lathe and things seem to be better.

Cheers Ian

Maybe you haven't got the blank perfectly straight in the vise or your table may not be set up level, check it out by drawing a straight line on a piece of cardboard or thin timber and hold it behind the drill bit with the bottom edge of the cardboard/timber flat on the table whilst bit is in the drill chuck and pulling the drill down while it is not running and see if the bit follows the line drawn on the piece of cardboard or if it wanders a bit. Do this at the back and front and both sides of the bit. Make sure the piece of cardboard or timber is square though. Mark the line with a T square. I usually mark 2 lines running parallel to each other about the width of the drill bit apart. this way you can see more easily if the bit is going off course when you lower it.

BTW, much better to drill the blank on the lathe, much more accurate. I have also seen a couple of guys, mark the blank centre on both ends of the blank, drill the blank about half way and flip the blank and drill from the opposite end, seemed to work okay. Never tried it myself though.

Once I get a chuck setup on my mini lathe, I think I will start to drill the blank out there..

Thanks all for the suggestions.

Hey Trev,

No such thing as a dumb question, there are heaps of dumb mistakes because the dumb question wasn't asked,

I have a box of those blanks you are talking about,(Drill goes Walkies) mainly on 'Real fancy gunna look like a million Dollar blanks' that cost the most

HazzaB

Haven't been able to source one in Australia Yet BUT.I believe, from my reading, that Parabolic fluted bits are the best.

I know they can be sourced from America as ca n bullet point bits that are also supposed not to wander.

Be interested to hear what others say on the subject of these bit types.

Lot's of variables come into play here with drilling , long thin drills can bend while drilling ,such as the brad point 7 mm . If one edge is even slightly less sharp than the other the drill will tend to cut more on one side than the other ,it pushes slightly to the sharper side taking the line of least resistance ,also the materials can have a bearing ,trying to drill WW casts going from burl to acrylic can be a challenge . The end of the blank has to be square to the drill if its not the drill will wander slightly when starting off and continue to move more offline as you drill further ,keep clearing the shavings as a buildup can also push the drill off course . Some fixes that can help ,use a centre drill to start your hole correctly, use a short drill bit of the size you want till you are into the hole enough for the longer drill to have a good guide and support . Bigger sized holes are less problem as you can step drill ,and larger drills tend to be meatier and less likely to wander . Even with all that and years of experience drilling ,I still get the occasional run off ,usually in the harder woods . (note to self !!! less haste ,less waste ) cheers ~ John

[QUOTE=artme;1189917]Haven't been able to source one in Australia Yet BUT.I believe, from my reading, that Parabolic fluted bits are the best.

/QUOTE]

I am awaiting one as we "speak". ordered it from Jim and Irene

http://www.cws.au.com/shop/item/7mm-parabolic-drill-bit