Drilling through a round bar.

[BRIAN]

I came up with this while writing the clock book and just wonder if anyone else uses this method it works well even on a shaky drill.
Put the bar in the drill vice put a flat ended burr in the chuck, dab the burr on the work in the area you want the hole.


The mark shows the spot for the hole as you can see i am also below my line, put in a small centre drill and by moving the vice ( not the work in the vice) bring it on centre of the mark and on line, clamp the vice and drill the centre mark, change drills and drill through.



I works For Me Brian.

 

[george wilson]

Why not just use a lathe center drill? It will drill your starting place more efficiently than the burr will.

 

[BRIAN]

Hi george
the burr is flat at the bottom and when it touches it only touches at the highest point and therefore gives the point dead centre of the bar,even if the burr is off centre.
Using this point I then use a centre drill, the burr also gives a small flat that helps the drill to start without skiding to one side If the drilling machine is a bit shakey
This method gets you on centre . if you do it on a mill with a end mill, you get a fine line dead on centre.

Brian.

 

[DMS]

Never tried it Brian, but thanks for the tip. I usually do things in the mill, but barring that I will

1) Blue up the rod
2) Clamp it in a vblock, then place that on my surface plate, and mark the center line on (including on the end)
3) Center punch
4) Place the rod in the vice, and align the center mark up using the center line mark on the end of the rod and a square.
5) Drill with a small drill (1/16" or so)
6) finish with final size drill

Works well, but is time consuming. Do you center punch after the burr? If not, ever have any issue with walking?

 

[Bill C.]

Hi george
the burr is flat at the bottom and when it touches it only touches at the highest point and therefore gives the point dead centre of the bar,even if the burr is off centre.
Using this point I then use a centre drill, the burr also gives a small flat that helps the drill to start without skiding to one side If the drilling machine is a bit shakey
This method gets you on centre . if you do it on a mill with a end mill, you get a fine line dead on centre.

Brian.

Nice tip.

 

[Ray C]

I do something similar but instead of a burr, I use a small endmill. Yes, I know, you're not supposed to use a drill chuck for milling (because it will break the JT taper loose) but for a 3 second touch straight down with a 3/16" endmill, it's not going to hurt anything. After that, I follow-up with a center drill then raise the head enough to insert the drill bit and drill the hole.


Ray

 

[refinery Mike]

I like to use a mill bit in the drill press to make a flat spot as well. Even in a mill, if you do not need Space Shuttle accuracy you can clamp a round bar in the vice. touch the bar with a small mill bit, and the spot will give you the center of the bar to start your cross hole. Not totally accurate but close enough for many jobs. If i were doing it i would use a spotter bit to start the cross hole, they wander less.

 

[Ray C]

Mike,

Do you have DRO? With DRO on the mill, I don't bother to use an edge finder. With the motor off, I lower the bit alongside the piece and move it over juuuust until it touches then use the 1/2-axis feature to find the center. If it's off by a thou or two from eyballing the touch-off, it's of no importance for anything I do along these lines. Besides, when you use a drill bit to make a hole, it's usually for something non-critical.

Ray

I like to use a mill bit in the drill press to make a flat spot as well. Even in a mill, if you do not need Space Shuttle accuracy you can clamp a round bar in the vice. touch the bar with a small mill bit, and the spot will give you the center of the bar to start your cross hole. Not totally accurate but close enough for many jobs. If i were doing it i would use a spotter bit to start the cross hole, they wander less.

 

[george wilson]

For fairly close accuracy,I graze the rod with a center drill,leaving a very short mark across the top of the rod to be drilled. It is then pretty easy to eyeball the center of the mark(while the center drill is rotating for all operations) and drill the hole deeper too receive the final drill.

 

[BRIAN]

Thanks to all for your input on this thread.
I think I had better point out that the book is all about making a clock with simple, and quite often poor equipment.
The burr works even if the drill is in poor condition, with no snatch, it leaves a small flat on the centre line, that a small centre drill will start on
without centre punching.

This was the result.
Brian.