2mm diameter drill bit bends?

[dvddvd]

I'm trying to drill accurate using a drill press with a 2mm drill bit.
On the point of entry you see the drill bit bend a little until it get going, seems to slip on the surface.

It was just a test using HSS drills I had so will get some brad point ones to see if they are better.

The hole is only 15mm deep so would it also be better to cut the bit down as at the moment around 35mm is stuck out even with it pushed all the way into the chuck

thanks

 

[Fitzroy]

use a awl (on wood) or centre punch (on metal) stops the drill bit wandering before it starts to cut. A centre mark also allows you to align the hole directly under the centre of the drill press so that the force acts straight down the drill bit.

 

[J-G]

I somehow doubt that you'll find 'Brad Point' at 2mm Ø - as @Fitzroy has said, use a centre punch or Awl - I would have suggested a solid carbide drill but again it's doubtful if you could find one to drill 15mm deep - most would be 10mm, maybe 12mm max.

 

[flh801978]

I would use a centre drill designed for metal to spot your holes then go down with a good quality 2mm metal drill running it fast

 

[ChaiLatte]

A centre mark also allows you to align the hole directly under the centre of the drill press...

How do you do the alignment? The only tool you have is the Mk I eyeball (possibly optically-assisted).

If you do your best, but happen to align the centre mark off the rotational axis of the drill bit, it will exacerbate the problem, not reduce it.

It might be better to align a perfectly smooth surface as best you can, clamp it down, then use a short, stiff, centre or spotting drill to put a mark that you know is aligned with the drill's axis (even though it may be in slightly the wrong place), then change to the final drill bit.

On something where a large diameter bit is used, sure, an unclamped workpiece will tend to self-align with a centre punch mark, but with a 2mm bit, just the weight of the material alone is likely to prevent this.

If the 2mm bit were sticking out 2mm, the self-alignment would have far greater chance of success, but he is at a 17:1 slenderness so the drill will follow whatever it touches first wherever in space that might be.

To the OP: you do not say the speed at which you are running the bit. See:

https://www.imperialsupplies.com/pdf/3660-5_F_Drill_Bit_Sheet_Update.pdf
If you cut the bit down, it will not help if you cut so much off it that the chuck can only grip on the flutes.

 

[Fitzroy]

How do you do the alignment? The only tool you have is the Mk I eyeball (possibly optically-assisted).

If you do your best, but happen to align the centre mark off the rotational axis of the drill bit, it will exacerbate the problem, not reduce it.

It might be better to align a perfectly smooth surface as best you can, clamp it down, then use a short, stiff, centre or spotting drill to put a mark that you know is aligned with the drill's axis (even though it may be in slightly the wrong place), then change to the final drill bit.

On something where a large diameter bit is used, sure, an unclamped workpiece will tend to self-align with a centre punch mark, but with a 2mm bit, just the weight of the material alone is likely to prevent this.

If the 2mm bit were sticking out 2mm, the self-alignment would have far greater chance of success, but he is at a 17:1 slenderness so the drill will follow whatever it touches first wherever in space that might be.

To the OP: you do not say the speed at which you are running the bit. See:

https://www.imperialsupplies.com/pdf/3660-5_F_Drill_Bit_Sheet_Update.pdf
If you cut the bit down, it will not help if you cut so much off it that the chuck can only grip on the flutes.

I would extend drill when not running such that the drill bit makes contact with the workpiece and adjust with eyeball Mk1 until aligned with centre mark. Not perfect but I have found good enough to stop most deflection.

 

[dvddvd]

Thanks the lining up to the hole isn't a problem as I will use a notched metal plate/jig stuck to the piece of timber and have a fixed pin to allow the piece to be moved to the next hole.

 

[Sideways]

I'm trying to drill accurate using a drill press with a 2mm drill bit.
On the point of entry you see the drill bit bend a little until it get going, seems to slip on the surface.

You just learnt a vital lesson about jobber drill bits. They aren't very stiff compared to their length. Even the variation in hardness of wood due to grain can throw them way off.

Some good suggestions above.
Shortening the drill will help if you are able to put a new point on it. Grind it off so there are only 1-2 turns of the spiral leaving the solid shank untouched. That's what a stub drill is. Stiffer for getting a hole started on centre.
Swap drills to a standard one once the hole is drilled as deep as the stub will go.

 

[dvddvd]

Just found these at wickes2mm brad

 

[dvddvd]

I

You just learnt a vital lesson about jobber drill bits. They aren't very stiff compared to their length. Even the variation in hardness of wood due to grain can throw them way off.

Some good suggestions above.
Shortening the drill will help if you are able to put a new point on it. Grind it off so there are only 1-2 turns of the spiral leaving the solid shank untouched. That's what a stub drill is. Stiffer for getting a hole started on centre.
Swap drills to a standard one once the hole is drilled as deep as the stub will go.

was thinking about cutting the shank down by 20mm so it's still fully in the chuck but only 20mm stuck out

thanks

 

[Phil Pascoe]

More accurate the other way around.

 

[Bingy man]

You could these from s/fix or if you can source a 2mm masonry or multi material drill bit I’m assuming they are stronger. 2 mm is not going to fair well with the pressure of a pillar drill bearing down . Awl or centre punch to help line up ..

 

[Phill05]

I'm trying to drill accurate using a drill press with a 2mm drill bit.
On the point of entry you see the drill bit bend a little until it get going, seems to slip on the surface.

It was just a test using HSS drills I had so will get some brad point ones to see if they are better.

The hole is only 15mm deep so would it also be better to cut the bit down as at the moment around 35mm is stuck out even with it pushed all the way into the chuck

thanks

What are you trying to drill into? also any small drill needs to run at high speed you got your drill press running at max speed, and you really need to have a centre drill / punch mark to start with.

 

[dvddvd]

Thanks for the replies, I will be drilling into hardwood maple etc.

The 2mm holes are for the dot markings on the side of a guitar fretboard. So you drill 2mm holes and then push in 2mm plastic rod and snip it off and sand flush.

I have a metal fret template so was going to use that but stagger it so the holes hit the centre between 2 frets

 

[Sideways]

Get a 2mm slot drill (milling machine cutter that will drill, lots of milling cutters DON'T drill, but only go sideways)
You will have a thicker stiff shank, reduced to 2mm for the spiral only. It will be precison ground and cut a cleaner hole. You choose a length of flute that is enough for the job and no more. Only a few mm surely ?

The fluted section of a cutter is far more flexible than the solid shank so you minimise the length of the flutes.

I'd be thinking about a dremel or proxxon tool in a stand. It will give you the high speed and have less runout / wobble than all but precision bench drills. The these tools have a collet available to take 3.2mm shank cutters, there is probably a 2mm cutter with a 3.2 shank for not too much money.

 

[dvddvd]

Thanks, I bought one of these just to do the one job or any other small pieces work

Bosch PBD 40 pillar drill

I have a Axminster trade pillar drill but it seemed to large and brutal for the job. Plus I use it for metalwork so it's all a bit oily and greasy.

I bought the Bosch pillar drill locally second hand but unused so cost me just short of £200

Im impressed with it for small work. Its very quiet has electronic
speed control on the front. But the best thing is an electronic read out of the depth stop on the front screen. Zero it and it reads out the depth in 0.1 of a ,mm.
It seems ideal for small bits but then people use them with 42mm Forestners bits online

 

[clogs]

go to the highest speed poss on ur machine......
I use a ultra high speed Medding drill press just for that job on metal.....18,000rpm for 2mm....the machine will run at 23,000rpm....

 

[flh801978]

As i said these are metal centre drills they wont deviate from your position

 

[RogerS]

How do you do the alignment? The only tool you have is the Mk I eyeball (possibly optically-assisted).

Not strictly true. If you have deep enough pockets then you can get on these or variants thereof... 'optical punch' will get you there

 

[Yojevol]

Thanks for the replies, I will be drilling into hardwood maple etc.

The 2mm holes are for the dot markings on the side of a guitar fretboard. So you drill 2mm holes and then push in 2mm plastic rod and snip it off and sand flush.

I have a metal fret template so was going to use that but stagger it so the holes hit the centre between 2 frets

Are these dots purely decorative? If so why do they need to be 10mm deep? Would 4/5mm do?
Brian