Help with drilling

[robwilk]

I am building Elmers twin wobbler and so far all is going well except for drilling the exhaust port in the column which is 1.6mm i have to drill all the way through by drilling from both sides and meeting in the middle. I started drilling from the first side with plenty of WD40 and guess what 'Snap' so i thought drill from the other side then knock the broken drill out . So i started drilling from the opposite side guess what 'Snap' :'( . I have now remade the column and not wanting to make the same mistake again i thought i might seek some advice. I am using a pillar drill as i don't have a mill the work was in a drilling vice and clamped down so as not to move . Could it be the speed i am drilling ? my drill has five speed options 600 rpm 900, 1250, 1750, 2500rpm i was using the 600 rpm choice as that looked fast enough but i am often wrong.
Any advice would be appreciated

Rob

 

[arnoldb]

Hi Rob

What metal is the column ?

For a start, on a 1.6mm drill on any metal I'd suggest you go right up to 2500 rpm - small drills want high speed.

Don't try to drill the hole in one pass - you need to "peck" drill it; the first couple of millimeters you can most likely plunge in, but after that, you need to bring the drill out of the hole to let swarf clear off the flutes. If you're drilling aluminium, the flutes will clog up, and you might have to resort to using a stiff brush against the drill bit to clean it off in combination with your lubricant.

Regards, Arnold

 

[Maryak]

Rob,

I think you may be drilling too slow............ for steel, around 1800 rpm. Drilling also requires frequent clearing of the swarf at max 3 x drill dia of depth before you clear the flutes. Lastly with small drills you need to peck at it with a light down feed.

Hope this helps.

Best Regards
Bob

EDIT - Just like Arnold said. ;D

 

[robwilk]

Sorry i should of said in my post i am drilling aluminium .I will try a faster speed and more cleaning of the drill
Thanks Arnold & Bob

 

[mklotz]

If you're drilling aluminum, some kerosene (paraffin if you're in the UK) will help keep the swarf from sticking to the drill.

 

[Deanofid]

If you're drilling aluminum, some kerosene (paraffin if you're in the UK) will help keep the swarf from sticking to the drill.

So will the WD 40 you're already using, as it's about the same thing as kerosene/paraffin. Just
flavored with banana juice or some such..

Like most everyone else said, peck, peck, peck!

Dean

 

[ieezitin]

Rob.

Your advice from the forum is good.

Peck drilling is plunge the drill and let off extract clean the drill bit then do the same thing again its repetitive, your pecking like a chicken on the ground. This method more than likely will achieve a parallel hole but its not 100%.

Believe it or not there are hand tools to hold small drills to peck drill and obtain a perfect parallel hole in work pieces, watch and clock makers use this trick.

People explain to people when you mention terms what they mean. I bet this guy is tearing his hair out on drilling small holes.

Anthony.

 

[Ned Ludd]

Hi Rob,
If it happens again, you can dissolve drills in a mild Nitric acid solution. It will not harm the Alloy or Brass (but will harm Steel), but after a few hours the drill will be just a black cruddy mess, that can be washed away under running water.
If you wonder were to get the acid, it is a main constituent of cartridge case cleaner.
Ned

 

[stevehuckss396]

A good quality drill bit would go along way also. The bits in the $20 index are more trouble than they are worth. Try a good quality HSS bit. They are razor sharp when new and cut a very clean hole in aluminum.

 

[robwilk]

thanks for all your input just goes to show what this forum is about .

 

[tel]

Yep, for a 1/16" drill in ali crank 'er up to at least the 1750 step, plenty of kero/WD40 and peck, peck, peck, as has been said above.

 

[robwilk]

just been in the garage turned the speed up on the drill and peck drilled. It worked a treat thanks men....... :bow:
Rob...................