Drilling straight

If you have a mill I would forget about marking out and punching the holes.

Either locate the edge/end of the 6x6 bar and then use the handwheels or DRO to position the spindle where you want the hole and then make a dimple with a spot drill before changing to a good quality twist drill. If all holes are in the same position in 56 bits of brass add some stops so you only need to workout the position once.

Or locate your hole as above and just go straight at it with a split point stub drill, again good quaility such as Dormer A022 series.

Run your mill at it's top speed

Things to consider that may not have been explicitly mentioned:

1. Are the head/quill of your mill and bench drill plumb to the table and/or vice, both before and during drilling?

2. Are you resting the material to be drilled on parallels in the vice[s]? If not, how are you ensuring it is level?

3. Are the three sides of the material in contact with the vice truly square?

4. Are the vices holding the material firmly so that it can't move during drilling?

Things others have mentioned and I will too:

5. Make sure your drill is ground properly from new. Best way of ensuring this if you can't tell is never to buy cheap drills. A Dormer A120 would be my choice. A 2.5mm one I've got has flawlessly drilled hundreds of through holes in brass. For drilling brass I don't find it necessary to take the sharp edge off the lips when the drill is below 1/8" diameter. However, the bigger the drill is the more vital it is if you're going to be through-drilling brass with them.

6. Spot drill first even if the 2.5mm twist drill is a split point.

Thanks to all who provided help with my problem I'm going through all of your suggestions .couldn't believe how much response I got, amazing

If you do that, minimise protrusion as others have said, feed *very* gently at the start and loiter as the point cuts its initial location in the surface - gives the best chance for a true start and straight follow-through. Can save faffing with centre- or spot-drills.

If you are using a mill, then check if the mill quill is square to the table. You can do this by placing an indicator in the chuck and measure a square object. A 1,2,3 block or an angle block. Measure on both sides (X and Y).

edit: Checkout this video: https://www.youtube.com/watch?v=asmH4HjZLRY

Edited By Huub on 08/11/2022 22:45:58

Edited By Huub on 08/11/2022 22:48:12

I drill down to 0.3mm and although it’s a pain I always drill brass with a doctored drill for brass because when it bites it can pull the drill bit to the side it bites, I have a separate set for brass.

Dell