Drilling 20-25mm holes into box section

[Dbzrocks]

Hi just wondering what’s the best process for drilling 20-30mm holes into box section. I want them all to line up 2 inch apart. I did this awhile ago with a magnet drill and rotabroach and took quite awhile. Can’t you get the same ends that you use on a mag drill that fit into a pillar drill? I’m guessing it would save having to constantly move the mag drill to the piece all the time and save time? Any ideas?

Thank you guys

 

[steve t]

Yes you can get a morse taper adaptor someone will be along shortly to give you the proper name of it or a link

 

[Rrobson]

Morse taper to Weldon arbour.

However the easiest option is to get a supplier to laser cut it for you. That way they’ll be perfectly aligned and exactly spaced in whatever size you require.

 

[zzr1200]

Get an adaptor.

Drill/Broach the first hole then make up a jig with a location pin, move the fist hole to a distance location pin, drill second hole > repeat.......

 

[Agroshield]

Morse taper to Weldon arbour.

These are relatively expensive for what they are. A possible alternative is a Morse shank ER32 collet chuck and a single 19mm collet.

 

[Agroshield]

...make up a jig with a location pin, move the fist hole to a distance location pin, drill second hole

Depending on the number of holes (e.g. if you had 50 in a row to do), it would be wise to manually measure every ten to reset the jig. If there is any initial error, it will be multiplied by 50 if you start at one end and keep going.

 

[TEO]

The carbide hole saws work well in a drill press, I bought a cheap selection from Ali express & haven't regretted it, this one's been chewing through 8mm no probs.

sorry about the image quality, smashed the camera lens on the phone

 

[Dbzrocks]

The carbide hole saws work well in a drill press, I bought a cheap selection from Ali express & haven't regretted it, this one's been chewing through 8mm no probs.View attachment 522208 sorry about the image quality, smashed the camera lens on the phoneView attachment 522209

Do these last quite awhile?

 

[Pete.]

Hard to drill inch holes faster than a TC rotabroach bit with spring ejector. Unless you have heavy equipment that is.

 

[TEO]

Do these last quite awhile?

Difficult to quantify that but I they seem to & they're so cheap that I might buy doubles of the most used sizes. I'm sure the rotabroach ones are excellent but not having a mag drill I didn't even bother looking. These have a shaft that fits in a Jacobs chuck so I've been able to put them in the hand held drill when necessary.
I've been trying to work out when I bought them & thinking back I realise that yes they have lasted really well, they've been absolutely indispensable and I think they averaged out at about a fiver each... total bargain.

 

[Turbo]

To use a rotabroach cutter you need a drill that has a low enough speed to suit the cutter. Plus a strong enough motor to drive it.
This will rule out most hobby drills.

You can grip a cutter in a 3/4" jacobs chuck but they can spin if you push too hard.

I have tried those cheap carbide hole saw cutters and they were rubbish. The teeth keep falling out, often jamming in the cut. Maybe ok for soft metals but on steel they were useless.

 

[Pete.]

My rota broach micro will drill 25mm holes all day long with a TC cutter. The cheap ones might be rubbish but a proper one will do hundreds of holes on a single cutter.

 

[8ob]

Hi just wondering what’s the best process for drilling 20-30mm holes into box section. I want them all to line up 2 inch apart. I did this awhile ago with a magnet drill and rotabroach and took quite awhile. Can’t you get the same ends that you use on a mag drill that fit into a pillar drill? I’m guessing it would save having to constantly move the mag drill to the piece all the time and save time? Any ideas?

Thank you guys

You could make up a simple jig whereby the mag drill stays put and you pass the box section under it, two holes in the top, one for the broach and one for a locating pin, use the locating pin to set up the broach for the next hole. Should come out spot on without having to think about it, Just thoughts.

Bob

 

[zzr1200]

You could make up a simple jig whereby the mag drill stays put and you pass the box section under it, two holes in the top, one for the broach and one for a locating pin, use the locating pin to set up the broach for the next hole. Should come out spot on without having to think about it, Just thoughts.

Bob

You just have to workout how to build your jig to do the job, with your available tools.

Me, I'd turn up a location pin, "T" slot mount it to the mills bed then fix a guide fence, broach/move/broach, but I do have a mill and I'd used a piece of plywood as a table protector...

For the OP:-

A bit of 12mm plate, a bit of 20/30 bar with center hole just over hole depth, a piece of angle iron, and a mag drill.

Yellow angle iron, red pin locating pin, Green next/new hole black mag drill and blue plate......

Drill first hole in position, put box on pin, re-position mag drill, then drill hole/move box/drill again/repeat....sorted.

.............................................................................................................................

And as a NOTE to those pedantic members here, this jig is designed for those special Banana shaped box sections, that turn up every so often.....................

 

[Pete.]

Cone shaped pin on an old door hinge