drilling rows of holes

[fizzy]

I need to drill lots of 6.5mm holes in lengths of 50x50 angle iron 6mm thick. Or better 1/4" holes in 2x2 - why do we use metric sigh.

Anyway I have a drill press but the obvious choice my milling machine isnt set up yet.

I need to drill 24 holes with 2" spacing in each piece. Bit like an oversized piece of meccano!

What is the easiest way to do this accurately? Once I have 1 I can use it as a jig for the others I assume?

Do I have to do a lot of tedious marking and measuring or is there an easier way?

I saw on the net a neat riveting guide like a fan that opens up for accurate hole drilling. Are they available in the UK?

 

[ukracer]

use your drill press. set up a jig that the angle will just slide along and then mark of each 2 inches. once you do this once you can use a couple of g clamps to hold the angle with the holes on top of the other piece and so on.

 

[fizzy]

That is what I was thinking - just being lazy wondering if there was an easier way?

Also do I need to centre punch or can I just use a pilot point drill? I bought some nice ones the other day - are they accurate enough?

 

[Digger6135]

Or use a small length of bar with a 1/4" peg in one end and a 1/4" hole 2" away, put the peg in the first hole drilled then step it along, using the hole as a drilling guide.

Many ways to skin a cat!

 

[DanielW]

Hah! I did this once a few years ago,didn't want all that marking out so.......

I bought two lasers and affixed them to the vice on me drill press 1.5" appart,marked out where the first hole to be drilled on the flat bar,lined it up with the right laser and drilled hole,pushed the bar through till the left laser aligned with that hole and then drilled the hole on the right aligned laser,it was just a matter of pushing and aligning with the lasers and holes sobasically I ended upi with even spaced holes at 1.5" apart bearing in mind I did lock the bar on each drilling of hole so it would not be out..

You might get the idea?

 

[gordon stephenson]

X2 with Digger6135,Thats the way I would do it, What accuracy are you looking for on the hole ctrs?

 

[DanielW]

Or use a small length of bar with a 1/4" peg in one end and a 1/4" hole 2" away, put the peg in the first hole drilled then step it along, using the hole as a drilling guide.

Many ways to skin a cat!

This is a better way by far.

You could even get a piece of bar the same as what you're drilling,drill 5 or 6 holes 2" apart then peg and drill 5 holes with just a push of the bar until you need to peg again on the last drilled hole.

cor wished I'd have thought about this one,not often I'm stumped for thought.

 

[optima21]

by the time you've messed about making jigs etc, its as easy just to mark it out on the angle, depending on how accurate you need the holes to be. once you have drilled one length you can then clamp that to the other lengths and use it as a drilling guide

 

[rtbcomp]

by the time you've messed about making jigs etc, its as easy just to mark it out on the angle, depending on how accurate you need the holes to be. once you have drilled one length you can then clamp that to the other lengths and use it as a drilling guide

If you're doing more than one length use the original as the guide each time, otherwise you could get a cumulative error in subsequent pieces.

 

[Paul G]

Firstly, in the time it takes to write a post on here, and then check for replies and evaluate the suggestions,
make any jig that you think could be a time saver……………………………………………………………………………………..,
you could have marked it out in the first place.

Secondly, moving along from one point to the next just multiplies the errors.
Far better to use a rule and mark off each point without moving the rule. That way your 24th hole, at 2 inch centres,
will be 46 inches from the 1st, give or take the thickness of a scriber line.


Cheers
Paul G

p.s.
Please note the use of imperial dimensions.
Personally I find them difficult as I went metric in 1971.

p.p.s.
Must type faster.

 

[CRB]

Or use a small length of bar with a 1/4" peg in one end and a 1/4" hole 2" away, put the peg in the first hole drilled then step it along, using the hole as a drilling guide.

Many ways to skin a cat!

Beware compound error. 24 holes x 0.1mm error in the jig = 2.4mm error in the last hole.

Marking out individually will be more accurate over the 24 holes. Using dividers, and stepping out the spaces will allow you to adjust the step to fit the overall length.


PPS PaulG I must type even faster.

 

[Kent]

Make a jig, it must fit well and take its reference from one end only and clamp it. I have 1 x16mm and 5x 12mm clearance holes to drill in 12x50 bar shortly as an 89 off myself.
If it was a regular job gang drilling might be an option (line up drills to work together)

 

[monkeymark]

http://pages.ebay.com/link/?nav=item.view&id=121357063410&alt=web

 

[Wedg1e]

What I usually do if I'm making something out of plate and it's within the size of an A3 sheet of paper is to draw it in AutoCAD, print out at 1:1 scale, tape the paper to the plate then centrepunch the hole centres through the drawing.
Probably not much help here, just thought I'd share

 

[Wedg1e]

Anyway I have a drill press but the obvious choice my milling machine isnt set up yet.

I need to drill 24 holes with 2" spacing in each piece. Bit like an oversized piece of meccano!

To be fair it'd have to be a large mill to have 48" of table traverse...

 

[fizzy]

It is pretty big - weighs 4 tons! 56" table movement. Trouble is it is up on rollers to be moved and not wired in yet.

 

[Bill Edwards]

24 holes really isn't that much work when you knuckle down and just crack on.
Rather than make a JIG for the one job which will either be a lot of work or not very accurate (anything that works off the last hole is a recipe for error by the time you're near the end) I'd grab a tape measure and scriber. Not too hard with it left to measure from the end each time you can't go far wrong.

 

[ukracer]

24 holes really isn't that much work when you knuckle down and just crack on.
Rather than make a JIG for the one job which will either be a lot of work or not very accurate (anything that works off the last hole is a recipe for error by the time you're near the end) I'd grab a tape measure and scriber. Not too hard with it left to measure from the end each time you can't go far wrong.

Thats why I marked mine out with a rule and scribed a line. I then used a sliding jig (jig being two parallel pieces of steel the angle would push through/along) Mine did not need accuracy but if it did need it I would have used a sharpie in the drill chuck as I pushed the angle along it. Then center punched the required points.

I still think a single pattern with holes between centers, (not flat bar though) so the first hole had a pin through it and the drill press used to align the hole, the angle would move with the pattern as it was positioned , would be a quick way to do a lot of holes.

The only error would be if there was any in the jig/pattern as long as the resultant hole was used to peg the pattern.

 

[MattF]

Like others have mentioned, less time just to measure and mark for a one off. With stuff like this, I always tend to approach it from the point of whether it's just going to be one or two needed or whether it's something you'll be doing quite a few of. If it's just a handful, measure and mark. If you're going to be doing quite a few, either soon or over the space of time, then make a jig or device to help. Making a jig for a one off is usually a waste of time though, and you end up with something floating around the shed which you probably won't even remember why you made it, a year or two from now.

 

[waddycall]

What I usually do if I'm making something out of plate and it's within the size of an A3 sheet of paper is to draw it in AutoCAD, print out at 1:1 scale, tape the paper to the plate then centrepunch the hole centres through the drawing.
Probably not much help here, just thought I'd share

You need to be careful doing that. I nearly came unstuck when I was about to bandsaw a piece of teak with a cad drawing stuck to the top. Thought I'd best double check to make sure it measured up right before cutting and it was a couple of mm out. I'm not sure printers are that great at printing 1:1 unless they're a proper CAD plotter