Drilling lots of big (ish) holes
liam.mccaffrey - 7/8/12 at 12:57 PM
I have a project coming up where I need to drill about 200 1" holes in various 4"x4"x1/8" square hollow sections.
The way I see it I have a couple of options.
1. Rent a mag drill and rotabroach them
2. Pilot Drill and increase drill sizes to 1"!!! (Don't fancy this to be honest though I do have 1/2" shank drills right up to
1"
3. Pilot drill and step drill to 1".
4. Farm it out.
5. Make a circle jig and do it with the plasma cutter.
I have time to burn on this project but little money. I have a medium sized pillar drill which I could set up with a jig to roll the sections
through. Plus a big hand drill and plasma cutter.
Any thoughts, tending towards the plasma to be honest
TAZZMAXX - 7/8/12 at 01:22 PM
I'd mag drill them but mainly because I've got one at my disposal. I've always put the kiss of death on plasma cutters and I don't
think you'd get very satisfactory results with it. Might end up with a load of heat distortion as well? If you're not bothered about
appearance or distortion then the plasma cutter is the way to go, for speed.
Staple balls - 7/8/12 at 01:55 PM
Suppose it comes down to how tidy the holes need to be, and how you value your time.
mcerd1 - 7/8/12 at 02:17 PM
unless you know somewhere local that could do it for you cheap, I'd go for the mag drill out of those options
if it were me I'd get it done at my work, we've got exactly the right tool - a CNC 16m drill-line 
(it even writes the part marks on and
cuts them to length aswell)
(could get you a price if you drop us a u2u - but I thing the delivery cost would be a killer 
)
[Edited on 7/8/2012 by mcerd1]
loggyboy - 7/8/12 at 02:34 PM
Holesaw?
http://www.toolstation.com/shop/Power+Tool+Accessories/Holesaws/Electricians+Holesaw+Kit+9+Piece/d80/sd1530/p41247
http://www.toolstation.com/shop/Power+Tool+Accessories/Holesaws/Progressor+Holesaw+25mm/d80/sd1530/p30593
http://www.toolstation.com/shop/Power+Tool+Accessories/Holesaws/Bi+Metal+Holesaw+25mm/d80/sd1530/p56846
coozer - 7/8/12 at 02:39 PM
Two hand drills and the pillar drill.
Pilot hole (5mm ish) in first hand drill,
1/2" in second hand drill,
1" finisher in the piller drill.
Obviously best way would be 3 pillar drills if you can get your hand on them.
Some kinda coolant recircular on the last drill as well.
Or, some kinda punch set up...
[Edited on 7/8/12 by coozer]
ashg - 7/8/12 at 02:43 PM
Farm it out to a laser cutter.
daviep - 7/8/12 at 02:52 PM
Bearing in mind that it's just over 3mm thick I'd go for a good centre dab followed by a 10mm "pilot" and then straight in to the
1" drill with a cuple of drops of cutting lubricant such as rocol RTD. I would ony do it this way if your pillar drill has a slow enough speed
and you can sharpen a drill.
I would do all the pilots in the pillar drill before changing to do the full size, a drill which goes straight in to the taper would be better than a
reduced shank drill..
Cheers
Davie
ReMan - 7/8/12 at 03:52 PM
quote:
Originally posted by loggyboy
Holesaw?
http://www.toolstation.com/shop/Power+Tool+Accessories/Holesaws/Electricians+Holesaw+Kit+9+Piece/d80/sd1530/p41247
http://www.toolstation.com/shop/Power+Tool+Accessories/Holesaws/Progressor+Holesaw+25mm/d80/sd1530/p30593
http://www.toolstation.com/shop/Power+Tool+Accessories/Holesaws/Bi+Metal+Holesaw+25mm/d80/sd1530/p56846
IMHO they are worse than useless for anything harder than ally?
1 hole maybe if i had a lot of time
paulf - 7/8/12 at 03:56 PM
If you used good quality hole saws then that may be the easiest way as long as a coolant supply could be rigged up , the cheap ones are no good at all
though.
If drilling with a 1 inch drill then a good pillar drill with a geared head would be needed or it would tend to just snatch and jam the drill unless
going very slowly.
Paul
loggyboy - 7/8/12 at 03:57 PM
quote:
Originally posted by ReMan
IMHO they are worse than useless for anything harder than ally?
1 hole maybe if i had a lot of time
Used the cheap multi set to open up some holes in my prop brace with no problems, and went on to use them to make up a basic tube notcher, thru some
3.5mm thick tube they did the job nicely, lost one or two teeth, but only beacuse the home made tube notcher id set up kept jumping.
fixed in a good pillar drill, with lube I think you could do 200 holes on and expect to blunt only 2-3 of them, which at a few pound each isnt bad
going. Buy the slightly more expensive bosch cobalt jobs and would likely last the duration.
ReMan - 7/8/12 at 04:26 PM
I wonder if its because I've only ever had to use them face on against a flat surface?
Your pic looks like it would stand a better chance of actually cutting...
gazza285 - 7/8/12 at 06:00 PM
Buy a second hand mag drill, drill the holes, sell the mag drill on.
I bought one for £180, use it for 12 months then sold it for £220.
Wadders - 7/8/12 at 11:35 PM
Not sure if they are available to buy, but what about a rotabroach arbor to fit in your pillar drill.
Al.
NS Dev - 10/8/12 at 11:10 PM
I'd buy or rent a mag drill, long time since i did so can't remember what the hire was but it wasn't a lot