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View Logan Craig's profile

How do I drill a VERY precise hole?

by Logan Craig
posted 12-04-2011 01:18 AM


17 replies so far

View Logan Craig's profile

Logan Craig

35 posts in 1250 days


#1 posted 12-04-2011 01:33 AM

Thanks WudnHevn, I did try that, but found the next size up was chewing into the hole somewhat randomly and not following the guide hole as well as I’d have liked. Maybe I should take smaller steps though. I’ll try again tomorrow taking more (smaller) steps.

-- Logan, Virginia

View ajosephg's profile

ajosephg

1860 posts in 2305 days


#2 posted 12-04-2011 01:55 AM

Brad point drill should work. You might need to drill a smaller pilot hole to start with. – http://www.amazon.com/Timberline-606-154-Brad-Point-Drill/dp/B000P4OQYW

-- Joe

View KayBee's profile

KayBee

1020 posts in 1990 days


#3 posted 12-04-2011 01:57 AM

You might try a center punch. Then you can put the center spur into the dimple, so less likely to skate. This is the same way you start drilling a hole in metal, but it works in wood too. Especially good in end grain and really hard woods. If you don’t have a center punch, give an awl or small phillips screwdriver a good whack.

-- Karen - a little bit of stupid goes a long way

View jim C's profile

jim C

1455 posts in 1842 days


#4 posted 12-04-2011 02:04 AM

Logan,
The 31/64th’s drill is probably a good choice for the 12MM barrel hinges, as it gives you a .004 clearance fit.
I would suggest starting out by carefully center punching a mark on your layout lines and drilling a 3/16 or 1/4 inch hole with a brad point drill. Hold the wood loosely so the drill can find and “center” itself on the center punch.
Next, follow with a 3/8th regular drill, and then follow with a 7/16th regular drill. Finally with the 31/64th’s drill.
BE CAREFUL. The drill will want to grab when “drill-reaming” to larger sizes, so make sure you are blocking the workpiece against the drill-press column and be aware of the workpiece trying to climb the drill. This can be dangerous.
Obviously the best way to ensure location and hole size would be to drill the holes in a mill with x-y table movement with the piece clamped down. Then it’s a piece of cake.
Make sure your drills are sharpened to even sides, as a drill with unequal sides (point off center) will cause location problems.
Hope this helps.

-- When I was a boy, I was told "anyone can be President", now I'm beginning to believe it!

View jim C's profile

jim C

1455 posts in 1842 days


#5 posted 12-04-2011 02:13 AM

Or to solve your problem and save a lot of hassle:
http://www.amazon.com/CMT-537-120-31-12mm-Forstner-Bit/dp/B000P4HLEY

By the way, make sure the drill press table is as close to being perpendicular as possible to the quill. Indicate if possible.

-- When I was a boy, I was told "anyone can be President", now I'm beginning to believe it!

View Dallas's profile

Dallas

3167 posts in 1231 days


#6 posted 12-04-2011 02:14 AM

Why not use a Transfer Punch to set the exact center of the place you want the hole to be?

http://www.harborfreight.com/28-piece-transfer-punch-set-3577.html

-- Improvise.... Adapt...... Overcome!

View John's profile

John

15 posts in 1887 days


#7 posted 12-04-2011 02:16 AM

The recommended bit size for the 12mm barrel hinge is 12mm or 15/32”.

You can purchase individual drill bits (Brad Point/Forstner) in those sizes from Lee Valley.

View Don W's profile

Don W

15516 posts in 1311 days


#8 posted 12-04-2011 03:26 AM

I’m with Joe with the brad point bits.

-- Master hand plane hoarder. - http://timetestedtools.com

View PurpLev's profile

PurpLev

8476 posts in 2392 days


#9 posted 12-04-2011 03:58 AM

center punch the hole first then use a brad point bit centered on the dimple left from the punch. make sure you work part is clamped securely to the DP table/fence.

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View HorizontalMike's profile

HorizontalMike

6967 posts in 1658 days


#10 posted 12-04-2011 04:08 AM

If you do not have a center punch to start with and have to start with a smaller bit, then make sure that that bit is SMALLER than any brad point you are thinking of using after starting the hole. The last thing you want is to NOT have any meat for the brad point to guide from. If you have eliminate all of the material around the brad point it won’t center properly.

-- HorizontalMike -- "Woodpeckers understand..."

View rance's profile

rance

4147 posts in 1904 days


#11 posted 12-04-2011 04:12 AM

The older I get, the more I realize it is nice when I can use the right tool for the job. Look up “Vix Bits”. They are self centering and are made for drilling holes for hinges etc.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View rimfire7891's profile

rimfire7891

123 posts in 1646 days


#12 posted 12-04-2011 05:35 AM

Hi LC,

Most of the above suggestions will work fine if you are working with steel or other metals. However with wood if you use a guide of some sort to “guide” the drill to where you want the hole. You can use a piece of maple to make a guide or if you have lots of holes then a piece of steel would work best as you won’t wear the guide out as quickly. Maple drills well with sharp tools and the bit doesn’t have tendency to follow the grain.

To make a wood guide drill the holes first at the linear spacing you want between the two hinges and then glue a strip of wood along side of the holes to act like a fence to position the guide on the side of the box. Much easier to sneak up with fence to the holes than drill the holes in the right position in relation to the fence. You could incorporate stops on one end of you guide block so you holes are positioned where you want them in relation to the end of the box. Clamp your guide to your box and drill the holes with a brad point the correct size. You can make you own brad point drill from a regular twist drill, use a disc grinder with 1/16 thick cutoff disc and copy the pattern from larger store bought brad point. A deft hand helps, if you screw-up cut the sore end of the drill and start again, HSS twist drills are cheap. Clamp the drill bit in a vice and shape the business end until you happy with the outcome.
Drill the holes in you jig on your drill press and use a hand power drill to drill there holes in your box. Higher speed work better for smaller drill bits. A stop on the drill helps get the depth right. You will know when you have the right speed, too fast and you will likely get smoke.
Using a guide jig means you don’t have to centre punch the hole which is only modestly successful in wood. If you add a fence to both sides of your jig you can use it to drill both the top and bottom portion of your box. That way the spacing will be exact and lined up with the two edges you use as datum.

Hope this helps.

Thanks jb

-- Playing with wood and metal for the last 50 years, driving and building Land Cruisers for the last 40. Experience is what you get when you don't know what you are doing.

View David Kirtley's profile

David Kirtley

1285 posts in 1741 days


#13 posted 12-04-2011 05:32 PM

The one thing that I have learned with since I started working with metal is to always use a center drill. If you are not familiar with them:

These short stubby drills will not deflect. Then once you have the hole spotted, follow up with a regular bit.

Since you are drilling wood, I really wouldn’t suggest the drilling up in steps. The guide mentioned by JB is a better way. The reason is that the wood is soft enough that you can cut to the side with drill bits (just not dependably.) Go ahead and go for the full size because it is less likely to deflect. Thicker bits don’t bend like thin ones.

Clamp well and hold everything stable.

-- Woodworking shouldn't cost a fortune: http://lowbudgetwoodworker.blogspot.com/

View Logan Craig's profile

Logan Craig

35 posts in 1250 days


#14 posted 12-05-2011 07:14 PM

Thanks for all the help. I found a nice set of brad point bits at the Harbor Freight outlet and got the holes perfect on my first try. I’ll still be keeping an eye out for a good 16th inch increment forstner bit set.

I posted the completed box in projects.

thanks
Logan

-- Logan, Virginia

View rance's profile

rance

4147 posts in 1904 days


#15 posted 12-09-2011 06:07 PM

On sale at Rockler with free shipping:

3-Pc. Self-Centering Bit Set #4, #6, #8

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View rance's profile

rance

4147 posts in 1904 days


#16 posted 12-09-2011 06:38 PM

Actually, they are SOSS, but yeah. These bits sure come in handy for all kinds of hinges with counter sunk holes for the screws. Hey WudnHevn, welcome to LJ and thanks for your input.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View MrRon's profile

MrRon

2970 posts in 1987 days


#17 posted 12-09-2011 07:58 PM

Whenever I need a hole to be perfectly located, I make a jig from metal or a hardwood and drill a hole for a drill bushing (see http://www.mcmaster.com/#drill-jig-bushing-liners/=fafwac). The drill bushing keeps the drill bit from wandering; the jig is made to straddle the wood I want to drill into. It may take you an hour to make, but it will be a time saver later if you are repeating hinge installations not to mention eliminating the possibility of damaged wood due to holes not being where they should be.

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