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Never tried it, but how about a radio arm saw with a drill chuck on it-- I would use a spade bit. Place the wood on the table, with the motor turned to point the bit forward, and slide the slide. Just a concept.
Or even a motor with a drill chuck mounted on it (grizz has them). This would be mounted on the table of a table saw at the appropriate height so that a crosscut sled could be used to slide the wood into the bit. Also, just a concept.
I'd probably drill each piece before laminating and use something to align the holes during glue up.
Got a lathe? I attended a recent demo where the demo'er advocating drilling long holes (for things like lamps) using a spade bit where the spade profile had been ground to more of a pointed oval shape. His claim--I have not tested--is that given the forces on the drill bit from wood that is moving faster/slower relative to the drill bit because of the rotation of the lathe, that the bit is naturally self-guiding to the center.
+1.Quote:
Ship auger bits are made for this type of work
A good brace and one makes short work of the job.
I suppose a .50/90 Sharps or Ballard would work too ;).
Dock builders drill accurate 1/2" holes through 15" pilings all day long. They use templates and jigs. Among a number of good methods, I would add the use of a high torque 7amp slow speed drill like the MILWAUKEE MODEL NO. 3002-1 (you can probably rent). I borrowed this drill from a neighbor to drill 45 degree blind cross corner holes through building support timbers to pull my hurricane damaged shop together with stainless rod. The 3003-1 drill right angle gear can be removed to allow for straight slow speed drilling. Trick is using a laser pointer attached to the drill (easy to make a bracket). I used an old Harbor Freight mini laser level (model 90725, now outdated, which I still use for various projects and would recommend). Trick is to carefully align everything and set up an accurate laser target BEHIND the drill. In other words, the laser points backwards from drilling direction. It points to an an accurate target. With a powerful drill and proper bits, you can shoot very accurate holes in large timbers. I can dig for pictures if anyone is interested.
This sounds like a great idea. Some big drills even have a threaded hole on the end which would be perfect for this.Quote:
Originally Posted by Patrick Grady
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I would cut the piece in half. Run one of the pieces over the table saw with the blade raised 1/8". Glue them back together. Drill using the blade score as a pilot hole.
I second Eric's suggestion. If it is not already glued up, laminate together pieces that you can drill perpendicularly with your drill press. Then use a 1/2" diameter steel rod to align the subcomponents together in the complete glue up. Drive the rod out after the glue dries.Quote:
Originally Posted by Eric DeSilva
On some long bits the spiraling ends anywhere from 4-6" from the tip. These bits are not designed to drill through solid wood. As soon as the last spiral enters the wood there's no way for the chips to clear so the bit binds, bogs & burns. Plus it will wander all over the place. Hence the recommendation for an auger style bit so there is plenty of room for the chips to clear. Clearing chips out of a 15" deep hole there's a lot of friction along the sides of the hole. I'd split & rout a channel as suggested.
As others have stated, a jig makes this task easy.
Drill a ¼" pilot hole from both sides to establish a path for your ½" bit. I’ve made jigs like this to accurately align the holes. Use your drill press to make the ¼" holes in the jig. The 1/4" thick flat bar maintains proper alignment.
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