boring machine not boring

[son reech]

i tried using my boring machine for the first time today, and it did not work very well.  i scored a 1.5" bit on ebay and it arrived today.  didn't look too sharp, but i stuck it in the chuck and attempted to bore a hole through a wrc 4x6.  it went in as deep as the screw threads, and then just started turning, not boring in.  what's going on here?  is the bit not sharp enough, or is there something i'm not doing right?

[Furby]

Was it a corse thread tip?
If it's fine thread, it's for hardwoods.

[beenthere]

   If it didn't look too sharp, then it probably wasn't sharp. Needs to be sharp to cut wood, just like a chisel, or a saw tooth, or a chain saw tooth, or a planer/jointer knife blade, or a knife. Otherwise, the cutting edge won't cut and when it won't cut, no threaded tip will pull it into the wood.
Hope that isn't too blunt. Don't mean to offend you, but gotta be sharp. And error on the side of too sharp, if that's possible.

[Raphael]

Be sure you sharpen only the top surfaces of the cutters and inside faces of the spurs, safety files work best.
The other surfaces will lap themselves smooth (if they aren't already) from friction on the wood.

[Loghead]

If you had a dull bit point is there a way to resharpen??

[Raphael]

Lead screws can be reshaped (carefully) with a feather file.  Finding a file fine enough for a hardwood lead screw can be a challenge, I got a couple of diamond grit feathers from a jewelers supply catalog.

[Jim_Rogers]

Also, you need to look at the piece of wood your trying to bore a hole into. If you run into a hidden defect such as a knot that come in from the side through the area where the bit tip stopped its forward or downward movement then this is because the lead screw tip threads got filled up with knot sawdust.
You'll have to remove the bit from the hole and clean out the threads from any knot dust, and then try again.
But this time have someone else take a small piece of say strapping and lean on the top end of the carriage to give you some extra down pressure as you turn the bit.
With a properly sharpened bit and some extra down pressure the wings of the bit and the cutting surfaces of the bit should cut through the knot and once that happens then the lead screw's threads should re-engage the regular wood and continue cutting, and moving downward.

Also, remember to make a through mortise you bore in half way from each side.

If the bit lead screw tip breaks through the unside's surface it has no wood there to help pull the bit an it will stop downward motion. And it could blow out the bottom face, larger then what you want, so don't try and bore a hole all the way through from one side.

As mentioned carefully sharpen the bit.....

Jim Rogers

[Stumpkin]

Sharpening drill bits can be tricky, I would recommend the book "The Complete Guide to Sharpening" by Lenard Lee.  There is a whole chapter on sharpening drill bits. Tom

[Tony_T]

What I've done to prevent blow through when boring a through mortise is to put some deep scores about the edges of the mortise opposite side with a chisel.  Granted this does not help with the fact that the lead screw will break through and no longer pull, but does prevent the ugly break through of the whole bit.  I've done this mainly as a time saver to avoid having to flip the beam.

P.S. I'm still envious of those with the boring machines, I'm still using a hand brace.........

P.P.S. The hand brace keeps my arms in shape for the ice auger I use for boring holes for ice fishing 

[Dave Shepard]

I would look to see if anyone has sharpened the outside of the bit, this will make the bored hole smaller than the diameter of the bit and it will bind up. I have run across a couple of bits that were ruined this way. Good luck.


Dave

[son reech]

of course, i realize that cutting tools need to be sharp to do the job they are designed to do.  the bit appeared to be "not too sharp," but not so dull that it wouldn't work at all.  the outside edges look good, so i'm not concerned with the diameter being off.  i contemplated using some downward pressure to get the bit going, but didn't have someone to help me at the time.  i figured i should file the top of the cutters and the inside edges, but was hesitant to take the file to the bit as i am inexperienced in filing bits.  this bit looks like it is old and has not been in service in quite some time.  i feel lucky to have found one of the "elusive" 1.5" bits and want to restore it to proper working order.  thanks for the advice.....