Round or Hex Shank Forstner bits

[Cr23484]

Hi everyone,
I need to drill some 1 1/2” blind and through holes in maple ( fresh logs )
I am using a Delta 14” drill press and it is working, but unless I pull up every or every other slow plunge to clear any chips, the bit SLIPS.
These are round shank , bits.
Hickory, steel not carbide.
Any advice on which bits and type of shank would be appreciated.
Drill press has a 5/8” chuck and set to the lowest speed at 215 rpm , chart recommends 250 rpm.
Thanks J
I hope the pic shows up.

 

[benmychree]

Par for the course with wet wood.

 

[Bluedog]

Milwaukee 48-25-1501
Still not going to be fun with green wood.

 

[dirty tools]

Slow and easy
wet wood bites the drill bits and the particals want to stick, you might want to blow the chips out as well go

 

[Flyinfool]

Hex shank gives a MUCH better grip.
even with the round shank sometimes if after just a bit of cutting you will be able tighten the chuck just a little more.
I have found that the vibrations can loosen a chuck slightly. Especially when you are starting with an interrupted cut.

I have converted some of my drill shanks to 3 flats by using a 5C collet in a hex collet holder on the surface grinder. In a pinch I have added 3 flats on the bench grinder.

 

[Cr23484]

Thank you
I am not in any hurry, I will probably rip the logs on my bandsaw to make 1 1/2” - 2” thick boards, So I won’t have to deal with drilling thru 5-6 inches of green maple.
On the plus side, it is all spalted maple.
J

 

[whitmore]

Hi everyone,
I need to drill some 1 1/2” blind and through holes in maple ( fresh logs )
I am using a Delta 14” drill press and it is working, but unless I pull up every or every other slow plunge to clear any chips, the bit SLIPS.

I've done a few logs for planting fungus (plug the holes and grow tasty shrooms).
The Forstner will make a square-bottom hole, but it takes a lot of chip-clearing and friction
is higher than a twist drill.
Brad point twist drills, in smaller sizes, work.
For big diameters, I'd recommend a ship auger (twist drill without a pilot screw) for unseasoned logs; dead
slow is a good speed for the job. There are (for shallow holes) some short bits for renovation work,
that would also muscle through a tough log, that have hex shanks and would clear the waste a little
better than a Forstner, like these:
Irwin Speedbor Max

 

[Martin W]

Instead of using a forstner bit, could you make a jig and use a router with a 1/2" pattern bit with a bearing. Just drill a hole in a larger piece of plywood the correct size and clamp this to your 2"boards
Cheers
Martin

 

[projectnut]

Hex shank gives a MUCH better grip.
even with the round shank sometimes if after just a bit of cutting you will be able tighten the chuck just a little more.
I have found that the vibrations can loosen a chuck slightly. Especially when you are starting with an interrupted cut.

I have converted some of my drill shanks to 3 flats by using a 5C collet in a hex collet holder on the surface grinder. In a pinch I have added 3 flats on the bench grinder.

The better grip only lasts as long as the hex section remains attached to the rest of the bit. I was doing some deck repair last week. Part of the repairs included new trim boards for the permanently mounted benches. The main body of the benches are treated 12, 2x4's on edge held together with a series of through bolts. The 'bolts" are actually 1/2" threaded rod with nuts and washers on each end.

The trim boards are also treated and have blind holes on the insides do cover the exposed nuts and washers. I started drilling the first holes with a spade bit. The first few went well, but the second board was so wet I swear you could wring the water out of it. The spade bit didn't do nearly as well. The chips were actually more like mud. It didn't take long for the bit to get bound in the goo and break off.

That's when I changed to the Forstner bits. Not only do they do a better job on a bling hole, they also expel the chips better. Rather than getting spread around the perimeter they move to the center and get expelled upward. I still had to stop after a few revolutions to clear the mess, but at least enough was expelled bit the bit to prevent binding and breaking.

For the record I used round shank Diablo Forstner bits made by Freud at about 200 rpm.. I didn't see or feel any slippage in the chuck. On the other hand I'd rather they slip a bit than snap off and go flying across the shop.

 

[Flyinfool]

In 50 years I have never broke a bit in wood. Worn a lot of them out and resharpened a lot of them, but never broke one.