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View Full Version : Augar Bits for Deep Holes?



Mike Goetzke
12-26-2014, 2:15 PM
I need to drill some deep holes for pepper/salt mills. I've seen some suggest augar bits work best but, at least on the bits I have, there is a threaded tip which pulls the bit into the work piece. I take it this is not good for lathe drilling. Do the work if you just file down the threaded tip?

Thanks,

Mike

Don Bunce
12-26-2014, 3:02 PM
Forstner bits will do the job, but if you make a lot of them, you might be interested in this:

https://www.youtube.com/watch?v=L74X67UHX0s

Faust M. Ruggiero
12-26-2014, 6:14 PM
Mill drill works well but you still need a 1" pilot hole the full length of the pepper mill. I have often wondered if the auger would work. I know the threads would have to be ground away. Some sort of cutting edge would have to be ground in place of the threads. If anyone has successfully done this I would also be anxious to try. By the way, Don. Auger bits are expensive. I wondered why until I watched the production on the Science Channel. They are mostly hand made and ground.

Scott Hackler
12-26-2014, 6:48 PM
Don't buy the Harbor Freight forstner bits, spend a little money and get a decent set of bits for mills. I bought mine from Craftsupplies. I don't know what brand the are but they work well and are just another tool that we need for our projects. You will also need a heavy duty extension for the long hole.

Somewhere I remember seeing a video of a fella that has designed a bit the was flat like a paddle bit, that cut the entire mill in one pass and didn't clog. It was expensive, but not if you are doing a mess of mills.

Thom Sturgill
12-26-2014, 8:51 PM
And if you are making really tall mills look into gun drills - a 1" bit runs $180 - $220 depending on length (22"-48") but they drill straight and use air to keep the bore clean. Only worth while if you are doing production or can build the price into a special order, say like a 36" grinder for a restaurant.

David Heathcote
12-26-2014, 9:23 PM
The screw tip on an auger bit is part of the overall design of the tool. It both helps feeding and prevents the bit from "wandering" off course.
Without that, I'd be surprised if the tool could be relied upon to maintain a straight course through the wood, and I can't imagine it could outperform a decent forstner bit either for speed or for accuracy.

A decent forstner with only a 6" extension will handle a 16"-18" tall mill easily by coming in from both ends, which is best practice anyway.

Most folks are going to run out of lathe bed length before they exceed the capabilities of a good forstner with extensions.

Lee Watermann
12-26-2014, 10:52 PM
Brenden Stemp uses a auger bit in deep pepper mill drilling.

Mike Goetzke
12-27-2014, 9:22 AM
The screw tip on an auger bit is part of the overall design of the tool. It both helps feeding and prevents the bit from "wandering" off course.
Without that, I'd be surprised if the tool could be relied upon to maintain a straight course through the wood, and I can't imagine it could outperform a decent forstner bit either for speed or for accuracy.

A decent forstner with only a 6" extension will handle a 16"-18" tall mill easily by coming in from both ends, which is best practice anyway.

Most folks are going to run out of lathe bed length before they exceed the capabilities of a good forstner with extensions.


Thanks for all the suggestions. I didn't realize mills would be a tool vortex in of itself! I saw someone mention using spade bits for the through hole but I noticed my Bosch bit had a screw type tip. I took it to the grinder and was able to duplicate the non- threaded point edge on another bit I had. Then I started thinking the spade may be to flexible. Some time back I received this 1" auger bit for free from Bosch. It also has the screw end but may be trickier to grind it to a point. I will also need an extension for it. So may as suggested go with a Forstner & extension for these two mills and then look into something else if I get hooked on mills.

Thanks

Peter Blair
12-27-2014, 10:38 AM
Years ago as a boatbuilder we often ground the threads of auger bits, usually we made them into pyramids this seemed to work. Our reasoning in those days was the bits we had around were designed to be driven by hand and it was easy to keep up with the threads but as we moved to powered hand drills the bits would drill so quickly that they would bind or spin the drill. This as you can imagine was very dangerous. As I recall it did take a lot more pressure that originally was handled by the threads.

Peter Fabricius
12-27-2014, 10:54 AM
Mike.
The Auger bit you have is fine for doing the through hole. Take your Dremel and grind some of the threads off the tip. When boring the Mill hold the Jacobs Chuck and clear the hole frequently. Drill from both ends and you do not need an extension.
The standard Forstner bits you probably already have are fine for the mills. Use a 1 3/4" bit first then the next smaller size as per the plans. Measure the hardware and if needed upsize the holes to get a snug fit. ( 80 grit gouge or a parting tool makes holes bigger if needed)
If doing the Crush Grind mechanism then put a small 1/4" tenon on the Top to fit down in the body through hole and the two parts will line up much better. 1.5" tenon is good and will allow space for the plastic drive plug to fit into it.
(if the body through hole is 1" then just pre drill the upper body to 1.5" for about 1/2" deep before boring the through hole from the top.)
Making two mills should not cost you a fortune in new tools.
Hope to see your mills soon.
Peter F.

Mike Goetzke
12-27-2014, 11:46 AM
Years ago as a boatbuilder we often ground the threads of auger bits, usually we made them into pyramids this seemed to work. Our reasoning in those days was the bits we had around were designed to be driven by hand and it was easy to keep up with the threads but as we moved to powered hand drills the bits would drill so quickly that they would bind or spin the drill. This as you can imagine was very dangerous. As I recall it did take a lot more pressure that originally was handled by the threads.


Mike.
The Auger bit you have if fine for doing the through hole. Take your Dremel and grind some of the threads off the tip. When boring the Mill hold the Jacobs Chuck and clear the hole frequently. Drill from both ends and you do not need an extension.
The standard Forstner bits you probably already have are fine for the mills. Use a 1 3/4" bit first then the next smaller size as per the plans. Measure the hardware and if needed upsize the holes to get a snug fit. ( 80 grit gouge or a parting tool makes holes bigger if needed)
If doing the Crush Grind mechanism then put a small 1/4" tenon on the Top to fit down in the body through hole and the two parts will line up much better. 1.5" tenon is good and will allow space for the plastic drive plug to fit into it.
(if the body through hole is 1" then just pre drill the upper body to 1.5" for about 1/2" deep before boring the through hole from the top.)
Making two mills should not cost you a fortune in new tools.
Hope to see your mills soon.
Peter F.

I looked up Brendan Stemp and someone had the same question as I about the leadscrew and he said he has never had a problem with the bit pulling suggesting at 500 RPM the threads just strip. So I went and gave it a try on a trial hunk of oak and it cut very well. I didn't really need to pull the bit to eject chips the auger action was very efficient. Only issue I have is (little hard to explain) after the flutes are completely in the hole it can't eject chips. I did get to 4-1/4" w/o much effort. Suppose I could make several small cuts and eject to get to 4-1/2" (my body of the mill will be about 9"). Also, if I bore the crush grind mechanism larger 1-3/4" and 1-1/2" holes before the through hole that will allow my through hole to go much deeper before the flutes are blocked.

Now to find a nice shape and figure best way to turn the blank. I see some chuck the square in the 4-jaw chuck (this is what I did for the example) and others turn between centers and cut tenons. And some shape the top attached to the body while others cut it off at the start.

Mike

David Heathcote
12-27-2014, 12:10 PM
I didn't realize mills would be a tool vortex in of itself! ..... So may as suggested go with a Forstner & extension for these two mills and then look into something else if I get hooked on mills.
Many turners are hopeless tool junkies, and I don't exclude myself. I can drool over a new tool catalog with the best of them.

But the vast majority of turning projects, including peppermills, can be undertaken without sluicing oceans of cash at new widgets first. Then after making a few, if I get the peppermill bug, I'll be in a better position to know what else I might need/want to make the process easier or faster.

Drilling the blanks, even without any special tools, is actually only a smallish part of the overall time investment in making a hand-turned and finished peppermill anyway, so even halving the drilling time doesn't reduce the overall production time by much in terms of percentage.

If you end up addicted to peppermills after making a half-dozen or so, and especially if you end up making them taller than usual (mills in the 8" - 10" height range are by far the best sellers in my own experience, and a 4" mill is almost as much work as an 8" one anyway, so it can't be anywhere close to half the price), then looking into alternative drilling methods might well be worth it.

Be aware that even mills that are extra-tall can be made in sections which are drilled out separately then joined together for the final outside turning. With all the sections parted off from the same piece of wood, and with the careful placement of beads or some other turned decoration, the join lines can be made almost invisible.
Unless one has an unusually long lathe bed, a 36" or longer mill is likely to require that kind of approach anyway, no matter what kind of drillbit is used, and even if one does come in from both ends.

Peter Fabricius
12-27-2014, 5:07 PM
Here is the Mill design I use, designed by my Son. 11" tall, 2 3/8" Diameter. Note the tenon on the Top fits into the through hole.
Peter F.

Clint Merrill
12-27-2014, 8:19 PM
Hey Mike; I share your enthusiasm for making pepper mills and have found good bits are worth much more than the cost in relation to the irritation and frustration of drilling the necessary holes. If you choose to use the Deluxe Mills , sold by Craft Supplies, Packard Woodworks and others, only 2 sizes of bits are necessary and an extension if you wish, these are great working mills bty.

The CMT brand of Forstner bits are very well made and available thru Amazon at very reasonable prices too, as an optional choice, you might check them out.

Best of luck and have fun making them. Clint Merrill

Stan Smith
12-27-2014, 9:53 PM
I realize that there's come controversy about buying tools for specialized (single?) purposes. I confess that I have very mixed feelings about this since I've bought some myself and I've ended up selling most of them. However, if it's a tool that you will use a lot on the same project, I agree that the cost might be worth it....if you have a lathe with the power to handle the tool.

I've used forstner bits on the few mills that I've done and had burning. Sharpening did help with this problem but not totally eliminate it. I used some bit cleaner that helped clean off the burned parts. I did buy some better quality forstner bits from Lee Valley that are HSS. They do work better than the cheaper ones that I have. The plans for mills that I did came from CSUSA and I had to drill the same size hole from both directions. Luckily, this worked out okay for me on a Jet 1014. I have a 1221 vs now though. I enjoyed the pepper mill projects.

robert baccus
12-27-2014, 11:43 PM
I drill 18-20"holes for deep vases. Blind hole!. I use a 2" fostner HF bit set and heavy extensions from Craft supplies. The secret is to be able to sharpen the bits easily and quickly. I use 6" diamond lapidary discs from the cheap web supplier. They appear to be made for sharpening fostner bits and gouges. Many will say this is impossible but I do one weekly.

Dale Winburn
12-28-2014, 9:22 AM
I use Colt Maxi Cut Forstner Bits with the morse taper holder and extension. These are the best I've used, no set screws or slippage of the extension. These are available from Craft Supplies, Packard Woodworks and others.

Robert Willing
12-28-2014, 10:28 AM
My vote is for the Colt Maxi Forestner bits sold by http://www.packardwoodworks.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=drilling-bits-maxicut with the biggest selection I have used them for years with out a problem for S & P mills. You will need to keep the hole clean I use a vacuum to remove the chips, and keep the rpms to not more than 500. Some use an air hose to keep the hole free of chips. I use the 1 1/16" for the deep bore and the standard forestner bits for the remainder shallower holes. I bought most of my bits at Woodcraft but the store did not carry all of the supplies so packardwoodworks is the best bet online.

robert baccus
12-28-2014, 10:29 PM
I've been using HF fostner bits with heavy extensions to drill vases 15-20" for years. Any bit will need sharpening--I find the 6" diamond lapidary discs just right for the various angles involved. I minute sharpening. This setup seems to not wander at all.

Eric Gourieux
12-28-2014, 10:46 PM
Mike
I use a 1"x 17" auger bit for my deep vases, and it works fine. I did NOT grind off the threaded tip, and I feel like it makes drilling much easier. Once I get the bit started in the wood, I release the lock-down for the tailstock and let it advance itself. When I want to stop, I simply lock down the tailstock. This takes some practice and you must have the lathe turning slowly (I prefer 250 RPM or less).

john taliaferro
12-29-2014, 7:56 PM
I have been useing the colt bits from Packard with great results .smooth cut

robert baccus
12-31-2014, 9:40 PM
Question---does the long auger bit cause any length problems. I use 6" add on extensions to get around this.

Eric Gourieux
01-01-2015, 9:41 PM
Question---does the long auger bit cause any length problems. I use 6" add on extensions to get around this.


Robert,
I can drill any length up to the capacity of the 17" bit simply by locking down the tailstock when I want to stop the bit from advancing further.