Auger bit question

[Salem Ganzhorn]

I recently bought a box full of auger bits and had the opportunity to try them out on the bench I am building. But I ran into an issue: when drilling a 1" hole the lead screw stripped out. This made completing the hole very, very difficult. What is the fix for this?

By the way the lead screw looked a little puny. And I was drilling into some pretty Nast white oak.

Thanks!
Salem

[Archie England]

Greetings Salem,

I'm only about a few weeks ahead of you, and the verdict in my situation is, the cutting lip had been filed down and buggered! Follow the link http://www.youtube.com/watch?v=FO5ZRy_dnNM (http://www.youtube.com/watch?v=FO5ZRy_dnNM) and watch how one man files and sharpens old auger bits. Bob Smalser and a few others have posted articles on rehabbing these bits, as well.

The main idea I gleaned is this: the lead screw bottoms out when the cutting lip/leading edge is no longer engaging the wood. The only genuine time for the screw to bottom out is when exiting the wood. In that case turn your piece over and drill from the hole back down--leaves a clean exit.

Check out Wiktor Kruc's Fine Tools Journal for other info.

Arch
Near NOLA

[Jim Koepke]

I'm only about a few weeks ahead of you, and the verdict in my situation is, the cutting lip had been filed down and buggered! Follow the link http://www.youtube.com/watch?v=FO5ZRy_dnNM and watch how one man files and sharpens old auger bits. Bob Smalser and a few others have posted articles on rehabbing these bits, as well.

That is an interesting video. At the beginning some of the text is difficult to read even with full screen.

If someone has filed the outside of the spurs, an auger will likely always stall in the cut.

Bob Smalser put up a post that is wide ranging about braces and bits.

http://www.sawmillcreek.org/showthread.php?13090-The-Incredibly-Versatile-Sweep-Brace

He covers a lot of ground including sharpening a bit and drilling angled bores.

My post is more about the bit than anything else.

http://www.sawmillcreek.org/showthread.php?131238-A-Bit-About-Augers...

jtk

[Steve Branam]

Follow the link http://www.youtube.com/watch?v=FO5ZRy_dnNM (http://www.youtube.com/watch?v=FO5ZRy_dnNM) and watch how one man files and sharpens old auger bits.

Nice! I'll have to try that. I also have problems with lead screw stripping out with my 1" bit. My solution was to stand on my sawbench and lay my chest on the thing, which didn't always work, and wasn't very comfortable!

[Jim Koepke]

I ran into an issue: when drilling a 1" hole the lead screw stripped out. This made completing the hole very, very difficult. What is the fix for this?

By the way the lead screw looked a little puny. And I was drilling into some pretty Nast white oak.

Thanks!
Salem




Nice! I'll have to try that. I also have problems with lead screw stripping out with my 1" bit. My solution was to stand on my sawbench and lay my chest on the thing, which didn't always work, and wasn't very comfortable!

All my comments are based on trying to cut into edge or face grain. If you are cutting into end grain, all bets are off.

If either of you can post clear shots of the tips of your drills, I might be able to help understand why this is happening.

Went out to the shop to take a few pictures of 1" auger bits. They will likely get tacked on to my "A Bit About Augers" thread so they will be easy to find in the future.

First is a shot of the business end of an auger bit:

197211

This bit works pretty good, but I did notice one thing by taking this close of a look. The lead screw thread should go into the cutting lip. This bit has been sharpened a lot before it came to me. Thankfully, it was done without destroying the bits ability to cut. I think I will correct that in the future.

Here is a bit that was improperly sharpened:

197212

Notice the file marks on the wrong side of the cutting lip. The spurs are also cut down to being almost useless. The spurs should be able to scribe a good circle in the wood being bored before the cutting lips hit the wood. This is what makes a clean entry to the bore.

Here is another shot of the first bit:

197210

Notice that the outside of the spur and the bottom of the cutting lip (see first photo) still have their factory finish.

Fortunately finding a single bit to replace a bad one in a set is not too hard. I will often buy bits just to have back ups. I also like to save my best bits for working on wood that I know doesn't have nails or screws hidden inside.


Salem,
You comment that the lead screw looks a little puny. I wonder if it may have a broken lead screw or if it may have a coarse thread lead screw more suitable for soft woods like used in home construction.

There have been so many different kinds of bits over the years, it may have been made with a small lead screw for fast, rough work.

Steve,
After seeing the video you may have a better idea of what is happening with your bit.

Remember only sharpen the radial cutting lips on the top side. They should be cutting about the same amount of wood as the bit is working.

The spurs should only be sharpened on the inside. If they have been filed much on the outside, they do not cut a big enough bore for the rest of the bit to follow behind them. This will almost guarantee the bit binding.

A little very light stoning to remove a burr is OK, just a light touch.

jtk

[john brenton]

Auger bits are generally pretty simple, except for when they aren't, in which case they are a total pain. I've really found that to be the case with the adjustable bits, which are really cool one you get them dialed in.

I've never tried it, but I supposed you could file down the pilot like an old center bit....those didn't have screws and a sharp one does a good job. I have quite a few in the larger sizes and once they bite they work well.

On the topic though, I finally found a use for spent three corner files. If you grind the sides off and thin it down (only the first three inches or so) , it makes a great touch up auger file.

[Andrae Covington]

I recently bought a box full of auger bits and had the opportunity to try them out on the bench I am building. But I ran into an issue: when drilling a 1" hole the lead screw stripped out. This made completing the hole very, very difficult. What is the fix for this?

By the way the lead screw looked a little puny. And I was drilling into some pretty Nast white oak.

Thanks!
Salem

Taking a different tack here from what others have said. In my experience, there is an upper limit to how big of an auger bit you can muscle through wood. Various factors involved include how big of a gorilla you are and therefore how much downward force you can apply in the process, the sweep of the brace you are using, the coarseness or fineness of the threads on the lead screw, and how dense the wood is. Plus of course properly sharpening the bit. I generally top out at a 7/8" auger even with a 14" brace, but I am a featherweight.

[Salem Ganzhorn]

When I look over the links provided in this thread (thanks!) and I compare them to my auger bit I see some idiot filed the top of the cutter instead of the bottom (ps: I know this idiot very well). The spur though looks to be ok. Hopefully I^H someone has not ruined this bit.

But when you find yourself in this situation what is the best option? I tried the "put your chest on the brace and push with all your might" thing. It didn't work for me. In the end I took a very small auger bit and drilled through where the lead screw had stripped out. Then I took a forstner bit from the other side to finish the hole. Since I was just removing waste for a larger square mortise it was no big deal.

But what if the hole matters? How do you finish the hole cleanly if the lead screw strips out?
Thanks!
Salem

[Steve Branam]

But what if the hole matters? How do you finish the hole cleanly if the lead screw strips out?

Now that I've accumulated a few nice gouges, one thing that occurs to me is you could take an in-cannel gouge of the proper sweep (which is always a sector of a circle) and work it around the edge of the circle that has been cut so far. You could gouge out to the depth of the lead screw hole, then start over with the auger and see if it maintains its bite. Here the gouge is doing the job that the auger cutting lip should have done. Eventually you should get deep enough for the lead screw to pierce to the other side so you can flip the work over.

And if you don't have the exact sweep, you could use a smaller gouge, just have to work the scalloped edges of the circle a bit. Might not be quite as clean, but would probably be sufficient. If necessary, you could wrap sandpaper around a dowel to fair the inner curve of the hole to fine-tune it.

[Jim Koepke]

When I look over the links provided in this thread (thanks!) and I compare them to my auger bit I see some idiot filed the top of the cutter instead of the bottom

I'm thinking that you are referencing the bit with the lead screw pointing up.

I have not tried reshaping the cutters on any of my old non-working bits, but it might work.

It may also be easier to just find a replacement bit.

jtk

[Jim Koepke]

Thankfully, it was done without destroying the bits ability to cut. I think I will correct that in the future.

OMG - LOL!

Rereading this made me think of how it could be misunderstood... I mean to correct the lead screw and redirect it to the cutting lip. When this is done, I will post a few more pictures at the end of the "A Bit About Augers" thread.

jtk

[Jim Neeley]

I for one look forward to that post, Jim.. I haven't yet gotten a brace and auger setup but I loved them as a kid an plan to.. and now understand how to screw up a bit when sharpening. Now I just need to understand how *not* to!! :o