Clearing a clogged lead screw

Re: Clearing a clogged lead screw

Joe Rogers, Northern Virginia

>Tom Price at Galoots Progress has a nice tip on polishing lead screws so as to reduce this problem. Start a hole with the bit in question. Don't bury the lead screw completely at this time. This is because the lead screw is tapered. Add some abrasive...valve grinding compound IIRC to the started hole (no bit in the hole) and engage the bit again after the abrasive was added. Twist the bit into the hole until the bit starts to bore the hole with the flutes. Then reverse the bit and back it out. Repeat. This creates a perfect "lap" to polish the lead screws and the roughness that binds the wood fibers will soon be gone.

Tom, feel free to correct my rapidly failing memory.JR

Dental work

Christopher Schwarz

>Sam Peterson recommends dental floss. I tried it and it worked great.

Chris

Re: Dental work

Robert Tarr

>Dental floss wetted and dipped in abrasive powder like Comet or something like that, if memory recalls. Great article in the mag about that.

Robert

Yup

Christopher Schwarz

>I forgot the Comet part! Yes to Comet!

Chris

Re: Clearing a clogged lead screw

Adam Cherubini, NJ

>Jonathan,

You may not be surprised to hear this, by I find Watson not quite technical enough for my tastes. Its been a while since I perused those pages. I always loved the lore of it all. But I recall several Galoots commenting on inaccuracies in his books.

On the subject of lead screws, I have used needle files to sharpen them in the past, but this doesn't stop them from clogging. See clogging is a symptom, not a cause. The problem is that lips aren't sharp enough to cut. They stop cutting, the auger stops progressing, and the lead screw "augers off" it the wooden threads it has made.

If you are using a coarse lead auger in a difficult wood, you need very sharp lips.

Here's my trick: I find I use augers infrequently, some as little as once per annum. Immediately after use, I plunge the warm bit into a can of butchers wax, then invert the auger, allowing the wax to run down the auger and cool. I think this lubricates the next cut and staves off rust.

Adam

Re: Clearing a clogged lead screw *LINK*

Tom Price

>Tom Price at Galoots Progress has a nice tip on polishing lead

screws so as to reduce this problem. Start a hole with the bit in

question. Don't bury the lead screw completely at this time. This is

because the lead screw is tapered. Add some abrasive...valve grinding

compound IIRC to the started hole (no bit in the hole) and engage the

bit again after the abrasive was added. Twist the bit into the hole

until the bit starts to bore the hole with the flutes. Then reverse

the bit and back it out. Repeat. This creates a perfect "lap" to

polish the lead screws and the roughness that binds the wood fibers

will soon be gone.

Tom, feel free to correct my rapidly failing memory.JR

Valve compound would probably do fine. I use emory compound, the stuff that comes in stick form.

Turns out that I merely rediscovered a technique from the past. I've tried the dental floss route but the method described on my site seems faster, less fussy anyway, and laps the entire screw surface to a pretty good polish. The key to the technique is the pressure exerted on the lead screw by the wedge action as it bores into the wood. My site says 30 seconds for the polishing step but I normally only need to drive in and back the bit out a few turns of the brace.

The link to the description on my site is below - Tom


Restoring Auger Bit Lead Screws

Re: Clearing a clogged lead screw

Tom Price

>Regarding inaccuracies, it wasn't Aldren Watson the Old Tools crowd was talking about, it was Alex Bealer, especially for woodworking. I still refer to Watson's 'Hand Tools' and find something useful every time I look.

Doesn't matter how sharp you get the lips, if the lead screw is rusty, pitted or rough, the screw surface will 'stick' to the wood and the screw will get loaded with wood to the point where it won't pull the auger any more. You need both sharp lips and a polished lead screw for best performance.

- Tom

I agree

Adam Cherubini, NJ

>Hi Tom,

Thanks for straightening me out. You are correct, it was Bealer and not Watson I was thinking of. My mistake.

Also, I agree that a rusty or dull lead screw will always cause problems. You do need both to be sharp.

Adam