center punch

[Ronnie Connell]

how do you center punch end grain wood without the punch drifting off center?

[John K Jordan]

how do you center punch end grain wood without the punch drifting off center?

Almost impossible. (usually)

What's the application? I use various methods for precise holes but it depends on the situation (and the material).

A sharper point can help. When I want to mark precisely I use a sharp awl. Also, the center punches I have don't have very sharp points since they are made for metal work. You might try marking by tapping a sharpened rod to see if a sharper point drifts less, then if it helps sharpen the point on a center punch. Most automatic center punches, however, have powerful springs and I might be concerned they would drive a sharp point too far into the wood. (Some have adjustable force, though.)

BTW, I don't use a center punch in end grain, I always mark with a pencil then drill a small hole with a small gimlet:
374014
For me this is quicker and cleaner.

If the blank is square and not too big, you can use the type of marker that has four angled legs and a sliding center punch you tap with a mallet or something. (Sorry, I can't find a photo at the moment). This holds the punch better and keeps it from moving sideways as much.

But is this for putting divots in the ends of a spindle turning blank for mounting between centers? If so, I've never been too concerned if the center was off by a tiny bit since the blank will be turned round anyway, unless the blank didn't have enough extra.

JKJ

[William C Rogers]

I use a cup live center with the point removed, so no punch required. Without the point you can reposition easily small amounts to get best rotation. When you have a point it tries to go back to the original indentation.

[Don Jarvie]

Similar to John, I use a sharp awl. Place it over the spot and either push it in or hit it with a hammer to make the mark.

[andy bessette]

You should not be fastening into end grain anyway.

[Roy Petersen]

Don't recall where I got it, but for spindle turning blanks I have a wall mounted metal "V" that has a fairly dull "knife" blade that starts at the crux of the V and extends in a straight line half way between. Set the block in that, tap the other end with a mallet and rotate 45 degrees and repeat (flip around to do the other end. Exact center, and the fibers are mashed enough a live center sits very well in it. Fast, too.

Found a pic: https://www.highlandwoodworking.com/ProductImages/turningtools/037004.jpg

[Ronnie Connell]

i am doing inside out turnings so it is critical to be dead center. i have tried sharp awl but it follows the grain. i will try gimlet.

[Ronnie Connell]

Iam doing inside out turning so the center has to be dead center. I have tried sharp awl and it just follows the grain. Will try gimlet.
Thinks

[Marvin Hasenak]

I drill a shallow hole with a center bit. The center bit has a 60 degree point, as does the live center.

[david privett]

I agree with Marvin that process will get it as good as it can get, center bits are used to center metal lathe turnings so they will defiantly work with wood and they are not costly to have a few around in various sizes.

[John K Jordan]

Iam doing inside out turning so the center has to be dead center. I have tried sharp awl and it just follows the grain. Will try gimlet.
Thinks

Ronnie,

I'll call John Lucas tomorrow and ask what he recommends - he's done a boatload of inside out and other precision turning over the years.

JKJ

[John K Jordan]

I use a cup live center with the point removed, so no punch required. Without the point you can reposition easily small amounts to get best rotation. When you have a point it tries to go back to the original indentation.

As often the case, the best method used may depend on what is being turned. For some turnings, I do find the ability to reposition a good method.

But mounting spindle blanks between centers there is usually no reason to reposition the live center. In fact, the lack of a point in the live center might cause a disaster. I mark the center (by hand using the "fingers" marking gauge method) then make a hole with the gimlet in both ends of the blank. There are two reasons:

- When I place the blank on the lathe it is easier to put the drive and live center points in the holes than it is to bend down to look carefully at my pencil lines AND juggle to hold the marks on the blank on the drive center end while bringing up the tailstock. The points are positively engaged in the holes. Engaging the points by hand pressure is easier on softer woods but won't work on ebony or lignum vitae.

- For thin spindles from hard exotics or brittle woods (from blanks 1/2" square or so), tightening the tailstock may drive a point into the wood and split it. I've had that happen with the ends of "magic" wands before I started making holes first. For thin spindles I now almost always use 1/2" steb drive and live centers with spring-loaded points so this is not as important as it might have been, but the first reason is enough for all spindle blanks.

JKJ

[John K Jordan]

I agree with Marvin that process will get it as good as it can get, center bits are used to center metal lathe turnings so they will defiantly work with wood and they are not costly to have a few around in various sizes.

For woodturners not familiar with center drills, they look like this:

374080

So cheap (try Amazon) they are almost free. I never drill a hole in wood or metal without using the center drills unless I don't care if it is precise. In fact, I use them so much on the wood lathe I keep one mounted in a spare Jacobs chuck to make it quick.

JKJ

[Dan Hunkele]

For inside out turnings I take a small block plane and take a nick off the inside corners before gluing together creating an exact center without a punch.

[John K Jordan]

For inside out turnings I take a small block plane and take a nick off the inside corners before gluing together creating an exact center without a punch.

That sounds like an excellent idea!

[John K Jordan]

Ronnie,

I called John Lucas this morning about center marks on inside-out turnings. (Sorry, I had a couple of woodturning beginners here until just now.)

John said he he uses a technique very similar to what Dan described, knocking off the corners before the glueup. John said he uses a small carving knife. He said it is best to get all the corner bevels the same, of course, (I assume in both angle and size) but recommended also drilling a small hole since the point of the live center can still wander off. He said he's built jigs and things to drill the center holes but usually doesn't bother.

As for the center drills, Sir Lucas said in some circumstances he has still had them go off the exact center in wood with soft and harder sections - it's not the short, stiff drill bit that is flexing but the wood.

JKJ

[Kyle Iwamoto]

Have you tried an automatic center punch? That's what I use. Probably not a lot different than an awl. Yes I have tried an awl, and I like the auto punch. No explanation. It just seems to work better, in my mind.

[Keith Westfall]

You should not be fastening into end grain anyway.

How do you do spindle turning then?

[John K Jordan]

How do you do spindle turning then?

Most spindle turning is done between centers in the headstock and tailstock or with a chuck and a live center in the tailstock, or simply held on one end with a chuck. The method used depends on the wood, the size and length, and the types of cuts made. The chuck can be a scroll chuck, jam chuck, cup chuck, jacobs chuck, etc. In some cases a mandrel is used such for turning things like pens.

However, short spindles are often held by threads in end grain on a mandrel that fits into the morse taper of the headstock. This method is sometimes used for turning things like bottle stoppers and handles for kitchen gadgets. This works well, and in dense woods like cocobolo it is probably more secure than a screw in side grain of a wood like cherry. Typically when a mandrel with threads is used for something like that handle of an ice cream scoop the other end of the spindle is held by a live center in the tailstock until the piece is almost completed then the tailstock is removed and the end finished without support. Remember that turning spindles is usually done with more delicately controlled cuts than sometimes used in face turning so the forces are smaller.

Here is a typical mandrel with threads used in end grain spindle blanks: https://nilesbottlestoppers.com/index.php/woodturning/product/32-2mt-a-mandrel Hardware for bottle stoppers and such can be bought with the same threads as the mandrel.

JKJ

[Jeff Farris]

<p>
I stumbled across this one a few weeks ago. It is now my favorite automatic. It is sharp and penetrates deep, and it is a little more compact that the General and the General knock-offs. Lisle is mostly known for automotive and trailer wiring supplies and tools. http://www.lislecorp.com/divisions/products/?product=160&amp;division=1&amp;category=29</p>

[Keith Westfall]

Most spindle turning is done between centers...

Thanks, a bit of sarcasm is hard for me to convey... the post I quoted said you shouldn't fasten into end grain, which is what spindle turning is, whatever method one chooses to hold the work. Whether between centers, screw chuck, regular chuck, it all involves end grain.

Thanks for the info though - good stuff!

[John K Jordan]

[COLOR=#333333]You should not be fastening into end grain anyway.

Thanks, a bit of sarcasm is hard for me to convey... the post I quoted said you shouldn't fasten into end grain, which is what spindle turning is, whatever method one chooses to hold the work. Whether between centers, screw chuck, regular chuck, it all involves end grain.
Thanks for the info though - good stuff!

Oh sorry, I didn't read sarcasm. The first quote didn't clarify his thinking (nor did yours) so I took the chance that both were equally serious. For example, I know some bowl turners who hold face-work blanks with screw chucks but have no spindle turning experience and to them, and to flat wood workers with no turning experience at all, marking end grain with a center punch might imply preparing to drive a screw into end grain as the sole means of holding the work with no tailstock support. This could be a problem for larger end grain pieces and longer spindle blanks!

A secret: I actually had an ulterior motive to list those methods! I was asked to do a club demo on "Work Holding on the Lathe" and it was a good opportunity to think about end grain holding.

But what did I forget? One old I read about but never used: drill a hole in wood held with a faceplate, then glue the rounded end of a spindle blank into the hole. And yikes, I plum forgot about collets and pin chucks! Anything else?

JKJ

[Jim Silva]

Yeah, that line you quoted was a bit puzzling to me also. On a small spindle using a screw or the like would not be terribly safe but do any large end-grain hollowing and you'll find that a faceplate is the way to go. I'm thinking the initial responder was speaking of small stock mounting. (Hope they were anyway...)
Jim