Workholding question

[David Wrate]

I've been asked to make some handles for a woodworking vise.
Here is the handle to be copied:



Here is the stock I was supplied.

As the title says. my question is about workholding.
The through hole makes me think my best best is drilling the through hole and counter bore and then putting it on a mandrel.
I don't have a mandrel though I suppose a bolt of the correct diameter would work. If I use a mandrel then the only think I can think of is to stick my MT2 drill chuck in the headstock and hold the shaft of the bolt in the chuck. Except we all know that drill chucks have terrible runout.

To hold the blank in the chuck, I would have to get smaller capacity jaws. If I did get smaller jaws, I think I'd drill it, make the counterbore, turn it round then make the shape and part it off. Or just leave it in the orientation and make the narrow part be nearest the chuck.

But I'd really like some expert perspectives as I'm a bit nervous about doing this job. The workbench the handles are for is a woodworking tour de force, absolutely beautiful and I feel a bit like a hack because I've never done anything like this before :O

 

[hockenbery]

Turn it on a mandrel. Or on a short mandrel and cone in the live center if you have one

Will the handle turn on a shaft?

Do you have a cone to fit your live center.
You can turn a wooden mandrel

This may be the easiest for you
Another easy way is to turn it between centers with plugs in each end.
I’ll sketch this out for you. Later need to do some stuff now

I did a bunch of curtain pulls that the customer was covering with fabric
Same deal through hole…

 

[David Wrate]

Turn it on a mandrel. Or on a short mandrel and cone in the live center if you have one

Will the handle turn on a shaft?

Do you have a cone to fit your live center.
You can turn a wooden mandrel

This may be the easiest for you
Another easy warty is to turn it between centers with plugs in each end.
I’ll sketch this out for you. Later need to do some stuff now

The handle will turn on a shaft, essentially a bolt with a round, slotted head instead of a hex head.
I think my Nova centre has a cone.
Drawings would be really appreciated!

 

[Rusty Nesmith]

Maybe you could turn them on a pen mandrel.

 

[Brian Gustin]

If you have jaw chuck, chuck up a scrap blank or glue block and turn your own mandrel , drill out the hole in your handle blank, turn scrap "mandrel" down to a nice snug fit to the drilled hole , and turn your knob on that?

 

[David Wrate]

If you have jaw chuck, chuck up a scrap blank or glue block and turn your own mandrel , drill out the hole in your handle blank, turn scrap "mandrel" down to a nice snug fit to the drilled hole , and turn your knob on that?

I've thought about doing just that except the hole is only 3/8" so I am concerned there won't be enough strength or rigidity to hold the part.

 

[David Wrate]

Maybe you could turn them on a pen mandrel.

That could work. I've never seen a pen mandrel mind you...

 

[Brian Gustin]

I've thought about doing just that except the hole is only 3/8" so I am concerned there won't be enough strength or rigidity to hold the part.

would be plenty if you select the right piece of wood for the mandrel. I have a good dozen or so different "mandrels" of wood blocks from various projects where I turned the tenon / mandrel down as small as 1/4 inch (for a 2 inch diameter cabinet knob) However on the smaller tenons (AKA Mandrels) I will cut the matching faces to be pretty much square to each other and then either a paper glue joint or some hot melt glue - the mating faces takes most of the strain off the mandrel/tenon much like you would have a square "seat" on a bowl tenon to mate up with the faces of the chuck jaws (and for the same reason) One trick I used once on a project where I drilled a 3/8 hole into the project but it didn't go quite square and wouldn't mate squarely with the "chuck" was to turn away the waste block a bit more til I could jam the project wood onto it with tailstock support then squared up both faces to each other with parting tool, then re-formd the mandrel/tenon for the project to seat squarely on it.

 

[Dean Center]

I have a different approach:

Mark center point on one end and make a dimple with your awl.
Mount the other end in your chuck, centering dimpled end in live center point
Drill hole
Bring up cone tail stock into hole drilled, to center rather than compress
Turn the handle
Sand, apply USMC shoe dye (Feibings?)
Part off, sand top end, apply more dye
Apply finish

With this approach, you can drill through or part way, whichever you need. You can also cut the threads in the hole while it's mounted in the chuck.

I have a 3/8" mandrel, but I wouldn't use it for something that doesn't need the precise centering.

 

[hockenbery]

The handle will turn on a shaft, essentially a bolt with a round, slotted head instead of a hex head.
I think my Nova centre has a cone.
Drawings would be really appreciated!

Make a test handle from scrap wood.
Mandrels can be made from any dry wood. Piece of 2x4 would work.

This is one design for wooden mandrels. The wooden mandrels can be turned work piece.

If the wide hole is less than 1/2” deep the wide one can be the diameter of the through hole and a bit longer. These mandrels can be turned between centers in a few minutes. I prefer a cup dive center. Steb center 2nd choice, spur drive 3rd choice. Same centers turn the work piec and mandrels.


This shows how I would turn the mandel start with a taper on the end.. press the wooden hole over the taper and twist.
This will leave a ring of compressed wood cut the spindle from the back edge of the mark- cut off the red wood innthe diagram

Check the fit. If it’s too tight make a very light cut. A little wax can make it easier to put the workpiece on and get it off.


If the mandrel diameter gets too small there are two fixes.
1. rub a stick of hot melt glue against it with the lathe running. This builds up the diameter.
2. Wrap turns of masking tape. Be sure to end the last wrap just before it would overlap the star.


You could also glue a proper diameter dowel or metal rod into a piec of wood to make the mandrel.

 

[David Wrate]

@Brian Gustin

Make a test handle from scrap wood.
Mandrels can be made from any dry wood. Piece of 2x4 would work.

This is one design for wooden mandrels. The wooden mandrels can be turned work piece.

If the wide hole is less than 1/2” deep the wide one can be the diameter of the through hole and a bit longer. These mandrels can be turned between centers in a few minutes. I prefer a cup dive center. Steb center 2nd choice, spur drive 3rd choice. Same centers turn the work piec and mandrels.
View attachment 48436

This shows how I would turn the mandel start with a taper on the end.. press the wooden hole over the taper and twist.
This will leave a ring of compressed wood cut the spindle from the back edge of the mark- cut off the red wood innthe diagram

Check the fit. If it’s too tight make a very light cut. A little wax can make it easier to put the workpiece on and get it off.
View attachment 48433

If the mandrel diameter gets too small there are two fixes.
1. rub a stick of hot melt glue against it with the lathe running. This builds up the diameter.
2. Wrap turns of masking tape. Be sure to end the last wrap just before it would overlap the star.

That's super helpful Al, really appreciate the illlustrations. I'll noodle on this a bit and see what I can come up with.

 

[Vincent Vogel]

What is the od of the knob ? Does the hole go the whole way through the knob ? If it does Al's idea would be perfect, if not you could turn the knob then when done make some soft jaws to fit the od and reverse it and drill the hole last. Get some scrap stock and practice first.

 

[Brian Gustin]

Yup. Al described it far better than I did but pretty much what I do

- Also Dean Center makes an excellent point if you are only turning one or two and have enough of a wood blank, you can just chuck up an end of your blank in jaw chuck and turn your knob after drilling the center hole - The only issue I'd have with that is, it would be slow and inefficient if you were doing a batch of knobs - Just not so bad if you only need a couple.

Besides, turning your own wooden mandrels often comes in handy, especially if you keep them (and mark them for how they mount in chuck jaws if using chuck), as your collection grows (typically just for mandrel diameter) you'll be finding many uses for them (One I turned into a step "drum sander" to refine the I.D. of a stepped hole in a non-turning project......)

 

[David Wrate]

What is the od of the knob ? Does the hole go the whole way through the knob ? If it does Al's idea would be perfect, if not you could turn the knob then when done make some soft jaws to fit the od and reverse it and drill the hole last. Get some scrap stock and practice first.

OD is 1.25" the hole goes all the way through with a counterbore at one end.

 

[robo hippy]

Hmm, I think you should drill it through first, and the counter bore as well. After that, I think I would use a jamb chuck, so short spigot turned to just the right size, and a little spit on the wood will make it swell up a tiny bit, but not enough to crack the blank, then gently finish turn the blank. Jamb chuck and counter bore need to be spot on parallel, and the drill press should do that for the knob. For the jamb chuck, I would use a 6 inch steel rule to lay up against the jamb chuck spigot and then eyeball it along the lathe bed to see how good you did. If you go too narrow on the jamb chuck, tissue paper, stretch film, or any number of things might help. Oh, cone center on the tailstock. Not sure if you would need to drill the counter bore first and then the through hole or the other way around.

robo hippy

 

[Doug Freeman]

A couple of rules I try to follow if possible:

1. Drill hole and locate off of the ID to maintain concentricity with OD
2. Do counterbores 1st, then locate for the smaller hole off the center dimple

 

[hockenbery]

If you do find that you have a cone center.

For a one time super simple mandrel is to face off a small bock of wood in a chuck.
Put a drill bit of the right size in Jacob’s chuck mounted in the tailstock.
Drill a deep but non through hole. Stop the lathe with the bit at depth.
Turn the lathe by hand to lock the drill bit in. Loosen and remove the Jacob’s chuck.
Slide pre-drilled work piece over the exposed drill bit shaft and use a cone on the tailstock center
Turn and finish the profile.

This method I used for turning my first wooden pen kits.
Dale Nish had suggested it in a pen turning article he wrote before pen mandrels were available.
Drill bit can stick out pretty far but there has to be space between it and the cone point when the work is mounted.

 

[David Wrate]

If you do find that you have a cone center.

For a one time super simple mandrel is to face off a small bock of wood in a chuck.
Put a drill bit of the right size in Jacob’s chuck mounted in the tailstock.
Drill a deep but non through hole. Stop the lathe with the bit at depth.
Turn the lathe by hand to lock the drill bit in. Loosen and remove the Jacob’s chuck.
Slide pre-drilled work piece over the drill bit and use a cone on the tailstock center
Turn and finish the profile.

This method I used for turning my first wooden pen kits.
Dale Nish had suggested it in a pen turning article he wrote before pen mandrels were available.
Drill bit can stick out pretty far but there has to be space between it and the cone point when the work pice is mounted.

Ok that's pretty darn creative!

 

[hockenbery]

Ok that's pretty darn creative!

Thank Dale Nish. We all miss him…

 

[Dean Center]

As with most woodturning tasks and projects, there are many ways to get the job done. This is a good example on a simple project.

 

[Tom Gall]

For a project this small I would just turn between centers. Drill holes & counterbores first (drill press or lathe).
Have a "dead center"? - mount in headstock .... if not turn scrap wood held in a chuck to a cone shape that fits into a 3/8" hole.
Use a cone in your live center. Tighten enough to provide enough friction and turn to shape.

 

[Rusty Nesmith]

That could work. I've never seen a pen mandrel mind you...

They are only around $16.

 

[Mike Johnson]

You could also glue your wood blank onto a wood round that would mount in an adjustable chuck, then turn the profile of the
handle between centers, then drill the counterbore hole and then the smaller thru hole while it is still glued to the glue block, the
last operation would be parting the knob from the glue block.

 

[hockenbery]

You could also glue your wood blank onto a wood round that would mount in an adjustable chuck

Also you this method with double sided tape.