Illusionist Locket

That stupid locket from "The Illusionist".

Turn one half 180 degrees on a pivot...

Wow! It's a heart.

Slide the top open and reveal the picture of your love. Of course it's ripped in half and the movie used two separate prop lockets, neither of which worked fully.
I used this sketch from Curious Goods to do the layout and general geometry.

One half of my locket.

The other half.

The pivot pin is pinned to one of the halves. In either the open or closed position a spring bullet catch holds it against rotation. I would probably use a shallower detent than I show.

My sneaky half hinge. The undercut groove is essential. Each of the pair pinned to the one of lid halves of the locket.

The pin (and glue, probably) holds the half hinge to the lid half. The bent spring tongue slides in the groove of the half hinge, holding it to the bottom half while allowing rotation. You could use a half dovetail groove, a undercut boss on the bottom and a pin riding in a groove or sundry other methods, but any solution must hold the pin down and against the semicircular pocket while allowing it to rotate, and for the other half hinge to rotate into it and be retained as the top halves are turned to open.

The bent spring tongue is shown in the semicircular pocket in the bottom half. Notice the detent for the spring bullet catch.

A&B: half hinge, C&D: The bent spring tongues, E&F: pins to hold the half hinges to the top halves. G&H: parts of the bullet spring catch (should be secured to the pocket somehow so it doesn't shoot out when opened.) I: pin to hold pivot pin in one half of the bottom halves, J: Pin rides in groove in pivot pin to keep it in position so it has no axial play.

The 4 halves.


The 4 halves.

Well, what do you think, would it work? It is certainly doable. The lid halves are not mechanically joined, but are restrained against each other with the same axis of rotation.

This would take a lot of fine lathework under a microscope, more like clockmaking than carpentry. I have no intention of trying to make it. I'm sure it needs a lot of experimental refinement...

EDIT/UPDATE: See here for a design that uses common materials and can be made with hand tools...



(copyright 2007 Nick Carter)

Finally!

Sorry for the lack of posting lately, we were wiped out by some sort of plague that lasted for weeks.

Here I am sick on the couch with a sleeping Henry.

Max weathered it fine. Did we mention that he likes airplanes?
Henry likes trains and Max likes airplanes. Interesting. No idea why.

I'll try and post something more interesting soonish. Just wanted to let everyone know I'm still alive.

I finally put a copy of my article, The Involute Curve, Drafting a Gear in CAD and Applications, up on the web today. Converting a magazine article to html takes a bit of work.

More Masterpieces of Photography by Henry

As promised, here's the latest round of pictures taken by Henry. The camera used is a Fuji Finepix 2400Z. Captions straight from Henry's mouth.

"That's a wum-wum."

"It's a cup, your cup, what's it say? "

"Crash Lego"

"It looked like a good picture. "

"I though it was a good picture of mommy, I thought the other mommies would laugh at it."

"For Etsy"

"I muttered."

"It's Fred, laying on the track, he's shunting. "

"Henry."

"Daddy's a lamping."

"Max's Flying Scotsman, I liked the way it is."

Making Earrings on the CNC mill

I went on a creative jag this week, playing with fabricating earrings on the CNC mill

Milling a piece of aluminum flat to adhere the silver sheet to.

24 ga. (.019") sterling silver sheet. I use 3M carpet tape to adhere the silver to the aluminum, after cleaning both surfaces with rubbing alcohol.

Milling a pair of earrings. I first used a 60 degree engraving cutter to do the text, then a 1/32" endmill to drill and profile the earrings.

The earrings stayed in position and strongly adhered to the carpet tape, I had to use WD-40 to unstick them from the aluminum

The finished earrings (on sale on Etsy)

Milling a pair of steampunk-ish gear earrings (gearrings). In spite of the cutouts the carpet tape still held well.

The finished earrings.

The omma earrings took a bit of doing, two online dictionaries, a brief lesson in hangul typography and a bit of CAD magic. I tried out a diamond drag engraving tool for this time, which you use with the spindle off. I think I prefer the results to the 60 degree engraving bit.

Korean Hangul Omma (mom) earrings.

I also did a pair of emoticon smiley earrings and I'm working on a few more designs. It's pretty addictive and fun to be playing with textual jewelry.

Just a Few More Pictures of the Rose Engine Turning

I thought I'd add a few more pictures of my experiments.

Diminishing straight rosette

Spiralled rosette. The toolbit was too high above center in my opinion. 4 degree spiral.

A better spiral, 2 degrees and a finer pattern with less depth of cut, tool tip slightly below center.

Engine Turning and Boxed Children

The other night I was watching "John Ratzenberger's Made in America" and a segment came on about the RGM Watch Company. The segment showed them using a rose engine to do "engine turning" on various watch parts. I looked them up on the interweb and they had a lovely page about their engine turning. Inspired by the examples, I did some thinking and set up a rough approximation on my CNC mill.

The first pattern I produced in a piece of brass.

Although the pattern looks deep, it is just a series of grooves in the face of the work. The light ends up reflecting in lovely patterns when you move it around.

The basic rig. A tiny round nose lathe tool is clamped to the z axis of the mill, and the work is rotated in the 4th axis.

In action the y axis moves the work side to side, and the rotary 4th axis, um..., rotates. The x axis is used to retract and engage the tool, and the z axis sets the tool height. Relative to the tool tip, the work looks like it is rotating while wobbling back and forth
Here's the code that generated the pattern:
G91
M98 P1000 L25
M30

O1000
G01 Y.02
G01 X-.005 F10
M98 P1234 L20
G01 X.005
M99

O1234
G01 Y-.1A9
G01 Y.1A9
M99

That code took some serious head scratching. I haven't used nested subroutines (M98,M99) before, and I was happy they were so easy to implement in Mach (the control program I use on the mill).
This site has more information on engine turning which was of great use to me, I also relied on my well worn copy of Holtzapffel's The Principles and Practice of Ornamental or Complex Turning to grasp the finer points of the process.

Here are the instructions for building your own (non-CNC) rose engine, should you have nothing better to do.

Now on to children in boxes:

Henry isn't sure that the mail is the best way to travel.
Max and Eben share a box.

Ok, that whole box thing was tenuous as I only had those two pictures.

Here Henry shows his love for the cat.

Pizza beckons, but I thought I would close by saying that I am extremely excited about the upcoming production of Neal Stephenson's "The Diamond Age: Or, a Young Lady's Illustrated Primer" .

Finally, The Important Things...

Well I can finally get back to important stuff like blogging about how cute the kids are. I really wanted to blog earlier but I have been working without rest (cue violins).

Max shows me his butchered chocolate Santa. Probably second to the easter Bunny to being a horrific item to consume. More about chocolate Santa below...

Henry looks out the vinyl window of his huge playhouse, courtesy of Aunt Betsy.

Max the buckethead, pets a horse on a geta.

Henry practices his karate (I took out a video, "Karate for Kids" at the library). Notice the playhouse in the middle of dismantling.

Max shows off the new blue marker he got for Christmas.

Max in a TV coma, Henry as a mountain lion.

Awww. Cute...

Max and Henry play together (!) with yet another Thomas set.

I look alert, don't I?

Max shows off his Kung Fu.

So anyway, getting back to the chocolate Santa...Henry was eating his in the kitchen and I asked him for a bite - he trots over to the computer and gives me the bottom 1/5. I pop it in my mouth and immediately am disgusted. Felice is laughing hysterically in the kitchen because Henry was using the bottom of the Santa as a spoon for his chicken noodle soup. So I had Santa chicken noodle soup in my mouth. Bearing in mind that I am a) a vegetarian and b) not accustomed to mixing sweet and savory tastes, or the textures of chocolate and chicken, you can see how this was a less than desirable gustatory mix...

As Felice noted on her blog, we had quite a storm before Christmas, which left us without power for 3 days. In the course of reading up on generators and such I came across this site about survival (not survivalism). It's interesting reading. We really need a small generator for the fridge (TV, light, computer...) Reading email on my ancient laptop via dialup was not satisfactory. In terms of survival we had plenty of lights and candles, the woodstove heated us dependably (although splitting wood for 3 days used some muscles that had atrophied, thus pain) and the Coleman stove was adequate.

I started research into the repeating crossbow, as I thought it would be in interesting project - when if ever I have time. Through that I came across this site about Chinese siege engines.
Will I ever do any fun projects? Oh and this led to me finding Canadian made siege engine kits...

I had planned on linking to this site about St. Nicholas before Christmas, but I didn't get the time...

The Puzzling World of Polyhedral Dissections is now online...like you didn't already know that...

Who knew that there was a tablelegs.com?

Here's a good blog about the Korean pop world.

I caught an odd movie on TCM, "It's Trad Dad!". It introduced me to both the surreal non-antics of the Temperance Seven, and the unbelievably deep voice (and beehive hairdo) of Helen Shapiro.

The Dapra website has tons of interesting machining products and some good tech info...

So now that I have vomited out all of these links, what lies ahead for the New Year?
Well my immediate to-do list has the following entries:

1) Update Web Pages
2) Pay 4th quarter estimated taxes
3) Get a SSN for Max (need the deduction!)
4) Make more business cards
5) replace a part for an Atlas turret tailstock and ship to a friend.
6) Perform an inventory of Taig items in stock
7) clean shop.
8) Blog

Hey, #8 is done!

Happy New Year!

PS) I should list what else I've done today
1) modelled an elastomer spring in Rhino for a my guy in MA.
2) reamed holes in 5 timing pullies for a customer in TX.
3) packaged up items to send to customers in Canada
4) emailed 500000 people (or so it seemed) in response to questions