Gears and Gravity, Day 5: Pinion Assembly

Assembling pinions is a lot of work and all of the students worked hard. Three eight leaf pinions are required for each clock.

The drilled holes are a little undersized so we must use this very sophisticated pointy stick to increase the diameter.

The drilled holes are a little undersized so we must use this very sophisticated pointy stick to increase the diameter.

Five of eight pins inserted.

Five of eight pins inserted.

They don't have to be straight.

They don’t have to be straight.

Little smears of hot glue hold the pins in place.

Little smears of hot glue hold the pins in place.

Love the pink hot glue guns.

Love the pink hot glue guns.

Gears and Gravity, Day 4: Arbor Tube Rolling

Each wheel and pinion must be secured to a paper arbor before being attached to the 1/4″ dowel pivot. The arbor is 1/4″ ID and 3/8″ OD. As I was designing the clock, I looked for off-the-shelf tubes that I could purchase but what I found seemed expensive and I wanted to ensure a consistent size so I decided that I’d have to roll my own. This video presented and excellent solution. Still, these are a challenge to roll consistently and I had to experiment for quite a while before I found the best technique to teach my students.

Applying glue thinned with water and a little rubbing alcohol to prevent wrinkling.One person holds the paper on the steel rolling-pin to prevent the two from getting glued together.

Applying glue thinned with water and a little rubbing alcohol to prevent wrinkling.One person holds the paper on the steel rolling pin to prevent the two from getting glued together.

Glue applied, starting the roll. A helper tries to keep wrinkles from forming.

Glue applied, starting the roll. A helper tries to keep wrinkles from forming.

Slow and steady.

Slow and steady.

All most there.

All most there.

A finished arbor tube.

A finished arbor tube.

Gears and Gravity, Day 3: Pinion Construction I

Center Punching

Center punching the pinion pin holes. I am impressed by how accurately these 4th, 5th, and 6th graders can punch these center marks. They did better than many college students I’ve seen. Perhaps their small hands and young, sharp eyes give them an advantage.

After Day 1, I knew that this group of students would benefit from the additional challenge of drilling their own holes. I drill all of the 3/8" holes for safety concerns but I'm confident that the risks of injury when drilling an 1/8" hole into chip board are minimal. Everyone has handled the drill press very well so far.

After Day 1, I knew that this group of students would benefit from the additional challenge of drilling their own holes. I drill all of the 3/8″ holes for safety concerns but I’m confident that the risks of injury when drilling an 1/8″ hole into chip board are minimal. Everyone has handled the drill press very well so far.

Cutting 1/8" dowel rod into 3/4" lengths for pinion pins using a custom jig. The Xcelite 170M flush cutters do a pretty good job and fit young hands very well.

Cutting 1/8″ dowel rod into 3/4″ lengths for pinion pins using a custom jig. The Xcelite 170M flush cutters do a pretty good job and fit young hands very well.

Each plate is a double thickness of cereal box chip board plus a paper pattern all spray-mounted together. The average thickness of this material is 40 mil so it's a bit of a challenge to cut through.

Each plate is a double thickness of cereal box chip board plus a paper pattern all spray-mounted together. The average thickness of this material is 40 mil so it’s a bit of a challenge to cut through.

We often emphasize the importance of cutting parts to a rough shape first and then trimming the last bits off.

We often emphasize the importance of cutting parts to a rough shape first and then trimming the last bits off.

Gears and Gravity, Day 1: Best Scissors for Cardboard

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The first task we tackled in class was to determine which which set of shears worked best for each student to cut double-thick cereal box chipboard. To my delight nearly everyone had strong opinions about the best and worst. I’m so glad I did this as most of the class prefers a pair that I don’t really like and they hate my favorite.

However, I was not surprised to hear their disdain for the #1 pair pictured above. These are your basic cheap-o-always-on-sale craft scissors and they are generally awful for anything other than opening bags of chips.

#2 are an older version of the Fiskars 9911 “Softouch Multi-Purpose” scissors. Even after years of use in my studio these were still a strong favorite.

Though the #3 Fiskars 12-9936 work great for certain things (Lexan for example) I think the blades are just too short to be efficient for the task of cutting cardboard.

I really like the #4 Fiskars 12-7927 “Titanium Nitride Ultimate Craft” scissors. Like the #2 and #3 thease are a “Softouch” spring return set of shears. They feel good in my larger than average hands so I was concerned that they would be too big for the students but they seem to love them.

I thought that they would also love #5, the Fiskars “Premier Quick-Release Multi-Snip” but for reasons I still don’t understand, they hated them. I’m going to leave them around the class room and see if I can catch anyone using them. They are a little smaller than #4 and seem to have a little bit better leverage due to curved blades. Perhaps this curvature is what they don’t like.

#6 was also initially panned by my young reviewers. These very thin blades tend to flex considerably when cutting thick material but they do work well for trimming little bits of the edges. #8 is basically the same set of blades molded into “Softouch” handles.

The #7 Clauss blunt-tip 6″ trimmer was by far the favorite. They are wicked sharp but also fit smaller hands the best. They are a bit strange in that they have very coarse serration close to the pivot which can leave a ragged edge on one side of the cut but most of the students don’t find it comfortable to open the shears that far so it hasn’t been a problem. I ordered two more pair for the class. As for myself, these shears don’t fit my hand very well and I prefer the spring-opening action of the rest.

Items #2-4,6,8 can be purchased at widgetsupply.com (excellent prices and service).

Items #5 and #7 are from McMaster-Carr (items 3512A21 and 3610A12 respectively).

I found item #1 in the bottom of a forgotten box of glitter and pipe cleaners. A few days into the class the handles broke and we threw them away.

Cereal Box Clock: Working Prototype

I’ve spent perhaps 150 hours working on this in CAD and less than 30 in the studio prototyping. Once all the patterns are printed and stuck to the double thick cereal boxes I think my students will have a shot at building their own in 12 hours of class time.

Materials include cereal box chip board, corrugated cardboard, wood dowel, hand-rolled paper tubes, recycled #1 plastic sheet, and brass grommets. Hot glue and quick set white glue are used for bonding as well as spray adhesive to mount the patterns. Tools include scissors, utility shears, snap blades, flush trim side cutters, sand paper, and a pull saw to cut dowels and paper tube. Class begins on Monday.

Cereal Box Clock

I finally have a complete design. There has been a lot of back and fourth between CAD and studio: design an element, build a prototype, redesign, tinker, second prototype, sketch, think about it for a while, third prototype. So even though I have yet to build a complete clock I do have some confidence that it will work.

But first a vacation back to the Fatherland to celebrate my Dad’s 70th Birthday!

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Wire and Cardboard Escapement Mechanism

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Moments after I took this video the escapement stopped. Then I made “improvements” which made it worse. Likely the whole thing needs to be scrapped but it only took me 30 minutes to make so no big deal. You can’t get too precious with cardboard.