Overkill?

Two ink jet printers, two ubuntu desktops, monitor, KVM, Arduino, Motor Shield, two motors, two shredders, enough T-slot to support the Golden Gate Bridge and a bunch of acrylic. Overkill you think?

Arduino & Motor Shield mounted

The Arduino & Motor Shield that drives the advance wheels is now mounted. Also added a couple of wire strain guides. We have a backup Arduino and Motor Shield just in case! Good news is that one motor shield will drive both motors (hours and minutes) so there is no need for clock-syncing across multiple Arduino's (although that would have been overkill. Who really cares if the hour advances 8ms behind the 59 -> 0 advance... ;-)

Adding covers to the paper guide

Difficult to see in the pictures, but the top and bottom covers of the paper guide are now going on the frame. Have to do this in two stages as I don't have sufficient clamps! Once the covers have set I'll cut out the slot for the wheel.

It's Alive (and keeps pretty good time!)

Ubuntu desktop now configured to print out the "minute hand". As long as the printer doesn't run out of paper and the printer queue doesn't back up we're good to go! Configuring of the second desktop will be done this week (of course I could have used just one desktop -- but over engineering is much more fun!).

Only 5 days now until Maker Faire and much still to do. I have the final design for the hero paper guides and time booked on the laser cutter this afternoon. The Arduino Motor Shield is now built and running smoothly (solid soldering foo in action!). The rest of the T-channel hardware is sitting in a pile in the garage and just needs cutting and assembly. The last shredder is on its way from Amazon as is the black drape. Gonna be a race against time!

Progress with Paper Guide

Laser cut the latest design modifications. The guide now has the braces moved to the front and includes a panel that will support the grabber wheel (to move paper into the shredder). Currently using 5mm Acrylic (the blue you see below is the protective wrap). Also learned how to cement acrylic today thanks to a super video made by Tap Plastics.

Here's the final assembly after the protective wrap has been removed and the parts welded together.

Motor (30:1 gear ratio for maximum torque) and Arduino Motor Shield have been ordered. The Shield comes in kit form so I'll be soldering next weekend!

Paper Guide Prototyping

Booked the 60watt laser cutter at TechShop today. Objective was to cut out the parts for the paper guide from wood (much cheaper than acrylic -- that will come later). Also used the time on the machine to cut out an iPod stand I've been working on (fail on that and back to the drawing board!).

I now have a copy of Corel Draw at home so I can prepare the designs before I get to techShop. Since I did my last Intersession at the design studio at Stanford University I'm much faster at laser set up and operation.

Cut the parts and assembled the with super glue (hey! for prototyping it works fine).


When assembled I put a thin sheet of plastic on the bottom of the guide for the paper from the printer to follow on it's path to the shredder.


Picture below shows the guide in place on top of the shredder, resting in front of the printer. Measurements were spot on. Now the first problem became apparent: the guide is too deep. When the paper exits it misses the shredder enter-slot. Really needs to "funnel" the paper into the shredder. Good news that that is an easy design change. I'll revise the Corel model and laser cut a new guide on Monday.

Building The Stand

Thanks to those fine folks at 80/20 I received the three 96" lengths of T-Slot necessary to build the first clock stand. My Dad switched out the wood blade in the saw for a metal-cutting blade while I calculated the optimal cuts. Once done I sliced and diced for about an hour.

T-Slot looks much less impressive in short lengths! After deburring the ends it was assembly time!


I'm using simple right angle plates to connect the parts. Since the stand is only holding a very light printer and guide cut from acrylic I don't need anything stronger.


After assembly I tried the printer on the stand and dropped the first sheet of paper (with a little manual assistance) into the shredder. Success!