Driving a unipolar stepper with the Arduino

I decided to get around to playing with the Arduino again. I had a few unipolar stepper motors laying around so I decided that it was about time that I figured out how to interface them with the Arduino. The first hurdle was figuring out how to wire the motors. All three of the steppers are five wire unipolar, but none of them have wires. They all have PCB's with connectors on them. I had a connector or two that I took out of an HP printer so I just had to figure out which wire did what.

Finding the center tap on the motors was easy enough as you do so by using an ohmmeter to check the resistances between pairs of wires. The common power wire will be the one with only half as much resistance between it and all the others. Finding the order of the remaining four wires in the end required good old fashioned trail and error.

When I finally figured it out I made sure to label the wires. The wiring order worked on all three steppers, two of which are Mitsumi's and the third is a Minebea.

It was easy enough to get the stepper to turn once the wiring order was determined. The Arduino stepper library provides a pretty simple method of doing so. The Arduino website gives adequate instruction on figuring out how to use it so I won't bother documenting it again. I just figured that it might be helpful to post a picture of the wiring order that I found to be shared among the steppers that I have so that I may spare someone else the effort of figuring it out in the future.

Toolbox organization

I purchased a new Craftsmen tool chest to hold my ever expanding tool collection, as well as to free my old toolbox to use for bike specific tools. I was unhappy with the lack of organization on my old toolbox. Whenever I opened a drawer tool would roll around and get all mixed up, especially my sockets as they are round and roll quite efficiently.
The first step that I took in preventing tools from rolling and sliding was to line the drawers with something that had a non-slip surface. My toolbox had foam drawer liners but they didn't really have the grip necessary to do anything more than simply protect the paint of the toolbox. I found some Con-tact brand shelf liner at Home depot that claimed to be quite grippy and when I touched it I felt that it seemed much more promising than the liners offered by Sears.
I cut the liner using a utility knife and some flooring that was leftover from my basement remodel as a cutting guide. The flooring had a cork backing that made a nice cutting surface that didn't dull the tip of my knife, and it had a nice straight edge to guide the knife with.
After the drawers were lined(Except for one as I did my math wrong and didn't get enough liner. Doh!) I wanted to make sure that I had somethign to really prevent the sockets from rolling around. I remembered that I had some Komplement drawer divider in the garage that we had forgotten to return with the Hopen wardrobe that we assembled, only to find that our ceilings were are too short to fit it. I had to modify the drawer dividers to fit and to separate the multitude of different types of sockets that I have. I used a utility knife to do this. I feel as though a small hand saw would be much better for this, but I lack such a saw, so the utility knife was what I used. The most difficult part was cutting the notches that interlock the dividers in place. The dividers are thin plywood with three plys and the middle ply was difficult to get though with the knife, but I managed. All things considered, it came out pretty well. I do want to cut the height of the dividers that run horizontally in the shelf, in order to make it easier to get to the tools in the back of the drawer and to add some labels to let me quickly see what the sockets are in each compartment. Aside from that I'm pretty happy with the outcome.

Xmas present for my sister

My sister has said for years that she would ride a bike if I found her one with a banana seat. This year for Christmas I did just that. I happened to mention to my friend Lee that I was hoping to find such a bike to give to my sister and he happened to have one in his basement. Lee has one of everything, by the way. I did some research and determined that the bike was a Ross Barracuda, made in the late sixties to early seventies.
The bike needed a bit of work, but it was in pretty good condition overall. I disassembled pretty much everything, down to the wheel hubs, and cleaned, polished or replaced anything that needed it. I decided not to go to the effort of repainting the frame as the many little rust spots gave it character, in my opinion. The only things that I ended up buying, in addition to the bike, were a bottom bracket and tires. Luckily I found a bottom bracket at Harris Cycle and tires on Amazon. Whitewalls kick ass. Below is the "after" picture. I thought it came out pretty nice and my sister seemed to agree as she jumped up and down in the driveway as I unloaded the bike from the car.