Thursday, May 24, 2012

Instagram center foot

If you've wondered what an Instagrammed photo of a partial center foot would look like, consider:

Wednesday, May 23, 2012

A variety of progress

I won't be doing much droid building over the next week or two because of a cross-town move. On Sunday, my father and I advanced the project in several ways:

  • We removed the outer legs to allow for the center leg drop track and figured out where to drill holes for the power wires from the batteries and foot drives.
  • We installed the tracks for the center leg drop into the frame.
  • We trimmed the center leg and added a trial L-shaped wooden bracket that will allow for the leg to be positioned on the tracks.
  • We sanded down the excess resin on the new radar eye (that'd be the one to replace the first radar eye I messed up with a bad paint job)
  • We cemented most of the styrene center foot together.
  • We assembled the new metal foot drives, adjusted them and tested them.

Sunday, May 13, 2012

Forstner bits

This is my new favorite tool for the next couple of days: the Forstner bit.

Wikipedia, which is always true, all the time (right? right?) says Forstner bits are named after Benjamin Forstner, who invented them in the 1800s. They don't drill their holes so much as plane them with radial cutting edges that scrape and scrape in a circular pattern. Gunsmiths liked them, Wikipedia says, because they can drill very smooth holes.

I like them for that reason and because they are an example of a noun properly capitalized (in this case because they are named after a person). That's the copy editor in me speaking.

They've been useful in making large holes for some of R2-D2's parts, including some pieces for the styrene foot shell I cut today while my father was working on a center-leg drop design.. Here's a Forstner bit cutting a hole for the second foot drive, with my father at the drill press:

Aluminum work

These videos are of my father making the necessary cuts and holes for the second aluminum foot drive on Saturday, May 5, 2012. He is using woodworking tools. The only special equipment used for a heavy-duty metal brake that a neighbor contractor handled and gloves.

Dealing with aluminum turned out to be not much more difficult than working with wood.


Saturday, May 12, 2012

Using wood tools to work aluminum

My father and I spent the morning of May 4 creating the third version of foot drives for R2-D2. These are based on Ted's designs, which he posted under the R2 Builder's Club Yahoo Group files section. We used only woodworking tools for the cutting, drilling and wheel-cutting. A contractor neighbor graciously bent each sheet into the three-sided drive for us.

Dad punching guide holes into the second piece:

Tuesday, May 8, 2012

Foot drives

My father and I have produced three versions of a foot drive in the past year. Each has been designed for the 135-watt Currie scooter motors I bought from All Electronics some years ago.

The first was based on Jerry Greene's drive for R2-R9 and was made out of wood. We included ball casters for support. Since we didn't have plans, I eyeballed the rough dimensions, used the actual motor and wheel to mark drill holes and circles and made a posterboard template for the final wood pieces. It was larger than it should have been for the outer foot shell and had the motor sticking out in the wrong place, but I took it to DroidCon in May 2011 and showed Jerry, who was encouraging. Best of all, when we applied current, the motor turned the belt, which turned the wheel.

The dimensions bothered me. Early this year, I came across Ted's -- buhatkj on the group -- blog and saw a promising aluminum design. It was clean and simple, and Ted had uploaded his design to the Yahoo group three months before DroidCon. I printed the full-sized templates at Staples, and my father and I used hardboard to execute it. The design required cuts for two rectangular sides, drilled holes for the three mounting screws and the motor cap and two circles for the other end of the motor. We cut and added a top rectangular piece with some angle aluminum. With spacers, screws, the belt, wheels and motors, it also turned.

If the hardboard came into contact with water, however, it would disintegrate. My father wanted to try again with the same design, but this time with sheet aluminum. Neither of us had worked with aluminum before, but the foot drives were a project that came with full-size templates and our experience with the other two foot drives. It really was a re-execution of the second foot drive with only a few adjustments. My father ordered the aluminum, I ordered new templates, and on Saturday we went to work.

The cutting, drilling and circle-cutting took only a few hours. The problem came with the aluminum brake my father had bought for the job. We didn't really know whether it would be powerful enough for the job and ... well, it wasn't. We both tried several times and succeeded only in lifting the aluminum and brake up from the workbench and finally in bending the brake's handles.

Here's how we solved the problem: My parents have lived in Cross Plains for more than 15 years now. In that time, they've had work done to their house -- roofing, new tile floor for the downstairs workshop, that sort of thing. They're big believers in the local economy, so for these jobs they've turned to Carl, a general contractor who also lives practically down the street.

Carl said he'd be over in an hour. He arrived as my father was cutting the last hole on the second drive and I was taking video. Carl didn't have the tools to bend that metal, either, but he had a relative who did ...

The job was done Monday. Take a look: