Friday, June 12, 2009

37> Coming …Soon?

At the very beginning of this blog, I envisioned the possibility and intention of collaboratively designing a PRT system, and I have taken a step in that direction. The first problem was the fact that not everybody who could make a valuable contribution to a design has access to, or knows how to use, AutoCAD, or even a vector based drawing program. (Or a decent paint program for that matter)
Alert reader and frequent commenter akauppi, when asked about this matter, suggested Inkscape for a Drawing program and Acorn for a paint program, both free to download. Apparently Acorn is only for Macs, but I have found what I consider to be a great, free paint program in Paint.Net, which, by supporting layers of variable transparency, allows on-screen positioning of separately created parts. The most exciting to me, however, are the tools provided by Google. Besides hosting this blog and my email account and analytics, they give away a very competent 3D design program called SketchUp, which I used to draw the second illustration of the last post. But there’s still more. Google also hosts space and tools for project collaboration. Although they are intended for code development, there is no reason why they can’t be used for the design software listed above. They even include tools for revision control and a wiki. So coming soon, you’ll be able to modify my designs and post those revisions. But I have to warn you, I know very, very little about SVN (look it up in Wikipedia. I had to) and Sketchup takes time to learn as well.. Meanwhile, a simple question was asked about my last post. What’s so special about the layout of those wheels? (Refer to the illustrations from the last post) well, if akauppi, doesn’t get it, I guess I better explain for all.
A good design begins, foremost, with a good understanding of what you’re trying to do and what you have to work with. In the case of all of those wheels, vs. the expected forces exerted on them, it is geometry. Move the wheels up or down, forward or backward, and the performance changes. (I would like to note, however, that these illustrations are consistent with PML’s wheel-motors and my scheme for climbing steep slopes) And then there is the track (which, because track is reproduced into infinity, is really, really important to get right)
I could write a few paragraphs on every dimension and every angle, but have not, because I recognize that I have attracted many readers who are not engineering oriented, and this is a good thing, because we’re not designing transportation for engineers. This blog has attracted a group of very thoughtful contributors, and I feel confident that the core design issues are being dealt with in a forum that will eventually yield superior results to the “top-down” approach that commercial enterprises have to use. I want to urge patience, however, because good designs take a long time, even for teams of full-timers.


akauppi said...

Good luck with the "PRT bazaar" approach, Dan. (You may use the name if you like).

If you wish to ask something about svn, just trouble me. I've been using it for 5+ years now I guess, and it is a good work horse. I find it simple, as well.

Another good technical resource is If only to join and see how an Internet 2.0 time interactive FAQ engine works. It's cool.

"Alert reader and frequent commenter" bows in and retreats. :P

A Transportation Enthusiast said...

Google Sketchup is a good tool to use, not only for the reasons you mentioned, but also because it has direct integration with Google Earth, so once you get to the point of guideway design you'll be able to visualize the guideway in 3d in an actual city. Many cities are already modeled in 3D on Google Earth.

michaelmclay said...

Take a look at Not only could you build 3D models of a PRT system, you can also animating the PRT system in motion. The Blender game engine could even be used to take it to the next level and build a complete operational model of a city's system and then use a traffic simulation application to control the movement of pods within the game.

Blender can import and export many file formats including the AutoCad design files and the Google Earth files. It is open source and includes a Python API, which makes adding custom extensions to the tool very easy. (Most of the import/export filters are written in Python.)

Dan said...

Dan The Blogger Responds-
Thanks, akauppi (a.k.a. Asko) but not to confuse my readers….I guess the first thing to do is to start with something that won’t get “round filed” a week later. (That’s the one down at the curb) Right now all I get out of SketchUp are components that are slightly mis-aligned yet fused together, and I really only have estimations of wheel size, wattage, turning radius, weight, etc. Anyway, I guess svn is in my future.

Welcome back, A Transportation Enthusiast, … Yeah, that thought has crossed my mind. I should have put that fact out front in the post. Maybe I’ll have a contest for the best station design some day.

Welcome to the site, michaelmclay,
I had run into Blender in my search before, but was a bit intimidated by it. I have a lot more experience building real machines than virtual ones, and I have very little spare time to get proficient at new programs. It is obvious, however, that Blender is an awesome program, and I would encourage my readers to check it out. I will also put out the call for any Blender users once I get the svn thing going. I’m not sure how many SketchUp users are reading my post either. My principle concern at the moment is to be able to allow as many mechanically inclined people as possible to be able to move components around and resize them and study how they interact. Frankly, an interactive “white board” would practically be good enough. As for the animations and simulations, that would obviously be of tremendous benefit, both for this blog and for PRT in general. All I need is volunteers. I would add, however, that 75% of all readers I’ve ever had have discovered this blog in the last 30 days, so anything is possible.