Derby Talk

Changed the video link in the first post to a longer video with four runs.

Maybe try searching .edu's for course content. I haven't found many cheap references on the topic. If nothing good shows up, I'll try to get around to making a short write-up on the relevant terms. There is some risk of me not getting something quite right, but should be good enough for pwd. Some of...

(This is a request for citation sources for metrological nomenclature and definitions, as available.) ASME Y14.5-2009 is the latest standard on Geometric Dimensioning and Tolerancing, but it will cost you. Much more common at this point is the Y14.5M-1994 version. These standards are quite technica...

Yes, the third switch is the master power switch, aka the arming switch. It is a push-on, push-off switch that is recessed in the body, and requires a pin or spare pwd axle to operate. This is to keep inconsiderate people from being able to turn the car on. In line with this switch is a flashing LED...

that body is pretty neat, would enjoy trying to add than onto a thin wedge and see how it goes. Sporty Well, the material is pretty dense. The body and subframe for this car (3"x8") weigh about 2 oz. For just a derby car cap, maybe it could be 1 oz, but that would still hurt weight placem...

Here are some screen shots with the body shell transparent: In the top view you can see the motor and gears (teeth not modeled) and the three switches (arm, start, and cutoff). All of the drive and electronic components were assembled to the subframe, and then the subframe assembly was attached to t...

The body is "printed" on a Z Corporation Z510 rapid prototyping machine that I bought for our center last year. I designed the body with CAD software, then printed it out. The material is a plaster powder that is bound together in layers with colored binders (the Schlumberger logo was prin...

Rod Turnbull wrote: Any one got some official BSA wheels I can put on this?

I have a BSA wheel modeled in Pro/Engineer, but I don't know what format I could export to that would let you use it in Sketchup...

Just got the data, my times were:

1.686
1.678
1.695
1.664
1.662
1.662
1.669

That's it. Not many cars in outlaw this year, so not many runs.

My company location has a yearly PWD competition (usually in September), and this year I entered my second electric motor powered, direct-drive car in the Outlaw division. Last year's entry performed okay, but stopping was the problem, and DNF'ed due to damage. This year I changed from rear-wheel dr...

That sounds like it should be fine for the "oil crowd", but what about those of us in the "graphite crowd?" How many months can a car sit in our humid Houston (or Peoria or Seattle,...) environment between pack race and district race before performance degrades from corrosion if...

Another question ... since even basic work on axles leaves bare steel exposed (shaft and nail head ridge removal), how long should one expect the "polished steel surface" to be sufficiently free from corrosion ... sufficiently free as to not affect car performance? How do various lubricat...

Looks like a lot of drag area to me. If you are going to have the full body, at least go for an airfoil shape, with as much taper in the back as possible.

Argh, I had replied to this earlier, but apparently it didn't take. Looking at this from the viewpoint of energy: The energy spent through friction is equal to the frictional force times the relative distance traveled between the frictional surfaces. Power is the time rate of work (expending energy)...

For Derby work, even the 7x10 is overkill. It also requires some accurizing, but can be pretty good after that. I have a Unimat-3, which is a nice size. Harbor Freight sells a Micro Mini Lathe that is very similar for less than $300. On my Uni-3, I've turned BSA nails down to less than .040", a...