Derby Talk

Wow those numbers don't equate so well with that site, perhaps the mesh size is significantly different.

Lead is reported to have a density of 11.34 g/cc After reading FS's related topic... I found this tungsten powder web page . And it reports the density of their tungsten powder packed in (tap density) as 11.25 g/cc This page also reports the non-packed density (bulk density) as 18.50 g/cc These two ...

... But I'm wondering if I woudn't be better off keeping the rear holes high and just lowering the DFW axle hole slightly to allow room to raise the the non-DFW axle hole. Keep in mind this will mess with your camber if you drill for that vs bending axles. Other than that I doubt the typical racer ...

Here's some pics and a short video of the the first and last race. Great event for the younger kids. Gotta keep it movin' though as they get rowdy. Getting staged... _____ https://lh6.googleusercontent.com/-LERYgbkcnCM/URgdAJGzAuI/AAAAAAAAATQ/6nYH1cF3M5I/s549/KoltenMatchboxDerby_20130206_57.JPG The ...

no personal experience with modeling this stuff, but I once used a lightweight drywall filler/patch. It was probably good for joints that were suspect to move becuase it never fully hardened, but was still kinda sandable. But I specifically remember it being very light.

Wish I was closer, I'd take it off your hands.

rail riders usually produce fairly consistent times. Those times seem fairly scattered for both cars even though run on different tracks. Adding graphite to any car will give the illusion that the car got faster because the first time will usually be slower. I would be hesitant to draw the conclusio...

Would it make sense to make rail-rider test cars? I think so, but they would have to be built so as to have the greatest chance of getting affected by a bad joint. Have two cars--one car with the DFW on the left, the other on the right. That means two cars, right? Or would a well-designed thin car ...

I'd leave it alone for only 4 races. I added extra this year in preparation for 20 races (we only did 7). It took 4 races for the car to finally break free and start turning better times by .01 for each of the last 3 races.

Positive camber the DFW (if your rules allow) and you won't need to worry about jumping the rail if aligned properly.

Here's what we did this year from inspiration of the Scrollsawer's first post in this thread. We didn't have thin wood to make a shelf so I just used a small end mill in the drill press and milled out the weight pockes and left maybe .02" at most on the bottom. Easy to see light through. I didn...

Very professional looking!

TedBull wrote:...But I have read that oil produces more speed...

Oil done "right" will produce more speed. Done wrong and it will be slower than graphite or rather is implied. I can't be of much help with what is "right" as I haven't done it yet.

What about the hot wheels radar gun..........I know there cheap and they say they work.and you tube has a guy that dismantled one and made it bigger using house hold items..( I THINK) but you'd have to search for it. A radar gun would give you a speed of a car at a certain point. I would wonder jus...

Oh my... Now that is what I was looking for. Gives me something to think about and I think I almost understand the basics of the two ideas. With the first one it seems we may be able to control how much a car may come off the rail by making sure the net drag thingy stays close to the CM thingy majig...