From: lowell@techbook.com (Lowell Brunson)
Subject: Re: Pinewood derby finish (was help. . .)
Organization: TECHbooks of Beaverton Oregon - Public Access Unix
Date: Wed, 8 Apr 1992 18:04:58 GMT

slice@gagme.chi.il.us (Steve Steiner) writes:

>In article <69542@ut-emx.uucp> CCEB001@UTXVM.CC.UTEXAS.EDU writes:
>>Jorgenson@plains.nodak.edu asks how to determine finish order on a
>>six lane pinewood derby track.  I would advise against using such a
>>device.  It is usually pretty easy to pick the winners until very
>>late in the eliminations.  Also, if you race 6 cars per heat, the
>>derby wont last long enough to make it worthwhile to the kids, some
>>lanes will be faster than others, and you will spend more time setting
>>up heats than racing.
>>
>>For 2 lanes photo diodes and a dual trace scope would be a quick and
>>dirty solution.  I just switched lanes and ran the heat over which
>>was adequate to produce a clear winner without electronic aid in all
>>but one case.
>>
>>One pack near us used a camcorder that does slow motion and freeze
>>frames.  Point it at the finish line.  A "blimp shot" is effective.
>>Monitors for the audience are optional.  If you have a choice
>>of camcorders, try them all.  Picture quality varies.  Provide bright
>>light to improve picture quality.  This requires no research and
>>development on your part and no headscratching by your successor when your
>>boy turns 11 and joins the Boy Scouts.  I just (barely :-) lived through
>>this so additional non electronic advice can be had by private mail.
>>
>>Mike.Coyne@utxvm.cc.utexas.edu
>>Coyne@utxvm.bitnet

>The pack that I'm cubmaster of, has built our own track from scratch.  Its
>an eight lane marvel.  It has an electronic finish line, that works on the
>principle that the first car through will push a plastic strip connected to
>a switch, that will illuminate a light over the lane of the winner.  It
>also has the capability to be used as two four lane tracks.  With eighty
>boys in the pack, this is a big win.  Our races now last about one and a
>half hours.  Down from the two to three.  But the best thing is there is no
>arguments about who won the heat or the race.

I programmed my commodore 64 to time up to 7 lanes down to 1/1000th of a
second and enter the times into a spread sheet looking thing.  I run the
race based on the Cub Scout Motto - Do Your Best.  Any boy can run in 
whatever lane he wants to  as many times as he wants to.  I maintain a list
of each boys best time in each lane.  At the end we sort by the best time
in any lane.  I print out the sorted list and give each boy the printout
for his car.  I only make the top three times public.  If the boys want to
compare their times between themselves, that is their buisness.  
  We run the race by age group and also judge for lots of other things 
including paint job, style, etc.  In fact, everyone gets at least one award.
  I like this method since boys who have spent lots of time on a car can
race as many times as they really want to (time permitting).  It is too bad
when someone puts lots of work into a car and gets eliminated early.
  By the way, the sensors interface to the C64 parallel (user) port.  I
used some cmos exclusive or gates with proper static protection on the
inputs.  One of the inputs on the gate is run to a pull up resistor and a
dip switch to ground so I can invert the signal on any line - that way I
can use different sensors.  We borrow the track and sometimes add our own
sensors.
  Good Luck
  Lowell
.

>The track is made from 4 sheets of 4x8 plywood with strips for the cars.
>The finish line electronics, sit on a bar suspended over the track. and 2x4
>for the legs.

>If any one would like more info.  Please e-mail.
>-- 
>Steve Steiner                                 | Telephone: (708)860-2754 (home)
>slice@gagme.chi.il.us                         |            (708)773-5864 (work)
>If the elevator to success is out of order... |   Address: 564 Gilbert Drive 
>Use the stairs                                |            Wood Dale IL 60191
-- 

Lowell Brunson
KC7DX @ N7PWF.OR.USA.NA (Packet Radio Only!)
lowell@techbook.COM  Public Access User --- Not affiliated with TECHbooks