Interesting Race-Girl Scouts-Longish story. Laser Gate Issues?

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race#67
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Interesting Race-Girl Scouts-Longish story. Laser Gate Issues?

Post by race#67 » Mon Nov 06, 2017 1:58 pm

My daughters local girl scout service area staged a race for them this weekend. It was for our entire area, not just her troop so the turnout was large. About 80 cars in four age groups from K thru 12th grade. She was excited to be racing in the main event, and not just against a few other siblings as she has the past few years with her brothers group. I inherited the duty of buying and setting up the track and software for my sons group three years ago, so I was equally excited to "just show up and watch".

We were given a Maximum Velocity kit which is my first experience with. A great kit. One thing DO NOT try using Studio 35 q-tips stems on these wheels. The bores are a tad smaller and we damaged two wheels trying. We got replacements and switched to Tamiya swabs and were much better for it. The Studio 35's went out of the shop and into the house for household work from that day forward:)

Race check in the night before was OK, using two scales to weigh in (booo!!) and little inspection aside from weight and length. Rules were strict, stock slots, no wheel mods, axle polishing only. No verbiage about canting on 4 wheels touching. We built a 3 wheel rail rider .5" thick wedge, CG 1' ahead of the rear axle. Polished and pledged axles, polished and waxed bores. Three inches of drift on a 48" board. Negative camber rears, positive camber DFW.

Race day we finally saw the track. Six lane best track, Microwizard timer, and new to me a laser start gate. Race being run by a local Cub Scout pack. Volunteer race coordinator said in opening statements track was "old and electronics were grumpy". Scoring would be total time of a run down each lane, with the lowest of the six runs being thrown out for each racer. Top two in each of four groups advance to a grand finals. Fair enough. The track did look well used. The sections all sagged noticeably between each joint, creating a ramp effect at each section, fun!

My daughter won her six preliminary heats, and her group. In her third heat in lane six (closest to the hand operated start gate) her car left the line noticeably behind the rest of the field. I am talking the other cars were over a foot down the track before hers moved. She caught them after the bottom of the hill and went on to win the heat be a length over second place. Even the coordinator (also the MC and timer guy running the GPRM software commented about the "come from behind win". He did not seem concerned and I was determined to just be a spectator, so I stayed quiet. Through the day only one other car was near her in speed, but the huge time deviation made it hard to know how close she was. I did notice that her times varied from 2.8xx to a 3.1xx for her first round and thought, "Wow, this track is terrible".

Several odd things happened as the day went on before the Grand Final. In one heat the cars all started normally and ran a typical race. Instead of 3.3-ish times there were in the five second range. The parents in the group brought it up and were told "that is why we throw out the worst time". Eventually they lobbied for a re-run of that heat at the end of the group. The re-run was times all in the 7 second range! They re-ran it again and got 3.3's to 3.9 and all was right with the world.

Finally the Grand finals came along. In heat 1 of 11 my daughter raced the other fast car. My daughter won with a 2.838 to the other cars 2.846. Wow, close, but a head to head win. good news. In heat #5 may daughter raced without the other fast car but posted her low for the day, a 3.272, hmm. This time was slow for her car, but within the average that other cars were running all day so no red flag was raised to the coordinators.
The two fast cars raced again in heat 9, my daughter again won this race but with but 3.244 over the other cars 3.246. I began to realize the cars were so close that it would come down to throw-outs. In the final heat my daughter again raced the fast car but my daughter was in lane 6. She was nervous about a slow start (which I only saw happen one other time that day to another car and captured on film). We also witnessed several cars jump lane six in the flat during the day. I told her gravity would be the judge.

My daughter got a great start and was leading the other car by at least a length as she approached the final two flat sections. Then it happened, Her car hit the transition ramp two sections before the finish line and "wheelied" up and over the rail, dropping the left front between the rails and sliding sideways across the finish before being ejected onto the floor upside-down at the stop ramp! (I also have this on film, it is haunting to watch in slow motion!) Her slide dropped her position in that heat from first to third. Still even with a non rolling finish her time was 2.963, with the fast car winning the heat with a 2.893.

As the race software completed the final race the dreaded "There is a 100% chance that a timing error occurred in Heat 5 as all racers recorded their lowest times of the round in that heat" dialog box popped up. I was sitting next to the coordinator and asked him rather calmly "what does that mean?" (knowing full well what it meant). He said, "Oh nothing" and closed it. So it was time to stress. My daughter won 11 of 12 heats, including two of three 'heads up' against her closest competitor. Even that race she was clearly ahead until she jumped the lane. How would it sort, especially with the wildly fluctuating times. I knew that heat five was going to be here throw-out, especially since her rail riding finish was even faster.

The results were slowly revealed for 9th thru 1st place, and sure enough my daughter's name was revealed for the #2 spot, with a total time of 15.182 to 15.176! I hugged her and told her "great job" and she got a ribbon. I think for the most part she was happy. I was on the outside, but stewed on the inside. We took pictures and went home. It was not until later that night that I was able to piece together the times, by reviewing video my son took to get the times written down.

Here are her heat times by lane:
1) 3.272-Heat 5, flagged as 100% timing error by GPRM. Beat 1st place overall finishing car.
2) 3.147-Heat 3
3) 2.838-Heat 1
4) 3.244-Heat 9, beat 1st place overall finishing car.
5) 2.990-Heat 4
6) 2.963-Heat 11, car jumped the rail and slid sideways last section of track, finished 3rd to overall 1st place car and overall 3rd place car.

So she had a difference of .434 on her best to worst run, and lost by a total of .006 seconds! Standard deviation of here runs was 0.172. Our cars last year had a .003 standard deviation on the track I maintain.

What the heck happened? I did not want to in any way shape or form make any problems for the volunteer crew doing a fantastic thing of organizing a first time derby for Girl Scouts. So I never said a word. I perhaps could have lobbied for a re-run of heat six since her car jumped the track, but the rules did not mention doing re-runs for jumped cars, and actually her car did finish. I think what was happening involves the race organizers enthusiastic son. He was on a chair opposite the person actuating the start gate for most of the races. Some races he would enthusiastically reach his hand out over all six lanes once each time for his loud "3-2-1 GO!" starting count down. I think his chair or body occasionally bumped the emitter of the laser, which was enough to get a false start trigger before the cars were released. This did not affect the outcome of the particular heat so the speak, but it surely would have been altering the times of each heat, which in total time racing is a big deal. If points were used the outcome would have been much different. My daughter had five 1sts and a 3rd for a total of 8pts. The actual winner had three 1sts and three 2nds (the third place car did beat her in a race) for a total of 9pts. I know the scheduling of 8 cars on six lanes is not ideal for points racing....but I digress.

At the end of the day I still feel bad for my daughter, likely more so than her (as exposed in the novel I just wrote) but used it as a teaching moment that nothing in life, especially sports is a guarantee. Some day the best car win, some days a lane jump gets in your way. Sadly I think it was the starting helper and not the lane jump that did her in, but I will not share that with her.
So, in review my questions are:
1) Is a 0.434 run variation uncommon for laser start gates?
2) Is a .17 Standard Deviation a red flag?
3) Is there another possible cause for the time variations
4) Would a sincerely worded letter of thanks but advise on improving future races to the organizers seem like sour grapes at this point?



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Vitamin K
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Re: Interesting Race-Girl Scouts-Longish story. Laser Gate Issues?

Post by Vitamin K » Mon Nov 06, 2017 2:28 pm

Wow, not much time at the moment, so I can't think too hard on it, but those time variations seem WAY out of spec from what I'd expect. In pinewood derby, a few hundredths of a second is enough to put you a car length in front of somebody else. We're seeing variations of 3-tenths of a second. Something is definitely wonky.



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Re: Interesting Race-Girl Scouts-Longish story. Laser Gate Issues?

Post by Scoremaker » Mon Nov 06, 2017 4:31 pm

Race#67
I feel that the laser gate isn't a true time due to that the first car that breaks the beam starts the time. I feel that once's the car's are release from the gate the timer is started. We use GPRM and we throw out the worst heat time. Some people like to use the laser gate and some don't. I would suggest next year that you help with the event or have a suggestion box that everyone can comment how the make the event better. We have a suggestion box every year and it helps us make our race event better we use 3x5 cards with no name's when they suggest something.



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Re: Interesting Race-Girl Scouts-Longish story. Laser Gate Issues?

Post by Vitamin K » Mon Nov 06, 2017 5:42 pm

Scoremaker wrote:
Mon Nov 06, 2017 4:31 pm
Race#67
I feel that the laser gate isn't a true time due to that the first car that breaks the beam starts the time. I feel that once's the car's are release from the gate the timer is started. We use GPRM and we throw out the worst heat time. Some people like to use the laser gate and some don't. I would suggest next year that you help with the event or have a suggestion box that everyone can comment how the make the event better. We have a suggestion box every year and it helps us make our race event better we use 3x5 cards with no name's when they suggest something.
This is absolutely true. I'm not sure why anybody feels a car-started laser gate is a workable solution for timed races.

Don't some laser gates trigger when the gate itself breaks the laser?



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Re: Interesting Race-Girl Scouts-Longish story. Laser Gate Issues?

Post by gpraceman » Mon Nov 06, 2017 5:59 pm

See my post regarding using a laser start sensor.

The simple solution is to use a mechanical switch instead. Every Micro Wizard timer ships with one. If they cannot find it in their gear, they can order a replacement from MW pretty inexpensively. Obviously, they know there is a problem, so why not fix it?


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Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.

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