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I Need A Simple Mechanism

08/06/2011 6:51 PM

I am in need of a simple mechanism for indicating the winner in toy car races. I'll have a wooden track about 40" long, with two cars racing side by side in shallow grooves. I just need a way to show which one wins. I want something mechanical since these kids don't have much experience with electrical stuff and might not believe it. Mechanical, they could trip with their hand and maybe "get it". I've seen something somewhere similar to this, but it's not coming back to me. Worst comes to worst, I'll use dropgates with the other lane tripping the "hold up" latch, but I'd like to be a bit more elegant.

What's more (Oh yeah, I'm being picky), I need something that's reasonably easy and cheap to make - I want to make maybe 5 of these.

Rube Goldberg ideas welcomed!

Thanks.

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#1

Re: I need a simple mechanism

08/06/2011 6:59 PM

Did you want a girl in a bikini that kisses the winner and presents a trophy too?

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#24
In reply to #1

Re: I need a simple mechanism

08/08/2011 4:04 AM

I do!! photos please!

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#2

Re: I need a simple mechanism

08/06/2011 7:50 PM

In the spirit of Rube Goldberg:

Two vertical tubes the diameter of a marble that feed downward into a single tube the diameter of a marble. This "Y" tube assembly is in between the two tracks. Each upper tube has a different color marble in it. Marbles are held up by a pin running across the tube. Each pin has a ring on the end of it and the ring is stretched tight across the car's lane. Each lane has it's own pin & string. The first car to hit the string will pull its pin and cause that color marble to drop first. The color of the first marble in the tube indicates the winner.

The far side of the pin may need to go into something like a pencil eraser to allow some tension on the string without pulling the pin out of it's hole in the tube. Or, dropgates and strings or rods release the marble.

Possibly PVC tube and a "Y" fitting for the tubes? Drill holes or cut gaps to allow the colors to be seen.

To make it more fun for the adults the dropping marble hits a lever that pulls on a long string and releases another marble from a higher altitude. That higher marble rolls down a curving track, causes an iron to drop on an ironing board, drops a cage over a mouse and does something (I forget what) to a tea kettle.

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#5
In reply to #2

Re: I need a simple mechanism

08/06/2011 9:46 PM

That sounds good too, but I'd probably just lose my marbles.

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#3

Re: I need a simple mechanism

08/06/2011 7:59 PM

The ribbon: cheap, simple,

Principle: a ribbon is over the tract, first on arrival takes it. Second NADA.

The ribbon can be: sticky, shiny, dry, weatherproof, colored and can give a nice appeal to your ugly wooden track with dangerous grooves. Are there no safety regulations?

I have a plan B in case I get no good points - 2 flags, one on each groove, but this is not approved yet and very tricky (can be cheated on)

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#4
In reply to #3

Re: I need a simple mechanism

08/06/2011 9:44 PM

I don't gotta show you no stinking safety features.

That might work. Colored Christmas Scotch tape - the winner gets it, the loser gets zilch. That's not a mechanism, but it's so simple even I could make it. Course, it might not stick to a moving car. What's plan B?

I could use a lever flipped by the two cars and let the lever grab the tape. I probably could even use Velcro if I had to.

A GA. Thanks.

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#9
In reply to #4

Re: I need a simple mechanism

08/07/2011 12:40 AM
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#10
In reply to #4

Re: I need a simple mechanism

08/07/2011 12:57 AM

Read this first.

All went wrong. Our Cat designer died. My browser failed to combine this proza with the image.

As promised PLAN B. While safety is no feature we continue in destruction:

This system needs some space on the track (central), or in the track or under the track. If you drill some tiny holes in your wood, you need no bearings for the first 300 races. Because of the economic situation we propose 1 flag (stiff = viagra type)

It will create less jobs but will cut expenditure with a higher profit margin.

I hope this decision to change the 2 flag gig, is not too disappointing. Please don't get depressed.

I have no idea of the scale of your racing business but the flag pole can be e.g. a TIG welding rod that has to be cut and bend to specs.

The triggers can be paperclips, they come in all kind of sizes. The spring can be a modified ball point pen one.

I have not written a user manual yet or a troubleshooting sheet and the copyright is herewith free to you.

The two triggers put the flag in a pre-stressed (spring) center position. First trigger moves the flag to its track.

Have fun

Your cherry.

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#11
In reply to #10

Re: I need a simple mechanism

08/07/2011 1:17 AM

Although I don't understand anything you've said so far, I think you are on the winning track. Be it right or left.

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#6

Re: I need a simple mechanism

08/06/2011 10:29 PM

Okay I'm not so sure about the "cheap" part but this is inexpensive and will remove all doubts! Forgive the lame "paint job" but I'm tired and about to sack out after I post this. Before you bite my head off it isn't a complete schematic, but if you understand electricity you'll get the main reason of what I'm emphasizing.

So if you look at the first pic you'll see each lane has an embedded micro or momentary switch. So lets say Lane 1 wins...what happens? Coil 1 is activated. If you look at the lower diagram you'll see Coil 1 has 2 contacts labeled "R-1". BEFORE the race started BOTH LEDs were lit. Once Lane 1 was the first to cross the lower set of contacts were activated. Lane 2's LED goes out and stays out, and the coil for contact A opens and prevents Lane 2 from activating Coil 2. Lane 1's light stays on and it's time to pop the cork on the champagne! Should Lane 2 be first the inverse happens.

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#14
In reply to #6

Re: I need a simple mechanism

08/07/2011 1:37 PM

I ain't gonna bite yer head off. Thanks for the idea. I want to find something mechanical if I can. I'll only go with that new-fangled electricity if I have to.

Cheers and get a good night's sleep.

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#18
In reply to #14

Re: I need a simple mechanism

08/07/2011 2:00 PM

If you go with a piece of tape or ribbon you can still get a lot of mixed results. It's a very short distance so the races could be very close, like in millimeters. If it was a ribbon and the second car was finishing with more speed it could cross the line second but still have more momentum and appear to win as it took the ribbon off the winners bumper.

In reality its just a few 12V relays, a 12V source (batteries) and a few cents for resistors and LEDs. And as to it being a kids toy, what kid doesnt dig LEDs???

But I admit the only real part that's mechanical is the micro switch.

Whatever you decide on you should post a few pic for us to admire.

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#7

Re: I need a simple mechanism

08/06/2011 11:57 PM

A single long bar over all tacks movable in slots at both ends and spring loaded, when spring releases all tacks door will get closed, A rat catcher like trigger provide on all tracks to release the spring force. Car that hits trigger first will close the doors for all others.

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#8

Re: I need a simple mechanism

08/07/2011 12:38 AM

Wow, talk about weird responses to what is obviously a child's game.

Girls in bikinis and electrical circuits? Come on.

With a 40" track the cars must not be very big, so I'd keep it as simple as possible. Go with the trip gates. The kids don't care about sophistication at that age. You might find a way to have the winning car knock the runner-up off the track and wreck.

Good luck.

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#15
In reply to #8

Re: I need a simple mechanism

08/07/2011 1:40 PM

Ooh, I like that! Just a small hydrogen rich atmosphere at the bottom and the winning car strikes a flint for the other track. Crikey, the kids'll love it!

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#20
In reply to #15

Re: I need a simple mechanism

08/07/2011 11:26 PM

did nobody mention firecrackers? perhaps this is going to end up on the 'crazy things parents do for their kids' thread...

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#12

Re: I need a simple mechanism

08/07/2011 3:41 AM

Although it isn't purely mechanical, how about a "photo finish" Webcam, with a way to store the last second's worth of images as the racers cross the finish line? The right two adjacent images from this set should resolve any questions.

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#16
In reply to #12

Re: I need a simple mechanism

08/07/2011 1:41 PM

Yeah, that was a fall-back idea. With everybody carrying a cell-phone camera these days, they could get into that pretty easily.

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#13

Re: I Need A Simple Mechanism

08/07/2011 11:26 AM

This sound like the Boy Scouts "Pine Box Derby" type of racing?

If you have ever played with Mattel "Hot Wheels" when you were a kid you would remember the simple Finish Line mechanism they used to sell with their racetracks to indicate who the winner of the drag race was. Ohhh my, I'm dating myself back to the late 60's and early 70's! LOL My mom still have those cars and tracks that my brother and I used to play with....my kids, nephews and nieces all played with them too when they younger. They're probably worth small fortune now days as they're all in great shape! Still love the chromed Mustang and Barracuda I received when my Bro and I joined the Hot wheels Club back in ???1969???

May you could take a look at one and make a reasonable facsimile of one out of wood or glued together plastic parts......ie, make a modified version of it, but not copy it per Se. Not sure if the patent is still in effect for that gizmo or not. If you're not selling these you will probably be okay, but then again I'm not an attorney either...

Good luck playing with the kiddies! Wish I was there too, as the Pine Box race cars are always pretty kewl!!!! Now I play with HO railroads and HO slot-cars (the 'ole Aurora AFX cars to be exact) instead......

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#17
In reply to #13

Re: I Need A Simple Mechanism

08/07/2011 1:43 PM

Yeah, that's what I'm trying to remember. All the pinewood sets use electronic timers these days. But the Mattel idea might be good if I can find one. I'll watch yard sales.

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#19

Re: I Need A Simple Mechanism

08/07/2011 10:54 PM

Why reinvent the "wheel"? The system you are requesting help on is almost identical to that used by Cub Scouts for their "Pine-wood Derby". A gravity track with several lanes, a parallel starting gate at the top and some kind of "first finisher" indicator at the bottom. Contact the local Cub Scout Pack and ask to see their arrangement. If your requirements are similar to theirs they may let you use it. The best thing about that would be you don't have to store it!

To find the local Cub Scout Pack, not the Boy Scout Troop, ask some 7-10 year olds who runs their pack. If that doesn't work ask their parents. If all else fails look in the telephone directory for the local Boy Scout Counsel. There usually is one every few county's, at least in the USA.

When I was involved with this in the early 80's we used three reputable individuals to "eye-ball" the finisher with the Pack Leader having the final tie-breaker authority if necessary. Being tall and of muscular build usually helped me when it came to having to make the decision. Now I have seen sophisticated optics with elap. time indicated for each vehicle. I even saw one which does a photo finish just like at the horse race tracks! Each contestant was eventually given a CD of all the races and all the finishes.

Good Luck, Old Salt

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#21

Re: I Need A Simple Mechanism

08/07/2011 11:27 PM

How about a couple of pieces of paper that the cars run over? They start off bent up enough that they don't touch at the center line, even though they are angled to make an arrow showing the direction of travel. After a run, it is easy to see which one is on the bottom. A little bit of fancy bending to make a very shallow cone in the middle can make the paper strips snap either up or down, to hold the reading better.

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#22

Re: I Need A Simple Mechanism

08/07/2011 11:37 PM

I think you just need a 90 degree cut pivoting wooden gate.. that intersects each lane at 45 degrees. When the winner passes through, it pushes the gate out of the way, which increases the blockage of the second lane, and if the race is close, can stop the second car completely.

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#65
In reply to #22

Re: I Need A Simple Mechanism

08/29/2011 12:22 AM

und mit sharp difference 2 dead or gate "kaputt"

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#23

Re: I Need A Simple Mechanism

08/08/2011 1:05 AM

A very simple and always entertaining method would be to blow up balloons and attach them at the end of the track. Afix a pin to the racers nose that is equal to the other racers' nose, and whichever balloon blows first is the winner. Good audio visual effects too boot.

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#25

Re: I Need A Simple Mechanism

08/08/2011 4:10 AM

Where is the fun in really knowing who has won, I say let them argue who was first, its much more fun.. IMHO!

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#26

Re: I Need A Simple Mechanism

08/08/2011 4:23 AM

When I read the question I came up with two mouse traps mounted on a goal post over the track with a vertical rotating shaft in the centre holding four flags, draw, win, draw, lose. As the winning car trips the mousetrap (extended wire on the cheese holder), the spring hits a pin through the shaft and turns it trough 90° so that the win flag (starts positioned up stream) is rotated to over the winning lane, and the lose flag moves over the other lane. At the same time the other side of the pin is rotated out of the way so the spring tripped by the second car won't hit it. If both cars trip at the same time, the two springs hit both sides of the pin simultaneously, the shaft does not rotate, and a draw flag is shown over both lanes.

Then I read the answers, and I like the marbles better than my idea.

From a health and safety point of view. A child with a marble stuck in it's throat is a hospital job, (mine once got a marble stuck up her nostril), whereas as finger in a mousetrap is a "there, there kiss it better and don't do it again job"

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#27

Re: I Need A Simple Mechanism

08/08/2011 10:11 AM

You seen the "no entry/ barrier one way spikes" www.borderlifting.com

Make similar (and install the opposite direction taht the spikes goes down upon contact) and fit on finishing lines on all 5 tracks. Each spike with spring and linkage (linked to a small flag x 5 flags each with each track). So the moment any car hits its end line first the flag will come up.

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#28

Re: I Need A Simple Mechanism

08/08/2011 11:05 AM

I conducted these type of races for 15 years for the Royal Ambassadors of our Church's Association. Based on this experience I strongly suggest you look to an electronic device like Fredski drew up.

Originally I tagged Preachers to be the judges but they can be indecisive on close races and caused more controversy than the cars.

Many of us tried to come up with a workable mechanical device that was 100% accurate but because of "ties" where the cars finished just mm apart the mechanical solutions did not work. Also since we ran double eliminations, you do not want to destroy the cars.

Two electronic (experts) built detector systems for us but neither worked well.

I eventually designed and built one using IC's and a few other parts with the "switch" being small brass hinges that struck the head of a brass screw for the contact. The "black box" sat in between the tracks at the finish line. You pressed the reset and a green light came on by the reset and the race indicator lights were dark. When a car tripped the hinge it latched the other circuit out and a Green LED glowed on the winning side and a Red LED glowed on the losing side. To "prove" it worked to the racers (read parents) we let them try to fool the indicator. No one ever did. The kids loved the Christmas Tree and we never had anyone argue with the results. A few even asked to see inside the box. The cost of the materials was less than $10. I can supply the schematic if you want.

One suggestion on the races, if you have a tie always have the cars switch lanes and then rerun the race. I have never found a track where all the lanes were identical and most of the time the second race was decided by a half a car length or more.

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#29
In reply to #28

Re: I Need A Simple Mechanism

08/08/2011 11:07 AM

thanks Griz! Some people know a good idea when they see one

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#30
In reply to #29

Re: I Need A Simple Mechanism

08/08/2011 11:12 AM

Fredski your idea is good but I read somewhere he requested mechanical for kids and not electrical.

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#31
In reply to #30

Re: I Need A Simple Mechanism

08/08/2011 11:18 AM

I read and comprehend quite well (most of the time). I actually took the time to consider his problem as well as the fact that he came to a group of engineers for a solution. My idea (depending on what final configuration he wants) costs about 10 bucks. It will never be wrong, there will be no ties or arguments. And as Griz suggested they should have to run twice, switching lanes for each run.

So try tape or ribbons or 2 cars hitting a gate and "almost" the same time...nothing but arguments. So yes I deviated from his original request but I gave him more than he asked for. The ribbon or tape method is weak, mine is an actual solution.

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#38
In reply to #28

Re: I Need A Simple Mechanism

08/08/2011 2:38 PM

I know the electronic solution would be "better". I even have a pile of 12 V relays in the basement that I could use and still make it "Rube Goldberg". But I'm old. I remember mechanical dogs on railroad logic circuits. Humor me.

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#32

Re: I Need A Simple Mechanism

08/08/2011 12:11 PM

Try something like this using a piece of wire. Create a wedge about 2 to 3" long with a pivot arm. Drill a hole in your track medium for the wedge to pivot on. Before the race center the wedge at the medium. The car that makes it furthest through the wedge is the winner. See pictures below, Car in line "B" is the winner. A thin piece of wood cut in the shape of a wedge and a nail for the pivot would probable work as well if not better. Please don't tell my boss what I've been doing for the last hour.

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#33
In reply to #32

Re: I Need A Simple Mechanism

08/08/2011 12:13 PM

Your secret's safe with us.

I think you've hit on a simple solution.

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#40
In reply to #33

Re: I Need A Simple Mechanism

08/08/2011 3:14 PM

Thanks, Lyn

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#34
In reply to #32

Re: I Need A Simple Mechanism

08/08/2011 1:44 PM

Score one for the vintage flash drives used as cars.

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#35
In reply to #32

Re: I Need A Simple Mechanism

08/08/2011 1:47 PM

I like your solution and it should work in any case where the cars rectangular or at least similar in shape.

The two conditions where I believe there will be a problem is:

1. The contestants are similar shape but arrive within mm of each other with the second car having slightly more mass. There is a possibility of the second car forcing it's way farther into the trap.

2. One contestant builds a car that is shaped like your jump drives and the other builds something resembling a rail (Top Fuel) dragster (very pointed front end with narrow taper to the rear) or a car shaped like a wedge (very low front tapering to higher rear). In both cases the tapered car could be the clear (visual) winner and yet the slab sided car would trip the indicator first and be shown as the winner. The wooden vane/wedge would help but not eliminate the false result.

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#37
In reply to #35

Re: I Need A Simple Mechanism

08/08/2011 2:37 PM

IBGizzly,

Your right, I just had a race with an ice cube relay. Clearly the relay won, but without my high speed camera you would have though the vantage stick drive was the winner. I guess using this device you will have to have classifications in the vehicles you race.

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#39
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Re: I Need A Simple Mechanism

08/08/2011 2:43 PM

If it is Pine wood derby style racing it will be the wheels that win the race not the nose as the wheels are standard on all cars. So the wheels will be the item triggering the mechanism.

The micro switch is a good idea but one upping that is a light reflective relay at the end of the track that turns on the winners light at the top of the track.

Break the beam and you win.

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#50
In reply to #39

Re: I Need A Simple Mechanism

08/09/2011 9:02 AM

The wheels touches my no-entry barrier which triggers the flag. I win

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#58
In reply to #50

Re: I Need A Simple Mechanism

08/10/2011 5:57 PM

That is NG. It's the most extremity that crosses the finish line first that wins, not the wheels. BTW, I think this is a great question; getting back to basics that sometimes eludes us.

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#59
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Re: I Need A Simple Mechanism

08/10/2011 6:15 PM

"Psalm 109, verse 8", A prayer for our leaders

Very Wise Psalm for our current administration.

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#36
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Re: I Need A Simple Mechanism

08/08/2011 2:33 PM

I do like that!

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#41
In reply to #32

Re: I Need A Simple Mechanism

08/08/2011 6:13 PM

This isn't the mechanism I remember, but it's so darn clever I made a mockup. It works and it's cheap and easy to make. I haven't figured out how to add flames and explosions, but we'll see.

I widened the wedge a little, added side walls on the outside, put a felt washer under the pivot to give it friction and put a crude pointer on the front. Either car now jams in the wedge, but the winner shifts the wedge, turning the pointer, before jamming. The angle is shallow enough that the loser can't backdrive it. Oh, I made the wedge solid so it couldn't deform.

Thanks a ton. That's good for 25 000 points. Save those points. I don't know what they're good for, but you never know.

For my critics-in-waiting, I really do have a set of ultrasonic rangers that will give me the velocity and position profiles all the way down. I'll break those out after everybody buys into the results of the mechanical indicators.

I'll post photos as I get these up and running. Thanks to all who helped me. I spend my days around non-engineers and I lack good people to bounce ideas off.

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#42
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Re: I Need A Simple Mechanism

08/08/2011 7:01 PM

Right on!

Am I correct that the width/shape of the cars is fixed, or at least not an issue?

Send pix.

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#44
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Re: I Need A Simple Mechanism

08/08/2011 9:34 PM

Not an issue. It's like racing at Pimlico; only the nose counts. I'll get pix.

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#45
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Re: I Need A Simple Mechanism

08/08/2011 9:55 PM

Really? How about a swordfish nose?

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#46
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Re: I Need A Simple Mechanism

08/09/2011 3:36 AM

You should probably do some testing of "photo-finishes" -- if the cars are closer than a few millimeters, you may not get an accurate indicator with the mechanical device.

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#47
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Re: I Need A Simple Mechanism

08/09/2011 6:46 AM

We'll just call those "ties". Although, I'm told, there were more ties in horse racing after photo finishes were added.

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#48
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Re: I Need A Simple Mechanism

08/09/2011 8:30 AM

Excellent, we look forward to hearing from you about how your racing track it turns out.

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#43
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Re: I Need A Simple Mechanism

08/08/2011 8:53 PM

I thought your idea pretty clever, and TVP45 has clearly identified yours as a GA.

So, I vote accordingly. Well done!

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#49
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Re: I Need A Simple Mechanism

08/09/2011 8:34 AM

Thanks, Doorman

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#60
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Re: I Need A Simple Mechanism

08/11/2011 8:53 AM

Very Good and creative. GA.

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#62
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Re: I Need A Simple Mechanism

08/11/2011 3:28 PM

Thanks, rakest

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#51

Re: I Need A Simple Mechanism

08/09/2011 9:12 AM

Give me your address. If you don't make it, I will come to kill you. My in-box is getting 5 incoming messages by the hour.

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#52
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Re: I Need A Simple Mechanism

08/09/2011 11:55 AM

its the cops, at the in box Mr. killer

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#53

Re: I Need A Simple Mechanism

08/09/2011 4:10 PM

When I was young I recall my matchbox cars had a mechanical device to show which one was the winner. It looked like a single flag on a pole which sat in the middle between both tracks. The flag was hinged so it could fall left or right onto either track. Holding up the pole on both tracks was a lever. The first car to pass and press the lever would cause the pole to fall onto the track of the car that won.

I found a picture of what I was trying to remember, not quite what I recall, but this is what I was trying to think of.

http://2.bp.blogspot.com/_BXiLAmoEpMI/TPR7YPd3diI/AAAAAAAAHjg/9Oox4U6gzjY/s1600/Pinks%2B2.jpg

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#57
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Re: I Need A Simple Mechanism

08/10/2011 3:59 PM

Hey Frank, that's a Mattel Hot Wheels track and finish line gate in the pic, not a Matchbox one. See my posting (#13) above.

Thanks for the pic, and for bringing back the great memories!

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#61
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Re: I Need A Simple Mechanism

08/11/2011 11:43 AM

I figured someone had posted about this before but I didn't catch it in your post when I looked over the thread.

I guess when I was a kid match box and hot wheels were the same thing to me, I vaguely remember now that you say it that there were two different brands. I think the tracks I had were the hot wheels ones then because they look just like the one in that picture. I have a lot of the tracks and cars from my youth in a box although I don't know how good of shape they are in, they were heavily used and abused. I was going to look and see if I have the finish line thing somewhere in that box but I haven't had a chance yet.

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#54

Re: I Need A Simple Mechanism

08/09/2011 4:29 PM

The picture in my first post is the one I remember but I found a slightly different design on ebay, although the principle looks to be the same.

Here is the link for the ebay search on "matchbox finish line" for as long as it works.

http://shop.ebay.com/i.html?_nkw=matchbox+finish+line&_sacat=0&_odkw=finish+line&_osacat=0&_trksid=p3286.c0.m270.l1313

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#55
In reply to #54

Re: I Need A Simple Mechanism

08/09/2011 4:46 PM

Thanks. That's similar, though prettier, to what I had decided on before dkriley greatly simplified things.

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#56

Re: I Need A Simple Mechanism

08/10/2011 11:29 AM

It wasn't fancy, but we had a finish line that worked well for our matchbox cars. A flag with a central pivot point was held vertically between two flexible plastic pegs. When a car would cross the finish line, it would push back the peg allowing the flag to fall. To make sure that the flag fell the correct direction, the pegs exerted a force from the side that would force the flag to the side where the peg had been disturbed.

The following video shows what we had, but the video quality is poor.

http://www.youtube.com/watch?v=kR8beTLccR4

If needed, I could produce a sketch to try to detail this device a little better than in the video.

I also see that Sears or Kmart may have a track with a functional finish line.

http://www.sears.com/shc/s/p_10153_12605_004W730427110002P?i_cntr=1312989194269

I also found this post for a pinewood derby finish line.

http://www.uchobby.com/index.php/2007/05/21/pinewood-derby-finish-line-detector/

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#63

Re: I Need A Simple Mechanism

08/12/2011 11:49 AM

This is not about the detector but an observation on this type of race.

As race director, I noted early on that the best built/designed/painted etc. cars were from the 1st and 2nd graders. All races were divided into classes by age group so we added an additional class...Open. This was for anyone else that wanted to enter a car including parents, counselors, preachers, sisters, etc.

The effect was that at the next race all the 1st and 2nd grader's cars looked age appropriate and the Open class now had all the "fancy", detailed cars. The open class generated as much excitement as any of the others and sometimes more "debate".

After all class winners were determined, we had the winners run for "Top Eliminator". The winner of this race then raced the winner of the Open class for "bragging rights". It generated a lot of fun trash talking and bragging, especially when the Open class lost.

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#64

Re: I Need A Simple Mechanism

08/12/2011 3:40 PM

We all had Hotwheels when I was a kid and used these:

http://www.youtube.com/watch?v=kR8beTLccR4

*****

Opps...I should have read all the way down....

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