Lap Timer
 

Exciting news, I have everything I need to make a simple ZZ lap timer/counter...all together, materials came to $4...not counting the computer..hehe. I'll build it tonight and if it works, I'll get the plans out ASAP. Wish me luck!

Great! I am looking for a decent timer. Good Luck!

GOOD LUCK!

excellent! especially considering the cost!

i just *knew* someone would come up with a lap timer!

i'm definitely interested! (actually more in the counter capability)...

or you could use this one i used it and it works perfecthttp://www.kyosho.com/gallery/lapcounter.exe

and this file is what? an executable for DOS? for Windows? a statically linked standalone Visual Basic file created by Miguel A. Frontera?

the URL/file won't help me unfortunately - i don't use *any* Microsoft products (too much of a security risk)...

thanks anyway...

its not a virus its from kyosho.com the makers of the mini z it works finehttp://www.kyosho.com/cars/kyod01x1.html heres a link to the site what kind of security risks are you afraid of its a lap counter that you press a button on your keyboard each time a car passes by. and someone could possibly port it to any os.

IT WORKS!!!
 

Woohoo! So here it is...in all it's unfinished glory.

List of Materials:
:eek: Laser Pointer - $21.00
:eek: Phototransistor - $1.50
:eek: AC Adapter - $15.00
:D Software - Free
:confused: Old 9pin or 25pin Serial Port - buried in the junk heap
:cool: Soldering Iron / Solder - if you mod you have this
:) Laptop or PC - I used a 486 DX2/50MHZ laptop with a bad LCD panel..I just knew it would be good for something. Oh yeah, you need Win9x or XP...you might get away with Linux and Wine

How it Works:
You put the phototransistor (light activated switch) on one side of your start/finish line, and then put the laser pointer on the other side and aim it at the transistor. When a car breaks the laser beam, a signal is sent through the serial cable to the PC. The software does the rest. I can see drag racing having one for each lane...the software supports 4 lanes I think, keeps track of laps, lap times, fastest lap, and speed.

The Bad News
It actually costs more than $4.00 because my original idea (flashlight) was a failure, and I had to upgrade to a laser pointer because of the distance I needed the light to travel without dispersing. So, a cheap laser pointer modified to plug into the wall will run you about $35.00, unless you can find a 3v AC adapter in your heap.

The Good News:
You don't have to attach any kind of transponder to your Zip.

More Bad News:
Because there's no transponder, any car that crosses the line is timed, if two cars cross at the same time...well you get the idea. I designed this mainly for drag racing and solo time trials around my track...forget about using this for multi-car racing purposes.

More Good News:
No more guessing about performance increases, track lines, or driver ability.

The Future:
Because the software supports more than one switch, adding a second spaced about a foot apart would give you a nice speed trap for testing high end and/or acceleration on the drag strip.

pics to come.

this is more or less the setup, without the track, which isn't done yet. Because it's a laser, it doesn't matter how wide your track is.

good job would love to see pics i have a hundred spare lap tops around here and dying to use em

you posted em as i was talking


nice find on the software i see me building one for our drag strip good job

the phototransistor only has two leads, so I only soldered those on the PC connector end. The software has a great utility so you can test your I/O ports in order to find the right pins. I also picked up a little led holder to put the transistor in, it acts like a lens to focus light into it AND it will eventually allow me to mount it flush on a retaining wall.

The software was originally designed for 4 lane slot car racing...with a phototransistor mounted in each lane and a bright light above them...slot cars can't change lanes so it works.

So, you can run 4 transistors, using different pins on the serial cable, and the software will track them all...it's pretty neat.

Slot Car Site

I tried using the pinouts from that site, but ended up using a paperclip and the ol' hit and miss method to find the right pins.

wow your lap timer looks great=)

but i had an idea, since most people might not have a spare lap top and all of that stuff to make a lap timer, I was thinking maybe there was a device or something for a TI-83 calculator that records time of a moving object somehow. I mean TI has craploads of tools to do tons of stuff, I tried looking on their site to see if they had a tool like that, but their site is pretty poorly organized and I couldn't really tell. anyone think there might be a device or something that they have for TI's that records time of something?

Laser Pointer Plug-in MOD
 

The first thing I did was rip the silver backing off to expose the guts...it's just glued on (be careful not to mangle it too badly). Unscrewing 4 really tiny screws gets the board out. (Theres a really tiny spring that I lost almost instantly, not sure what it does as I didn't bother looking or it and it still seems to work ok.) I pried the microswitch off the board and put a blob of solder in it's place to jumper the four terminals under the switch...this way the thing is always on once it's plugged in. Then I soldered a lead to the positive upright terminal and another to the flat negative terminal (the board is marked). I dremmeled the battery holder to allow my leads an exit, and put it all back together with the leads hanging out the battery access door. Putting the door back in made it all nice and tight (hehe). Solder the leads to the AC adapter and remember not to look at the beam with your remaining good eye ;)

sorry i ment how many lap tops at once