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View Full Version : DIY lap counter [how?]


bmxtrev
2008.10.14, 08:06 PM
I remember reading somewhere that you can build a lap counter out of a laser and a few other parts, for around $20 or so.

Can anyone explain to me how to make my own lap counter? [for around $20]


Thanks :)
Trev

mikedw
2008.10.15, 09:31 AM
http://mini-zracer.com/forums/showthread.php?t=20805&highlight=laser
or use lap timer 2000 and a PC.

bmxtrev
2008.10.15, 07:42 PM
there it is. :)

Thanks

jb1
2009.05.23, 08:02 AM
http://jbwid.com/img_09/052309a.jpg

This is an old thread, linking to an even older thread, but the info is still very useful! Microsizers lap counters are still available on eBay for about $5 and I found an economy laser pointer w/AAA batteries for about $13 (+S&H). I thought it had an off/on switch but it turned out to be a momentary contact switch; however, the cheapie RS plastic vise (purchased long, long ago) holds the switch down, and makes it easy to target the detector.

As the original post details, the only real lap counter modding is to add an extension to the detector LED wiring so that you can locate it where you want to and so you don't mess up its alignment by operating the lap counter controls. Clipping out the emitter LED is optional, but a no-brainer since it extends battery life. Everything else is about coming up with a way to align the laser and detector (which isn't critical since the laser blasts the detector with a lot of light). The MR-02LMs are pretty low and don't have antennas, but the RCP guardrails are low enough for the beam to clear and trigger across the whole width.

This system suits my needs perfectly, as I wanted some basic metrics for practice, to see if I was improving and to compare different setups and cornering strategies. The minimalist battery-powered system "boots" instantly, so it's ideal for quickie sessions in my un-air conditioned garage. Also, everything dismantles quickly in case my 1:1 car needs shelter from hail.

A belated "thanks!" to Spoon for his original tutorial!

-Jim

Timmig
2009.08.02, 06:37 PM
Man that's AWSOME!!! Just what I need for home practice sessions!! I've got to go "shopping" on Ebay now!!
Thanks
Tim

Spoon
2009.09.09, 01:48 PM
Wow! It warms my heart to know that this is still getting some use.

I just wandered back into the forums after a significant hiatus from Z's and am looking to get my timer setup and running. I'll be trolling but I've been out of the game for a while so I won't have too much to contribute for a while.

HaCo
2009.09.09, 02:32 PM
With a webcam and some software it should be possible as well.

Something like this: http://www.webcam-project.com/using-motion-detection-to-count-laps-with-webcam.html

Maybe if you play with the code, you could let the software look at the color of the car to see difference between cars. Maybe contact developer of software.

Keep in mind that some webcam only record with 15fps, which means every 0.066sec a frame is recorded, which can be max precision.

Maybe other software exists, but I think this is one of the cheapest solutions available and ones I have my own track at home I think I go for it :)