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46u
2005.09.21, 11:04 PM
Have you ever whished you had a lap counter timer for personal use? Lets say you want to go to your local track on days when there is not any races and the equipment for counting laps or lap time is not available? You want to do some testing and tuning but have no way to see if you are actually improving your times? Or like in my case where I have my Mini-Zís with a nice RCP track and no one to run with so I wanted a clock to run against with out spending a wad of money for a lap timer counter!

So I bought a MicroSizers digital lap counter (Radio Shack makes one to for Zip Zaps) and timer that are available from Towers or off ebay for under $5. The only problem is the control unit and sensor platform have to be no more then 8 inches apart which is to narrow even for Mini-Zís much less 1/10 and larger. KEEP READING! So I go on the net looking for other solutions and came across this web page where I can use my $4 lap counter and timer with some modifications and when it is all said and done you can have a personal lab counter and timer for $20 to $35!
http://www.snipx.com/comersus/store/fun_cheaptimer.asp

46u
2005.09.21, 11:06 PM
Just in case the web site is taken off.

Cheap Personal Laser Timer in 15 Minutes for $35
"Why did you make this?"
I came up with this as an alternative to some more expensive transponder and RF based personal lap timers. I use it when I practice to better my driving skill. Being timed and having the lap counter give audible feedback as you run a faster lap helps simulate the pressure of a race and tells you when you have found a better 'line'.
The Hobbico Lap Counter itself is for Microsizers and only has a usable range of 8-12 inches through its internal IR sensors. This modification makes the capable lane width infinite. I have tested it with the laser transmitter 40 feet away from the receiver and it registers the laps perfectly. I have used it on 1/10 and 1/18 scale cars.
I have used it at tracks by tucking the laser transmitter on the inside of a corner where it is out of harms (or causing harm) way. I have yet to have any track personel tell me not to use it. Most think it rocks.
What You'll Need:


This Modification voids any warranties on the Hobbico Lap Counter!
Hobbico Microsizers Digital Lap Counter $19.99 - This is available at most hobby stores. Features: Accurate to the nearest one hundredth of a second. Counts up to 500 laps or up to ten minutes of elapsed time. Special feature displays best lap time throughout the race-and beeps each time you beat the previous best lap time.
Keychain Laser Pointer or Laser Diode $10-$15 - These are available at most department stores (KMart etc.). I chose to get the Radio Shack Laser Module (P/N 277-1101) because it was on close out for $4.99 NOTE: do not use a "Bright LED" Keychain light. It is not the same thing.
2 X AA/AAA battery holder (If using Laser Diode Module) - Enough said $ .99 at Radio Shack. You may want a simple On/Off switch to solder inline.
Telephone or Network Cable - Do NOT use speaker wire or anything else. The low current of the transmitter requires the electrical properties at least of telephone wire, preferably network (Cat5) cable to run any good distance. Length should be from Trackside to Driver Stand Rail height plus some. I have run a 20' length no problem.
Soldering Supplies
Small (Jewelers) Phillips Screw Driver
Electrical Tape or Shrink Wrap
1.5" section of a ballpoint pen tube - Bic round type
Glue or Glue Gun
Small "Project Box" From Radio Shack (Optional for mounting laser)
How To:
Begin by unscrewing the 5 small screws that hold the back cover of the Lap Counter on. Set aside the cover and the slide in bottom plate that is now loose. Locate the Infra-red housing assembly that looks like two small circles to the lower right and has a single screw holding it down. Remove the screw (you may discard this screw).
Remove the IR housing and turn it over. You will see an IR Transmitter (Blue) and an IR Receiver (Clear). Use a scissors to cut both wires to the Blue Transmitter (you may discard this).
There is a Green and a White wire running to the IR Receiver. Note which color goes to which lead on the Receiver for later. The unit will not work properly if reconnected in reverse.
Unsolder the Green and White wires from the receiver and remove and set aside the receiver.
Take one end of your length of Telephone or Network (T/N) wire and push it through (from the back of the Lap Counter) the large opening that was left from removing the IR assembly. Pull it several inches through and tie a knot in it about 2 inches from the end. This will keep it from slipping out or putting undue wear on the small wires inside while you are using it.
Expose a the tips of any two wires in the inserted T/N wire and make sure you have clean ends on the Green and White Lap Counter wires. Tin each end with your soldering iron. If you are using shrink wrap to seal your connections put your pieces on the wires now. Solder the Green to one of the T/N wires and White to the other T/N wire. Note what color T/N wire is attached to each so you know what wires to use to reconnect the IR receiver correctly in the next step.
Tape or shrink wrap the new connection.
Put in the bottom plate and screw the back cover on again using the 5 screws set aside earlier.
You are done with the main Lap Counter unit modifications.
Next, go the the other end of your T/N wire and expose the two wires you used earlier. Put the 1.5" pen section over the wire. Now recall which color T/N wire was attached to Green and White and solder them to the appropriate lead on the IR Receiver. Be careful not to overheat the IR receiver too much. Pull the Pen tube up over the IR receiver so that the IR receiver tip is passed about 60% through the tube. The tube serves to keep outside light from the receiver allowing it to react only to the Laser light we will point at it.
Use Glue or Glue Gun to secure the IR receiver in the tube. Apply only to the end where the wires come out.
That is it if you are using a keychain laser pointer. You may skip past the next section.
If you are using a laser module (like pictured above):
You can create the laser a couple ways. You can be utilitarian and hot Glue gun the laser module to the side or back of the battery holder, solder Red lead to Red lead and Black lead to Black lead and be done with it (removing the batteries is your On/Off switch) or you can buy a small Project Box and an On/Off switch from Radio Shack like I did to make a nice package. Albeit bigger. Solder the On/Off witch in line with the battery and Laser module. Drill a small hole at one end of the projcect box for the laser light to emit from and Hot Glue the laser module just inside. Make an opening for the On/Off switch to protrude and mount the switch.
I use electrical tape to close the box so I don't have to remove the screws to change batteries.
Here is the finished rig:

Setup:
Mount the transmitter and Receiver however you want (see tips below) on opposite sides of the track lane at THE SAME HEIGHT. Put them at a good starting point for a race and where the cars will not likely be hitting top speed yet (although speed should not be a problem). Turn on the laser and make sure it points directly into the IR receiver eye. Put your car with antenna mast on the track in between the transmitter and receiver and note where the laser crosses the antenna. Take a 3" piece of electrical tape and mount it on the mast folded in half to connect to itself making a 'flag". Make sure that the laser hits in the middle of the vertical height of the tape (usually 3/4 inch to 1 inch wide).
Turn on your Lap Counter and run your hand through the beam to make sure it counts properly.
That's it!
That is it for the Hack! Now some other thoughts and tips:
If you use a keychain laser pointer you may want to attach it to the 2 X AA/AAA battery box anyway to get longer life out of it. Most of the lasers operate at 3-4Volts.
It is UGLY!!! - Yes, well. You can mount the laser and IR receiver in any box you want or permanently mount them on a stand etc. This tutorial is really just to get your rig functional.
Do what you want for stands - make them from wood, metal, PVC Pipe, use table top camera tripods or whatever (You can tape the transmitter and receiver to a pole as well!) but make sure they are placed on an area of the track, usually in front of the drivers stand, where they will not be hit by crashing cars. I have to say though that this unit can work TOO good. I have built two now. The first counts very well with the 1.5" flag noted above. The other is so sensitive it is tripped by just the antenna mast! It seems the cheap IR receiver the manufacturer uses must have a wide fluctuation in quality giving these varied results. I will be trying an IR receiver unit from Radio shack and some additional electronics to see if I can make it less sensitive and potentially allow multiple racers with these rigs to run on track at the same time!.
If your car is so fast that the laps aren't counted - First make sure the Lap Counter is reading and that the transmitter and receiver are aligned. If it is indeed a fast car then try putting the transmitter and receiver right out of a turn so the cars will be travelling slower. Or Make a longer flag on your mast. This will increase the amount of time the laser beam is broken allowing the Lap Counter to register properly.
Run Practice Races: This rig can be used to challenge yourself and better your performance for the big races by running against time (can be set for up to 10 minute race) or laps (like 900 or something). At the end of the race you can push a button and it tells you your fastest lap for the run. I document all this stuff in my Pocket PC on this RC Setup Sheet spreadsheet I made. This allows me to tie my different test and race setups to best practice race/lap times etc. so I know how my tweaks perform.

-Enjoy
-Scott Hill

Ken Mifune
2005.09.22, 12:22 AM
great project. got pics for this tutorial?

briankstan
2005.09.22, 12:38 AM
this is not anything new. there is no comparison between this and say the core timing system. for those that just want a cheap lap counter this may be a good place to start cheap.

46u
2005.09.22, 12:51 AM
this is not anything new. there is no comparison between this and say the core timing system. for those that just want a cheap lap counter this may be a good place to start cheap.


I am not trying to compare this with fancy high dollar timing systems. That is why the thread title is what it is. For the applications I stated it is just fine and the price cannot be beat As far as pictures check out the web site in the first post.

fatboy1
2005.09.22, 10:57 AM
FYI
I did it previously using a website I can't remember...anyway, it works great. Cost for me for the microsizer system was about 30 CDN and then a trip to radio shack and the dollar store (laser pointer) cost about another 30 CDN, so for a like a total of 60 bucks, it a great system and very portable.

I would recommend for those wishing to try out new setups etc.. to see what is faster. I used to be a big 1/10 electric guy with a personal AMB transponder. It really showed how much faster the car (and driving) was between setups. All i know is that you may think you're faster, but in fact you're slower.

Have fun and build away.

46u
2005.09.22, 11:18 AM
Like I said you can pick up the microsizer timing systems for less then $5 US on ebay or at towers. All so it does not seem people are over looking the web site I listed with my first post so here it is again.
http://www.snipx.com/comersus/store/fun_cheaptimer.asp

With as cheap as you can pick up the microsizer timing systems now you should be able to build one for around $25 US.

Here is just one of the 5 or 10 listings on ebay.
http://cgi.*******om/Mini-Micro-Microsizers-R-C-Digital-LCD-Lap-Counter-NEW_W0QQitemZ6000459280QQcategoryZ34063QQssPageNam eZWDVWQQrdZ1QQcmdZViewItem

Then the tower has them.
http://www2.************.com/cgi-bin/wti0001p?&I=LXDRE1&P=7

jaeneke
2005.11.20, 06:50 AM
hey ! i bought such a lap counter on ebay for 4 dollars...
but like mensioned before it doesnt work great on rcp tracks !

now i can make it work ! tnx guys ! :)

Draconious
2005.11.20, 10:38 AM
Hmm...

Any one try 6 of them, with 6 laser pointers, at different hights, like the other home made laser pointer counters?

Make one of those black boxes, with 6 lasers on top of each other, and another box with the IR sensors on top of each other, wich run a wire to each display box... could be done in a not so ugly way... lol :) The flag on each car antenna would be at diff heights same as the other laser pointer counters...

Advantage here, no PC connection needed... cuz well u dont need a PC lol.

So.. for 6 cars, that would be 6 counters for $30, and 6 lasers for about $12

$42 counter...

Guess I will have to try it.............. lol.

Blackranger3d
2006.02.14, 03:25 PM
Sorry to resurrect such an old topic

Hey Draconious did you ever try the multiple timers, that is what I was thinking of doing.

Spoon
2006.02.14, 03:50 PM
Sorry to resurrect such an old topic

Hey Draconious did you ever try the multiple timers, that is what I was thinking of doing.

I am sure you could get 6 timers going. If you could link all of the start signals together, that would help.

Here's an update on this thread (how I did it) with pictures.

http://www.mini-zracer.com/forums/showthread.php?t=20805