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Krazy Kal's "Pin Switch Mod" to replace reed switches for lap detection

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  • Krazy Kal's "Pin Switch Mod" to replace reed switches for lap detection

    This is a posting extracted from another thread that deserves to have its own title.

    Thanks to Krazy Kal and Slot Car Rental for theorizing and then creating this new concept to replace the reed switches in the track for improved lap detection.

    As always, anyone attempting this mod is doing it @ their own risk and thus Educa Borras (formerly Tecnitoys) will not be held liable for damages.

    __________________________________________________ __________________________________________________ _____________________________________________

    KraZy_Kal, on Sep 29 2010, 03:00 PM, said:

    Hello Everyone,

    This subject of track reeds and proper detection of cars is an age old dilemma for SCX.

    Kal Labs is proud to share with you the Newest technology in Reed less S/F Line Track.

    Yes, this has been implemented before by some of our Spanish speaking members and well documented as a way to help solve missed lap counts at the Start/Finish Line.

    The most noted version uses a copper contactor in the bottom of the track slot/groove to act as a momentary switch. The car guide blade activates this switch as the car passes over the Start/Finish Line.

    Up until now, this was the best concept of mimicking the reed switch’s function.
    A couple of months ago, a new idea was posted on this very forum and was cast aside as not being practical and would probably damage the car or pitbox unit if implemented.
    I even PMed the author about this idea and praised him for his thinking outside of the box. He still was unsure of its merit….

    I have taken his simple idea that is so revolutionary, It will probably change the way SCX constructs their Digital Start/Finish Line track pieces from here on out !!!…. Or maybe NOT.

    It has no moving parts and effectively replaces the reed switch under the track. This will allow converted cars of all motor makes ( anglewinder, sidewinder and inlines) to effectively trigger the lapcounts.
    You can even run magnetless and have the car sliding around the track and still be guaranteed to trigger the S/F line counter. This advanced modification will hopefully make our tracks more reliable in counting laps during those big races.

    Right now it’s in the Beta stage of testing at Green Acres Speedway, but shows so much promise that I have decided to share it with the SCXWorldwide community.

    Thank you Ron for thinking outside of the box and sharing your original concept photo. Ron also known as Slot Car Rental and is a regular contributor here on the forum.
    I took his basic idea to Kal Labs think tank and spent hours pondering the proper way to engineer this modification into GAS (Green Acres Speedway).

    The following slideshow helps show everyone the way I implemented the modification onto a spare PitBox compatible S/F line track Piece.

    Disclaimer: What you are about to read is in no way implying that everyone should be expected to modify their Start / Finish Line. This is merely a guide for those curious enough and comfortable with electronics to explore at their own will. In addition, because SCX does have a two year warranty on everything they make, messing with the original SCX electronic configuration will void the warranty on this track piece and the related PitBox control unit that is attached.

    These are the super strong magnets used to ensure reed closure in the cars.

    Conclusion: This modification eliminates the need to worry about if the car's downforce magnet or motor is properly triggering the track reed switch.
    This will allow many motor configurations to work properly and the removal of the magnets (or raise them up high into the cars) for much fun magnetless racing.
    Yes, we still will need magnets under the track to trip the reeds in our cars.
    So, I have installed super strong magnets to ensure the best magnetic field to do this.
    So if a car is experencing lap counting issues, I am pretty sure now that it is the car's reed switch at fault. I can just change the chip to prove it....

    Hope everyone finds this new modification helpful in solving our track lapcounting issues.
    Thanks again to Ron for placing the seed,

    Last edited by LDFan; 04-27-2014, 04:07 PM.

  • #2
    You mean Educa Borras? ;-)

    Excellent mod, though.
    Thanks to Kal for inventing and sharing such an excellent guide with the world.


    • #3
      Originally posted by MrFlippant View Post
      You mean Educa Borras? ;-)
      Yes, I stand corrected. . I was thinking of changing that fact but the original posting was written back then and I didn't want to infringe on making changes to someone else's work.



      • #4
        I wasn't suggesting it needed to be changed, but I was referring to your own part of the post, not the copy of Kal's post. ;-)


        • #5
          Originally posted by MrFlippant View Post
          I wasn't suggesting it needed to be changed, but I was referring to your own part of the post, not the copy of Kal's post. ;-)
          Oh.... That's right.

          I guess I can change that and probably will. I wrote that section after SCXWW shut down with the intention of getting this posted soon after. Obviously, I've lagged behind.



          • #6
            I do miss SCXWorldWide, but I do not miss how much time I spent running it.

            Thanks for getting this up Dave. You have been and remain, "The Man!"

            Ahab out . . .
            Last edited by AhabDarab; 05-09-2014, 12:58 PM.


            • #7
              If a cars braids do not over lap one another wont this setup count 2 laps for every one? I have some F1 Cars where there is a gap of 1/8" or so


              • #8
                Originally posted by shady14u View Post
                If a cars braids do not over lap one another wont this setup count 2 laps for every one?
                Not to sound facititious, but if that were the case, I wouldn't have had this great idea posted in the first place because it would have been such a bad idea.

                Just for clarifications sake, this is how the SCX-D lap counting system works.
                • There are always two reed switches involved to complete a lap counting cycle.
                • The first activation occurs in the car as it approaches the start/finish line and the magnet in the track activates to prime the chip to send its data.
                • As the car continues to move across the finish line, the magnetism from the motor / traction magnet sets off the reed switch in the track (the topic of this posting is about replacing that reed switch).
                • Once this reed switch in the track gets activated, the system has a split second power outage (buss command) to accept "any" ID from a chip that just got primed (I say "any" because if two cars were approaching the finish line almost neck and neck; only one activation of the buss command from the track reed is needed to accept both ID's and the system will still know which car was ahead of the other).
                So to clarify, what you were asking I believe was in reference to a belief that the pin switch dictated the lap count which led you to believe it could cause a dual count (if I am wrong, please clarify). Obviously, that is not the case because the pin switch just activates the command to accept the ID's. The true lap count occurs w/ the activation of the reed in the chip.

                I have some F1 Cars where there is a gap of 1/8" or so
                Not sure what you mean by 1/8" gap. It is true that the position of the reed switch in the F1 cars are much further back of the guide vs. a V1/V2 chip but not sure if that is your meaning. Regardless, where the reed is positioned on the F1 chip is not a factor since it still gets activated just before tripping the reed in the track.

                I should also note that I will be posting pics of my version of Kal's dead switch concept. I went about it in similar fashion but it's different enough where it deserves a look.

                Last edited by LDFan; 05-10-2014, 10:10 PM.


                • #9
                  Where did you find that Square stock with hole? I have looked everywhere... Its either Solid or has huge square hole.


                  • #10
                    Originally posted by shady14u View Post
                    Where did you find that Square stock with hole? I have looked everywhere... Its either Solid or has huge square hole.

                    You'll have to ask Krazy Kal since this mod was his. I only re-posted what he had from the now defunct SCX Worldwide.

                    However, I'm sure either Evergreen or Plastruct must make a square piece of tubing w/ a hole that is the same diameter for a pin. I've found something similar awhile back but in the end I didn't use it since my alternate method didn't require it.

                    Like I said, I'll post my version as soon as I have time.



                    • #11
                      Hi Dave , your "alternate method" can you repost it please. I've been lookkng for a post , but can't seem,to find it

                      Greetings from Belgium


                      • #12
                        Originally posted by Bartie1967 View Post
                        Hi Dave , your "alternate method" can you repost it please. I've been lookkng for a post , but can't seem,to find it

                        Greetings from Belgium

                        I've never posted it.....not yet at least...


                        • #13
                          Step 14 questions

                          Hello Dave,

                          I am in the process of planning for this modification, I have a question about step 14. Are the two red wires soldered together with the two black wires (see pic below - my comments are in yellow on the image)




                          • #14

                            Let me state once again that this is not my mod so anything you do is at your own risk.

                            But back to your question, the only thing I can say is to just follow the wires to where they go in the track to wherever it ends up on the orange connector. Also, SCX didn't care about wire colors so it's normal to see red and black wires connecting to each other. If you see them encased in the hot glue, they are part of the same circuit.

                            Anyway, as I have stated before but have been too busy to post, I do have a version of this mod that doesn't require the need to modify the PowerLine. If you can be patient, I'll try and post it soon.



                            • #15
                              A different approach

                              A different approach to showing the wiring changes for this mod....

                              First off Dave, I apologize for asking you directly in this forum, I do realize that you did not create this modification and in turn are not the person to ask regarding the individual screen shots for the mod. My main issue here is not of who or how it was done but rather for clarification of which wire went where as it was not clear in the original post. I turned to you as a source of knowledge, hoping that you would know which wire belonged to which terminal and could clarify a specific connection. Again, my apologies...

                              Another important note that Dave had mentioned, this is a modification, and as such it will absolutely VOID any potential warranty you have with whatever company has this product. Additionally, before you make any changes to your system, please verify the connections as they are on your track section and adjust connections as necessary to make them work for yours. It is possible that I may have made a mistake of which wire is connected to which pin on the orange clip, I did make every effort to ensure it was correct, but PLEASE just cover your bases first!!

                              As an alternative approach to this modification I wanted to provide a clearer wiring diagram for those that wish to do this modification to have a better understanding of which wire goes where. In order to accomplish this, I removed my back from my pit box terminal straight, and began tracing wires. As Dave had mentioned before, SCX did not seem to care about what color wire they were using, only where it went. To that end, here is a Microsoft Paint rendition of my original wiring for my pit box terminal track.

                              Note: The pink and light orange wires appear to be the signal wires from the reed switches, the opposite wire on the reed switches (light green and tan) are grounded to the track rail, where the purple wire connects.

                              Here is a drawing of the modified track section....

                              Note: the location of the pink and light orange wires now connect to the new sensors. The other two wires that were on the reed switches (light green and tan) are no longer needed as we are using that track rail to make the ground connection

                              The main differences here is are that the only two wires moved are the ones that connect to the reed switch and orange clip, the wires from the opposite side of the reed to the track are not needed. All other wires stay where they were in the first place.

                              Hopefully this will help make this process much easier

                              Last edited by Ranzumze; 06-18-2014, 08:49 AM.