[RobFitz]

If I got this right in my head a lange change piece is a 90 deg radius 2 curve BUT in front of it you need a half straight (the bit with the detection gubbins)

My question is ... Does this half straight have to be immediately in front of the lange change piece ?

 

[Jimster71]

Good question!

In a way it makes sense to have it there, because instinct would make you press the lane change button just before you hit the corner. If the sensor was further away, you'd have remember to press for the lane change as you pass it.

If you started spacing the sensors away from the lane change pieces, would the system know which corner the sensor 'belonged' to?

Also makes me wonder what would happen if you put two sensor pieces before a curve!

 

[Xlot]

I couldn't look at the track underside, but I suppose there's some wiring between the sensor(s?) and the LC proper

The real issue is that if the sensor were far ahead of the flipper point, a car immediately in front of yours would be affected
Also, the LC seems to operate in a flip-flop way, i.e. the flipper stays in the last position until another car "tells" it differently - so you would be stuck behind !

BTW, I've read in another post that with Carrera you shouldn't put the LC after a radius 1 curve - so it's confirmed that with a sliding car the sensor might not be "lit". I wonder how much this applies to SSD (non mag) - I suppose less, since the LED is rather closer to the guide post

 

[Jimster71]

That would mean you'd have to remember the way each changeover was 'flipped' as cars passed over it.

Wouldn't it make more sense for the change over piece to reset itself after each lane change?

 

[Slot City]

My understanding is that the switch doesn't automatically go back after a car has changed lanes. It waits for the next car and if that wants to change lanes it stays as it is, if it doesn't then it flips back.

I thought this approach seemed a bit strange at the time, but I'm sure they have their reasons. I guess it does reduce the number of times it has to switch though.

It might of changed by now, but this was how it appeared to work back at the Toy Fair in January.

Jon,
Slot City.

 

[moped rider]

QUOTE That would mean you'd have to remember the way each changeover was 'flipped' as cars passed over it.

As I see it the last car over the sensor determines the position of the flipper based on the signal you send to the car. If you send a signal to the car after it has passed the sensor it is not going to flip until the next sensor point and the next flipper. The distance between the sensor and the flipper is so tiny that you as a human cannot react in the speed that the car has travelled between the sensor and the flipper and you can send a signal to the car anytime ahead of the next signal point.

Now as to the answer to the question it is pretty much down to whether the sensor track and the flipper has a physical link other than the standard Sport track connection. I do not believe it does to keep things simple and that any flipper signal is passed down the conductor rails. Otherwise it would surely have been easier to have the sensor and the flipper in the same track section. That to me is the logic of good design.

Moped

 

[Fergy]

QUOTE I thought this approach seemed a bit strange at the time, but I'm sure they have their reasons. I guess it does reduce the number of times it has to switch though.

Actually, it makes perfect sense, if there are enough LC's to support a "best line" style of driving. Mind you, the driver will still have to hit the button or the LC will reset. Not as good as BLST's system, but perhaps possible for nimble-fingered types. It also saves wear-and-tear on the LC switches if the change is a common one - otherwise it will just reset anyway.

On most tracks, it probably won't save more than a very few percent of LC switch actions. But I suppose it doesn't hurt either.

 

[astro]

it cannot be right that the flipper stays flipped! That if someone ahead of you changes lane, you will also change lane UNLESS you guessed he was going to change lane and held you lane change button so you stayed in the same lane!!!!!

I knew scalextric had solved the accidental lane changing of a car following another, but this solution (making the following car also change ON PURPOSE!) makes no sense

 

[Xlot]

Jon/Slot City explained it perfectly - so your lane selection is not affected at all (otherwise, I would have mentioned it in my mini-review !!)

 

[astro]

oh - i think i understand now

 

[Slot City]

I appear to of caused some confusion with my description of how the lane changer flipper works, so I'll try again.

The easiest way to look at it, is that if you want to change lanes you press the lane change button and you will change lanes. If you don't want to change lanes, don't press the button, and you won't change lanes.

Whilst the lane change flipper doesn't reset after a car changes lanes, it will switch back if the next car doesn't want to change lanes - or it stays where it is if the cars does want to switch lanes.

A cable connects the sensor track section to the lane change track section, which carries the signals to control the switch. Hence the sensor has to be placed directly before the lane change section.

The reason for having two seperate track sections is to cater for future enhancements, ie new lane change sections. Whilst this obviously helps to reduce the tooling costs for Scalextric, it also means that you might be able to buy a lane change section on its own without having to get a new sensor straight.

Hope this all makes sense.

Jon.

 

[Jimster71]

Nice explanation Jon.

One thing I was thinking about:

The sensor is a little way before the actual lane change flipper, so there is a time delay between reading what your car wants to do and your car actually hitting the flipper.

Say you have 2 cars right behind each other, the front one wants to change lanes and the rear one doesn't.

How does the system know when to move the flipper for the second car? If it is only based on cars crossing the sensor, is it possible for the rear car to have crossed the sensor, before the front car has reached the flipper? If so, what happens?

 

[Xlot]

The distance between sensor and flipper tip is so small, the effect you fear just isn't there (maybe read here :

http://www.slotforum.com/forums/index.php?showtopic=4363 )

I believe the reason for a separate sensor track is that the LC takes up an entire 90 degree curve - plus it's the same piece as the lap timer track
And, obviously the two parts are wired together : sending the message via the rails would be more expensive, slower, and add to the overall number of digital messages being circulated

 

[Jimster71]

Thanks for the link.

 

[Slot City]

QUOTE Say you have 2 cars right behind each other, the front one wants to change lanes and the rear one doesn't.

How does the system know when to move the flipper for the second car? If it is only based on cars crossing the sensor, is it possible for the rear car to have crossed the sensor, before the front car has reached the flipper? If so, what happens?

This is something we checked on all the digital systems at Toy Fair.

The distances between the sensors (or switches) on all of the systems is at least a car length, so there shouldn't be any problems with accidental lane changes.

Jon,
Slot City.

 

[jonny s]

We had cars nose to tail at the Toy fair and no prob with the following car, the switching is very fast and the following car does not make an unitended change. That was on Scaley.

 

[thomas]

..had intesne nose-to-tail-racing at the toy-fair in Nuerberg on Scaley - no problems with the switches! Worked well!
FYI - same with Carrera, sometimes problems with SCX...

 

[jonny s]

Yes I found the LC didn`t always react with the SCX system.

 

[knapp_creek]

I have had my SCX digital system for over a month now with 10 changeover tracks and have never noticed any problem with the changeovers not working. Part of the problem could be that you are pushing the switch button to late. It must be pushed before you reach the changeover section not while you are just entering it. Tecnitoys have put together a very high quality versatile system with its passive two-way changeover track, 6 cars and over 108VA's of electrical power. Being able to change lanes at many locations around the track is a great asset and I find the length of change over track not a factor. Digital racing requires rugged cars(which SCX has done) since crashing is going to happen. Retrofitting older cars I feel is a waste of time since they will not stand up to the type of crashes that digital cars will be seeing. Full speed rear-ending does happen but these cars are designed to take this type of punishment. From the Carrera Pro-x review of their system it appears they have done a good job also in car structural design. To show the versatility of the SCX passive changeover system go to my thread on SCX pits and see my layout section of my pit and behind the pit wall section.

 

[jonny s]

Good point. Perhaps using each system so close together,time wise ,we did not take that into account? I have also read that the SCX system may have been pre production?

You have highlighted what may well be THE deciding factor in choosing digital or not...the surviveability of the cars. I wrote off the option of using SCX because I do want to run all my cars,including F1 on a home and club digital track.