SlotNav: A Navigational Slot Rallying Framework

woodcote · 26th-Mar-22, 06:35 AM

Do you fancy a true navigational slot rally, one where the driver drives – and a co-driver navigates a complex route through dozens of junctions?

Thanks to a moment of genius from Jason, we have come up with a framework that might just do the job. Okay, it's a bit of a departure from traditional slot rally, but if you want to replicate your own classic Coupe des Alpes or Tulpenrallye, a modern-day 12-Car club event, Targa or a bonkers Welsh all-nighter, then this might be for you. There’s one core navigational element required – and then it’s in the hands of the route-planner and their imagination...

The slot car technology is off-the-shelf – indeed, you might have the kit already. By its nature, navigational slot rallying is most suited to a group of friends, a club or dedicated event – with the focus on navigation, puzzle-solving and a fun social occasion. Having said that, I’m sure a SlotNav event is possible via Zoom – and Autotest-style formats with signs rather than navigation would be a fabulous single-person offshoot. Please remember, this outline is just a start – I'd love to see what people can create with the building blocks described below...

What’s different about a navigational rally?

Until 60 years ago, the majority of rallies were navigational events on public roads, usually with some car-handling ‘tests’ thrown in – and perhaps a timed special stage on private land. For a crew to be successful, the navigator (or co-driver) was as important as the car and the driver. Today, most rallying is based on exciting flat-out special stages with pace notes. The co-driver prepares and reads those notes, but it’s more akin to a driver-aid than navigation. In 1:32 scale, slot rally is all about the special stage, the car and the driver – an exciting replica of modern rallying.

Traditional navigational rallies still happen and are very popular, especially at the grass-roots of motorsport. In the UK, these are usually referred to collectively as ‘road rallies’ – but that label covers a wide variety of events and formats. In a modern navigational road rally, the navigator is the most important member of the crew. Although toned-down in terms of horsepower and speed, road rallying today is a more complex navigational challenge than ever. Think of it as a mix of driving fast down country lanes and solving mind-bending cryptic puzzles on the move... then furiously plotting the course on an Ordinance Survey map with a 2B pencil, all while trying not to annoy the local residents too much.

Driving home from a 12-Car rally event in Hampshire earlier this month, I wondered how a modern road rally could be simulated on a 1:32 scale slot car track. The big problem is: to navigate, you need junctions... and traditional slot rally stages don’t have those. I happened to mention this to Jason and asked if he’d ever come across navigation used in slot rallying. He said he hadn’t… but a few days later came up with element I’d been missing: digital. And he created a track plan (of course!) which might help…

This design was a brilliant starting point for the navigational rally framework that I’ll develop below – a framework that means any type of event that uses navigation can be re-created in 1:32 scale.

This is what I’ll be looking at in this thread:

There is quite a lot to get through and explain, although the keystone of SlotNav is really quite simple...

Fluff · 26th-Mar-22, 06:44 AM

What an absolutely fabulous idea Wrench

Steve

woodcote · 26th-Mar-22, 08:24 AM

Navigational basics – or how SlotNav works

The crux of any navigation is having to choose which way to go at a road junction. A lane changer (or pit entry) on a digital layout acts as a junction. There’s a choice of ‘straight-on’ or ‘turn’ at every changer. That’s just a binary choice – unlike the wide variety of real-life road junctions – but it’ll certainly do!

The next step is to create some navigational complexity from that basic choice of ‘turn’ or ‘don’t turn’. Jason’s track plan has at its core a central spine – two return loops connected by a straight, which sprouts a circuit of track on either side, running off the spine from digital pit-lane entry pieces. I think it looks a bit like a butterfly.

If each ‘butterfly wing’ contains more lane changers, this gives plenty of ‘turn / don’t turn’ choices that string together to create any number of unique point-to-point routes – as long as we accept we are always travelling round in various circles… But in our imaginations we can be turning or not-turning at every junction on a route map from Havant to Margate – or from Liège to Rome and back again.

It’s the job of the route planner – or Rally Master – to create a route for the driver-navigator crews to try and follow. If the Rally Master uses a real-life route as their inspiration, those real-life junctions are linked to the lane-changer ‘junctions’ on our slot car layout. The navigator interprets the information received from the Rally Master and then tells the driver to turn or go straight-on at each lane changer.

How the Rally Master provides this route information could range from a simple written list of ‘turn / straight-on’ instructions, a sheet of Tulip diagrams, a Herringbone chart, a marked map (real or fictional) – or cryptic clues that must be solved and then the route plotted on a fresh map… But in all cases, a binary ‘turn / don’t turn’ instruction must be communicated by the navigator to the driver as the car approaches a lane changer...

In addition to the junctions, I also decided to introduce a second navigational element – a Stop Box. This covers one lane of a half-straight track piece – and the car must stop with at least two wheels inside the box. I have included four Stop Boxes on my development layout, each coinciding with a scenic element that can also be found on an Ordinance Survey Landranger map – the bread and butter of British road rallying. These Stop Boxes double as the start or finish points (the Main Time Controls) and could also become intermediate Time Controls, if an event format requires them. I’ll talk more about Stop Boxes in the next post.

With just those two elements – junctions and Stop Boxes – the potential for creating complex navigational puzzles is endless. However, it’s sensible to start simply and build up gradually to any advanced navigational puzzling. That progression is similar to real road rallying – the same route is used, but the clues become more complex for more experienced navigators. The challenge is mostly in the navigation, but if you’re thinking road rallying is just a gentle pootle through the countryside, think again…

Next, I'll look at the technical requirements and build a basic SlotNav layout...

Nonfractal · 26th-Mar-22, 08:49 AM

Awesome concept. A new way to race.
I can see that that manufacturers might well want to lift and package this concept.
I've never really been interested in slot rallies but this would be a concept to follow.

Are you thinking that:
- a missed turn/change would equate to an "off"? How would you detect a car that went off-route and stop the car? (or push it into a pit lane) ?
- the pace note /navigator voice would be human or somehow automated?
- there could be multiple cars on the track with the drivers using earpieces?

AlanW

woodcote · 26th-Mar-22, 10:20 AM

Thanks Steve and Alan!

Alan - most of that will be revealed in due course!

What I'm presenting here is a human and relatively low-tech model, much like real-life navigational events of the past, present and future. The human quality of driver-navigator teamwork is important to me - and probably fairly crucial to the rally side of this idea. The other key human element is the Rally Master - who is route-planner, puzzle-setter, race controller, time-keeper and judge of fact. Of course, the role of 'Rally Master' would ideally involve a team of people - and that would allow more than one car on the route... although, to begin with, it's certainly easier to go with the traditional slot rally format of one car at a time. As you'll see (yes, there's a video coming), things happen pretty quickly.

However, the only core element of SlotNav is the 'turn/don't turn' binary choice offered by the digital lane-changer... and really anything can be developed from there. Okay, there are a few technical caveats, but otherwise we're only limited by our imaginations.

Next post coming soon - and that will explain more of the nitty-gritty technical stuff...

BAracer · 26th-Mar-22, 11:50 AM

Woodcote, I think this might earn you the first ever knighthood for services to SlotRacers!

woodcote · 26th-Mar-22, 12:09 PM

SlotNav technical requirements & track design basics

Because most of the challenge is wrapped up in the navigational gameplay, a SlotNav layout need only be functional. However, any constraints on the design of a SlotNav track are mostly down to the space you have available and the extent of your imagination… There are a few technical limitations – and that’s what I’ll look at here...

1. The Spine

I’ll start with the ‘spine’ of the layout – a straight section with a return loop at each end, a powerbase in the middle and two pit lane sets branching off either side. A SlotNav layout might not 100% absolutely need this spine, but it's certainly very neat and concentrates all the potential digital power issues into an easy-to-test unit. I think it works perfectly for the navigational aspect too.

The two pit lane sets need to be the same to work with the return loops – ie both need to be left-handed or both right-handed. This just means the active ‘pit-entry’ junction turns off to the left or to the right of the track. I've gone for two 'lefts' in the plan and in my actual layout. The ‘pit exit’ is simply a passive ‘merge’ piece and is not classed as a junction in SlotNav, since there is no choice whether to merge or not. It’s the same with any curve piece, chicane, jump or return loop you include in a SlotNav layout – none of these involve a ‘turn / don’t turn’ decision and so don’t require navigational instructions.

This is a digital layout – the car changes lanes at a press of the lane-change button on the controller. I am using Scalextric Sport Digital (SSD) – and have successfully tested SSD and oXigen-chipped cars running on ARC Pro or the older 4-Car Digital Powerbase. Any digital system that has both a lane-changer and pit lane system should work, although may need careful testing and tweaking.

Standard digital controllers aren’t bad, but higher-quality alternatives are available: a Slot.it oXigen controller can be used with oXigen cars (or with ARC Pro) and Truspeed digital controllers can be used with older wired Scalextric, SCX, Ninco and the current Carrera powerbases. Timing is entirely manual, so any associated apps or PC software are mostly redundant… that means the much-maligned Scalextric 4-car digital powerbase is a perfectly good budget option, especially paired with a lovely Truspeed SSD III controller.

Because of the return loops connecting the two lanes, most powerbases will go into ‘safety mode’ when powered-up. To get the spine to function, you’ll need either an electrical break in the return loop or to modify the powerbase. It’s a simple mod – remove the track piece from the digital powerbase, disconnect the track power wires to one lane and either tie them off or re-solder them in the reverse direction. With my 4-Car Digital powerbase, it was a ten-minute job – mostly waiting for the soldering iron to warm up. For an out-of-the-box solution, the original ARC Pro base is perfect for this set-up – it has the two lanes already wired in opposite directions.

This is what I have used for my development track...

Original (2017) ARC Pro Upgrade kit – unmodified – with standard ARC controller
2 x C7014 Pit Lane (left-hand) – two entry pieces with sensor, two passive exit pieces
2 x C7016 single lane half straights to connect to the pit entry pieces as they enter the ‘wings’
1 x half straight with power taps soldered to each lane – these are necessary to power the ‘wings’. I ran the taps to the single-lane sections nearest the spine.

You have plenty of choices in creating a spine – it can be as long as you want, not necessarily straight and using whatever return loop designs you fancy. Jason has two possible return loops in his original design – a ‘doughnut’ loop (which is great fun) and a tight Radius 1 loop. I’m using a pair of Ninco loops, connected via Ninco-to-SCX and Classic-to-Sport adapters. The same method can be used to fit specialist SCX and Ninco rally pieces into the wings...

2. The Wings

I put together the most basic layout possible – a Radius 2 oval – as one of the two ‘butterfly wings’…

However, this wing contains all the navigational elements we need: a lane changer junction and two Stop Boxes…

A Stop Box functions as a punctuation between strings of navigational instructions – to give the crew a breather (a ten-second timed pause works well) and also allow them to reset their navigation. It’s possible the car has ended up at the wrong Stop Box… in which case, the Rally Master will tell the crew the correct location to drive to, where they will then take their ten-second breather – it’ll take some extra time, but they will on the right track to start the next string of navigational instructions.

Because it’s quite easy to get lost – and the slot track goes round and round in circles – I thought a reset mechanism was important. The Stop Box / Time Control doesn’t look out of place on any navigational rally, but its function on the slot car track is slightly different. Essentially, it allows you to ‘turn back’ and recover the route.

I could have simply added another oval for a very compact SlotNav track, but I’ve gone to town a bit more with the second ‘wing’ of my development layout. I found the most difficult bit to get right is the single lane section on the inner lane. I cut up some Radius 2 curves and standard straights into single lanes – and with a lot of traditional hands-on trial-and-error came up with something I was happy with. A word of warning: when using sliced-up standard pieces, the connection tabs don’t always match up. The C7016 and C7017 single lane pieces are designed to create a single-lane track – and have tabs to match any eventuality – so keeping a few handy is certainly a good idea.

Although there are more driving challenges in this second wing, there’s the same number of navigational features – another lane changer junction and two more Stop Boxes. I’ve given all four Stop Boxes on the track a scenic theme… The OS map symbols are simply planning ahead for more advanced navigational gameplay, but the scenics will look good too – a church, a pub, a small river and lay-by with a phone box.

A Google search will give links to download cheap (or free) model railway card-stock models that can be scaled up to near 1:32 scale by printing an A4 design to an A3 sheet – or simply build them in OO gauge to give a quirky board-game feel. A 1:32 scale marshal should probably be stationed at each Stop Box too. One Stop Box will act as the start time control and one (unknown to the competitors) will be the finish…

Using just one lane changer in each wing is sufficient. In trial runs, the ‘junctions’ came along quickly enough. I wouldn’t be tempted to throw in more lane changers – unless I had a large space to work in and could spread out the lane changers with a comfortable time gap of between 2 to 3 seconds between each junction.

That's my development track laid out, ready for testing some basic navigation and driver-navigator communication. I'll post that later, but before that, expect a brief interlude to look more closely at the digital kit...

AdeC · 26th-Mar-22, 12:48 PM

What an awesome idea. A whole new spin on slot rally and a great way to run different stages on the same layout. Love it!

Kevan · 26th-Mar-22, 01:17 PM

Following with interest, slot rally is a favourite class for me and a few club members.

woodcote · 26th-Mar-22, 01:45 PM

Thanks Jeremy, Ade and Kevan!

As I'll repeat later on, I'm cooking up an event format to trial here on the south coast in a couple of months. And I am very happy to help any groups or clubs who are interested in setting something up - that is, if you need need any help. Although I could plan a visit with the development track in the boot of my car, the kit is fairly easy to put together...

A quick note on digital equipment

If you don’t already have some digital track, a basic layout for SlotNav doesn’t need to be super-expensive. Any navigational slot rally racing is likely to be a group effort and start-up costs can be shared.

For those in parts of the world where used Scalextric Sport track is abundant, the very basic 4-Car digital powerbase is definitely a budget option for SlotNav. These came in most Scalextric Digital sets from 2007 to 2017. You can now find nearly-new 4-Car powerbases for less than £10 on eBay, plus you’ll need a £10 Toshiba-clone PA3469U1ACA 15V 5A brick to power it. Although you do miss out on the ‘walk around’ benefits of ARC Pro wireless controllers, you could buy a wired Truspeed SSD controller for £50 and have a much more refined driving experience.

And here’s how you do that reverse-polarity mod on the 4-Car pb…

New pit lanes can be had for £25-30 a set if you shop around – or slightly less for used items at swapmeets or on eBay. The C7036 straight lane changers generally cost around £40 new, but as low as £20 used. The only digital stuff I probably wouldn’t buy second-hand are the in-car chips, you never really know if they're alive, dead or mortally wounded. The Scalextric chips are perfect for lower-powered motors, but if you're looking at torquey long-cans, the Slot.it SP15B is a safer bet.

If you have any questions on the hardware, just ask.

One thing that is a must-have for digital is a small bottle of Inox MX3. This Aussie magic seems to be the perfect elixir for keeping a digital race track running smoothly. Pendles stock two sizes – the pump-spray should be decanted into dropper bottles, otherwise things get messy. Just a drop of Inox on each braid of the course-opening car will do the trick at the start of the event.

With the tech side more-or-less covered, I'll move on to a practical demonstration of the navigation. Expect that later this afternoon...