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Monza Track with Banking

21492 Views 69 Replies 29 Participants Last post by  ncng
So i've been toying with the idea to build a track for some time now.

Choice of Circuit
For me one thing is a given it has to be a historic track used for Formula One events. Then from that flows the fact that I'm in Italy so it seems logical to choose Monza.

Now I've read threads that suggest that real tracks don't make good slot tracks but I have a theory about that…. It seems to me that is because people choose tracks with many curves that once scaled down to reasonable slot track scale create too many sharp corners, very few decent straights etc.

Consider for example that Barcelona has a straight of about 1.2km. At scale that would be 37.5m long and you start to see where the problems lie!!

So to overcome that as best I can I've taken the Monza track as used for the Grand Prix of 1955-6 and 1960-61. That is the combined track with banking but without any of the 'variante' or the Ascari bends. In that way I have a fast flowing circuit which will scale well. The Parabolica for example becomes essentially a hairpin bend and is the tightest corner on the circuit.

Of course what is fundamentally different about this circuit is the banking. I hope to create this fairly accurately and this was already the subject of a thread some months ago. It seems that a real dish shaped banking has never been built so this will be a first. If I'm wrong and one exists please let me know……

Apart from the banking the circuit will be routed MDF, the base boards are already in construction and look like this:

As you can see the track is in the unused ground floor of my house so it can be BIG. In fact the lane lengths are 29m (90 odd feet).

Its early days yet for the banks but they will be made from polystyrene cut by hot wire and then skinned with resin or fibre glass. The geometry is worked out but I want to get the road section sorted first to test some of my other ideas…..

Basic banking is half down and half up as per the real thing....

The bridge section will look like this......

1. I want a decent track to 'play' on with my collection of old and new F1 cars.
2. We (Graham Lane and I) need, here in Umbria, a wood routed track to design, tune and practice on for UK events like Early Birds, otherwise we are sssooooooo unprepared.
3. I like a challenge…….
4. I have a dream to eventually run a CLASSIC Italian GP event in a few years when the track is fully running and Graham's Mini Monte Carlo Rally has reached its natural conclusion. In fact with this in mind I'm keen to get feedback on my circuit design BEFORE I route it to ensure that if this event does attract interest the track is capable of hosting it.

Given the space, after much design, thinking and restarting I've settled on 4 lanes.

Analogue or Digital
Here too I've thought a lot. I like digital for GP racing. Lane changing, racing line corners, pit stops, fuel load simulation are all part of GP racing and on Graham's track we've had a few great nights 'messing around' with all that.

The problem though is simply that we've had only a FEW nights since most of the time there seems to be some bugs in the system. I've become slightly convinced that if you're running anything more than a smallish box standard track SSD can't really handle it, or at least it gets easily overloaded.

Added to that the competition standard is still analogue so it'd be difficult to run a digital event in the future for '50's, '60's and '70's cars.

Finally I have a collection of some 150+ classic F1's and I simply can't chip them all. I once bought 4 chips to run on Graham's track and learnt that chipping these early GP cars is not so easy due to space etc. so having 'some' chips and moving them from car to car is also not really an option.

It's a great pity as I'd like to do pitstop strategy type racing. Maybe this will get added later in a digital / analogue option track…… But let's keep it simple for now. I've seen a thread or two with analogue pitstop systems with a simple button push 'point' for pit entry. This might be the way to go in due course too.

Race Type
This is where my idea starts to unfold and dictate the track design!
I want to run GP type races. That means one driver one lane 1 hour minimum. For me that's NOT endurance. You should be tired by the end, your finger should hurt, your lap times will change during the course of the race and the car might well need pitstop maintenance.

What this means is that 4 stints of 4 minutes on 4 lanes is very much NOT what I call a Grand Prix. Most so called 'serious' racing (especially that in Italy) seems to work like this but its not for me.

So, we have a big problem then. How do we make the racing even slightly fair? I measured my 4 lanes and they are over 2m different from inside to outside which is obviously a HUGE amount and over an hour where each lap takes say 10s would multiply up to several laps of advantage.

I've done the research on equalising lane distances and have found that there are only two ways to do it:
1) exactly symmetrical circuit with flyover (figure of eight type stuff), or,
2) yes you guessed it - crossovers……

Now I know some will say that equalising lane length is not crucial since tight corners v's. wider corners will equalise things anyway but I have another set of ideas:
a) I don't like tight hairpins R1's or anything like that. I think they're really unrealistic, far too tight to have decent racing without flying off and do give a huge disadvantage to that lane.
Realism. I like racing lines. I like the cars to move about on the track. I really can't understand why any routed tracks EVER have radiused corners or 'real' straights. They look odd and are so predictable to drive….. (I'm sure I'll get some responses on that one….). Real cars rarely if ever go all the way down a straight in a straight line. Then, especially if there are other cars around they weave!!
c) I am very much against single track, 'rhythm' type racing where one has his car, one goes into a sort of 'trance' with the controller and the corners without even noticing what is going on around them. For me skill is not in doing the best fast lap over and over its very much about adapting, braking and interacting fully with the other cars. Just like in real racing…… (Again I found a whole thread debating this and I don't really want to go over it all again here. Some like single track 'trance style', others like 'interaction'……)
d) Given the era in which my track is designed and the cars I want to predominantly use on it the 'special feature' I want to integrate is SLIPSTREAMING…. I very much want to integrate a section of the track on the banking where the cars run almost directly behind one another to simulate the slipstreaming effect, before they weave apart and then take different lines into the next bend. It's a 'gimmick' if you like but in slot racing jargon it's a simple 'squeeze'. Again squeezes have been discussed at length elsewhere suffice to say I LIKE the idea both of slip streaming and of deliberately making cars have to take notice of one another before choosing the moment to overtake.

Now, given all of that I also realised that once you've allowed squeeze(s) and the cars CANNOT OVERTAKE for a given period there is no longer any reason why they shouldn't CROSS over as well. In the sense that the skill is needed to brake before the squeeze, and once in you can cross back and forth either for aesthetic 'weaving' or indeed to equalise lane length.

OK, enough chatting this is what I've come up with:

So I've drawn it all out in Autocad. Its virtually all spline curves and although much of the circuit is made up of roughly parallel lanes there is a lot of small divergence and convergence which might or might not be visible in the final result. We'll have to see.

I've measured these lanes and they are all accurate to within 1mm of each other.

I'm thinking of having a staggered grid on 25mm as shown by the cars rectangles (cars). This will allow that as they approach the first squeeze and cross section (the Lesmo curves) if they have all taken off at exactly the same speed (which is of course only theoretical anyway) they can all slip through without crashing. You will see that at this point the cars are 'paired' so that not all the cars cross one another. In fact this corner is designed so that cars 1&2 don't squeeze or cross one another and nor do cars 3&4.

This idea came to me so that if one wanted just to race 2 cars then on this section at least they wouldn't squeeze or cross.

I liked this concept, that the pairs didn't cross, but soon found that it was impossible to make the whole circuit like that as one immediately got back into the whole lane length problem….

So the lines in the corner are supposed to show a sort of 'range' of racing lines so that the cars forced onto the inside of the first part of the corner obviously need to run wide into the next part of the corner and exit…..

So, having arrived to the parabolica one has travelled some 13m from the start line and so the racing should have become slightly at least spaced out. This is the most complex and dangerous part of the track. The rule will be simple. The first to arrive gets right of way just as in real racing. You will need to be very aware of who is around you and how well you are driving compared to them and their line in the corner and exit. It is the slowest corner on the track and there are a range of lines from the tight apex one to the one slithering round on the 'marbles'.

My personal opinion is that as one learns the track it will become obvious that it is not absolutely fundamental to pass BEFORE the corner since on exit from that corner, as the cars begin to accelerate away the lanes make a long squeeze as the cars start to 'slipstream'. So if you missed the pass before you have time to settle in behind your opponent on the same line essentially and then blast out the other end.

Except before 'blasting out' you will weave and cross one last time on the back straight……

From there you will have half that straight, all the last banked curve, the whole start finish line straight and round again to the Lesmo curves. That is about 11.5m of very fast motoring in which you really should be able to overtake!!!!

You will see that I've plotted the position of the cars if they are all running as 'pace' cars at the same speed around the circuit and they do not collide at the crossing points.

The only other detail to add is that with the racing lines the cars will of course pass over the top of the 'kerbs' and I'm not sure yet whether these will be just painted on or slightly raised. That might depend whether the inside lanes need any slowing in reality to further 'even up' the racing……

Well that's about it really…… I've said my bit - now tell me what's wrong, what you like and what you don't and more than anything whether you think you'd like to race your old F1's (including scratchbuilds) on it???????
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Presumably then some of you can see the plans??? I can't on my PC in the office but can on my iPhone which is very odd. I've asked Doug to edit the photos so hopefully then everyone can see them...... It seems to happen sometimes when I transfer data from Autocad into photobucket - not sure why yet.

I add the plan here again to see if that helps for those that can't see it yet:

Anyway thanks to everyone for the positive feedback so far although most seems to be about the space not the track!!!!!

I think in general the advice so far has been softly softly suggesting that exact lane length is less important than making a workable track which i'm going to try to take on board a little but without losing my starting point too much.

It seems to me from my experience of racing / running cars that one needs sufficient space to 'think' in order to accelerate / brake / miss other cars. I think this is often why squeezes and crossovers fail. 1. because they are too close or too often for one to actually line the car up to make a pass and 2. they are in positions where the cars are flat out so that the driver simply cannot think ahead that quickly.

My first plan then attempted to space the two zones out enough whilst still having two areas of cross over.

I think i'm going to try to eliminate the first squeeze and cross over in the Lesmo curves in order that from the start one has a real long way to go before the parabolica and on subsequent laps lots of space from the exit of the first bank all round to the parabolica to line up for a pass.

I will lose the racing line effect in the lesmo curves but actually think now relooking at my plan that between the Lesmo curves and the parabolica there is insufficient space to do any passing and the Lesmo cross over will indeed cause crashes a lot coming after the long fast section.

This will also mean that I might need to adjust the lines in the parabolica and the first banked corner in order to get better lane length balance but maybe without mm perfect equality.

I also agree with others that indeed how each lane is effects how fast it is more than just the length. However I think this is often due to the presence of far too tight hairpin bends. I haven't got anything like a R1 inner or outer on this track as I think they are simply unworkeable for any slot cars after about 1980.....

Finally the track is 1/32 and lane widths are a fairly slim 75mm (scaley are 78mm). The thinking on this is that my widest car is 70mm ('70's F1's) and with open wheel cars if they touch you're off so extra width doesn't really help......

Once i've got the alternative arrangement without the Lesmo crossover i'll post it.


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OK, so the new track looks a bit like this. Its a compromise in some way on my original idea of racing lines but I think in the long run it will offer me more pleasure and flexibility in use.

I've also added in a switch back after the parabolica to the starting grid. This will do 2 things:
1. allow me to get the track up and running long before the banked turns are complete since they will take some considerable time before they are functional!
2. allow one to have two different circuits if I eventually introduce a proper manual point system which could be quite simple.

So the other point of feedback i'm getting is to go digital.

I think in general terms the future is digital and I imagine that eventually I might convert as an option this circuit but I also think that I have enough to worry about without it and all the reasons I originally gave still stand so analogue for now.....

Cheers, and thanks again for all the positive feedback so far.

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QUOTE (Graham Lane @ 16 Jun 2011, 09:44) <{POST_SNAPBACK}>Could I be honoured by making some buildings for it please? Whadduwan?

Not that many buildings needed (pits i guess) - if you want to make about 1.000 trees though i'd be much obliged.......... It is in a mture parkland setting after all.....

Oh and i'll be needing about 10.000 spectator figures too.......

Any ideas how we could make them real cheap and easy??????

See ya

QUOTE (300SLR @ 16 Jun 2011, 11:38) <{POST_SNAPBACK}>There's a big risk that real cheap and easy = doesn't look much good
It's worth asking if smaller numbers well done is a better compromise than larger quantities less well done.
Also its worth checking out the trees and scenery don't block the drivers view of the corners. Yeh scale model trees are lovely, but isn't this project much more about cars than trees.
Sometimes less is more (did I get the quite right?)

Yeah don't worry i've never done anything by halves..... The sight lines will be important but the track is reasonably low so this should be OK.

QUOTE (HuntTheshunt @ 16 Jun 2011, 11:55) <{POST_SNAPBACK}>Very nice design & I think you've got the crossovers spot on now - flows nicely. I watched 'Grand Prix' a couple of weeks back - shows just how awesome this track was - it'll be great to see it done really well as a slot track. Nice Autocad work by btw - are you printing to jpeg for photobucket?

I've watched Grand Prix a few times myself - I wonder how smooth or not that banking should be.............

From Autocad I 'print' to a thing called "postscript level 2" which is a .EPS file. That creates a vector graphic version of the drawing file. That graphic file can be imported into Illustrator or anything else and retains the line attributes. Actually for this I just open it into Photoshop, pluging in 300dpi as it opens, remove the layers and then save first as TIFF and then that as JPEG. Then resize as appropriate. Its long winded but the only way I have found to really get the necessary quality of dithering......... Then photobucket the JPEG.

So it seems its going in the right direction and i'm now more happy so hopefully this weekend i'll start making the underpass and getting some routing started very soon.

BTW to transfer those compex lines i'm going to print at 1:1 from my plotter and simply cut the lines through into the MDF with a scalpel. Lots of paper but accurate.


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QUOTE (biedmatt @ 16 Jun 2011, 13:28) <{POST_SNAPBACK}>I think David Reineke had trouble with his crossover lanes on his routed track. The guide flags would nail the "point" where the two lanes cross. I think he filled them with bondo and rerouted it. If you make the lane crosses with sharper turns you might avoid the problem, but then you have added all the turns your first post said you do not want.

Hmmmm Matt - you know a long time ago I thought about that and then completely forgot when I was designing. Typical architect I get immersed int he detail and forget how it will actually work.

In fact I also remember thinking that my pin guide cars are likely to change lanes all the time.........

I wonder if anyone has had this problem and found a solution?

Maybe i'll have to make the crossovers have slightly more angle between them. I wonder what angle would work.

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Hi dave
There is a huge geometric difference between a truncated cone and a segment of a sphere.
Bending flat objects make pieces of cones and that is what every banked curve i've ever seen so far is.
What I want is a double curvature just like the real banked curves.
In fact they aren't even pieces of a sphere since they are a curve in cross section that is then extruded on a mathematical trajectory to form the whole curve in plan.
I've not seen that done yet.....

Hi Chris et al. and thanks for offering advice. I think the transitions are a risky area.

My current thoughts are twofold:
1. My banking will be set half above and half below the datum of the track. Thus inner lanes will go down onto the banking and outer up onto it.
This is exactly how Monza was built. This should mean that there isn't one lane with much more risk than the others, although the central lanes will be advantageous since they will be virtually flat (although twisted if you see what I mean).
2. Although the track is supposed to flow and be fairly quick the 'technical' aspects of it will actually mean that much care will be needed both to get round AND to avoid your opponents. What i'm saying is if you need to slow down to avoid coming off then so what actually???
Surely every corner needs to be 'learnt' and tested to the limit and the transitions are the same. The transition like each curve is an area where damage can occur if you go too fast!!
Yes Chris you are surely right! I'm going to give this a bit more thought over the weekend and see what I come up with. Maybe I do need to modify my approach or maybe I just have to follow my own path at my risk.

Honestly first I want to resolve the angle of crossover problem and then come back to this transition question. I'm sure when I do i'll ask your advice.

Cheers for now

I've measured that and the curvature from a car with of 70mm is only about 0.6mm and so the braids should be able to accomodate the difference.

This is moving quicker than I can get answers out.....

QUOTE (Chris Frost @ 17 Jun 2011, 22:04) <{POST_SNAPBACK}>The problem is that not all transitions present a consistent challenge, I've seen rather too many that occasionally launch cars out of the slot for no apparent reason. The best professional track builders long ago mastered the art of producing banking transitions where staying in was down to driver skilfully rather than something of a lottery. I have tried to explain ways of doing that.
Lanes dropping as they go into the banking or rising as they come out will increase the risk of these sort of problems. With a cross over on the transition its more likely one or more of of the lanes will be dropping at the wrong point.

I've given that much thought over the weekend and have this to say...

So i've been giving some thought to Dave Frost's treatise on banking.

I started by calculating how long the transition length needed to create a change in vertical level of 45mm (my maximum required) with his notional convex curve of 10m diameter with a car then having to run at less than 10m/sec. (Most of my cars don't run that fast but of course I want to be able to accommodate all types of racing. If cars are running faster than that they'll just have to (learn to) slow down for the transition and very probably the curve too!!!) I understand that you didn't mean this as a necessary 'limit' Dave, but it seems to me that it is a useful limit for my designs. I never intended that the cars would be running 'flat out' round the banking although some might. Those that aren't running flat will need skill to judge the speed needed.

If Dave's calculations are correct then I would need a transition length of 1.35m (measured at the slot).

Now the banks at Monza were built so that the central 132° of the 180° curve on plan were an exact extrusion of the desired bank. The remaining 48°, divided into two were used to make the transitions. So that the transition occurred in the first and last 24° of the curve itself.

In my scheme, before checking Dave's calculations I had increased that 24° to 28°, giving me roughly 500mm of the curve as the transition zone but knowing too that a little of the straight could be used.

Now with Dave's calculation and my own I know I need to use about 850mm of the straight as transition in my worst case. Now the straight between the two banked sections is in fact 3.3m long. So 850 is almost exactly ¼ of the straight such that the first and last ¼ would be transition and the middle ½ would be 'flat'. Not too bad.

We must however consider another couple of things:
1. Only the right hand bank needs this long transition as the lanes are spaced wide apart for passing.
2. On the left hand bank the lanes are close for slipstreaming so the cars move up and down the banking far less and thus move 'vertically' less (and so need less transition to accommodate Dave's calculation. In fact they need 1125mm and less the 500 of the curve leaves just 625 in the straight). This might mean my two transition zones are 'asymmetrical' but will also mean the straights are flat for longer - which should look better.

There is of course another way to approach the whole business. I have chosen, for reasons of construction, to have the slots in the banking PARALLEL. (I am worried that in those banks I will NEED the router to be fixed on a pivot point otherwise it will be just too complex and imprecise!!).

Actually it occurs to me that the trajectory (slot) in the banks should be parabolic&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;. In plan.

What I mean is that a car approaching would want to cross the transition in the centre of the track where the vertical transition is essentially flat and then 'carve' up onto the 'berm' and then use the gravitational effect in the second half of the curve to get acceleration down onto the next straight.

(I've used Skateboard / BMX terminology here as I experienced this as a youth in 'realtime'!)

If I could achieve this I think Dave's launch problem would go away but actually it then brings in a whole lot of other complexities and unknowns that this project really doesn't need any more of!!!!!

QUOTE (Spa67 @ 19 Jun 2011, 22:14) <{POST_SNAPBACK}>I've given this some thought. If you do build this I have a feeling I'll be asking for an invite on my next trip to Italy! Such a legendary circuit. That room you have for it. I can not think of a more picturesque place for a slot race track.

A few friends, a setting sun, a little wine, some good cheese, someone making dinner up stairs, and hard-core slot racing at MONZA

I want to go now!

The only solution I can think of is to have a minimum number of x-overs, and have them in the slowest possible places so the drivers have plenty of time to avoid accidents, and the accidents are as low-energy as possible. I know you said you detest the R1 type corners, but the slow speeds they require may be very useful. I would at least consider the following...

A very slow, tight radius entry for the paribolica. Maybe as little as 12-15cm radii. Close, if not the same for all lanes. I think the closer you can get the intersections to 90deg the better off your going to be. More importantly the straighter the car is traveling on the x-overs the better the chance they will stay in the correct lane.

thanks for the advice i'm considering this......

QUOTE (Swissracer @ 20 Jun 2011, 08:00) <{POST_SNAPBACK}>Looks a stunning project Andi and the wisdom and advice is priceless too ............

Good luck with this great looking project, I look forwards to trying it one day

Hope you come over for it when its done Allan. You were missed this year at the MMM.

I managed to get a lot of the underpass built this weekend and if next week I can 'skin' that I can start routing.......


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Well thanks Graham - we had a great time entertaining you too.....

I did manage to get the underpass 'finished' last weekend but haven't had time to post until now...

So the road part is done and the transitions are smooooooth.

I made it from two layers of 4mm MDF glued and temporarily screwed down to a wooden structure.

The transitions have radii of between 4m and 6m so you wont be taking this section flat out!!

I hope to start routing next weekend if I can find time to buy the bits.....


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Sadly i'm not able to read that!
Looks like an interesting read. I'll have to buy it I guess.

I do have an Italian book all about Monza though which i'm using for source info.
Sadly this project stalled due to life circumstances and has been broken up...

One day in many years perhaps I'll start again?

Thanks for your interest.
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