# Unsuccessful Curve Combinations



## Grandcheapskate (Jan 5, 2006)

Hi Guys,
In using plastic track, with 1/8 curves from 6" to 15", I'm sure each of us has tried combinations that have simply not worked out as well as we had hoped. On my current four lane layout, I have a 180 degree turn (four pieces of 1/8 curve) which is made up of the following - inside lane (12" followed by a 6", 6" and 12") and outside lane (15" followed by a 9", 9" and 15").

I have found the innermost lane very difficult to drive. I know a lot of guys hate the 6" curve in general, but I can handle all the other places the 6" curve is used. However, in this one spot, it is very hard to get through the inside lane on a consistant basis. I'm guessing that having a 12" curve lead into a 6" (actually two of them) and then back to a 12" is just not a good combination. I am now trying to figure out how to change the layout in that one spot without disrupting a huge part of the track.

Has anyone else tried this combination with success? Are there other curve configurations which you have learned to avoid?

Thanks...Joe


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## demether (Aug 26, 2008)

In my opinion, difficult turns is part of the race. See some real road tracks, like Laguna Seca, Le Mans, etc... they all have well known difficult turns on their layouts. 

I guess it depands of the driving style and cars you plan to race. But for me, it's not an issue, but a challenge :thumbsup:


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## 1976Cordoba (Sep 20, 2000)

I didn't do any 6" or 9" turns on my road course, but I like a fast track, so that's just me.


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## SwamperGene (Dec 1, 2003)

Grandcheapskate said:


> Hi Guys,
> In using plastic track, with 1/8 curves from 6" to 15", I'm sure each of us has tried combinations that have simply not worked out as well as we had hoped. On my current four lane layout, I have a 180 degree turn (four pieces of 1/8 curve) which is made up of the following - inside lane (12" followed by a 6", 6" and 12") and outside lane (15" followed by a 9", 9" and 15").
> 
> I have found the innermost lane very difficult to drive. I know a lot of guys hate the 6" curve in general, but I can handle all the other places the 6" curve is used. However, in this one spot, it is very hard to get through the inside lane on a consistant basis. I'm guessing that having a 12" curve lead into a 6" (actually two of them) and then back to a 12" is just not a good combination. I am now trying to figure out how to change the layout in that one spot without disrupting a huge part of the track.
> ...


Hey Joe :wave:

To me it would depend on the rest of the layout. I like mixed radius sections as it forces you to pay attention to the track, but at the same time you want a good flow. If it's buried in a technical section, I'd leave it for a while and try to conquer it. If the entire curve has straights of any decent length on _both_ sides of it, you might want to rework it.


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## Dslot (Sep 2, 2007)

*Going over the Low Side*

I had a similar problem on one of my temporary layouts - a 4-lane, 135° curve made with Tomy track. The outer part, 12"-9"-12" was just a slightly tricky curve, but the inner lanes, a 9"-6"-9", were deadly. Even when you knew they were coming up, and threw in extra braking, they'd spin you. You could only get through on Dead Slow, or so it seemed. It quickly got dubbed "Undertaker's Bend."

I checked it a number of times for even surface and rail-height at the joints, smoothness of the slot, etc., and it came up innocent. I finally figured it out - the inside section was slightly off-camber (reverse-banked) from pressure of the adjacent straights. Pulling the track-nails for a couple of feet each way and renailing, starting with the problem curve, fixed the problem. 

Either the outer lanes weren't off-camber, or else the effect is more manageable on the larger radius curves. But everybody who drove it had a great deal of trouble adjusting to the 6" section. Since we did short crash-and-burn races with no lane rotation within a race, if you drew the inside lane, you might as well sit it out and save the wear and tear on your car. It was not just a challenge - it was an impediment to a fair and fun race.:drunk:

That may not be what's causing _your_ problem, Joe, since your Tyco curves actually fit properly inside one another. With Tomy, you're always fudging with tension and pressure to close the dreaded centerline gap. But it might be worth checking. If your adjoining straights are at angles a bit less or greater than the intended 180°, you might be pulling or pushing the curve into a higher inside shoulder. A high spot on the tabletop could do the same thing.

Good luck. :wave:
-- D


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## twolff (May 11, 2007)

In years of fooling with Tomy track in 4'x8' four lane road course layouts I've found that it has more to do with the flow of the course than the individual track sections. If the tighter curves are buffered into the layout with sections that compel the driver to slow down before reaching the tighter section, you will barely notice the 6" curve. I have an "S" curve on my layout made of 6" and 9" curves. It is fed by a 12"/15" and then a 9"/12" section. It is not difficult to navigate, but does force you to slow down.

I found the Ultimate Racer 3 track editor very useful for eyeballing different options before physically moving the track sections around.

Here's a link to what I'm running on now:

http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=79419&d=1238115137


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## Pete McKay (Dec 20, 2006)

On my two lane Laguna Seca I used 6" for the Corkscrew portion. Since it was tight corners and a downhill very few drivers could get through it, and ultimately I think that led to guys refusing to race on it. 










From the top of the hill to the turn after the corkscrew was a 7" elevation drop. Doesn't sound like much but consider we were running T-Jets with DASH Cobra bodies and silicone tires. But even with magnet cars it was hard to get through there quickly.


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## Slott V (Feb 3, 2005)

*6" turns can be fun*

6" turns are tough because your back tires really break traction with the tight radius and solid axle. If you run strong magnets and silicone tires you really work the gears.

One of the toughest corners to master on my track is the dog leg of turn 6 with the 90° 6" turn coming after a sweeping 270° 12" radius leading into a 9". You come down nearly 20 feet of straights, blip your way through it and again back on the gas to another long straight- it's a common source for "360" spin outs coming out of the 6" because it's easy to hit the gas too soon for the approaching straight. Your timing has to be precise. It's a lot of fun once you master it but it takes a lot practice.









The outside lane (white lane) is the hardest, with the inside lane also getting a taste of the tight quarters.









Turn 6 often sends guys into the grass as you can see the years of wear and tear here-


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## NTxSlotCars (May 27, 2008)

All interesting stuff guys.

For me, I only use different radius combinations to make an increasing, or decreasing radius turn.
I think the 6" turns are tough because most cars rear tires ride on the rails to get through it.


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## Grandcheapskate (Jan 5, 2006)

HI Guys,
Thanks for all the replies.



SwamperGene said:


> To me it would depend on the rest of the layout. I like mixed radius sections as it forces you to pay attention to the track, but at the same time you want a good flow. If it's buried in a technical section, I'd leave it for a while and try to conquer it. If the entire curve has straights of any decent length on _both_ sides of it, you might want to rework it.


Gene,
You have identified what I also consider to be the largest contributor to this problem curve. This turn is at the end of a 39" straight (three 9" straights and two 6" straights); and that's after coming off another straight using the outside lane of a 15" curve (180 degree turn). So you can get a pretty good run going heading into this curve. I have been trying to see if I can either put a more technical section in front of the curve to reduce the speed into this corner. Failing that, I will need to rework the corner.



Dslot said:


> That may not be what's causing _your_ problem, Joe, since your Tyco curves actually fit properly inside one another. With Tomy, you're always fudging with tension and pressure to close the dreaded centerline gap. But it might be worth checking. If your adjoining straights are at angles a bit less or greater than the intended 180°, you might be pulling or pushing the curve into a higher inside shoulder. A high spot on the tabletop could do the same thing.
> 
> -- D


D,
If the problem is not in the design of the curve itself, then I believe the cause is a layout which allows for too much speed entering this curve. There is no tension on this curve as everything fits together perfectly. And the problem is really only on the innermost lane. On the other lanes, the turn is manageable with all types of chassis.

Thanks...Joe


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## NTxSlotCars (May 27, 2008)

Slott V said:


>



By the way, that's one heckof a track SV :thumbsup:


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## 1976Cordoba (Sep 20, 2000)

I probably mentioned this last time you posted pics, but SlottV you have a hell of a track there - I love how it is beat to crap in certain areas - gives it a lot of character! :thumbsup::thumbsup: You can tell there has been a lot of good racin' on that baby.

We now return to our regularly scheduled discussion about 6" turns.


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## Dslot (Sep 2, 2007)

Grandcheapskate said:


> If the problem is not in the design of the curve itself, then I believe the cause is a layout which allows for too much speed entering this curve. There is no tension on this curve as everything fits together perfectly.


Okay, Joe. But you might want to put a level across the 6" curve section, just to see. Could be a simple fix, compared to tearing up your track and re-designing to change the layout. (For that matter, sliding a shimming wedge under all four lanes at that point to give a bit of banking, might just give you a driveable curve, no matter what the cause).

Tyco track geometry_ is_ better, but but there could be other reasons than compensating for the Tomy midline canyon that a curve might have enough tension to buckle toward the outside. It could be that adjacent straights aren't quite parallel. Or that the piece of track in question had got warm sometime, and warped slightly. Or there's a bump in the table or a bit of something under the track's inside edge.

I was interested in the other responses, wondering if anything else might have contributed to my own problem. I'd say no. My killer curve was on an uphill stretch, was preceded by only 3" of straight, and the 9-6-9 curve was introduced by a 12" 45° curve. If drivers needed an additional reason to slow down, they had several. 









One other question that this discussion brings up is: What is 'flow?' I think I know it when I see it or drive it, but what factors contribute to good flow in a course, and what detracts from it? I think I'll start a new thread for that one.

-- D


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## Rolls (Jan 1, 2010)

Yes, Slot_V - First time I've seen your track. It looks fantastic!


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## Slott V (Feb 3, 2005)

It could be a connection misalignment issue if its just that piece. The radius is so tight if something upsets the chassis the back end comes around. There is a flared area to the slot at connections and if the chassis is pushing the pin to the wall of the slot it might be catching on something when it enters that piece. What kind of cars, magnet or AFX/TJet?

Ever try just staring at that section closely while someone runs the lane or video taping it to try and see what's going on in slo-mo?

Thanks for the comments on the track. Yes it's old and been covered in dust for a while. I don't want to detour the topic- someday I'll post more pics when I clean it up.


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## Grandcheapskate (Jan 5, 2006)

Dslot said:


> Okay, Joe. But you might want to put a level across the 6" curve section, just to see. Could be a simple fix, compared to tearing up your track and re-designing to change the layout. (For that matter, sliding a shimming wedge under all four lanes at that point to give a bit of banking, might just give you a driveable curve, no matter what the cause).
> 
> Tyco track geometry_ is_ better, but but there could be other reasons than compensating for the Tomy midline canyon that a curve might have enough tension to buckle toward the outside. It could be that adjacent straights aren't quite parallel. Or that the piece of track in question had got warm sometime, and warped slightly. Or there's a bump in the table or a bit of something under the track's inside edge.
> 
> -- D


D,
I put a level across the curve and found that inside-to-outside, the curve is level. There is a very slight drop from entry to exit. This is to be expected as I put this table together using only scraps of plywood (that were laying around) mounted to folding table legs. I've never screwed the track down either, so doing a modification is not the major undertaking it would be had the track been more permanent.

I'm also wondering if anyone else has a 12-6-6-12 180 degree curve and if they find it enjoyable to drive.

Thanks...Joe


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## pshoe64 (Jun 10, 2008)

I have several 6's in my road course portion of Woodrum Ridge Raceway. Of course I have the banked oval to fall back to if I need the speed rush. The 6's are a challenge, but it hones the skills too (and patience!) Here's the design view of WWR.

-Paul


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## demether (Aug 26, 2008)

On my track, 6" turn parts are only in relatively slow parts of the track. I've got a massive 3.50meters (about 11 feet) straight line, finishing on a 9" inside 12" outside turn. 

The mixed 9"-6" are placed after short straight parts ( about 3 feets). 

Last thing, I think 6" turns works better mixed with other radius. On my track, I've got one 9"-6"-9" turn, and a 9"-9"-6" turn (inside lanes). It's technical, but it allows the drivers to brake or re-accelerate easier


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## Grandcheapskate (Jan 5, 2006)

I was able to make a simple adjustment to the track and change the 12-6-6-12 to a standard 9-9-9-9. I tried to put an "S" curve in front of the 12-6-6-12 but because of space restrictions, the "S" required a pair of 6" curves and it was not fun to drive; it looked really great, but didn't drive well. However, with the "S" in place, the 12-6-6-12 was no longer a problem.

So now I have removed the last of the annoying spots on my track, but it is kind of bland. So I'll still be tinkering until I find that good mix of drivability and looks.

Thanks...Joe


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## jensen b (Nov 3, 2009)

*Tomy Track problems*

Another problem that has recently come to my attention, is that not all tomy track is the same size length or width, i.e. 15in straights vary in length, not by much, except when you get several together and some are even bent making the track turn away from the intended direction and some bends don't fit snugly inside one another.


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## twolff (May 11, 2007)

jensen b said:


> Another problem that has recently come to my attention, is that not all tomy track is the same size length or width, i.e. 15in straights vary in length, not by much, except when you get several together and some are even bent making the track turn away from the intended direction and some bends don't fit snugly inside one another.


I've observed the same inconsistencies in the 15" straights. I may give some AutoWorld 15" straights a go. The AW track is compatiable with Tomy and hopefully made in a different factory with fresh molds.

I spent a considerable amount of time pairing up the 15" straights to make the straights on my track as straight as possible. They are actually really long chicanes I guess.


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## 1976Cordoba (Sep 20, 2000)

Dang it you guys - that's called 'character.' Don't you know anything?


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