22 replies to this topic

[dalek]

I only have JK and Mossetti chassis but the following question might apply to most, or maybe all, other chassis.

 

Does anyone have any idea as to why the manufacturers don't angle the guide tongue upwards 2 or 3 degrees so the buyer doesn't have to do this (especially helpful if we want to attract newbies to the hobby)?  

 

The angle could be done at the same time the rest of the chassis parts are being folded upwards.

 

The Mossetti Striker, with it's strong steel and coined tongue, is particularly tough to bend.

 

When JK, Mossetti, etc. are developing a new chassis, do they bend the guide tongue up 2 or 3 degrees when testing or do they leave the tongue just as it was when manufactured?

 

[Ramcatlarry]

Age old question.  Is the way (it)  ANYTHING comes from the factory the perfect state to be?  Or is the end user responsible to alter and tune it to their own needs?  I say 'TUNER' since rear tire diameter and clearances ultimately affect what the final ANGLE needs TO BE.

 

Most stamping dies are made to make parts to be flat or at right angles.  Different metals have 'memories' of their last state and tend to resist certain bends.  One set of dies designed for a certain metal thickness and used with a thinner or different material may not turn out as desired.

 

I worked in the sheet metal industry for many years and parts cut from ROLLS of material can change over the length of the parts run due to the forces needed to return the metal to a flat state  The end of the roll will have natural curvatures that the start of the roll never had.  Even the way the die cut takes from the roll can show 'cupped' parts.  Cutting from flat sheet stock is best for our slot car frames.  Sometimes these fabricating processes are out of the hands of the designer unless specifications and close quality control is in place - like ON SITE.    To me - make it local.

[dalek]

I say 'TUNER' since rear tire diameter and clearances ultimately affect what the final ANGLE needs TO BE.

 

According to the calculations I just did, the angle of the guide tongue would only change about plus or minus 1/3 of a degree when chassis clearance changes.

 

Let's assume a manufacturer makes a chassis so the guide tongue is angled 2 degrees upwards with the chassis rear clearance of .060 with .750 tires installed.

 

If you change to .690 tires, resulting in a rear clearance of .030, the guide tongue angle would only increase about 1/3 of a degree (to 2.34 deg).

 

With .810 tires, a clearance of .090, the angle would only decrease about 1/3 of a degree (to 1.66 deg).

 

It still seems to me that the chassis makers could, at least, get us in the ballpark -- a tongue angle that would be acceptable to most of us -- or at least much closer than it is now.

 

[dalek]

I just talked to Ernie Mossetti.  He doesn't personally test his chassis but he does get feedback from racers in Italy.  His impression is that angling the guide tongue upwards does not appreciably improve handling.

[MSwiss]

The point of angling the guide tongue is to insure better braid contact.

Any perceived handling improvement would only be that the car is reacting properly to controller responses.

[Jay Guard]

Through many years of slot car racing I have found if the guide is angled too much forward (i.e. down in front) the car will have a tendency to push out of the slot at the beginning of a turn.  If the guide is angled too far back (i.e. up in front) the car will have a tendency to push out of the slot near the exit of a turn and burn/wear the rear of the braid.  In fact I once made a chassis with an adjustable guide angle feature and got consistent results as stated.  Therefore the question is what is "too much" angle in either direction?  In my experience 1-2 degrees "angled up" seems to give the best all around performance for both braid contact, as Mike Swiss mentioned, and for keeping the car in the slot in turns.

 

Note too that the actual angle the guide has with the track will change slightly when tire size is changed, but if you set the angle in the range mentioned changing tire sizes (within reason) doesn't appear to effect the handling or braid wear significantly.

[Matt Sheldon]

Through many years of slot car racing I have found if the guide is angled too much forward (i.e. down in front) the car will have a tendency to push out of the slot at the beginning of a turn.  If the guide is angled too far back (i.e. up in front) the car will have a tendency to push out of the slot near the exit of a turn and burn/wear the rear of the braid.  In fact I once made a chassis with an adjustable guide angle feature and got consistent results as stated.  Therefore the question is what is "too much" angle in either direction?  In my experience 1-2 degrees "angled up" seems to give the best all around performance for both braid contact, as Mike Swiss mentioned, and for keeping the car in the slot in turns.

 

Note too that the actual angle the guide has with the track will change slightly when tire size is changed, but if you set the angle in the range mentioned changing tire sizes (within reason) doesn't appear to effect the handling or braid wear significantly.

Very accurate! Also some guides intended or not have a little pitch to them. A few years ago I was stuck in the 5-6 degree crowd, but now 2-3 degree (tongue + guide angle) seems to be my sweet spot with angle. Just how tire size can adjust angle, a rubbered up track can do the same thing.

[swodem]

Very accurate! Also some guides intended or not have a little pitch to them. A few years ago I was stuck in the 5-6 degree crowd, but now 2-3 degree (tongue + guide angle) seems to be my sweet spot with angle. Just how tire size can adjust angle, a rubbered up track can do the same thing.

 

Im interested in how everyone actually measures the angles they say they're setting...

[dalek]

I just sent a Facebook message to Ernie, suggesting that he read this thread and consider producing future chassis with the guide tongues angled. 

 

The angle he decides on might not be the "sweet spot" for every racer, but could be acceptable to most racers and certainly an improvement to the downward angle that now occurs.

[swodem]

I just sent a Facebook message to Ernie, suggesting that he read this thread and consider producing future chassis with the guide tongues angled. 
 
The angle he decides on might not be the "sweet spot" for every racer, but could be acceptable to most racers and certainly an improvement to the downward angle that now occurs.

I haven’t seen a Mossetti chassis come with a downward angle!?


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[MSwiss]

Through many years of slot car racing I have found if the guide is angled too much forward (i.e. down in front) the car will have a tendency to push out of the slot at the beginning of a turn.

Jay,

I'm surprised you got adequate enough braid contact to analyze the handling characteristics.

 

Does anyone have any idea as to why the manufacturers don't angle the guide tongue upwards 2 or 3 degrees so the buyer doesn't have to do this (especially helpful if we want to attract newbies to the hobby)? 

Dale,

I checked with an expert, Chuck Gambo, and he contends it could be done, if it was top-notch tooling, for the forming.(IE-a one step process)

 

You are assuming  2 or 3 degrees upwards, or any kind of angle, is considered optimum, by the slot car chassis designers.

 

A prime example is when one buys a built Horky chassis.

 

Chuck Gambo confirmed they come with the tongue soldered on flat.

 

If the top scale racer in the world, doesn't angle his tongue, why would the chassis makers?

[SpeedyNH]

maybe he doesn't want his customers to beat him.

[MSwiss]

Then he wouldn't sell him his chassis , at all.

 

Nothing is stopping his customers from from heating up the tongue, and angling it,  if it was important.

 

Here's another response from a national caliber, podium Eurosport/flat track racer, when I asked;

 

Do top scale racers change the tongue angle, to tune the handling?

 

I don’t think eurosport racers “tune” the guide tongue. Should we? How?

 

He did add, and I agree 100%, that angled forward, is never good.

 

[Matt Sheldon]

Jay,

I'm surprised you got adequate enough braid contact to analyze the handling characteristics.

 

Dale,

I checked with an expert, Chuck Gambo, and he contends it could be done, if it was top-notch tooling, for the forming.(IE-a one step process)

 

You are assuming  2 or 3 degrees upwards, or any kind of angle, is considered optimum, by the slot car chassis designers.

 

A prime example is when one buys a built Horky chassis.

 

Chuck Gambo confirmed they come with the tongue soldered on flat.

 

If the top scale racer in the world, doesn't angle his tongue, why would the chassis makers?

I am no Chuck Gambo and I will definitely never be a Horky, but in general I believe Horky is a Flat Track racer. Most flat tracks have a consistent flat surface and braid depth. The tracks I run on are far from smooth and flat. I have always found my cars to handle better with a little guide pitch to them. I guess my theory and testing found that the guide did not force the braid to dig in or ramp as much with a tongue that had a little degree of pitch to it. Same theory also applies to why I have never had great success with running my braid perfectly flat locally, but do when I travel to other races that have a better race surface. I also don't have the same deslot issues some of our local racers have. The introduction of running a little angle to my guide came when I needed a cut guide. Red Fox was all that was available that day and until then I had always run Parma or the occasional Slick 7. Parma guides are very consistently flat. When I installed my first Red Fox it was noticeably not. The degree of pitch varied, however my car immediately handled better. That theory has carried through over the years with using an angled guide tongue or adding angle to a nose. That being said I am mindful to what guide I will be using as I vary my brands by what type of chassis and or track i will be running on. The 2 things that I believe are the biggest factor in car setup is the guide (pitch, squareness, height, etc.) and tires. 

 

Additionally we could question why some put so much emphasis on what the trailing edge of the braid is doing. Fanning the braid out, wear characteristics, when to shorten and when not to. Seems like the braid is doing a lot that last 1/4" of it. Flatter equals more contact patch, but that comes with friction and drag, both in a straight line as well as cornering. 

 

I have also learned over the years that just because it works for a World Champion does not mean it will work for me or other mid packers. Driving style, braking points, etc. drastically change how a car handles. Testing confirms 100% what works or doesn't work for you.

[MSwiss]

And that's why you can adjust it to whatever you want.

 

My point was there isn't a consensus.

 

I'm happy with a stamped chassis, if it's not bent down.

[Matt Sheldon]

 

Im interested in how everyone actually measures the angles they say they're setting...

I use a protractor like this, the same that I use for verifying our guide tongue degrees and new motor brackets post forming. 

 

[Matt Sheldon]

And that's why you can adjust it to whatever you want.

 

My point was there isn't a consensus.

 

I'm happy with a stamped chassis, if it's not bent down.

Sorry, I agreed with you that the chassis itself should not come anyway, but neutral. It is an easy process to add angle, sometimes as simple as just the guide flag itself.

[MSwiss]

Yes, I originally addressed Dale and his post#1, where he assumes 2-3 degrees upward, is the consensus among all/most racers.

[Jay Guard]

Jay,

I'm surprised you got adequate enough braid contact to analyze the handling characteristics.

Mike:

I made this comment based on two pieces of evidence.  The first and most obvious is when the car has a hard hit into the wall and as often happens the guide is bent down in front.  The car will invariably push out early in a turn,  I know you know this Mike.  The second is when i tested this theory using the car I made with the adjustable guide angle.  Sure enough the results were the same with a bent forward guide.

 

Now as far as a 2-3 degree consensus among racers goes I think it comes from the fact that most cars have more clearance in the rear than in the front.  Generally this gives a chassis angle of around 2-3 degrees forward (i.e. down in front).  To offset this chassis angle and achieve a relatively flat (i.e. parallel to the track) guide most racers I know put a 2-3 degree up angle on the chassis.  If you don't build this up angle into the chassis the guide would necessarily be angled forward which I think most everyone agrees is a bad thing.

 

All of this makes me wonder whether we are all talking about the same thing.  That is, the angle the guide makes with the track or just the angle built into the chassis?

[Eddie Fleming]

Two thoughts, more like questions.

 

1 A reputable provider of slot products produces a guide tongue with 2 degrees of angle cut in. Is that necessary?

 

2 I think many if not all new wing car chassis have the guide cut in as part of the main chassis. this would seem to me to create a little down angle in the ready to run car. How does that work out so well?

[swodem]

So if you had a 2.5 degree angle on the guide tongue, that would have your braids running flat when the rear clearance was 2.82mm

Seems way overkill to me

We run 0.6 minimum clearance here so 0.5* angle would be sufficient for our setups

How much rear clearance are you running??


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[Matt Sheldon]

 

1 A reputable provider of slot products produces a guide tongue with 2 degrees of angle cut in. Is that necessary?

 

 

 

It's a good question which brings up another element. We are now talking about a car that has wheels touching which limit the what the front of the car does under braking and cornering. 30 grams minimum more car weight to support as well. Personally I think it is necessary for overall performance consistency. 

[MSwiss]

Two thoughts, more like questions.
 
1 A reputable provider of slot products produces a guide tongue with 2 degrees of angle cut in. Is that necessary?
 
2 I think many if not all new wing car chassis have the guide cut in as part of the main chassis. this would seem to me to create a little down angle in the ready to run car. How does that work out so well?

Like Matt mentioned, I sell sell these primarily for Retro cars, which have a definitive rake, and (usually) rides on the front tires.
 
That said, I sell non-2 degree, of the same item.
 
Guys can buy and use whatever they want.
 
I don't have a real strong opinion on anything other than angled down is always bad.
 
As far as wing cars go, they have much higher downforce, so maybe not a great comparison.
 
But at least your timing is good.
 
Below is a pic of the car that's going to win tonight's Group F race.

 

It's sitting on an adjustable Backtrack recess block, set to my tracks .015"-020" recess.