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Discussion Starter · #1 ·
Just trying to stop this topic from blocking up another thread, Thought I would create a new topic for it here.

I put out the idea of building a steering system for slot cars linked to the blade, relatively easy to do, mainly for the look of it so you could see the opposite lock around corners etc
, but was looking for opinion of people who had done this or had thought of it or even just wanted to comment on the idea.

David
 

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I have an scx F1 (jaguar). It has only one linking bar at the back, not 2 like yours.

The wheels on this assembly are not held on to the 'axle stubs' very securely, so they have a lot of wobble in all directions. I am not sure if this is to add some kind of suspension and play to them, or just poor design/engineering.

The steering seems to work well, it certainly looks nice when going slow enough to see. The car is pretty fast, though not as fast as my scalextric F1's without the steering. I can't tell if this is due to the steering or not, really you would have to have the same model and set-up with and without steering

oh- and whats the ackerman angle?
 

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Discussion Starter · #8 ·
Ackerman Angle is something you dont really need to worry about
, basically in a standard steering setup both wheels turn by the same amount, so as a car turns one wheel is turning the car and the other is scrubbing the tyre nicely, so serious racers set up the steering so that the wheels turn at differing angles, so that both wheels are angled correctly for the corner. I never bothered with it for rallying


Wobbly wheels doesnt sound good, I would like something nice and solidly mounted. I suspect instead of having two linking bars it may instead use the chassis as a linking bar? does one end of the hub attach to the chassis and the other to the linking bar? I could see a case for doing this. I will have to take the time to look at one sometime, I think if I do it, it will have to be to a non mag car, designed for looking good round the track rather than speed, problem is most of my cars are so flaming fast round the trackits hard to even see if they are sending the back end round - let alone which way the wheels are turning at the same time


David
 

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the hubs hinge/pivot on bars attached to the chassis, in line with the centre of the hub. then they have a rear spur, which attaches to the linking stearing bar. I didn't realize that in your design, the wheels were not fixed to the chassis
 

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I'm just looking at my SCX Arrows F1 right now. Another reason for wobble is the poor fit of the wheels on the hubs themselves. Also the hubs can move up and down at their pivot point by about 1mm in total. The steering bar is quite a good fit on the rear of the hub, but has a bit of slop where it fits over a pin on the guide blade. In addition this steering arm is quite thin and flexible, presumably to protect the hub assemblies from terminal damage (for a while anyway!)

Hope this info is of some use.

Mark.

I might try some PTFE tape to take up the slop in the wheels. What do you reckon?
 

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Discussion Starter · #11 ·
I had just came up with the idea of how to get steering to link to the blade
not a finalised design
, I figured I would see what people had to say about other attempts to do steering, and see if I could improve it somehow.

When the wheels turn is it just the back of the wheels that move then leave the fron in effectively the same place and the rear swings through an arc behind? That would lead to a decidedly dicey handling I should imagine, it would possibly have the effect of pushing the car out of the slot more rather than steering it in the right direction? not sure having never sen it, but that would be my logic.
 

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No David, the SCX steering is similar to that on a real car. The "ball joint" and "track rod end" are certainly at the rear of the wheel. The wheel and hub pivot along the centreline of the wheel, so that the front of the wheel also travels in an arc.

Erm just re-read you post and unlike your design, there's nothing to drag the front of the hub around. I think that's what you were implying was it?

Mark.
 

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the pivot point is on axis with the centre of the wheels, and just inside the wheel as well, so the steering angle is very realistic

On another thread, someone (can't remember who or where, sorry!) was talking about 'passive steering' where the wheels can turn, but are not linked to the guide, rather turned by the road/track on the rubber. This reduces the complexity, friction points, weight, and any discrepency between the guide angle and the ideal wheel angle. I haven't seen this done in practice, and i'd imagine it would work best if the 2 wheels where linked together...
 

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Yes- look on Al Penrose's BWA site. He has a 'passive' or 'castor' steering set-up there. I want to try it on my M7A, but when I'm going to get round to it I have no idea. Slight problem is that on the original car, the steering arm seems to be at the front of the hub, which would be a bad idea with a 'passive' set-up I guess! Still, you can go too far with scale accuracy.
Airfix/MRRC cars in the 60s were advertised as having true 'Ackerman steering', where the geometry is set up so that the inner wheel follows a tighter radius than the outer one, as logic would decree....
For a 4WD steerer, look no further than the fascinating thread on the history of MRRC in the History, Culture and Literature section! The G.P. Merc, Indy Novi-Ferguson and Felday-Ford were miracles of miniature engineering. Treat your eyes!
Nice one David!
 

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the pivot point is on axis with the centre of the wheels, and just inside the wheel as well, so the steering angle is very realistic,

Excellent, sounds like they've done a good job will have to take a look


Wow Ackerman on a 1/32, that was some serious dedication, I never bothered with it when rallying, although I could see the logic behind it, messing around to that degree with steering angles seemed like a ure fire way to introduce some weakness to the already stressed steering
hitting ruts at 90 mph sideways does wonders for track control arms
, I have a large collection of "pre loved" skoda felicia track control arms hanging around - typically only 150 miles use
.

4 Wheel Drive with steering, guess someone had to have done it, but wow seems like some real engineering talent has been involved. I guess now that we are going digital gear change wont be beyond the realms of possibilities, I wonder if there's any room for playing with the system, spare signals etc that could be sent
Perhaps an ability to swap fron to rear wheel drive on a twin engined vehicle or switch on and off magnets, just to add a greater degree of challenge to driving \ modifying cars
, imagine a nice low gear for accelerating and a tall one for the really long straights
, or would that just be far too much work at the speeds the circuits are lapped at
 

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Hi

I think I posted elsewhere liking to watch the car steer. I have antiques that do it, and modern cars(MRRCs, 4wd MRRC, modern SCX srs, Nincos), and scratchbuilt.

Love it.

Does not make for better handling. The slop is a good idea! Simply cars work best as tripods where the guide carries the front end and the front wheels perform cosmetically. Enjoy the looks but try to keep the front tires out of the way.

Fate
 

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QUOTE Wow Ackerman on a 1/32, that was some serious dedication, I never bothered with it when rallying, although I could see the logic behind it, messing around to that degree with steering angles seemed like a ure fire way to introduce some weakness to the already stressed steering
Ackerman stearing is no big deal in Slot cars,and in 1:1 cars is fixed in the design geometry of the Steering arms.This is not generally a user adjustable parameter,unless you have access to different steering arms,of different lengths and angles.On many cars,the steering arms are part of rhe front hub/knuckle assembly,and cannot pe changed anyway.

The Ackerman effect is produced by having the track rod end pivots at an angle inside the Ball Joint/Spindle pivot line to form an unequal parrallelogrom that automaticaly turns the inside wheel sharper than the outside one.

On Slot cars,it is a waste of time and complexity to bother connecting the steering Link to the guide.

Here's how its done.
 
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