Independent Turning Front Wheels?

[glasshorsevh]

Does anyone have an opinion about the benefits of independent turning front wheels? I have built proxy cars with them, but I’m questioning the practice. It would seem that a slot car would have an inherent oversteer condition because of the guide anchoring the front end. One might think that a solid front axle would introduce some understeer which should be a good thing. Thoughts anyone?

Val

[bdsharp]

I did it on one Showdown car and in my very limited experience, I don't think it made any appreciable difference. But if you did it with some kind of stub axle arrangement, you could build in some positive camber so that only the outer edges of the tires touch the track for maybe less drag. Worth anything?

[glasshorsevh]

I did it on one Showdown car and in my very limited experience, I don't think it made any appreciable difference. But if you did it with some kind of stub axle arrangement, you could build in some positive camber so that only the outer edges of the tires touch the track for maybe less drag. Worth anything?

Bob, I did try that once, but the results were inconclusive (the car was destroyed by the P.O.)....

[4424ever]

IMHO it’s not worth the effort unless what you’re looking for is the aesthetics of exaggerated camber
I don’t think there’s any performance aspect unless the guides is mounted along way from the axle centre line
PS sorry to hear that about your car

[bdsharp]

I think you're right. Especially for Showdown-type cars, KISS is probably the way to go.

[waaytoomuchintothis]

The HO guys are going to line up to take this one on! I don't remember seeing a non-independent HO front end in years.
Meanwhile, in the bigger scales, I have to disagree with others. I have made independent fronts on oval cars, and they have been been easier to handle the wider the front track is. I do it by telescoping brass tubes with axles inside, then using a C-clip to hold the inner axle.

[4424ever]

Rob I can’t disagree with you’re comment on track width. The wider the width and tighter the corners will magnify front axle chatter.
My question is when you say the car was easier to drive was it smoother was it faster how was it easier ?

[waaytoomuchintothis]

Just easier to control at full speed. Running at the edge of deslotting is easier when our butts aren't in the seat. So, we bite our lips and go the limit, knowing that we won't get our heads mushed in the roll cage. I do love slot cars.

[Brumos RSR]

I have a 908 that if I run an independent front the rear rotates too much, if I lock the front the car is easier to drive. My other 908 runs much better with an independent front end. My Can Am Proxy car ran an independent front end and the runner up did not have an independent front and based on the notes, it was easier to drive than my car. Your results will vary.

[Kevan]

I prefer independent fronts as I run all my cars with 4 tyres on the track. I solder a 2mm length of brass tube on the end of an axle, slide an 8BA washer on, then a wheel without a grubscrew, slide the axle into a brass tube which is the front axle carrier then slide the other wheel on which is held with a grub screw as normal...voila, independent front wheels.

[War Eagle River]

Depends on the car and how it reacts. Test, test, test!

[RichD]

Almost all of my 1/32nd cars have independent turning front wheels. I either use a hollow axle with a ferrule on one end or a solid axle with a spacer soldered to one end to act as a keeper. The wheel on the keeper end has no set screw and is free to spin on the axle. The wheel on the other end has a set screw and therefore turns with the axle. Since I do not have a 1/32nd track I have never done any testing to confirm that there is any benefit from doing that, possibly it reduces friction in the front end. Many of my HO cars also have independent turning front wheels. Those cars all use aftermarket front ends with press on wheel retainers on either end of the axle. Once again I have not done any testing to confirm the benefit of this practice.
I have a few 1/32nd cars that had stub axles instead of a solid axle in front and that setup allowed for independent turning front wheels. In most cases the stub axles were poorly engineered causing the wheels to wobble or the tires to touch the body from time to time. In that case the front end was likely to be a liability.
I expect that in most cases you put a car together and if you win races with it your future builds will be similar even if you are not certain that any particular feature is actually useful.

[slothead]

When building 1:32 scale cars with 1/8th inch axles it was easy to have independently spinning front wheels by soldering a small washer on the end of one side of the axle so that wheel didn't need a set screw. For oval racing I'd let the outside (right front) wheel spin free while the inside wheel turned the axle. This worked well for me. Having the right front wheel firmly planted on the track helps an oval track car not rollover in the turns.

Just about all my RTR cars now have press on plastic wheels so that won't work. A few have stub axles so the front wheels can spin independently but they don't seem to have an advantage over the solid front axle cars. I have 2 HSRR McLaren's with stub axles and front wheels that turn with the guide which I like the looks of and they race well with the competition - Monogram, MRRC, Scalextric, Fly and a Carrera 917K. The 2 Slot.It Chaparral 2E's I have are a bit quicker, but not so much they dominate things.

[HO RacePro]

The whole issue is moot unless all four wheels are in contact with the track. And if the front wheels aren't loaded equally, much the same.

I believe it is important to design-in some chassis flex in order to assure all four wheels do their bit. Then we can talk about independent fronts.

Moving in a straight line a solid front axle will create additional drag unless the front tires are exactly the same diameter, or one isn't loaded.

A solid front axle, on a car with adequate chassis flex, will create a torque that promotes understeer, and tend to keep the rear end from sliding out. But it will also create additional front-end drag, which has the opposite effect. Complicating the situation still further is the fact that cornering tends to unload the inside front wheel.

On total I prefer independent fronts just because the dynamics are simpler. Less things to go wrong. I also prefer to have both front wheels turning independent of the front axle. And given a choice, I prefer to have the front axle free to rotate too. But I'll use stub axles if the clearance is needed for the guide, and typically my stub axles don't rotate.

The reason HO cars tend to have independent fronts probably has to do with the prevalence of strong magnet cars. The extra downforce magnifies any front-end drag, so a free-running front is crucial.

Of course all this theorizing is just so much blather without good experimental data from the track. And even that can be open to dispute. It would be nice to see some data.

Ed Bianchi

[Pappy]

I'm not sure if independent front wheels help but I'm pretty sure they don't hurt. If I can get a few hundreds of second faster times with independent front wheels I'll take it. In an endurance race it really adds up. I also like both front wheels to turn on the axle. That way I can tighten down the axle and stiffen the chassis if I want to. I use 3/32 piano wire for front axles, it's straight, strong, easy to solder a wheel retainer to, cheap and easy to cut off with a Dremel Tool if I need to. You can buy a 36" piece for about the same price as one axle.

A lot of people don't think 1/10th of a second in lap times matters. If you are racing 3 minutes a lane on an 8 lane track (24 minute total) and someone can turn 4.7 second laps and you can only turn 4.8 second laps you've already spotted them 6.38 laps before the race even starts (everything else being equal). That's why I say if I can get a few hundreds of a second I'll take it. In a 24 hour race it's huge.