Steering Link Rule - B 6.5.1 - Steering Belt?

[FIREotter]

Today I submitted this question to the rules committee but would also like to see the opinion of people on the forum. I have followed this forum for some years and respect the opinions of its members. I know that Pat Clark also uses these forums and I would like to make it clear that this is not a dig at him; I understand people have different interpretations and opinions of rules.

This question concerns the rule:
‘B6.5.1 The steering wheel must be mechanically connected to the wheels, i.e. “steer-by-wire” is prohibited.’


We were thinking about using a toothed belt and pulleys between our steering axel and steering rack. This system would allow us to mount the steering rack closer to the centre of our car and our steering wheel while allowing very good support for the steering axel (where universal joints would not as the axel has a shorter supportable length), this would help reducing rotational inertia, let us change steering ratios quickly and easily for testing and is much cheaper than a 90 degree steering gear.

We ran with this system in 2009 but were pulled up at the design judging by Pat Clark for “clearly not reading and understanding the rules” and “using a drive by wire system”. The scrutineers said they could see no problem with our design so long as the belt was correctly tensioned. To my understanding a drive-by-wire system is similar to a fly–by-wire system of an aircraft, where a sensor detects input and an actuator of some kind moves a control; therefor using a linear actuator or electronic servo motor in place of your steering rack, controlled by a sensor on the steering wheel would not be allowed.

I believe a pulley system would be classed as a mechanical link. I realise there may be some concerns with the belt slipping or breaking but in our testing the steering wheel mounting bracket would sheer before the belt would slip a tooth. We're using an oversized belt for this reason.

So really my question is it acceptable to run with this type of system? Have I missed something in the rules which disallows it?

I have attached a render of a simplified design

http://i55.tinypic.com/314f6tk.jpg

Thanks, Alan Easdale

[FIREotter]

Today I submitted this question to the rules committee but would also like to see the opinion of people on the forum. I have followed this forum for some years and respect the opinions of its members. I know that Pat Clark also uses these forums and I would like to make it clear that this is not a dig at him; I understand people have different interpretations and opinions of rules.

This question concerns the rule:
‘B6.5.1 The steering wheel must be mechanically connected to the wheels, i.e. “steer-by-wire” is prohibited.’


We were thinking about using a toothed belt and pulleys between our steering axel and steering rack. This system would allow us to mount the steering rack closer to the centre of our car and our steering wheel while allowing very good support for the steering axel (where universal joints would not as the axel has a shorter supportable length), this would help reducing rotational inertia, let us change steering ratios quickly and easily for testing and is much cheaper than a 90 degree steering gear.

We ran with this system in 2009 but were pulled up at the design judging by Pat Clark for “clearly not reading and understanding the rules” and “using a drive by wire system”. The scrutineers said they could see no problem with our design so long as the belt was correctly tensioned. To my understanding a drive-by-wire system is similar to a fly–by-wire system of an aircraft, where a sensor detects input and an actuator of some kind moves a control; therefor using a linear actuator or electronic servo motor in place of your steering rack, controlled by a sensor on the steering wheel would not be allowed.

I believe a pulley system would be classed as a mechanical link. I realise there may be some concerns with the belt slipping or breaking but in our testing the steering wheel mounting bracket would sheer before the belt would slip a tooth. We're using an oversized belt for this reason.

So really my question is it acceptable to run with this type of system? Have I missed something in the rules which disallows it?

I have attached a render of a simplified design

http://i55.tinypic.com/314f6tk.jpg

Thanks, Alan Easdale

[Ben Coburn]

This forum can't ever really provide definitive answers to this sort of question, you should always always just ask the rules committee directly for questions of this sort.

That said, GT Motorsports ran a chain drive system basically like this last year without problems.

[Dash]

I think its fine. Its definitely mechanically attached, and a unique solution to the problem of connecting the steering wheel to the wheels. The baja team at our school made a chain driven solution and then a wire solutions ( no joke, it was wires and pulleys ) that both worked and passed tech at the baja competitions.
That being said, I like it, and hope that it passes. I considered making a chain driven one last year to go around the problem of multiple u-joints on a single shaft.

[MegaDeath]

There is always that fine line of meeting the letter of the rule vs. meeting the intent of the rule.

I feel that it is should be allowed, but that's just me. I personally don't like the thought of a belt driven steering system, it seems a little too "sketchy" for my liking. But then again, it is a design competition, and I applaud you for coming up with/designing/implementing and outside the box/contrary to "traditional engineering" idea.

I hope it gets allowed because it is a more unique design, but please don't get too close to me on the track with that thing. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[PatClarke]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I know that Pat Clark also uses these forums and I would like to make it clear that this is not a dig at him; </div></BLOCKQUOTE>

Hey, I take no offence. However, I would never have called such a system 'Drive By Wire'. I have always considered this to be a poor choice of words to describe an electronic steering control system, and yours certainly ain't that!

However, rather than make a comment here, you need to submit that design to the Rules Committee.

Cheers

Pat

(Hint...Have 'Plan B' ready!)