Soapbox tech

[istoo]

Tony
is the track twisty?
The other carrie folk keep the size down to reduce lateral losing and stop the wheels folding, but that might add more comedy value

Bit of a build delay for me in the short term but will try and find time.

[ClarkyBoy]

Its not that twisty by nature, but there will be 'features' added for the cartie race (based on my limited knowledge)

T will confirm.

[istoo]

Personally speaking.

If the goal is participation for the laugh, I would open up the sizes. Certain wheels are more available to some than others. Makes it a bit more viable to scavenge build.

The caveat being it may lead to wheel failures from lateral loads, depends of cart/driver/course.

But I get the feeling what the hell, the more the merrier!


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[campbell]

We're doing castors.

On a bed frame.

[robin]

Castors are very bad for steering ... best wear crash helmets and padded costumes

[campbell]

Fixed at the front. Rear wheel steer for rapid direction changes - inspired by B&Q Garden Centre trolleys. You know how manoeuvrable those are

On the look out for Sumo fatsuits for super safety.

[robin]

Like I said, castors are very bad for steering.

A functioning B&Q trolley works because the system is articulated - front wheels are fixed, rear "wheels" are actually your feet and the castors are really just propping up the load and allowing the articulation. You twist the system around the articulation and it goes around corners.

If you were sitting inside the trolley (not touching the ground) you couldn't steer - where would the lateral force come from? You need a point of articulation (steering rack, pivoting axle, etc.) that sets up an angle between two fixed points - this angle generates the lateral force that causes rotation. The steering is actually central in such a setup (the pivot point is above the castors, you are behind the castors).

So castors are useful for carrying loads without interfering with the desire to move that load in arbitrary directions, but they are correspondingly useless for steering. I assume you have a solution to this part ...

Castors are also bad for steering because they don't contribute to the steering but they do take load off the useful wheels. In extreme cases it can be like when F1 cars hit standing water - the chassis planes on the water and the wheels are lifted off the ground (almost) and so have no grip.

Rear wheel steering is hard to master, depending on the centre of gravity and the pivot point. As soon as you have a frame and wheels that can steer, try running it both ways and see which way is easier to steer - could go either way - but worth the experiment in case it is substantially better in the opposite direction - I am sure you can adapt your design to run "backwards".

Cheers,
Robin

[campbell]

So we'll keep the castors for a dolly jack to move the soapbox around the pits instead then!

Of course I was just a touch tongue in cheek before...all in the spirit of wrong footing the opposition

Still awaiting an update from our real wheel supplier. Stay tuned.

[istoo]

how about fixed wheelscampbell, less complicated and go for sheer speed, maybe fit a snowplough for just barging a straight line form a twisty track

[pshanks76]

I'm not competing but I could lend some MTB body armour (chest/back, elbows, knees) and full face helmets that would probably be not too bad a fit on a teen if that helps anyone.

[ClarkyBoy]

I'm not competing but I could lend some MTB body armour (chest/back, elbows, knees) and full face helmets that would probably be not too bad a fit on a teen if that helps anyone.

where is the fun in that!?

[anthonyyule]

Track will be more twisty than the hillclimb route as we are planning on using the very top of the driveway (hillclimb cool down area).

But then twisty is relative... with a good handling cartie it wont be that twisty - but with a dog of a handling cartie it could be an armful.

Bales will make the track seem narrower - a bit like Monaco (without the water and the highrise buidings, casino, girls, etc) - in fact nothing like Monaco.

Think redbull soapbox - but maybe a bit twistier at the top. We are hoping to build a couple of small ramps and will also have some bales for chicane purposes. Total length of the track will be circa 300-400m.

[anthonyyule]

will try to send a message to all soapbox teams relaxing the regulations. I had a chap on the phone today asking if he could get a waiver on the width of his cartie.

Participation is what its all about.... I don't think anybody is that precious on the reg's... I certainly know that I wont be scrutinising them. As long as the driver is safe and the cartie is race-worthy (from an HSE perspective) then we just want to see everybody have a good time.

Body armour could be used as part of your superhero costume....

[campbell]

Ramps? Hmmm. Suspension now then. (Shouts through to the garage "We need dampers as well now, team". Response unprintable)

[pshanks76]

I'm not competing but I could lend some MTB body armour (chest/back, elbows, knees) and full face helmets that would probably be not too bad a fit on a teen if that helps anyone.

where is the fun in that!?

More entertaining without, just depends how bothered dad's are about returning home to the missus with broken kids