Building a soapbox racer (aka go-cart.... aka gravity racer)

[derrick]

http://www.redbullsoapboxrace.com/uk/en/application/

 

[simon the viking]

Thread resurrection alert!!!...... Build Started......

Random bits of wood and the rear wheels accumulated over last few weeks....

Then some of the bits of wood 1 hour later.......

And Ben trying it for size.....

Half way through my cordless drill wasn't suitable... (sanding wheel required.....) got my dads old corded drill out..... and realised it was used to build another go cart probably 40 years ago.....

Next step is getting 2 axles (threaded bar from work) and the front wheels.... total cost at present £5 for the BMX donor..... The main chassis rail was a fence post I saw lying in next door's yard..... "Err.... can I have that fence post please?" ....... "course you can saves me a trip down the tip......"

And in true 'Dad build style" ...... No tape measure was used.........

 

[simon the viking]

Decided to drop the idea of an Ackerman steering system... going for traditional rope steer but (humour me on this one) what would happen if I put 'Gate close' springs on, attached to both side of the front steering board as in (badly drawn) diagram below.... would it help the steering re-centre itself or would it make make steering too hard for a 10 year old? opinions please........

I have googled it and no one seems to have tried it... does this make me an innovator like Henry Ford and Preston Tucker.......

 

[Crackle]

Decided to drop the idea of an Ackerman steering system... going for traditional rope steer but (humour me on this one) what would happen if I put 'Gate close' springs on, attached to both side of the front steering board as in (badly drawn) diagram below.... would it help the steering re-centre itself or would it make make steering too hard for a 10 year old? opinions please........

View attachment 346275

I have googled it and no one seems to have tried it... does this make me an innovator like Henry Ford and Preston Tucker.......

I don't think those spring are designed to stretch that way, so it might be too hard. I seem to recall putting one on a gate completely wrong once and the gate tried to eat you before you were through it. Luckily I realized my mistake. In front and parallel would probably be better.

 

[simon the viking]

I don't think those spring are designed to stretch that way, so it might be too hard. I seem to recall putting one on a gate completely wrong once and the gate tried to eat you before you were through it. Luckily I realized my mistake. In front and parallel would probably be better.

Not sure what you mean..... ( a diagram as badly drawn as mine is ok........)

 

[Crackle]

Not sure what you mean..... ( a diagram as badly drawn as mine is ok........)

The spring is not meant to stretch but to fold/compress, so fit them so they don't stretch, like below

 

[simon the viking]

So you mean run them from the chassis to the axle board at less of an angle.... almost parrellel? that might work.....

It was just an idea to help with over steer......

 

[PhilDawson8270]

You would also need to use 2 matching springs, and the mounting points be pretty damn symmetrical too if you wan it to pull straight

Just mount the wheel axles behind the steering axle So you have some trail and it will self centre

 

[classic33]

You'll add a hazard that wasn't there. What happens if the spring on either side were to give or the mounts come off?
With no feet on the front, it'll pull to one side.

Move the front axle back, allowing the feet to help steer. A lot less trouble than springs.

 

[simon the viking]

I can buy 2 matching springs from work.

 

[simon the viking]

You'll add a hazard that wasn't there. What happens if the spring on either side were to give or the mounts come off?
With no feet on the front, it'll pull to one side.

Move the front axle back, allowing the feet to help steer. A lot less trouble than springs.

Wanted to keep his feet away from moving parts but I assume you mean take away the foot rest (fitted as shown in picture) and use the axle board as the foot rest?

 

[Mo1959]

We had our front axle type thing with the rope fitted in either end but you could turn it with your feet as well as it had a bolt in the centre that let it swivel.

My little brother fell off the back of ours and broke his collar bone.

 

[classic33]

Wanted to keep his feet away from moving parts but I assume you mean take away the foot rest (fitted as shown in picture) and use the axle board as the foot rest?

More or less. Also help with the steering though. Should the rope break, the legs take over on their own.

 

[simon the viking]

More or less. Also help with the steering though. Should the rope break, the legs take over on their own.

could be an idea then... I think that's how mine was..... I'll could remove the footrest and shorten the chassis then.... will decide when putting the front wheels on

 

[classic33]

If you are going to fit springs, don't attach directly to the wood. Use small metal plates on the steering arm, with a larger plate mounted under the main post.

Allows for bolts to be used to hold the springs in place, not screws. And longer screws on the main post.