Soap Box Build - Team Ecurious Ecosse

[a4drk]

What about brakes ?

Ive got a lotus badge if you want it

David

[ClarkyBoy]

What about brakes ?

Ive got a lotus badge if you want it

David

What are these 'brakes' you speak of

[a4drk]

Oh crikey.... So it's a runaway train then !

[campbell]

Regs require brakes. Block of wood in our case

[Shug]

What about brakes ?

Ive got a lotus badge if you want it

David

First post - BMX forks incorporate brakes.

[campbell]

Jealous of those. Will look at bike brakes as an enhancement if time :-/

[istoo]

I was going discs but in trying to keep costs down, we have a brake bar just behind the rear wheels which has a centre pull brake on either wheel. Cheap way of doing it... Or just wear a mattress


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[campbell]

Hoped to fit my old centre pulls too. But can't find them

Wooden levers for now but may look to re-fit the drum brakes from the donor balance bikes. Lol

[Ferg]

I'm not sure what centre pulls are? Do they not need bosses on the forks?

Anyway.....steering part one!

Remember the design previously? Well here it is in amateur milling interpretation. Have to say how grateful I am to my old man for working through how to produce these on his small mill. He's learnt loads in the process, few mistakes along the way but the result is a robust functional part. Top effort.



We went to the trouble of tapping the upright to match the axle so the axle screws into the upright so it's more solidly attached.



And with a wheel attached.



It looks initially like the King pin angle has worked. I'm going to build this into the front at the weekend as we'll only really know once it's on the cart. Steering column and actuation still all plausible at this stage which is a good sign. Turns out removing material is quite hard work on a small machine so these are going in 'bulky'. But it just adds to the over engineered theme we've got going on...

[campbell]

Mental

[Dominic]

This thread is developing a "project Binky" like fascination. Great effort, keep the posts coming

[campbell]

Meanwhile, "Project Scrapheap Challenge" continues over on the Soapbox Tech thread, lol

[Ferg]

These are the two main articles I refer to.

Great coverage on basic geometry and considerations for building a human/gravity powered machine!
http://www.eland.org.uk/steer_intro.html

This is a bit more obvious. Good old wiki, this one on Ackerman Geometry. Importantly it includes some simple concepts for creating working example.
https://en.m.wikipedia.org/wiki/Ackerma ... g_geometry

[campbell]

I read the RDSF regs. And looked at a couple of pics. And that was it. Lol!!

[Ferg]

Getting the wheels on....

Offering up I realised I hadn't taken into account the track and how far inboard it brought the units so time for a big cut to remove chassis to make room. Measured a few times and went for it.



So the upward pressure is not just on the fixings I set the upright into the chassis leg.





And finally with a wheel on! The King pin angle looks good with the line of the shaft inline with the contact point of the wheel on the ground.



Proof that the castor and the self centering from the king pin angle have worked. There's nothing holding the uprights. We can push the cart forward and the wheels stay straight. It's actually quite impressive that the geometry works like this. If you push it backwards the wheels fold up.

Watch on YouTube

Getting there....