[SEL] Trailer Brakes - Question

[Dave Rotigel]

Hi Peter, If you are allowed 7 meters, why make the trailer 6.6 meters?
	Dave
PS, At least make it 6.66 meters!
PPS, Electric brakes would be the way to go. Sorry 'bout your laws!
PPPS, What kind of gun does Rita carry?

On Dec 5, 2010, at 4:53 PM, Listerdiesel wrote:

> We've got the trailer building hat on, and are looking at a new
> trailer, partly to carry the Ruston 1ZHR and also to provide a
> comfortable living area for us while we are at rallies/shows. In the
> UK, most folks go camping if they cannot bring a caravan along, as
> local hotels etc are pretty expensive.
>
> The overall length of the body is just over 6.6 metres or just over 21
> feet. It will have three axles in a drawbar/front steering axle
> configuration, maximum weight is 3.5 tons all-up. We are allowed 7
> metres for the class of towing vehicle that we have.
>
> So, we are limited to overrun braking (surge brakes) and probably
> mechanical. The front steering axle rotates on its centre pivot, the
> two axles at the back are in tandem and fixed to the chassis.
>
> To provide equalised braking, we have to fit two compensators, one
> between the front axle and the rear two axles, mechanically weighted
> to allow double the braking effort to go to the rear axles, and then
> another equaliser/compensator between the rear axles.
>
> To get an idea of the layout, see this image:
>
> http://www.stationary-engine.net/Forum/Images/Uploaded/ 
> Drawbar1Iss3.jpg
>
> What we are thinking about is the type of braking linkage:
>
> 1) Do we go for full hydraulic?  Possible but nothing is type- 
> approved.
> 2) Cables?  Easier but they take a lot of maintenance unless you get
> the newer stainless types.
> 3) Rods and swivels?  Less maintenance and friction, don't know if the
> parts are still made.
>
> Electric brakes are not approved in the EC, we have already looked
> into that one.
>
> With new-build trailers likely to need annual testing soon, we want to
> make sure that what we build isn't going to be a PITA to look after or
> get through its annual test, as and when that happens.
>
> The front axle pivots on a 75mm vertical steel bar which runs in two
> large flanged self-aligning bearings, with a thrust ball race taking
> the vertical loading.
>
> Any thought would be appreciated.  Half a ton of box section is at the
> machine shop waiting for a few clear days.... The main body is going
> to be standard truck body extrusions in ali, with honeycomb sandwich
> side panelling.
>
> Peter
> -- 
> Peter A Forbes
> Email: listerdiesel at gmail.com
> http://www.oldengine.org/members/diesel
> http://stationary-engine.co.uk
> http://www.oldengine.co.uk