Thursday, 29 March 2012

Ally Up!

Unfortunatly I didn't get chance to get anything done on the trailer last weekend. Between having to work on Saturday and good surf and the Grand prix on sunday that was the whole weekend pretty much accounted for. The good news is the clocks have gone back and its getting warmer so motivating myself to get out out there and get stuff done after work is going to be a lot easier with some decent daylight and no need for three T-shirts two jumpers and a hoodie just to keep warm.

The main reason for this interim post though is that three hundred quids worth of aluminium chequer plate aswelll as all the remaining metal I need to finish the trailer turned up the other day. All I need is a couple of clear days to get the runners built up and the ally fixed onto them and its going to start looking pretty finished.

Stay tuned..........

Sunday, 18 March 2012

Lets Get Hitched

I had kind of thought the hitch was beyond saving, but its amazing what a hour or so with a wire wheel angle grinder can do. The coupling damper was well and truly goosed and the handbrake lever had had it too, but ebay saved the day for about half the price of buying new ones. All i had to do was remember how it all goes together.

Now the hitch had been reconditioned the A-frame could go back on once and for all. so the next job was to break out all the lovely stainless steel nuts and bolt that I had ordered and get it fitted up. I had also made some 5ml thick, stainless steel back plates for the draw bar brackets to replace the rusty old ones. The guys at the engineering works cut them for me and still only charged me £1 each!, legends.
Now that everything was in its final position I thought I had better check that all the bits were in right places and pointing in the right direction. So I used some string tied to the hub centre and run around the back of the back of the tyre to check for toe in/out and to give a clearer idea of weather the coupling was dead centre to the wheels. I probably should have done this before I drilled and welded all the draw-bar mounts but I didn't think of it until now. As it turned out everything was spot on, there was a small amount of toe-in which is desirable, and the coupling was exactly in the middle of the wheels. Somewhat of a relief
The time has now come to stump up for the ally chequer plate for the runners so i can crack on with them next weekend. This is not going to be cheap!

Tuesday, 13 March 2012

Got Any Draw?

I'd all ready made one new set of chassis mounts to
account for the trailer getting wider

My Dad was down last weekend and we were standing around the trailer, cups of tea in hand, discussing the various options open to me concerning different aspects of the build when I thought it would be a good idea to loosely fit up the draw-bar (A-frame) to give us a better idea of where it would pass beneath the intended line of the runners so we could get a better idea of  where the runners could get some extra support. It hadn't occurred to me , but he instantly expressed some concern about the about the large distance between the leading edge of the trailer and the hitch. This is due to the fact that is was of course a caravan chassis, so a long draw bar was necessary to accommodate the overhang and wide front of the caravan body as well as the gas bottle box and still permit a decent turning circle, and a caravan being very light would not put too much strain on a long, un-supported draw-bar and would not become too nose heavy, a full ton of car would be pushing it.

The obvious place to take it back to would be the first cross bar just in front of the X section (top left of the picture) but that would have brought the hitch too close to the trailer (not enough room to turn). after much discussion and another cuppa it was decided that making an entirely new set of mounts on the chassis and the draw bar legs was too much hassle just to move it back 1/2 a foot so we agreed to leave it where it was.

But after a couple of days of to think about it I had to concede it was going to need doing.

The bracket passes beneath the side rail for
 extra vertical strength
Support from behind to counter any 'Pull' forces.

Sunday morning came along and out came the welder. The first job was to measure up and fabricate some new chassis mounts. the best place for the new mounts to go was about 500ml in front of the cross bar and 65ml in from the side rail. 30ml angle steel was the weapon of choice as its just as stiff as box section over short distances and you only have the one surface to drill through. An extra piece of angle was added to prevent the mount getting pulled forward too hard and I might yet weld in another piece to support it from beneath as this part of the draw bar is pulling the bracket down due leading edge of the trailer acting like a fulcrum to the hitch getting pushed up by the tow-ball.

Next  up were new mountings for the draw bar legs themselves. Pretty straight forward but they needed some carefull measuring up to get the holes in the right places. I just about had time to get a coat of paint on everything as it was going dark so it was a whole days work (not including a 3hr surf break) to move the hitch back about 8 inches, but at least I can sleep at night and the poor old Audi can have an easier time of it.

Boom! a few inches make all the difference

Thursday, 8 March 2012

The Trailer Takes Shape

Here's where I've got to so far. As you can see, not much different to the the picture of the old chassis exept that it's wider, a lot less rusty and the sub-frame has been welded up to the side rails and two X sections added either side of the main axle beam to give it some torsional stiffness.

A better look at one of the swinging arms, it pivots off a boss bolted to the underside of the main beam, then passes through, and seats on, the main beam as it drops below it. The trailing arm you can see holds the whole thing in line with the axle.

The bottom of the spring sits on top of the swinging arm but the top of the spring is retained by a top plate and a large bolt that passes through the whole lot through to the underside of the main beam.
And there it is, The brakes are back together and the wheels are back on. you can see the sub-frame and the X sections but I'll need to weld in some more beams to help support the runners between the X sections and the ends of the trailer
There's still loads left to do, next up is to recondition the hitch and refit the A-frame. once the A-frame is back on i'll have a better idea of where to take the extra support for the runners from.  Stay tuned......