Monday, February 11, 2008

So What's been going on this winter?

After some gentle reminding, and indeed some firm poking with a sharp stick from various readers of this blog I thought I'd do an update and answer the question "What has been going on?".  Indeed even Tim has been poked on his Blog to get me to update mine ... perhaps some people do pay attention after all :-)
So here's a fairly hefty update that will cover (at least in some degree) what has been going on for the last 8 months.
I seem to have spent most of the winter working at the back of the car.  Basically the new diff arrangement has taken a fair bit of time and energy to get right.  But it is finished now.
A rough sequence of activities is:
  1. I tried and tried to use the new starter motor that I had left over from the White Van as the motive power for the reverse system.  Unfortunately the motor span in the opposite direction to that required and didn't have enough clearance around the main drive pinion to give me enough adjustment for when the diff moved as the chain tension was adjusted.
  2. I then spent a large amount of time drawing up and making  a split sprocket adapter... this worked fine until I weighed it.  nearly 5Kg of additional rotating mass was just too much to carry. So I dumped that idea.
  3. Duncan and I spent a long time staring at the arrangement and have now come up with a setup which is just as simple as it can get.   Two bearings a quaffe diff in between and a chain sprocket bolted to that. In fact this is quite an old photo as I now have some new lightened sprockets with lots of holes in them to further reduce the rotating mass.  The chain is tensioned by using aluminum shims between the uprights and the bearing carriers.
  4. Reverse is enacted by the winch motor being pulled up into the chain by a tension cable... this is pretty chattery and now is sporting a block of beech above the chain to stop the chin and winch sprocket from bouncing apart. I think I may need to make the actuation a bit more positive b some sort of Cam action in the future.
  5. The other major thing we did before the season was to tidy up the bodywork around the roll cage and throw some lovely metallic British Racing Green  paint at the beast.  At the moment only the side pods are done so the car is an interesting two tone red/green.  In fact its been likened to an old Ford Cortina with each wing a different colour.  But hey at least it is distinctive!


No comments: