Just to prove I haven't been totally bone idle for the last couple of weeks
When I last raced, at Anglesey in June, the alternator bracket snapped just before my practice session, resulting in a boil up & qualifying in last place... We repaired it & carried on; but the next race, after practice & just before the race, the bracket again failed.
Therefore: Something Must Be Done About This.
The answer is a simple 2-part bracket; one part attaches firmly to the alternator, and has a threaded bar sticking out of it. The second part attaches firmly to the engine, and has a slot for the aforementioned threaded bar to slide through. The belt is adjusted by winding a
bolt nut down the threaded bar, until the correct tension is achieved; then a second
bolt nut is tightened against the other side of the engine side bracket to hold the whole shebang in place.
Hmm. Pictures might help...
The "bracket" is a simple block, with a pocket cut in it. The mounting ear of the alternator sits in the pocket, and a bolt goes through the hole & out the other side, allowing it to be bolted firmly in place.
In the picture above, the block is being set up to be milled to the correct angle so the threaded bar will be positioned correctly. Although the sine bar is an extremely accurate way of setting angles, I'm doing all of this by eye, it only needs to be there or thereabouts.
So, having got the angle & scribed the line, the whole lot is attached to the mill:
The sine bar & gauge blocks are removed, and the block milled down to the line. It is then drilled & tapped for a 1/2" UNC bar:
Next operation will be to drill & pin the bar in place. But, before I do that, I'll need to mount it to the engine to get the length. So, it's time to start on the engine bracket.
First, carve a piece of aluminium off the stock (the stock is some of what's left over from the sump project):
The block was then squared up & brought to size on the mill.
Now.... there's no point in having a shiny new CNC milling machine, and then not using it.... so, I knocked up a program to cut the pocket. Not being quite brave enough to jump straight into it, I used some wax to make sure it was correct. It was worth it too, I discovered a small bug in the program which left some bits unmilled...
So... sphincter duly puckered, I loaded the aluminium -
- and pressed the brown trouser button:
So far, so good...
Finished! A quick polish with one of Rob Wilson's patented cloths:
Unfortunately, my cloth is worn out
Tomorrow, another trial fit so I can get the length of the bar just right, and the adjustment slot in the right place... if you're lucky, I'll get some pics of the other things I've made for the car recently...
