Didn't quite get it finished today the Boss dragged me out shopping for a new bed cover:-
You know how the conversation goes:-
What do think of this one Stewart -
Yes thats Ok -
well what about this one -
yes thats Ok -
or this one -
yes thats Ok":-
after halve an hour of this Stewart's getting P****d off, picks up something hideous he knows the Boss won't like :-
I really like this one Love -
ho its hideous -
but I really like it -
I don't -
well you'd better hurry up and chose something from the hundred we've already looked at or I'll buy this one -
you never take these things serious -
but its a bloody bed cover we'll be asleep under we'll never see it."
Any way back to the Tram
Next job to fix the centre shaft to the T bar.
The shaft was deeply centred at one end.
At the other end it was turned down a nice fit on the T bar and the centre drilled and tapped M5
To fix the shaft to the T bar high strength loctite was used along with a washer and a counter sunk allen cap screw
Now comes an important part of making the tram. This design of tram gets its accuracy from the base length between the DTI's the longer the base length the more the error is magnified:- and the squareness of the shaft to the T bar.
To get the shaft square to the T bar John turned his shaft off his face plate having first skimmed the face plate up square,
The face plate of my machine being a 3 - 1 with a high throw is huge for what's required and as the machine has no cross slide outo feed I didn't fancy winding the handle manualy across that distance for an hour.
So I decided to use the sacrificial face plate I used to make my loco wheel's this face plate is basically a round chunk of ally I got of ebay.
Other option would be just grip it in the four jaw with the T bar pushed up against the face of the jaws, but this will rely on the acuracy of the jaws and any error would be transfered to the Tram and then onto the mill.
Another option would be to use a piece of bar, grip it in the four jaw face it off and clamp the T bar to this.
To prepare the sacrificial face plate the best position for the T bar was found and hole position roughly marked, one hole was drilled and tapped M8:- Note another use of heavy cast iron cube
The T bar was clamped to the plate and the position of the second hole spotted through to ensure the holes lined up, the second hole was then drilled and tapped M8
A quick assy to check all is well
The face plate was put in the four jaw and a centre used to help alignment, the shaft was roughly clocked true and the position of the bar on the plate marked this is so I can put it back in the same position and not disturb the plate.
The face plate was skimmed up. In the first shot on the right you can see where the plate hasn't cleaned up this error would have been transfered to the tram, the second shot shows the plate cleaned up
The Tram was clamped back on the plate and the shaft clocked up but this time the only adjustments was done with the play in the clamp screws, to move the plate in the chuck would have lost some of the accuracy.
and her's an action shot of the shaft being turned
Well that's as far as I got
Tomorrow it will be finished that's if the Boss lets me back in the house.
Have you a spare room John ???
Stew
