valve, expansion link and reverser adjustment

hi all, being new to all things steam i have what may seem to some to be a simple question!

i have a small problem with setting full reverse. in froward engine turns over by hand very well, but in reverse the expansion link tends to lift as you turn the engine over. This causes the reverser leaver to rock, i am worried this will cause a failure of the taper pins in the linkage. does this problem indicate a problem inside the valve chest? or do i need to extend the slot in the expansion link?
i also notice the two sides of the valve are different widths. is this correct or should they both be the same? Steve / Dave, can you let me know the dimensions for the valve.

thanks Jon

Hi Jon

Make sure that the die block does not foul the top of the expansion link at the highest point in its travel for forward and the bottom of the expansion link for reverse. The clearance needed is the minimum possible otherwise you will loose a bit of valve travel. If you can slide a bit of paper between the die block and the expansion link at their closest position then that would be fine.

The reason your reversing lever moves is either the ‘sticktion’ caused by friction in the various pins and linkages or the die block is fouling the bottom of the expansion link. You must not change the slot in the expansion link.

Regards

Steve

p.s. who's Dave??

thanks Steve, i will check it out later, oh Dave was a mistype, should have said Dean...

model is coming together very nicely, and starting to get very heavy now, I will need to invest in some lifting tackle when i get to building the 4" road loco. do you have a price for the 2" wagon yet?

HI STEVE, THANKS FOR ANSWERING FORGES QUESTION. WE TO HAVE SOME MOVEMENT OF THE LEVER IN REVERSE. WE HAVE VERY CAREFULLY SET THE DIE BLOCK WITH CLEARANCE AT BOTH ENDS MATCHING AT AROUND 0.3mm. SO I GUESS WE HAVE A 'STICKION' PROB. AT THE MOMENT THE PINS HAVE BEEN PUT IN 'FAIRLY' DRY (JUST A FILM OF OIL ON THEM) SO GUESS WE'LL HAVE TO CRACK THAT OIL CAN OUT AGAIN.

REGARDS
BUNGLE