K-house jig

I do not have a lathe (and probably not skilled enough to use it), so that would be beyond my ability. But it is a good suggestion. I saw the hack saw/ belt sander modification, but that's just not me. I saw people pull out / adjust the gaps of the rear axles with the greatest of ease with just a few twists.
 
I followed the directions from K-House and made this jig. I was using 2 dremels and my hand was not steady enough! I ordered a file but it was the wrong size so out of frustration I used the mini hack saw as suggested. It works really well. I made the jig very quickly as a prototype and it worked so well I never made a final draft.



 
I made one out of 4 Home Depot paint stir sticks. I'll take a pic when I get home. It looks similar to Bulldog's pics. Instead of cutting out a large notch like he did I used the existing curved cut outs in the handle end of the stir stick. Put 4 of the sticks together side by side and drill a hole in the center (lowest spot) in the curved end and place the axle in that hole.