bearing alining.

[stef_d]

I have been reenforcing the structure of my desktop machine, and replacing all the thin aluminium bearing carriages by thicker iron ones. the idea is to get rid of as much flex as possible.

this operation has been successfull on the x axis. i widen the carriages from 10cm to 15 cm, and managed to adjust the axis such that i have very smooth rolling and not play what so ever. flex is barely measurable, even if i grab hold of the gantry and twist hard.

now to the y axis. same operation. however, i spent 2 hours yesterday trying to get rid of all play in the carriages, without any luck.
I tried adujsting the position of the bearing my measuring the hole position acurately i tried alining everything precisely. i am getting close, but not close enough. i always have 1 wheel not making contact with the rod.
Is there an easy technique to aline all this correctly ?

here is a picture of the previous version of the carriage on the x axis. it is now 1/3 wider and made of iron.
the y axis is similar. on a similar rod.