minilathe ,, micromark / amadeal 7x14 problem

[grandads_shed]

i have a problem when winding the carrage back ad forth, in places it catchs on the long threaded bar that is used for the feed, how could i adjust it so that it dont catch ?? its as though its catching the tops of the threads in places,

 

[naughtyboy]

had similar on my clarke took cross slide off cleaned it found burr on casting.
sorted it then took ages getting gibb slides set right.

 

[grandads_shed]

im prity sure its catching on the threaded bar ,, when it catches , if you look closely you can see the bar flex downwards then spring up again as soon as frees up.

 

[gordon stephenson]

Is the split nut that operates on the threaded shaft clearing the thread when the feed is disengaged?

 

[grandads_shed]

i think it may be the problem ,, im new to lathes, never had one or used one, with the lever down it feeds the carrage fine, but when i lift the lever up i dont think its clearing the tops of the threads enough,