On 16/07/2020 17:57, Jim GM4DHJ ... wrote:
On 16/07/2020 16:19, JohnP wrote:
check that there's nothing in the track.


Maybe a bit of lubrication is needed.

I was told to wd40 the tracks now and again which I do ....


I advise use of a lubricant instead.

The WD40 will have dried to a sticky Water Dispersant film. Which
collects dirt like no tomorrow.

Andy