Butt_blaster: That would make sense. Yes, I did check the calibration of e-steps (spot-on) and Z Axis. As I've spent the money for the upgrades over a long period of time it's doesn't feel like a lot (probably is).
I've produced a lot of stuff on the ender. I made a playhouse for the grandchildren and used it for a unicorn wind vane, nut covers, name plate etc. I've also printed a lot of bits and pieces for my wife for her greenhouse. I just finished printing and painting the collective lever, handle and switch panel for my simulator. It has been well used for what was a very cheap machine.

Up until now I've been happy enough with the surface finish.

Minnie: The blobs are on the sides and are worse on circles than on straight walls. I did have the problem you described a while ago, but increased the number of top/bottom layers and that fixed it. I have 100% cooling from layer 4 set in Cura.

I have just finished making the new Y axis rail and fitted it. When I went to put the carriage back on I noticed that the bearings on the wheels were "rough". There are also grooves worn around the tyres where they fit in to the extrusion. I've ordered another set of polycarbonate wheels to try and see if that fixes the problem. If the bed is not smooth that could explain the blobbing. They needed replaced anyway.

Cheers,

Andy