Hi Again,

It seems I spoke too soon.

I printed a replacement z axis shaft bearing brace and fitted it.
Then re-leveled the X axis with respect to the top of the frame.
Then leveled the bed to the x axis extrusion.
Set the Z offset, and cleaned the bed.
The test prints I did were fine, but when i tried something with a tight curve I had the blobs again. So frustrating !!!

I did a lot of online reading and finally found a post on another 3d printing site saying that Octoprint could cause this type of issue. Seems the Raspberry Pi or the 8 bit motherboard can't keep up with all the calculations required to produce a curve by making very short lines.

So - dug out the micro SD card that came with the printer and copied the model on to it. Put that in the printer and crossed all fingers and toes (very painful, but worthwhile).

It was PERFECT !!!! I tried another couple of circular prints and they were spot on as well.

I was already thinking of upgrading to a 32 bit motherboard so I've ordered an SKR Mini E3 one. For £36 you can't go wrong can you ????????????

I'll let you all know how it goes after fitting it. For just now I'll be transferring everything on the SD card.

Cheers,

Andy