As reported earlier I ran my Dremel 3000 for 10 minutes on full speed as suggested by Dremel support (although they did say 10-15 minutes) to see if it would cure the problem. I was gratified that this seemed to at least fix speed ranges 2 & 3 even though speed range 1 was still non-functional.
Unfortunately when I tried the tool the next day, once it had cooled down, all three of the low speed selections had returned to their previous faulty behaviour. So back to the supplier it went, once again.
The Proxxon FBS 115/E (240/E in the UK) arrived on Thursday. So far I am completely satisfied with it, my perception is that it it is smoother and probably a little quieter than the Dremel, long term of course remains to be seen. Best of all though, it only cost a few dollars more than the similarly kitted Dremel 3000 that I had returned.
Clive
Edited By clivel on 26/03/2017 16:35:04