, after having a chat with the Proxxon distributor in Australia late Friday, the bearings in the flexible shaft will be no match for those in the aluminium headed tool mainly due to the small size of the Flexishaft handpiece. So it seems this is yet another reason to suggest I was on the wrong track.
There is a new model of the ib/e for 2012, an ibs/e, with a new motor - it has a grey motor casing instead of the old yellow one.
When the motor brushes go on the ib/e (ibs/e), the speed electronics often go with them. Perhaps regular motor bushing replacement would be prudent - though at what interval I don't know.
Despite this, the robustness and accuracy of the tool seems to be the best out there, ib/e's are retrofitted to replace the spindle on expensive Roland machines and perform far better than the original.
The other point of interest is that the bearings on Proxxon rotary tools will still wear and can be replaced - even replaced with long life ceramic bearings which have been specially made in china for the ib/e (ibs/e) tools giving far greater bearing life.
Finally there are two ways to buy this premium Proxxon tool, in the retail packaging with case and accessories or as an industry item with just the tool on its own - this last way drops the price by about 15% I was told.
My real interest in the Proxxon flexible shaft was the reduced footprint on the z-axis, which increases the cutting area while reducing the weight in the same axis. No worries, as I learnt a lot from looking into the possibility.