So, the humble Tenshodo motor bogie in it's current coreless motor form, I've not gotten on well with the original form even with it's 5 pole motor but only 14:1 gearing, so I'm hoping that it's present form will be a better running chassis in line with a similar improvement witnessed in Kato N gauge chassis which were already good and the switch to coreless motors made them even better.
I would like to suggest few bits and pieces to have to hand prior to starting a gauge conversion on one of these chassis, also the odd caution! The old version had 2mm diameter axles while this version has a 1.5mm, also when you unclip the bottom from the top you will end up with a handful of loose bits and pieces, be careful.
A fairly broad flat bladed screwdriver (to remove the base), 1.5mm steel axles (check with your supplier, only spot on 1.5mm will do, don't even think of Chinese suppliers!), replacement wheels of the desired size (mine came from Branchlines in the UK), 1.5 to 2mm shaft adaptors from Nigel Lawton 009 (UK again), 2mm bore turned spacing washers (Alan Gibson UK).
One piece of advice, before consigning the warranty to oblivion do test your chassis to make sure it works, insidentaly my chassis/motor bogie came from Scalelink (UK cranky website but he guy says he's retiring!)
We'll pull thins apart soon.
John Bruce.