Having spent a lot of time reading forums etc. about printing and the various printers, the 'hobby' class printers seem to be let down by using cheap inferior components in the gantry systems i.e the rods, bearings and pulleys. That was certainly the case with the Wanhao that I bought and the Ultimakers etc. have the same problems. These printers are built to as low a cost as possible to make the prices attractive and inevitably corners are cut.
I replaced all the rods on the Wanhao as they were either undersize or slightly bent and also the two linear bearings that the print head slides on. Before, the head could rock from side to side which wouldn't help the accuracy of the prints. It's now rock steady and much improved. If you have to go down this route and go for the cheaper chinese linear bearings, buy at least twice as many as you need as you'll find all the fits will be different!
Fortunately, the mods to mine didn't cost that much compared to the cost of the printer and I expected to have to do some work on it myself anyway.
On the whole, the surface finish from the Wanhao is superb, much better than prints from most other 'hobby' machines that I've seen. I've used about 1 ½ rolls of filament so far and never had a failed print so long as the bed levelling is correct. I can happilly just set it going and leave it to it's own devices and often leave it printing overnight.
I still haven't got to the bottom of the problem with spoked wheels though, where the finish on the spokes is not as good as the hub and rim. It's really bugging me! There's no problem at all with solid objects.
John
Edited By John Baguley on 09/01/2015 12:12:05