My reveiw of the Velleman K8200 (3DRAG) - entry level machine for home users.
Out of the box, my K8200 presented a substantial challenge. As a 'build it yourself' project, it suits those with some experience in mechanical assembly and knowledge of electronics basics. The build instructions were available online to read in advance and were adequately detailed. Of great value was the forum (http://forum.velleman.eu/viewf... ) where many existing users have shared their problems and solutions.
My (and many others') main concerns with the stock machine were as follows: print bed not flat (solved by adding a glass bed plate), very long heat-up time for the bed (a separate 24v power supply is almost universally adopted by users wishing to reduce the heat-up time), variation in the nozzle position in the xy plane with changes in height - commonly referred to as "z wobble" (solved by upgrading the z lead-screw).
On my machine, one of the toothed pulleys ran eccentrically. A word at the place of purchase resulted in it's replacement (thank you Jaycar). There are some who claim that replacing the pulleys and belts with alternatives results in better print quality. Whilst I do not doubt this, it is not something that I have tried.
If you want out of the box reliability and high quality prints, there are better options if you are prepared to pay a higher price. For those who are on a tight budget and think they may enjoy the learning process (build, research, improve), spend some time on the forum before making your choice. Good luck and happy printing.