Desktop cnc, HELP

Hi everyone, I'm completely new to this DIY cnc business but really looking to get into it. I hav been looking online for a desktop cnc roughly A3 size table for the work I will be planning to do. I have seen the eBay specials lol the 3040 and 6040. Does anyone know if they are any use? I have also jus come across the fireball v90 which looks pretty sturdy, any help would be much appreciated.

Thanks
Walkz69

They can be useful. It all depends on what materials you want to cut with them, which you've not specified...
If, for example, you just want to engrave things, cut relatively thin wood and you're not too bothered about how fast it is, then they would be fine. The main reason for this is that all the machines you mention use unsupported rails, which are inherently less stiff than supported rails. This reduces the rigidity of the machine substantially, hence increasing the hardness of the material you're cutting, or the speed at which it's being cut (which both increase the cutting force), make the tool deflect too much for the machine to remain accurate. Fortunately they're quite small machines, so the effect isn't so bad, but it's still big concern.