The CHMT48VA looks very good to me also, but I've dealt enough with Chinese suppliers to know that you have to do your due diligence, so actual customer feedback is going to be important before I make a decision. From the information that I have come across, the Z-axis travel specified is 15mm. Whether this is factual, I do not know.
The similar looking TVM802A and TVM802B units from another manufacturer (QiHe / zjyingxing) do not give me as much confidence, despite that it has dual pickup heads, dual cameras and appear to be functionally the same. There are a number of videos of this machine on YouTube (from customers) that suggest to me that the pickup/placement accuracy is no better than what you would expect from a Neoden TM220A/TM240A without vision. The following website indicates that the machine only uses one camera directly, the second camera is strictly used by the software you run on a PC to assist with the initial alignment:
http://www.matthiasm.com/tvm802a_3.htmlThe other issue is the smaller travel area compared to the CMHT48VA and the fact that they do not use stepper encoders for step verification. This means that a misstep by one of the motors will result in a placement error without the machine knowing this. The CMHT48VA has a closed loop control system with encoders on the stepper motors, so I misstep can be corrected on the fly. The CMHT48VA also has a slot next to the feeders that allows you to feed the empty tapes down so that they are out of the way. With the TVM series you have to run the empty tapes underneath the PCB to the other side of the machine. Yes, it's mostly cosmetic but that matters to me. Lastly, the CMHT48VA uses an embedded Linux system booted using an internal flash drive that allows the machine to operate standalone. You provide the PnP file using a supplied USB thumbdrive. The TVM series requires an Ethernet connection and USB (presumably for the second camera) and requires software on a dedicated PC.
This is what I know so far, so I am leaning towards the CMHT48VA, pending the outcome of the Neoden4 evaluation that is being detailed by TheSteve on this thread.
My contact has been Kimi Liu:
Kimi Liu
kimi@charmhigh-tech.com
Tel: +86 135 106 75756
Skype: kimiliu89