I think we are talking about a small PnP machine used for DIY or R&D purpose. So it does not have to be fast but must be cheap and versatile.

Recently I am also planning such a machine for my own using. I was fed up with soldering hundreds of small capcitors manually for just one board. I have got a small X-Y CNC bed without any controller, to which I still need to add Z axis and and a R axis for rotating the head.

I'm going to add one or two webcams as a vision system. There will be a training zone on the bed, so that the aligment between the head and the camera will be done at the run-time.

There will be two types of heads: one for the paste dispensing another for PnP. I'll just discuss the PnP one here.

Basically that head is like a syringe and takes that type of needle for small devices. For a large package like QFP, that needle will pick up a bigger adaptor first. The adaptor is a plastic or rubber nozzle. The head can put the needle into it under the guide of the vision system, and the nozzle will stay with the needle for rest of the operation. To take off the nozzel, put the nozzel on the nozzel tray (a smooth even surface), turn the vaccum on, and the head puts up to get rid of the nozzle, then, turn the vaccum off.

For the feeding, there will be a component area with a variaty of slots and trays. The slots are for the SMD strips, e.g. up to 50 components. The strip is pre-cut and peeled mannually according to how many is needed for this board. For more than 50 piecs, just use a second slot. For a few less than 50 pieces they can be compined. However, there is no need to use strip and slot for just a few pieces, say < 10. There are also square trays, e.g. 20mm x 20mm for loose SMD. Again, the vision system is used to locate the components.

The head is rotatable. The head socket is like a cylinder with teeth on the outside, and a stepper will drive a timing belt to rotate the socket. The head socket may measure 20mm ~ 25mm in diameter and fixed to the Z platform via a ball bearing. The rotating motor is also no the Z platform.

I haven't decided how to put the head on the socket quick and easy, and also compatible with the paste dispenser head.

I know there are a lot for work for it. So it has to be well planned and ideally if people can cooperate on it, e.g. control software, vision software, system interface to a PC, making of the mechincal parts, etc.

ta
David