Until we have a host and website for the Wikiplacer we continue here.
In our first on-line brainstorming session, we got already quite some details accomplished.
We’ll need your and customer feedback on the requirement for max-min board size as well component range, upon which we make a decision on required placement accuracy and travel area.
Likely we’ll decide on linear motors (custom or off the shelve) for the X and Y positioning system.
We’ll strive for high accuracy for the lowest possible price. Also, the machine should run unattended at a 4 Sigma certainty, which we can only achieve with automatic and reliable component feeding method and closed loop positioning system.
In order to keep the masses low and cost for such linear motors, we’ll likely decide on a light-weight (carbon) fiberglass gantry, laminated over a foam core.
Unless we get convinced otherwise, we’ll inspect the component on the fly with a camera vision system. We briefly discussed the option to view the component from the top and through the nozzle, but discarded this concept due to development time while dealing with light reflections and background while the component is moving from pick up to placement.
With the component inspection at the placement head while traveling in X and Y, the Z axis either has to be raised in order to get a camera or mirror underneath, or the component has to be rotated or moved into the camera optics.
With many years experience in rotary heads, I conclude a small size 4 nozzle rotary head, would be best for this purpose.
A second camera will be used for board fiducial recognition and a third, stationary camera will be used for larger, odd shaped or micro BGA components.
The feeders, already proposed in the open source thread will further be simplified and size reduced. We’ll likely remove the sprocket wheel out of the design and only sense the perforation holes with sensors located at the feeder table. As a trade off, we will not be able to use clear plastic tapes.
The empty carrier and cover tape will need to be disposed properly, not requiring operators with scissors or clearing an empty tape mess.
We will also consider intelligent feeders with RF ID tag in order to store component information as well as remaining number of components in the tape. The feeder component information should minimize set up time, but should also provide early warning messages of feeder tracks going to run empty.
All we know, we are setting our goals very high. We will require your support and input but I’m convinced we get there.