We use Festo air systems to detect that our parts are in place. It measures the back pressure, so if the part is not seated properly not all of the air holes are covered and the back pressure will be too low. It works ok, but people get annoyed with nuisance faults and they adjust the air pressure so they do not get any faults. Then when there is an actual problem we ruin a spindle.

What other part detection systems are out there that may be a better fit?

I'm getting a system in from Vaccon to place surface mount chips on our circuit boards. It has a similar feature. In my case, the only other choices are vision or weight. Considering most of my components weigh a fraction of an ounce, its pretty impractical (and expensive) to do it that way. The vision system costs slightly more than a kidney and is very slow. What are you pickin' and placin'?

I have a customer that uses old drills(carbide) that have been reground to the point he can no longer use them. When the part is not seated correctly the swing clamp is at a different height than when properly seated. (roughly .100" difference)

In the program he calls up that tool first and does a pass over the swing clamp. If it's ok when he puts it away and does a BK Mikro check it reads good, if not it breaks the drill and throws a broken tool fault.

Wouldn't be my first choice to check part seat, but surprisingly with almost 3 years of running it hasn't had to have a new spindle put in.

I have another customer with a similar set up that uses a prox switch on each swing clamp to confirm it's pulled fully into the down position before running. Works really well on his machine but probably wouldn't work so well on a machine with a pallet changer.

I've also seen LVDT's used to check part seat but they're a pain to set up.