Thanks for the replies so far. A little clarification on why I am asking the question. We are designing a small surface mount connector, but we won't be assembling this component ourselves, so I can't test it with the machines that will be building it. What I am looking for is any guidance on the flat surface area that will be needed to ensure that it is unlikely to move about on the pick up tip as it is accelerated across from the pick to place positions. "As large as possible" isn't very large on this thing. If I take the largest flat circular area on the part, take off the tolerance of the part in the tape, then that gives me a maximum pick up tip inside diameter. From a reasonable estimate of the vacuum level I can then get the holding force. If I then guess a coefficient of friction between nozzle and part I can use the weight of the part to see if, say, a 3G acceleration is going to be too much for the holding force. Is this a good approach? Jenny -----Original Message----- From: Jenny Drake Sent: 05 June 2006 15:49 Subject: Vacuum pick up nozzle area for component weight. Is there a good rule of thumb for determining the minimum vacuum pick up nozzle size that will work with a component of a given weight? I am guessing that the problem is reasonably complex as the component mustn't move on the nozzle under lateral and rotational acceleration as it is moved from the tray, or tape, to the PCB. The strength of the vacuum, the friction between the nozzle and component materials and the centre of gravity of the component will all affect this for a give component weight and machine acceleration. Is there a simple rule that people use that gives good results? Jen --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------