PnP Z-axis nozzle movement - Page 1
Forum section: electronics / general

author: olkipukki
author_rank: Frequent Contributor
timestamp: April 19, 2020, 04:41:25 pm
content: I'm wondering what is mechanism in use on professioanal PnPs (except shootera) to move a nozzle up-and-down ?Is it something like that (in a primitive way)?

author: Mangozac
author_rank: Frequent Contributor
timestamp: April 19, 2020, 09:32:28 pm
content: The leadscrew system you show is too slow. The machines I've seen have a stepper motor with a cam system that pushes down on the nozzle assembly.

author: jmelson
author_rank: Super Contributor
timestamp: April 20, 2020, 12:31:47 am
content: Quote from: olkipukki on April 19, 2020, 04:41:25 pmMy Philips CSM84 uses air cylinders with needle valve restrictions to control the speed. (Yes, I know that is "old school".)It has a spring-loaded nozzle so there is no controllable Z stroke, it just plunges down to the same depth every time anddepends on the spring to apply the placing force. But, it works quite well and is simple.Jon

author: SMTech
author_rank: Frequent Contributor
timestamp: April 20, 2020, 08:18:40 am
content: Heres whats under the cover on Essemtec. Completely electronic, its relying on your data input to get the travel height correct, there is a little bit of a spring inside there to allow for some discrepancy but the nozzles are solid. if the height data is wrong the can hear them get slammed into the board. Some higher end machines have programmable placement force which eliminates this problem (helps with warping too) but I would imagine that would be quite hard to add to a DIY head. Our previous P&P an RV4S used a rack and pinion driven by a stepper(?) that was actually quite quick but it had quite short travel whereas the Essemtec can handle an 18mm part inferring ~40mm of travel.On Aliexpress you can buy a P&P head assembly for DIY systems, has anyone tried them?

author: Mangozac
author_rank: Frequent Contributor
timestamp: April 20, 2020, 11:55:45 am
content: In contrast to my comment above, I actually saw an I-Pulse pick and place today and noted that it uses a leadscrew based design but with an extremely coarse pitch for rapid movement. It has an enormous z-axis operating range of 40mm!

author: olkipukki
author_rank: Frequent Contributor
timestamp: April 20, 2020, 01:45:01 pm
content: I'm still trying to put pieces and bits togerther into my head, how it actually works, I guess there a lot engineering talent and time been investested, so not much available in a public.Is it more close to a reality?https://youtu.be/ZarIuXoSXF0?t=191https://youtu.be/6DCaZ7h2QDA?t=22

author: olkipukki
author_rank: Frequent Contributor
timestamp: April 20, 2020, 02:31:07 pm
content: Looks like there are two basic options how to do it: belt sytem or hollow stack up?Everything else would be some sort of hybrid that optimized for a specific machine and needs?

author: fcb
author_rank: Super Contributor
timestamp: April 20, 2020, 02:34:44 pm
content: I would use a NEMA/8 hollow shaft stepper motor to provide theta and vacuum.Mount this on a small linear rail, and use a spring to provide downwards placement force. Another stepper (NEMA17) with a cam on it then 'lifts' the Z axis trolley.

author: olkipukki
author_rank: Frequent Contributor
timestamp: June 22, 2020, 06:26:07 pm
content: Quote from: jmelson on April 20, 2020, 12:31:47 amAfter some quick and dirty tryouts of my amateurism in a mechatronics,I have stopped on a similar solution - a short-stroke air slide table and mounted a hollow motor with attached spring-nozzle.