what a nice project it is i read all the articles about it and realize that it is similar to those which i added in my blog here you can see on https://bestjigsawguide.com/best-jigsaw-blades/

Thanks for the [url=https://www.youtube.com]info[/url]

You may have a practical application! Archaeologists often have to piece together fragments of pottery. If you have software that can match where they join then that could speed up the process a lot. The problem is harder, being in three dimensions and some pieces may be missing. Then again, you won't have to physically move them, a computer model would do.

Awesome project! I can't wait to see this working.

One issue you might have is the NESW controls resulting in random movement from indecisive people. If that doesn't work then a grid system might work. You could divide the space into a grid and give the users a few seconds to choose a square. Once a square has been picked divide that into a smaller grid and let them choose again. Repeat until the required resolution has been obtained.

You could also remove the need to have pickup/place commands if you force a set sequence to follow: move->pickup->move->rotate->move*->place. The fewer options the user has, then the less chance there is of disagreements ;)

*move after rotate would allow the position to be refined

Also, if you don't need all of the functionality of the RAMPS, I would suggest the Arduino CNC Shield v3 or 3.10, which uses GRBL and is more compatible with a PNP machine: http://blog.protoneer.co.nz/arduino-cnc-shield/  Protoneer (Bertus Kruger) is also always willing to answer questions.  No idea whether it's compatible with the firmware that you've chosen though.

Or you might be able to use his Raspberry Pi CNC Hat? http://blog.protoneer.co.nz/raspberry-pi-cnc-board-hat/

I had a ramps in stock, it's pretty convenient.  You've given me a plan B. Thanks

This might also be a ready-made solution for your nozzle/vacuum if you can add a 3D printed soft tip to it, or maybe a piece of latex tubing: http://www.amazon.com/Viva-Decor-Vacuum-Rhinestone-Applicator/dp/B004Y9CXL2 (possibly also a cool desoldering pen somehow).  Hobby Lobby in the US sells them in-store (and you can use their nearly-always-available 40% off coupon for it).  There's also a professional version that has a much bigger control box.  I think I can get you in touch with the manufacturer through one of their importers in Philadelphia. (Nevermind, Aliexpress has them now: http://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20160121230419&SearchText=vacuum+rhinestone)  Also, you might be able to build the nozzle prototype and silicone mold it (Hobby Lobby also carries those supplies, or make your own with silicone caulk, corn starch, and food coloring - videos abound on YouTube).

For the robotics, contact Matteo Borri (https://hackaday.io/spiritplumber); he was on Team Bronco on Battlebots, does contract work for NASA, and is the inventor of the L-Cheapo laser attachment  (FD - I'm a distributor).  He seriously knows robotics and is almost always willing to help out if he has the time.  Also check out openbuilds.com for other PNP designs and assistance.

SMD pick and place manual pens come with a set of rubber suction cups. My SMD pick and place machine is an open source design and might give some inspiration: www.liteplacer.co

Very interesting project! I'm looking to use CoreXY on a medium format (where I'd consider your project large and the average 3D printer small) laser engraver. What diameter rods are you using and how much sag are you seeing on them when the carriage is at mid-travel? 

I'd imagine for your project sag may not be too critical, but I'd be very curious to know. I'm currently wondering whether I can get away with steel rod or whether to use 2020 extrusion. 

3/16"? It works out to 7.95mm, so 8mm linear bearings fit great.

Unfortunately, parts made with FDM printers are not very air tight.

Now we only need to wait for the next smart guy to use an algorithm to puzzle your jigsaw based on the image of the pieces ;-)

actually here you can buy just the vacuum pen cups here: https://www.tedpella.com/grids_html/Vacuum-Pick-Up-Systems.htm

Look for a vacuum pen and hack the suction cups on that into your nozzle.  They are tiny.  If you can live with slightly larger, mcmaster sells some that are 1/4" diameter you can trim down to 5mm probably.  http://www.mcmaster.com/#3766a77/=10lubzn

Ok - this is freaking awesome! I could totally see this being the next "Twitch plays... " as well!  If you're still looking for a nozzle design, rubberized filament like Ninjaflex could be used to make something custom.