Robin's smt Pick and Place build

[Robin Hewitt]

I've looked at lots of pick'n'place machines and very few people really go for it.

Put down a strip of components and peel it? No, I want full reels of 8mm tape and tubes of SOIC chips.

Change nozzles by hand? You're not really trying, pick them from a rack.

Look at the component from below with a camera then try and estimate where to put it? Sounds like you made it and now you are trying to fix it with clever software. Physical chip alignment on the nozzle for me.

Is it moving? How many components does it place in a week? Some degree of alacrity sounds like a good idea!

The board is stuffed, now how do you get it out without disturbing anything? Shouldn't you have thought about that before you start building it?

What's that ghastly noise? A modified aquarium pump generating the vacuum could drive you insane.

Is that a rubber pick up nozzle? You must have camera alignment because you ain't going to move it! I also have a notion that a pick and place nozzle needs to leak air. Without the leak your pick up force is limited by the nozzle diameter and vacuum pressure. If you let it leak Bernoulli tells us that air forced through a gap will try to close that gap. You can probably do more lifting with a leaky nozzle than with a hermetic seal

Whatever. I am going to have a go at building a 24 station pick and place machine and this is my build log. It's only purpose is to spur me on, a sort of motivator, I think I can rely on you lot to keep me going

First the XY gantry which is peculiarly floppy. There simply isn't enough space to make it rigid because I need access to the table on all 4 sides. The front is for loading pcb's, the back is for the tool rack and the chip alignment station, the left if for tape reels, the right is for chips and more reels. I am depending on 4 screw adjustable feet to keep it square.

First pic: The Y axis runs on two 16mm round rails. Each has it's own 3/4" pitch screw fitted as close to the rail as physically possible.

[Jonathan]

Do you have a CAD drawing of the whole machine you could show us?
Finish looks nice on the aluminium plate

[Robin Hewitt]

Do you have a CAD drawing of the whole machine you could show us?

My CAD drawings are there to make sure everything fits together and can be assembled. The perspective is reminiscent of ancient Egypt, I keep most of it in my head if I'm doing the machining :naughty:

My CNC package works exclusively with AutoCAD DXF files so I extract shapes as and when I want to cut them. There is no 3D pic of the whole thing.

Suppose I should show that there really is some kind of plan though...

[Robin Hewitt]

Taking shape and precariously balanced together fo a pic.

Machined the two 1" x 1 1/2" bars that locate everything to everything else. The 15 slots on the left are for reel feeders. The 10 slots on the right are for either reel feeders of tubes of chips, (needs more space between tubes than reels).

I think the Z axis and component rotation thingy is the next job.

[HankMcSpank]

Go Robin, go!!

Looking good - I can hear the suction pumps already!

[george graves]

I joined this forum just so I could watch this built. Thanks! Cheers from the US.

[sigicnc]

Hi, Robin!

This looks like something, I allways want to build (if I had skills like you)

Few weeks ago, I converted engraver to have some fun with placing SMD parts:



Will watch your build with great interest!

[Robin Hewitt]

Few weeks ago, I converted engraver to have some fun with placing SMD parts:

Blimey Sigi, I never thought that QFP would go down in place. Did you stencil the paste mask?

I had a bit of a software blip that slowed me down but I'm back cutting metal (and seaching for 2mm screws to hold a microswitch :whistling:).

This is the start of the Z axis and rotation. It lifts amd lowers by cam action with another NEMA17 for the rotation. Had to use a linear slide for the up down because it descends under gravity and I can't risk it sticking.

The lifting cam has to run on steel because aluminium would dent.

I sank the linear slide in to the 8mm plate so that it can't come apart now the tabs are off

AutoCAD side view to show how it goes together. Plates in cyan, linear slide in green.

Next the 3/4" pitch nut mountings and the component rotation motor plate.

[sigicnc]

Blimey Sigi, I never thought that QFP would go down in place. Did you stencil the paste mask?

.

QFP was easy, because it was positioned precisely, also PCB was positioned well by two pins. I assembled 14 boards (320 SMDs each) and QFPs went on without a glitch...
And yes, I had proffesional stainles steel stencil for paste.

WOW, nice parts you show in last post!

[HankMcSpank]

I fancy having a dabble too (I'm finding that some of the SMD parts I want/need @0.65mm pitch are just too small for this ageing hand & eyes!) - sigi, what the the pickup tool you used (& vacuum pump)...was it 'improvised' ....or did you buy? (if so have you any linkage that I can partake in?)

I'm curious how the pickup nozzle gets a good seal on the part? Also is the pickup nozzle 'sprung' to avoid stress of the component 'pickup surface' should the parts (or board) not all be completely level bed.