Flippersplace Pick And Place Machine MK1

[flippersplace]

$400 bucks! Ouch.

http://www.cotinc.com/smt_site/downl...er%20Flyer.pdf

[stewi]

On Eclipses thread:
IMHO no you can't, because the camera will be offset to the head pickup point. The camera needs to be vertical to be accurate unless you guarantee that all pickups & placements are the same height

Translate IMHO for me, I'm only a semi US citizen.
Siemens used to have a machine with board load at the front and feeders in the rear. If you apply the same offset to the feeder bank, than you would see the pick up.
Also, the very first Siemens machine had the capability to look through the hollow shaft Z-axis with a fiber optic camera. We could insert a glass with scale marks in the jaws and used this feature to teach PCB positions. In this case, you would not have to deal with any offset, regardless from which feeder bank you would pick.

However, Eclipse was looking for a method to move the board and align it, not using pegs. I'm used to an aluminum hollow shaft Z-axis and would be scared to death moving x and y while z is down.
Also, I do assume you do double sided boards as well, so, instead of mounting the PCB to a flat plate, you would rather clamp the board on the edges.

I got somehow fixed on the idea using the nozzle vacuum sensor to find the board position and correct all placement data on the fly (I would have to do that anyway if I would use a vision system).
In this case the regular nozzle would pick up an adapter slightly larger than the board holes, 4 mm diameter or so. There is a small hole of 1mm diameter in the center. Since the adapter is larger, the nozzle adapter will not insert in the board holes. Now, you move X and Y over the position of the first board hole and lower Z. You shouldn't get any change in vacuum, while air flows through the board hole. Move x step by step until the edge of the hole will block the nozzle hole. Do the other edge. Do the same in Y to get the hole center and a second board hole. I think it works. Haven't done the math yet.

[stewi]

$400 bucks! Ouch.

http://www.cotinc.com/smt_site/downl...er%20Flyer.pdf

I'll let them know.

[Eclipze]

I'd use the SMD tape index pin for moving the board around, rather than the placement nozzle. But I had another thought, that uses standoffs for the board. This would facilitate double sided boards. One corner would have a standoff post with a magnetic base. This would be aligned first, then the opposing corner aligned second... whereby it would rotate about the magnetically held first post.

This would probably need to be expanded to be a bit more universal... such as the standoffs having a 90 shelf to reference from the corner of a PCB, given the PCB doesn't have a suitable hole etc...

Perhaps with multiple posts using a magnetic base, boards could be successively loaded (gently) without need for re-alignment.

[James Newton]

IMHO = In My Humble Opinion.

Interesting idea using the nozzle vacuum to sense the position of the board.

[rgee]

re fliperspace question on component rotations
there is an IPC standard see links

http://landpatterns.ipc.org/IPC-7351...Convention.pdf

http://pcdandf.com/cms/images/storie...02hausherr.pdf

PR

[flippersplace]

Thanks RGEE exactly what I was looking for. Now to go and edit my footprint library..

[Eclipze]

rgee... great stuff!! Appreciated. Never looked for naming convention info, mostly because I dread the thought of renaming and loosing sync with all schematic components hahaa...

[flippersplace]

Selective Soldering Machine Jig Making Process

[phomann]

Selective Soldering Machine Jig Making Process

I didn't even get a chance to start my own thread.

actually, I'm about to embark on converting it to being controlled by Mach3. It should be an interesting exercise.

Cheers,

Peter.

[flippersplace]

I've had very good results populating Excel then having VB Script generate all the GCode for Mach 3

[rgee]

Hi there guys
There has been quite a lot of discussion in the top 3 pnp threads regarding drilling holes through stepper motor shafts.
I have the ability to do this but chose not to for a few reasons. So I thought I would share how I made my head, my aim was not sub light speed or even the speed of sound, My z axis is small, it was made out of an old hard drive head mechanism and has been used as a holder for a pencil die grinder for a cnc engraver. The other reason is I felt that you do not need the power of a larger stepper to rotate a small smd part. There is also the inherent problem with joining two shafts and keeping them concentric.
The basics head fits in the sleeve where the die grinder went, this has a diameter of around 18mm.
The head features the ability to rotate a full 360 deg. It Is also spring loaded with a travel of about 8mm.This is achieved with telescoping square brass tubing. My future aim will be to have multiple z axis units with different nozzle sizes, this would also allow for parallel picking. I believe that putting my energy into duplicate z axis will give me more flexibility than a nozzle changer. For the majority of the parts likely to be placed by the backyard technician 3 nozzles should suffice.
parts as labelled
A
this is a piece of delrin 6mm one end to fit the silicone tube to the vacuum ejector.
As my machine had a pneumatic die grinder and solenoidal value I just run the vacuum ejector
off the spindle on signal to create vacuum.
B
This is the sleeve that fits my z axis holder it has a hole all the way through and is fitted with 8X12mm bearings at both ends. These are glued in place with thread lock. Bearings are from old photocopier.
For those who do not know old photocopiers are a great source of parts for cnc'ers / hackologists
C
This is a sleeve that couples the 5/16 square shaft to the bearing in the top also to the drive gear
D
plastic 75 tooth gear from same flatbed scana as motor
E
This is a collar that stops the centre shaft from falling out, held in place with a 3mm grub screw
F
This is the vacuum delivery tube it is silicone fuel line for a model engine found in hobby shops.
Internal diameter of 1/16th ,the length is enough to allow over 360 deg rotation.
G
This is a short piece of silicon tube placed over the end of nozzle for picking large parts, any thing from tant B to QFP.
H
spring to give nozzle an override / travel of about 8mm.
I
delrin bush to keep spring centred on shaft.
J
Aluminium bush to fit square 5/16 square shaft to the front 8mm bearing this needs to be drilled to a diameter equal to the distance across the corners , made to a tight fit. If you do not have a set of fractional drills I recommend you add to your wish list as they are invaluable
K
Square 5/16 brass box section this is from hobby shops K&S metal products there is a large selection of profiles, I had square to hand so that is what I used, there is also hex profiles that would also suit.
Most of the profiles telescope making them ideal for this task.
http://ksmetals.com/resources/cuttolength.pdf
L
This is the business end of the nozzle the end has a .6mm hole with a reduced end to 1mm, this was used to descend into the part pocket to drag the tape forward before picking the next part. This was turned on a small lathe to fit the end of the 3/16 shaft with a flange to support the spring. This was soldered in place.
M
3/16 brass box section this slides inside the 5/16 box section. To make it slide easy I needed to polish the outside with 400 grit paper. When purchasing it would be wise to check that the two will slide together and have no bend. The top end of this shaft has a small tube soldered in, to allow the connection of the silicon tube.
N
stepper motor 72 steps per rev recovered from a flatbed scanner the pinion and plastic gear were part of scanner. To do one revolution with a gecko251, I need 35000 steps this is more than enough resolution. A full rotation takes a fraction of a second.


That's about it for now
Rgee