[Eclipze]

I’d be keen to have a look at that machine phomann
Early April is best, as I won’t get a chance to work on this until then.

I don’t wish to run the Y-Axis to both sides, as I don’t want to allow components to fall on the rail. It also complicates the design quite a lot. I only want to have a small placement area. This is a baby PnP ;-)

The weight is not an issue. The rail with such a short length is just not going to flex with such lightweight component, and such a short travel. A second rail becomes an alignment nightmare. I’ve tried this with several variations, mounted bottom, top, and even on their side. I dolly also provides drag and variation in the design. I’m placing my bets that this will be the optimal chose for both accuracy and simplicity, given its small scale and adjustable X-axis bearing.

The servo has a servo saver on it. If the servo pushes too hard, the mechanism will just spring back. I can control the torque by controlling the DC magnitude. I have tried spring arrangements too. Pneumatics I’m not familiar with, and prefer to keep the mechanism controlled by motor. 8mm travel (assume you mean the vertical Z-axis). Much shorter than I’d planned. I’m accommodating 20mm.

Very interested in seeing out this pneumatic coupler works. 180 degrees is certainly fine!

I’m not doing feeders. Too complicated and after a lot of though, not that practical for this small design. I want the machine to PnP only a few boards at a time. A strip of tape manually feed into place gives plenty to work with. For 0805’s, it will give around 80 components. Larger components have multiple tapes. The reels will be on a common rod, and manually feed through to expose the next strip of components. The machine will let me know when it has run out of a component and requires further feeding. Perhaps in future versions a feeder as you suggest would be worth looking into. I’m trying to narrow the scope at present so I can get something up and running first.

Cheers,
Tony

[phomann]

I’d be keen to have a look at that machine phomann
Early April is best, as I won’t get a chance to work on this until then.

Hi Tony,

Early April should be OK. Just let me know when you are ready.

As you your comments. The way you are proceedijng seems fine. At least you are actually building something. I never got that far.

Cheers,

Peter.

[Xerxes]

I'm not sure whether you have seem this video:
http://www.youtube.com/watch?v=bbBr9cbMqq4

It is a CNC mill doing SMT pick'n'place. At least there is an interesting way of component alignment

[Eclipze]

That's an awesome effort!!!

Quite interesting that it is operating without a rubber pickup. Without any spring back with the head, you'd want to be confident of the pickup hieight. I would have though using just the pick pin head and an alignment strategy as used would have resulted in a lot of dropped components. Obviously not the case!


Good video!

[phomann]

That's an awesome effort!!!

Quite interesting that it is operating without a rubber pickup. Without any spring back with the head, you'd want to be confident of the pickup hieight. I would have though using just the pick pin head and an alignment strategy as used would have resulted in a lot of dropped components. Obviously not the case!


Good video!

There is no need for rubber pickups. My Yamaha 84 has 3 heads, all without rubber pickups. Even if there is a bit of air leakage, the vacuum is still strong enough. Also, if there was rubber involved, it would be difficult to centre the component.

The 3 heads I have are;
1. 0.7mm nozzle - jelly beans, 0603 0804 1206 etc.
2. 2.0 mm nozzle - larger components tants, 16pin soics
3. 4-5mm Nozzle( Not sure) - Large components I use it for a 44pin PLCC SMT socket.


As for centring the first 2 heads have 2 sets of jaws. A long set and then a short set, that centre the coponent as it is raised from the feeder.

The 3rd head can use 1 of 2 centring methods;

1. a centering station with 2 sets of pnuematic jaws that centre the component. Does the same job as the centring in the video except the wall move instad of the component.

2. Upward looking camera. The component is positioned over the camera and software determines the X,Y,theta offsets of the component.

As to the machine in the video not haveing a floating Z axis, yes it is not ideal or advisable. That said there is probably enough give in the component tape and the paste to allow for a little leeway.


As to photos of my machine, they are still comming. By the way, I purchased my machine of a 2nd hand SMT dealer, and I glad I did. Initially the dealer was looking at brokering a deal for maching in Sydney, but at the last moment cancelled the deal as it was alleged that the machine appartently had a fault and had been flogged to death.

Anyhow that machine popped up on eBay the other day. Maybe the faults are fixed as the listing doesn't mention any , but I'm glad I didn't buy it.

There are a number of photos worth looking at though.

http://cgi.ebay.com.au/Yamaha-automa...QQcmdZViewItem


Cheers,

Peter.

[Eclipze]

That nozzle size information is really most useful, thanks phomann!

I'm still impressed at how well the square 'bucket' worked. I can see how a set of jaws for squaring would also work. It does however cut into the placement time. Although I'm not concentrating on speed, I do want to have a system that can be later tweaked to get some performance, but reliable. I'm also keen to reduce the number of moving parts.

Initially I won't use a square station (limit the scope initially), however there will be a position for an optical sensor from a mouse inbetween the PCB and the component pickup area. I want to suck the image back to the PC and process the orientation with Matlab. I believe the low resolution won't cause a bottleneck, and the placement will target the initial coordinate and receive a correction prior to final placement. I think an image sensor will give the most flexibility and speed, though a fair bit more complicated. Hence, I'II leave that for phase 2 hahaa...

Such a fun project

[ppBuilder]

had been flogged to death.

Anyhow that machine popped up on eBay the other day. Maybe the faults are fixed as the listing doesn't mention any , but I'm glad I didn't buy it.

There are a number of photos worth looking at though.

http://cgi.ebay.com.au/Yamaha-automa...QQcmdZViewItem


Cheers,

Peter.

Peter,
How is that upward looking camera arrangement? Is the camera actually placed in the base and looking upwards or is the main camera looking down at a mirror or what?

[ppBuilder]

That nozzle size information is really most useful, thanks phomann!

I'm still impressed at how well the square 'bucket' worked. I can see how a set of jaws for squaring would also work. It does however cut into the placement time. Although I'm not concentrating on speed, I do want to ..........

Such a fun project

You may find this useful:
http://www.apsgold.com/l-series.html
In this video you'll see the camera, squaring station, and centering fingers in action.
http://www.apsgold.com/video2d.asf

My design will be loosely based on this L60 series machine.

[phomann]

Peter,
How is that upward looking camera arrangement? Is the camera actually placed in the base and looking upwards or is the main camera looking down at a mirror or what?

The machine has 2 cameras, 1 itsattached to the head (well 3 heads). You use it for reading the machine where to place components. It works out the X,Y offsets for the particular head to be used.

It is also used for finding the centre of the fidicules. For a board you tell it the position of 2 diaginal fidicules. When the board is first loaded, the machine finds the 2 fidicules with the camera, and he software then works out the X/Y and rotation of the board position.

The 2nd camera is only for component centreing. it is fixed to the machine base, and it pointing upwards. The head moves the component over the camera and the software determines where the centre of the component is.
I haven't used thois camera yet.

Cheers,

Peter.

[ppBuilder]

......The 2nd camera is only for component centreing. it is fixed to the machine base, and it pointing upwards. The head moves the component over the camera and the software determines where the centre of the component is.
I haven't used thois camera yet.

Cheers,

Peter.

Ok,
so you can normally pick & place chips (805, 1206 and so on) without rotation and centering....despite the fact that it may be picked up with up to 20deg rotational error, and some offset error, and just place it?
I guess it works ok if the board is not too dense, especially if one uses pads that are wide enough so the chip does not overlap into adjacent pads right?

[phomann]

Ok,
so you can normally pick & place chips (805, 1206 and so on) without rotation and centering....despite the fact that it may be picked up with up to 20deg rotational error, and some offset error, and just place it?
I guess it works ok if the board is not too dense, especially if one uses pads that are wide enough so the chip does not overlap into adjacent pads right?

Nope! Head 1 (0.7mm) and head 2 (2mm) each have 2 pairs of centring jaws. For each head there is 1 pair of long jaws and 1 pair of short jaws. The long jaws come in first, they have softer compression tension. The shorter jaws then come in and centre the component in the other axis. The component slides along the longer pair. In fact the longer pair eventally wear.

When a component is picked up, you need to have the long set of jaws aligned with the long side of the component.

So every component is centred somehow.

The camera is for fine pitch components or none rectangular components I guess.

Cheers,

Peter.

[ppBuilder]

Nope! Head 1 (0.7mm) and head 2 (2mm) each have 2 pairs of centring jaws. For each head there is 1 pair of long jaws and 1 pair of short jaws. The long jaws come in first, they have softer compression tension. The shorter jaws then come in and centre the component in the other axis. The component slides along the longer pair. In fact the longer pair eventally wear.

When a component is picked up, you need to have the long set of jaws aligned with the long side of the component.

So every component is centred somehow.

The camera is for fine pitch components or none rectangular components I guess.

Cheers,

Peter.

Ok....
So the long jaws are still pinching the chip when the short jaws come in and 'pinch' it from the other two sides...so at this point it is pinched on all 4 sides?

[suske]

Hi to all.
I am new here, and I am to interested in building "Pick 'n Place" CNC machine.
First, my apology for bad English. :-(

Here on this link:

http://www.hobbycnc.hu/English.htm

on the left side of page, click on "Mechanical 29." and you can see an interesting solution for simple P&P machine.
By click on first photo you can see an video of machine in action.
Here is home page of author:

http://www.smd21.fw.hu/

but page is not in English.

As you can see it is an pneumatic machine width interesting and simple feeder solution.

I hope this can help you in your great job.

Best regards,

Suske.

[suske]

Hi to all.
I am new here, and I am to interested in building "Pick 'n Place" CNC machine.
First, my apology for bad English. :-(

Here on this link:

http://www.hobbycnc.hu/English.htm

on the left side of page, click on "Mechanical 29." and you can see an interesting solution for simple P&P machine.
By click on first photo you can see an video of machine in action.
Here is home page of author:

http://www.smd21.fw.hu/

but page is not in English.

As you can see it is an pneumatic machine width interesting and simple feeder solution.

I hope this can help you in your great job.

Best regards,

Suske.

[ciccio]

I have seen www.hobbycnc.hu/english.htm
(mechanical 29)
--------------my hat off: ------------
now it is really possible to build an home-made PICK & PLACE !
Again: c-o-n-g-r-a-t-u-l-a-t-i-o-n-s !!!!!!!!!!!

[ppBuilder]

I have seen www.hobbycnc.hu/english.htm
(mechanical 29)
--------------my hat off: ------------
now it is really possible to build an home-made PICK & PLACE !
Again: c-o-n-g-r-a-t-u-l-a-t-i-o-n-s !!!!!!!!!!!

Well...
It does "pick & place", but no rotation, no squaring, no toolchanger, no teach-in camera. Fun to watch but I doubt it is a very useful machine.

[Xerxes]

At least it has an interesting method for reel feeding. And perhaps some kind of rough squaring could be done in tape pockets? Might just be accurate enough and very fast because very little additional movement is required.

[Eclipze]

Very nice! Operation speed was quite good. Having tape on both sides at least provides the ability to place components at 90 degress angles.

I do wonder if the pneumatics is too hard on the component and could cause damage.

[Eclipze]

The method of tape feeding is certainly a neat solution. The length of the tape feeding block is probably to get enough friction on the tape that is won't move (pull out), and it looks like the tape is aligned in channels.

How are the tape covers striped with this approach?

[Eclipze]

This link provides some interesting information in maximising the torque vs speed for stepper motors.
http://www.hobbycnc.hu/English.htm

I still however intend you use a DC motor with precision optical feedback though.