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GSM Calibration

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GEB

#47058

GSM Calibration | 29 January, 2007

Hi,

I am wondering how often people have their GSM (1994 edition) pick and place machines calibrated. We have had ours installed for about 18 months now. It has not been calibrated since its installation. Head 2 has been picking components off centre (or not at all) even after teaching the feeder. Is this a problem which could be sorted by calibration?

Can you recommend anyone (other than Universal) who would be able to do this? We are based in Hertfordshire in the UK.

Thanks, Grant

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SWAG

#47061

GSM Calibration | 29 January, 2007

Are you using ghost feeders? If not, that could be causing poor feeder picks - not calibration.

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GEB

#47062

GSM Calibration | 29 January, 2007

What are ghost feeders?

I've been creating a feeder for each slot and teaching each one individually before running a job. eg. Using an 8mm tape in slot 20 = "8mm Tapeslot20" or 12mm tape in slot 56 = "12mm Tapeslot56"

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#47063

GSM Calibration | 29 January, 2007

What about the component placement with Head #2? Head # 1 is ok? Is it only the pickup that is the problem and if so, from all feeder banks (front & Rear)? Concider Z-axis height adjustment, procedure is in the manual. You normally don't need to re-calibrate the whole machine after that. Concider also to calibrate the feeder banks. No special tools is needed for that. Procedure in the manual and it takes about 1 minute to do.

If the placement is off with that head, there might be that your spindles has crasched into a feeder or something. Replacement of a spindle or the head req. re-calibration and also a special calibration kit is needed.

We use a known good test board (a dummy board or a rejected customer board) with a known good program. If we see placement offset on our products or suspect that something is not good, then we run this test board and program, placing some components of different package types (also fine pitch) on double sided sticky tape, using both heads and all spindles. Then we got a hint of where the problem is; wheter or not the machine maybe needs re-calibration or the fault is in the programs. It is also good to run this test product after each prev-maintenance, if you want to feel more safe.

Please let us know your progress or if you have any questions. /sincerly

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#47066

GSM Calibration | 29 January, 2007

You may be creating more problems by teaching feeders. We use one type of 8mm for whatever amount of feeders we have loaded. You shouldn't have to teach 10-8mm feeders with 10 different feeder names. Use only one.

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GEB

#47067

GSM Calibration | 29 January, 2007

The front banks and head are fine. The rear ones aren't. When I look at how it has picked up a component, I have noticed that it is way off to the right (looking from the rear). This is ok for large components (TQFP, Tant Case A) but has caused the smaller devices to be rejected because they are not picking up, or are just balancing on the edge of the nozzle. The positional accuracy is ok. I usually try running a "sticky" before a brand new job, spray mount glue is good for this. All this despite carrying out a feeder teach beforehand. How do you calibrate the feeder bank?

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SWAG

#47068

GSM Calibration | 29 January, 2007

That's what I'm talking about. Might need to calibrate, then. We usually rent a cal. kit and do the cal. ourselves. Just make sure you specify your block, head configuration, etc. when renting. As for frequency, we generally don't worry about it until we have problems although I suppose it would be smart to check level and calibrate a machine on a yearly basis. I don't know anyone to rent a kit from in the UK.

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#47069

GSM Calibration | 29 January, 2007

Is this a single beam (GSM1)or a dual beam machine (GSM2)? If it is a GSM1; how does the pickup works with Head 2 from the front feeder banks?

Do you have removeable or fixed feeder banks? If removeable, make it fixed, using screws through the bank down to the holes in the plate. Just for test purpose. A feeder name like 12x8mm should be eq. picked from either front or rear if the banks are in the right position. Make sure you compare with the exact same feeder.

Calibrate the feeder banks (or plate, can't remember the correct name) is from the same drop down menu as you choose feeder teach. It uses 2 pair of fid pin's in holes, just in top of the vertical feeder plate casting outside the rails(left & right, front and rear of the machine). No special tools is req. Important: before you do this, make sure that you have cleaned the linear x-y encoder scales and then do a full zero of the machine, not a quick zero before you proceed with any calibration or teaching. Use the scale-icon in the lower main window or zero from the manual control window. Remember that finger prints or other greasy stuff on the linear scales is worse than a little dust. /Sincerly

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MGC

#47070

GSM Calibration | 29 January, 2007

You might be wise to contact Universal's local office for support and or access to the required kits. http://www4.uic.com/wcms/WCMS2.nsf/index/Contact_Us_53.html#Western

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flipit

#47075

GSM Calibration | 29 January, 2007

If you teach your feeders, you can no longer gang pick correct? I have never had a dual beam or dual head GSM before. However, if you teach feeders with the fiducial camera and your picks are still off, there is an offset in one or several spindles on that head. Does the dual beam GSM or dual head GSM have two fiducial cameras or just one? If your placements are right on, then it would appear that your fiducial camera(s)are in the correct position and maybe the head was crashed. We used to crash our GSM a couple of times a year. The feeder latches would break and the head or spindles would hit the feeder.

I picked lots of 0402 in removable bank feeders with 08mpf nozzles. I had a C4 flip chip GSM with 4 spindles. The fixed feeder banks are much better for 0402 components. My experience with the Universal calibration kit is that it is difficult to use and calibration failed often when using it.

Chris

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GEB

#47119

GSM Calibration | 31 January, 2007

I think it might be the feeder banks, that is causing the problem. I've tried picking a SOT-23 component using head 2 spindles 1-4 from a rear feeder bank and it is picking off centre. Doing exactly the same, but putting the feeder in a front bank it works.

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#47134

GSM Calibration | 31 January, 2007

Have you verified that your X encoder isn't dirty?

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#47135

GSM Calibration | 31 January, 2007

BTW GEB; When you put the feeder in the front bank did you pick the comps with Head #2 and from the feeder bank just opposite from the rear non working feeder bank? Did you make your feeder banks fixed or is it already that?

It just hits me, if you have a PTF-loader Rear right or Rear Left between the rails, do you in such case have an inbound or an outbound rear feeder plate setup? It could be that the numbers (position) have been screwed up in the system setup. Have you done calibration of the feeder plate yet? /

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