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Problem with y-axis Yamaha84 SMT mounter

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#37306

Problem with y-axis Yamaha84 SMT mounter | 25 October, 2005

Hi, We have problem with y-axis offset at YM84 After setting the ORIGIN machine operate exactly but after sometime y-axis recieves offset bis 5-10mm.After repeated setting ORIGIN Y-coordinat became exact. The same things take place if we operate in WARM UP regime. WE suppose that fault Y-axis motor or decoder. May be somebody know how we could eliminate this failure Thank you Peter

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KEN

#37321

Problem with y-axis Yamaha84 SMT mounter | 25 October, 2005

What is the (initial position) ratio of pulse counts to home encoder pulse (relative to the home sensor). It should be 50% +/- 15%

Run this test several times in between a warm up. I bet your numbers are all over the place.

I bet you have a loose coupler and its allowing the lead screw to slip.

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KEN

#37322

Problem with y-axis Yamaha84 SMT mounter | 25 October, 2005

sorry. re-read your post. The problem is the home sensor relative to the home pulse. You're catching the wrong home pulse. a 10mm offset sounds about right for a 360 degree error.

You need 50% +/- 15 % to ensure you always zero to the same physical location. IF you're getting 5% or 90% it becomes possible to initialize on the following home pulse (which is about 10mm or so offset).

But, check all coupler torque settings anyways for good measure.

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#37323

Problem with y-axis Yamaha84 SMT mounter | 26 October, 2005

Hi Ken, Thank for your advice We suppose that with home position all is OK and ratio is in interval 40-60%.Y axis offset is not constant 5mm or 10mm but change ratio with working time and may be more than 10mm We think that problem is with Yservo motor or Y decoder but how to eliminate it we do not know Best regards Peter

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#37341

Problem with y-axis Yamaha84 SMT mounter | 26 October, 2005

The encoder on the Y axis motor is almost certainly kaput. Debris from the wear of the motor brushes or whatever else can find its way onto the encoder and give an ever increasing false pulse. The axis will start OK but progressively go out of whack. Remove the motor brushes and vaccuum out. This will probably NOT fix the problem though you may be lucky. If you do not wish to remove the motor to do this take off the side cover and this will give you access - awkward access but access nonetheless. Check brush wear as per manual, but again replacing worn brushes will probablt NOT fix the problem. Do not crack the brush covers when replacing. Your local motor guy may be able to fix or replace the motor/encoder. Motor; yes. Encoder; unlikely. You may be lucky. You may be able to just replace the encoder if you can source one. Replace motor and encoder. Sanyo Denki, (I presume it is a Sanyo Denki Super U), in your country may be able to help with a replacement - note shaft diameter and key lock on shaft. Do a google search on Sanyo Denki repairs, DC Servo Motor repairs etc. My bet is you will have to go through Philips/Yamaha. Get a new motor and encoder, install, recalibrate and you are up and running in several hours. See if you can then have the old motor fixed and you then have a spare. Good Luck!

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KEN

#37342

Problem with y-axis Yamaha84 SMT mounter | 26 October, 2005

If your sure your drive lines are staying put then it must be the motor. ... odd no servo feedback alarms though. That's why I thought problem might be mechanical.

Does the yv84 use servo's? IF yes, then no brushes to wrory about. Don't bother trying to fix it on your own. Buy another motor and move on.

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mike

#37348

Problem with y-axis Yamaha84 SMT mounter | 27 October, 2005

Peter, have you rany your local agent and got the service guy to fix it ??

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Jeff Roberts

#37349

Problem with y-axis Yamaha84 SMT mounter | 27 October, 2005

The Y-axis motor of the YM84 Series is well known for failures. The bearing between the encoder and the armature fails causing dirt to fall on the encoder wheel, hence the encoder mis-counts. If you re-Origin the machine the problem is resolved for a short time only, then comes back. You must replace the Motor/Encoder assembly. We have them in stock! Would like to buy one? (jr@hrltd.com.au)

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#37455

Problem with y-axis Yamaha84 SMT mounter | 31 October, 2005

Thank all for help Good luck

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