Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

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DEK print problem?

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#54149

DEK print problem? | 24 March, 2008

I have a DEK ELA and here is what happens. I print a board after going through the step and it is a dead on print. Then, with another print it will be off in Auto mode (sometimes up and sometimes down, seems to just be up and down not left to right and is random) Put it through step mode or cycle power and is fine again and sometimes fine in auto mode for a few prints then off and then on again (random). The screen is locked in and tight, the board clamps are tight (borad doesnt move) thinking a camera issue of some sort? Thoughts?

Thanx, Todd

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#54150

DEK print problem? | 24 March, 2008

What r u using for fiducials ?

fids? pads? thru-holes? video model?

What r u using to print the paste?

squeege blades? proflow? paste puck?

Why r u using Step Mode ?

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#54152

DEK print problem? | 24 March, 2008

Double check your supports. When run in auto this occurs a lot quicker than step mode. Just a thought.

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PR

#54167

DEK print problem? | 25 March, 2008

Make sure whatever you are using for a fid. is apart from any other pads or apertures. It'll grab a pad/aperture above or below (in auto mode) and screw up your print. We saw this alot when using pads for fids on DEKs.

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#54175

DEK print problem? | 26 March, 2008

I know you said you checked your clamps but another look will do no harm. we had a very similar issue a while back, and it turned out that the plastic shim under the chase clamp magnet was damaged. This caused the chase clamps not to release properly, so even though the actuators were moving to the correct position the chase couldn't. If you run it with the covers lifted and watch the actuators, you can see if a gap forms between the bearing and the chase frame. If this is the case then check your air gaps and the condition of the magnets.

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kpm

#54185

DEK print problem? | 26 March, 2008

When was the last time your ELA was calibrated? I had an operator ding the camera some how and the machine acted very much as you describe afterwards. A camera calibration corrected the problem.

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#54188

DEK print problem? | 26 March, 2008

Also check your belts/tensions/pulleys and motors on the camera axis. If you are getting any slippage then the camera will not be in the position the encoder says it is. It may still read the fids but will produce an offset.

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