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Assembl�on feeders

Views: 1874

AR

#42134

Assembl�on feeders | 13 June, 2006

Has anybody else noticed a problem with Assembl�on's mechanical 12 mm feeders, with 4 mm pitch? We are experiencing grave pickup problems with a MELF diode packed this way and fed with this type of feeder. If I attach a hefty weight to the blister tape in order to create additional pull to the blister tape the feeder seems to work much better. Not exactly a high tech solution but does help to some extent.

Quite obviously the spring-operated tape feed mechanism simply does not have sufficient power to advance the tape reliably. This would not be a problem with other types of components but MELFs are very finicky about the pick up position being just right, owing to the special shape of the MELF nozzle. Have tried stiffer springs but to no avail. With a longer pitch there are no problems so this problem clearly has to do with the short travel of the tape feed.

Has anybody designed an ingenious modification to their feeders to improve the situation?

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adlsmt

#42152

Assembl�on feeders | 13 June, 2006

You have already come up with what I consider the industry standard fix. Attach your weight to one of those heavy duty black paper clips and it is pretty easy to move it up as the tape runs onto the floor. I know of a lot of people doing this. Not aware of any other fixes.

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AR

#42175

Assembl�on feeders | 14 June, 2006

Thanks ;)

We even did some product development on that one. We took a normal bar of wave soldering alloy, sawed a suitable length off it and drilled a carefully measured hole through the bit of solder. The hole is wide enough so that the blister tape snugly fits through the hole but yet narrow enough so that friction locks the weight in place on the tape. No clips necessary. When the tape advances we simply slide the weight upwards before it touches the floor. Works on plastic tapes anyway.

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#42182

Assembl�on feeders | 14 June, 2006

Good afternoon,

1. Use only melf nozzles (Type 76) 2. In case if your melfs are picked up one after another try to increase feed time in machine setup, this will add additional delay and will allow feeder to complete feed cycle 3. Use the strongest springs you have, set the spring to the �hard� position

BR, Pavel

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AR

#42183

Assembl�on feeders | 14 June, 2006

Thanks Pavel,

Have tried all that, including some exorbitantly expensive MELF nozzles but it does seem that the good old weight method still works best.

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cloggy

#42408

Assembl�on feeders | 25 June, 2006

Problems like these are not caused by bad feeder quality. As described in the solution finding, the pull off forces of the cover tape are just too high. Cause is the blistertape and not the a feeder. Have you ever tested if the pull of force of the topfoil is within spec? I know, it is not solving your problem, the old "solder bar method" is a good solution, but it should keep your focus on purchasing proper tapes the next time.

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#42612

Assembl�on feeders | 8 July, 2006

Are you using the old type FV or the new CL Feeders? We place melfs all day long and never ran into a problem with feeder advancement. Sometime the manufactures of the components apply to much glue to the tape which can cause problems with feeder advancement.

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