Re: SMD Parts Tray Shoot Out: Who's the Winner?
Posted: Sun Apr 08, 2018 1:34 pm
I received a request for more detail about my parts trays. So here goes... (File this under "If you have a hammer, everything looks like a nail"): I am lucky enough to have a Carvey, which is a small CNC milling machine. I used that to create the parts trays.
0805 parts: The material I used was two color acrylic 1/16" for the 0805 Caps and resistors. First I made grooves of 8.4mm wide, and then made the end strips. The end strips are attached using double sided sticky tape, and they have grooves on the underside to allow the tapes to slide easily. One advantage is the rulers can be engraved into the material. At first I used tape at the bottom of each groove, but later found it much better to use one-sided tape on top. You need to hold the part-tapes down well, otherwise, the tape with bounce a bit when a part is extracted. This is very bad, since the bounce makes nearby parts, not yet picked, go flying.
Small parts in clear plastic tape: I used two color acrylic, but 1/8: thick for these. Since I find it hard to get reliable contrast on clear tape, I engraved reference circles as part of the ruler. Another trick was to mill cavities so the parts tapes are held in a consistent position relative to the engraved circles. Then it's just a matter of adjusting the part's offsets from the engraved holes, in my case x=5mm y=0mm
Large parts in clear plastic trays; I used basically the same technique as the small parts in clear plastic, but attached 1/16" two color acrylic on top of 1/4" HDPE, so I could mill much deeper cavities.
small parts in black plastic tape: I used the 1/16" two color acrylic for these, milling groves such that the tape fits snugly in them, in some cases eliminating the need for two sided tape. Once again I was able to engrave the rulers and also part numbers in this case.
Loose parts: These are on the same sheet of 1/16: two color acrylic, milling cavities so that the parts just fit to ensure repeatibility.
0805 parts: The material I used was two color acrylic 1/16" for the 0805 Caps and resistors. First I made grooves of 8.4mm wide, and then made the end strips. The end strips are attached using double sided sticky tape, and they have grooves on the underside to allow the tapes to slide easily. One advantage is the rulers can be engraved into the material. At first I used tape at the bottom of each groove, but later found it much better to use one-sided tape on top. You need to hold the part-tapes down well, otherwise, the tape with bounce a bit when a part is extracted. This is very bad, since the bounce makes nearby parts, not yet picked, go flying.
Small parts in clear plastic tape: I used two color acrylic, but 1/8: thick for these. Since I find it hard to get reliable contrast on clear tape, I engraved reference circles as part of the ruler. Another trick was to mill cavities so the parts tapes are held in a consistent position relative to the engraved circles. Then it's just a matter of adjusting the part's offsets from the engraved holes, in my case x=5mm y=0mm
Large parts in clear plastic trays; I used basically the same technique as the small parts in clear plastic, but attached 1/16" two color acrylic on top of 1/4" HDPE, so I could mill much deeper cavities.
small parts in black plastic tape: I used the 1/16" two color acrylic for these, milling groves such that the tape fits snugly in them, in some cases eliminating the need for two sided tape. Once again I was able to engrave the rulers and also part numbers in this case.
Loose parts: These are on the same sheet of 1/16: two color acrylic, milling cavities so that the parts just fit to ensure repeatibility.
