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Z-axis panel movement on full perimeter routing.

Paul M

#13150

Z-axis panel movement on full perimeter routing. | 30 December, 1998

Hi All, I work with CNC Routers . I use full perimeter routing of double sided populated panels, in a high volume/ mix application environment. We chose stand alone routing machines for our facility . I'm interested in your input for better ideas for Fixturing. Until now I've got by with simple fixtures made of fenaboard (tufnel) which are located onto an aluminium base plate via 1/4" dowel pins & bushings. Onto these fixtures I inserted hardened steel pins which would locate the panels via non- plated holes . I believed this to combat movement in X & Y directions when depanelising. To combat movement in the Z- axis we have a brush insert connected to our spindle housing (for vacuum purposes also )to exert a downward pressure on the panel.

This said , I still encounter problems with panels moving during the routing cycle , mostly in the Z-axis ; but also to a lesser degree in X & Y directions. We do not have any overhanging components on our panels interfering with the cutting path. Ideally I would love to be able to use a pressure foot ; but my information is I can't utilise this because I'm routing populated panels. I have 2 tooling pins in each single unit and a few extra on the outside "web scrap section" yet still I encounter movement. I get my pins made 0.002" smaller than the size of the hole . My spindle speed is fixed @ 24000 rpm and I'm routing FR4 @ a feedrate of 80 inch/min approx . My main concern is the movement in the Z-axis .Is there any type of pressure foot applicable to populated panel routing?

All feedback shall be welcomed with open arms. I realise that to engineer some solutions may be expensive; but if I like the sound of any of them , price may not be an option.

look forward to your response , thanks in advance ,

Best Regards ,

Paul . (Based in Scotland , U.K.)

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Chrys

#13151

Re: Z-axis panel movement on full perimeter routing. | 5 January, 1999

| Hi All, | I work with CNC Routers . | I use full perimeter routing of double sided populated panels, in a high volume/ mix application environment. We chose stand alone routing machines for our facility . | I'm interested in your input for better ideas for Fixturing. | | Until now I've got by with simple fixtures made of fenaboard (tufnel) which are located onto an aluminium base plate via 1/4" dowel pins & bushings. Onto these fixtures I inserted hardened steel pins which would locate the panels via non- plated holes . I believed this to combat movement in X & Y directions when depanelising. To combat movement in the Z- axis we have a brush insert connected to our spindle housing (for vacuum purposes also )to exert a downward pressure on the panel. | | This said , I still encounter problems with panels moving during the routing cycle , mostly in the Z-axis ; but also to a lesser degree in X & Y directions. We do not have any overhanging components on our panels interfering with the cutting path. Ideally I would love to be able to use a pressure foot ; but my information is I can't utilise this because I'm routing populated panels. I have 2 tooling pins in each single unit and a few extra on the outside "web scrap section" yet still I encounter movement. I get my pins made 0.002" smaller than the size of the hole . My spindle speed is fixed @ 24000 rpm and I'm routing FR4 @ a feedrate of 80 inch/min approx . My main concern is the movement in the Z-axis .Is there any type of pressure foot applicable to populated panel routing? | | All feedback shall be welcomed with open arms. I realise that to engineer some solutions may be expensive; but if I like the sound of any of them , price may not be an option. | | look forward to your response , thanks in advance , | | Best Regards , | | Paul . (Based in Scotland , U.K.) | | Paul,

A company called Transition Automation makes vacuum fixtures for double sided boards. They actually (I believe) thermoform them around a populated board, and then add a base tooling plate and vacuum cups. The fixture itself prevents X & Y movement, but the vacuum hold down prevents Z-axis as well.

The intended purpose of these tooling plates is screen printers, but they work well in CNC routers. We used them once for a fixutre on a hard-to-hold board for our router. Their number is 978-670-5500.

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