- Tue May 15, 2012 10:28 pm
#144574
I started using a Sable 2015 CNC machine to make PCBs.
Good enough resolution and accuracy for me and beats waiting X number of days for a PCB to get made.
http://www.youtube.com/watch?v=JcnumN8LPYg
Problem/Issue:
I built a "vacuum table" to hold down the PCBs rather than using clamps, screws, etc.
Works great on double sided PCBs. The copper holds down solid. I can't pry it off with my fingers and it doesn't move at all during machining.
Problem happens when I'm using single sided PCBs. The fiberglass/phenolic side won't stay down nearly as well as the copper side. I figure it's because of all those little ridges created by the fiberglass itself, all coming together to leak air.
I don't have any good ideas as to how to hold it down. Lots of silly ideas, no good ones. I've tried double sided stick tape which tends to pull up some of the MDF. Thought about spraying the back of the PCBs with a polyurethane, letting it dry, then sticking it on, but figure the poly would kinda soak into the MDF and cause it to swell up, thereby ruin the flatness. Tried using electricians tape, scotch tape, packing tape, etc, to seal the bottom of the blank PCB as well as going around the edges. No dice.
Any other swell ideas?
Good enough resolution and accuracy for me and beats waiting X number of days for a PCB to get made.
http://www.youtube.com/watch?v=JcnumN8LPYg
Problem/Issue:
I built a "vacuum table" to hold down the PCBs rather than using clamps, screws, etc.
Works great on double sided PCBs. The copper holds down solid. I can't pry it off with my fingers and it doesn't move at all during machining.
Problem happens when I'm using single sided PCBs. The fiberglass/phenolic side won't stay down nearly as well as the copper side. I figure it's because of all those little ridges created by the fiberglass itself, all coming together to leak air.
I don't have any good ideas as to how to hold it down. Lots of silly ideas, no good ones. I've tried double sided stick tape which tends to pull up some of the MDF. Thought about spraying the back of the PCBs with a polyurethane, letting it dry, then sticking it on, but figure the poly would kinda soak into the MDF and cause it to swell up, thereby ruin the flatness. Tried using electricians tape, scotch tape, packing tape, etc, to seal the bottom of the blank PCB as well as going around the edges. No dice.
Any other swell ideas?
I ignore "one post wonders".