LPKF rivets for via's etc

[charliex]

Did a quick test with the smallest LPKF EasyContac rivets. Made all the via drill holes 31mil.

[Jay C]

Can I ask where you got the EasyContac and how much you paid?

[charliex]

Surely, LPKF usa store, $92 for 1000 (of each size!) rather than buy the whole kit, i just bought the rivets and automatic center punch

i chucked some more pictures on my blog, with links http://charliex2.wordpress.com/2010/...sycontac-test/

[eSilviu]

Sorry to say, but I'm dissapointed about them: from yours other pictures, it seems that when you punch them, there is a big chance to break small traces to (or next) that vias.

[charliex]

its possible, but that didn't happen for me with 30 or so, the camera makes it look they're cut when they're shadowed plus i over cut those traces a little.

the bad one i did do was not align the punch and via correctly and that caused a short, but i just removed the copper.

you just have to design the board with them in mind.


also the center punch is designed to only come in contact with the rivet portion, i think you're seeing the roundish areas around the via's, that is just the way it looks on the camera after it comes off the cnc machine, if you look on the next page on my web thing at the microscope pages you can see the same board without via's that has those round markers. you can also set the power on the punch, to make them more flush you do enough force to fire the automatic punch, but you don't have to do that, its enough just to push on them. to much force and it dimples a bit, i need some practice finding the sweet spot.

[charliex]

captured a video of the software as i made one of those boards, thought it might be interesting.

YouTube- AccurateCNC test bus Pirate

YouTube- AccurateCNC test bus Pirate

the video based fiducial registration is visible.

[Jay C]

Interesting ... and confusing There was no audio or anything to explain what was flashing by on the screen. Also, did you speed up the screen capture portions by x 2?

The interesting part was the software ... very cool going from layout to video overlay. I assume that you were calibrating the flipped board's position?

[charliex]

I think it looks like its sped up because i cut some of parts to make it shorter, otherwise its all real time as i did it.

Next time i'll video the software and cnc at the same time so its in sync.

So i cut one side of the board, check the tracks are ok with the video camera, , drill the holes, check again then flip the board over, then i use the fiducial registration mode to align the backside of the board.

you find a hole on the PCB, align it with the red crosshair, then move the mouse to where it is in the gerber schematic, right click on the yellow cross hair and move it to the first point, then repeat for a second hole so it can move and rotate. The second point i set, then set again with a different hole.

then you can see me moving around checking that holes are lined up.

finally its a router cut


unfortunately since youtube scales it to fit in a window, it lose some of the vertical resolution and its hard to read the menu

[charliex]

I added some annotations to the video.

[Jay C]

Originally Posted by charliex you find a hole on the PCB, align it with the red crosshair, then move the mouse to where it is in the gerber schematic, right click on the yellow cross hair and move it to the first point, then repeat for a second hole so it can move and rotate. The second point i set, then set again with a different hole. then you can see me moving around checking that holes are lined up. finally its a router cut

That's what had me confused.You aligned the upper right hole and never got the red and yellow "exact". Then you moved to another hole on the right side and realign but still never got them exact. Is it a PITA to align them, or was this just a proof of concept?

I'll re-watch the vid.

[charliex]

The software won't let you align if its impossible to be there as referenced from the first point. So thats whats going on there. you're looking at a few mils difference. I redid the second point, the board itself lines up.

its pretty easy to do, find the hole, move the gcode, find the second, move and rotate (which the software does for you)