Just a note that you can tweak the size of the cream layer in Eagle to compensate for the laser cutting a little big. The setting is in the DRC under the Mask tab.
Yeah, I had it quite low in power and 100mm/s is quite fast as you can see in the video. I actually thought It would fail to cut that low, but it was perfect it seems. The few holes that were not cut fell out when I touched them :-)
If you import the pdf into illustrator you can rescale all elements to 80%, while in object centre mode and it will keep the position of all the elements the same and shrink the dimensions slightly. I find 100% tends to put a little more paste than you need down. I also fill the shapes and use raster rather than vector and it works a little better for close together pins on ICs.
Hey Tim. Yeah my current stencils I ship with my Neo7Segment kits have the pad sizes reduced to 90%. There are no fine pitch devices on these boards, so no need to reduce more, but I agree that shrinking the pads is super important! I'd not thought of going raster instead of vector.... interesting, thanks for the suggestion!
3 suggestion 1. speed up the laser speed. 2. make the hole data smaller (calculate the heat expand of the plastic) 3. try engraving with that laser, ussualy engrave making less heat than cutting act.
im trying to find 3 or 3.5 mil thick milky smooth mylar. That's 75-100 microns thicky. No luck. 😕 Big rolls for big money is all or special order costs. Ill never get a kit made, thinking of giving up.
Cool idea But does it work for spreading the paste well, or does the weaker mylar bend and move as you apply pressure from pasting? Damn I need a big laser cutter! I think I'd cut me dinner with it!! Steve
That is my next step... to see if I can use it to lay down the paste. I think it will hold up fine for 1 or 2 uses as it is quite firm, assuming it's taped down well, but it definitely wont last for too many.
Just a note that you can tweak the size of the cream layer in Eagle to compensate for the laser cutting a little big. The setting is in the DRC under the Mask tab.
Oh, I didn't know that, thanks! I actually shrunk it down inside Lightburn, my laser cutting software but i wont have to do that next time :-)
Nicely done Seon, I thought the laser cutter would melt the mylar, but it came through like a champ. Regards, Dave
Yeah, I had it quite low in power and 100mm/s is quite fast as you can see in the video. I actually thought It would fail to cut that low, but it was perfect it seems. The few holes that were not cut fell out when I touched them :-)
If you import the pdf into illustrator you can rescale all elements to 80%, while in object centre mode and it will keep the position of all the elements the same and shrink the dimensions slightly. I find 100% tends to put a little more paste than you need down. I also fill the shapes and use raster rather than vector and it works a little better for close together pins on ICs.
Hey Tim. Yeah my current stencils I ship with my Neo7Segment kits have the pad sizes reduced to 90%. There are no fine pitch devices on these boards, so no need to reduce more, but I agree that shrinking the pads is super important! I'd not thought of going raster instead of vector.... interesting, thanks for the suggestion!
That is very cool! I will have to keep that in mind!
Perfect excuse to get a laser cutter right? ;)
I mainly use it to make enclosures.
I wouldn't mind doing 3d art with it!
3 suggestion
1. speed up the laser speed.
2. make the hole data smaller (calculate the heat expand of the plastic)
3. try engraving with that laser, ussualy engrave making less heat than cutting act.
Glad it worked!
What is the format of the file? plt ?
Good job. Well done. Alot better than the one jlpcb gave you.
Ha! Thanks Gary! I have my new one from JLCPCB already... I might do some tests on the weekend :-)
im trying to find 3 or 3.5 mil thick milky smooth mylar. That's 75-100 microns thicky. No luck. 😕 Big rolls for big money is all or special order costs. Ill never get a kit made, thinking of giving up.
Yeah, I never had any luck finding super thin mylar. The stuff I am using (rarely) is "ok", but not ideal.
Nice! Do you think a 20W laser "marking" machine will do the job?
I'm really not sure, sorry. I've never used one.
First go! You beauty!
Yeah, what a perfect guess on the speed & power. No evidence of edge melting at all... but not sure how durable they'll be :(
Cool idea But does it work for spreading the paste well, or does the weaker mylar bend and move as you apply pressure from pasting?
Damn I need a big laser cutter! I think I'd cut me dinner with it!!
Steve
That is my next step... to see if I can use it to lay down the paste. I think it will hold up fine for 1 or 2 uses as it is quite firm, assuming it's taped down well, but it definitely wont last for too many.
Unexpected Maker yeah that's what i thought - like a 'one time use' for the kits would be great. Can't your laser cut thin aluminium?
I don't think so. I'd need something much stronger than 40W for that... Maybe 80 or more likely 100W I think.