EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: praveen_khm on January 17, 2014, 09:02:54 am
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Hi,
I develop pcb's and getting SMT stencil's are a pain. I was planning to invest on a good laser cutter which can cut thin steel sheets (for stencils), acrylic and wood. Can someone suggest a good laser cutter and approximate price.
Since I do not intend to do large production, I am looking for a less expensive one. All suggestions are welcome.
Thanks,
Praveen
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Budget ?
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Cutting steel with a CO2 laser (aka low cost laser) might be a bit too much to ask. Although you might get away with it at really high powers (>100W), at 10 micron wavelength steel is just a great big mirror. You really need an Nd:YAG laser for this sort of application. But then again, cutting wood and plastics is best done with CO2. They are quite different applications.
If you aren't worried about having to replace/fiddle with the controller yourself, I know of a few people who have bought a CO2 laser on Alibaba and had it shipped over for not too bad a price. Expect to pay minimum ~$50 000 for an Nd:YAG cutter (unfortunately they don't often make them small) and anywhere from $800-$50 000 for a CO2 laser depending on the bed size and optics (also brand!). Keep in mind that $800 is the low of the low end!
I also have a friend who has tried to do mylar/kapton stencils on a CO2 laser, he tells me that it melts a bit too much and you lose a lot of definition and accuracy on your cuts.
You will also need air filtration system for a lot of materials and a water chiller for cooling.
Have you tried doing stencils on a vinyl cutter? I have heard that it works surprisingly well.
Hope this helps.
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There's a good AmpHour (#153) that discusses kapton stencils with Ryan O'Hara. He discusses CO2 vs others for kapton.
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Laser has the cool factor, but people have good success using silhouette cutters, see this thread at dangerous prototypes...
http://dangerousprototypes.com/forum/viewtopic.php?f=68&t=5341 (http://dangerousprototypes.com/forum/viewtopic.php?f=68&t=5341)
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Thanks for the suggestions. Appreciate it.
Budget is around $2K-3K. I am planning to start stencil making business. If acrylic cutting is also in the list, would be added advantage. But if I need to purchase two cutters for two applications, then need to rethink.
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Laser has the cool factor, but people have good success using silhouette cutters, see this thread at dangerous prototypes...
http://dangerousprototypes.com/forum/viewtopic.php?f=68&t=5341 (http://dangerousprototypes.com/forum/viewtopic.php?f=68&t=5341)
That would be a cool thing to have. You can apparently scan a full-size image of your board and create a stencil on mylar. Do you have any experience with it?
I'm also looking for some sort of X-Y milling machine to cut prototype boards. Having both here at hand would make prototyping much easier but I'm not sure if that is actually cheaper and more practical than sending out for them.
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Have you tried these guys for stencils
http://www.oshstencils.com/ (http://www.oshstencils.com/)
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Laser has the cool factor, but people have good success using silhouette cutters, see this thread at dangerous prototypes...
http://dangerousprototypes.com/forum/viewtopic.php?f=68&t=5341 (http://dangerousprototypes.com/forum/viewtopic.php?f=68&t=5341)
That would be a cool thing to have. You can apparently scan a full-size image of your board and create a stencil on mylar. Do you have any experience with it?
I'm also looking for some sort of X-Y milling machine to cut prototype boards. Having both here at hand would make prototyping much easier but I'm not sure if that is actually cheaper and more practical than sending out for them.
On the CNC: Unless you have purely single sided SMD board, it can be a bit tricky. Not impossible, but it takes a lot of work to get your process down. Also at fine pitches (6-8mil and below) you will probably need some better than average mechanics (proper linear guides/ballscrews), a vacuum hold down system and a drill head that presses against the FR4 blank to keep it flat. I've looked inside a few high end PCB milling machines, and all of the mechanics was THK (search ebay for an idea of how much this kind of stuff costs).
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You will not cut metal stencils on a cheap CO2 laser cutter - you'd be well into 5 figures for that.
You can do plastic ones on a low power CO2 if it's set up carefully, but if stencils are your main requirement, definitely look into the Silhouette Cameo vinyl cutter - people have had good results using it for plastic. stencil cutting
I bought one recently but not yet tried stencil cutting - I was using it to mock up a wierd PCB outline.