Pantograph for PCB engraving (and more) - Page 1
Forum section: electronics / projects

author: randomtronic
author_rank: Contributor
timestamp: February 26, 2017, 10:49:59 pm
content: I just completed a project i'd like to shareThere is still some development/improvements to be made, but it is functional as it is right now.The idea was to be able to engrave PCB's without a CNC (too expensive for now), so inspired by one woodworking channel, I made a pantograph.First video is a virgin test of the device, at that time I didn't have the right engraving bit, so the edges are very rough. In the second video I have the carbide engraving bits already, and result is much cleaner.I am planning on improving on this design as I go along, but so far it is a lot of fun to be making things by hand using this device!

author: ale500
author_rank: Frequent Contributor
timestamp: February 28, 2017, 11:04:42 am
content: Very nicely done !

author: Cerebus
author_rank: Super Contributor
timestamp: February 28, 2017, 01:06:38 pm
content: Quote from: randomtronic on February 26, 2017, 10:49:59 pmViewed one way that looks terrible, but viewed another it looks fantastic. It makes it look like Robert Crumb has got into PCB layout - just needs a logo of Mr Natural in the corner.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: February 28, 2017, 03:42:22 pm
content: That is a good prototype tool for proving a circuit. It is not the first time that I have seen a pantograph used in this way, however, but then again, I am old and have seen a lot. Very cool, good job!I was toying with the idea of converting a printer with a flat bed into printing a circuit drawing directly onto the copper and then etching, allowing the ink to stay on while etching. Has anyone ever seen this done? The chemical would etch all the copper away except that which has ink, which would leave the traces and pads untouched. I have an old pen plotter that I was going to use for this experiment, but I have not gotten around to it yet.What do you guys think? Would it work or not?

author: elecman14
author_rank: Unknown
timestamp: February 28, 2017, 04:06:21 pm
content: Quote from: tpowell1830 on February 28, 2017, 03:42:22 pmI looked into converting a printer a few years back. A yahoo group existshttps://beta.groups.yahoo.com/neo/groups/Inkjet_PCB_Construction/info?referrer=rtdos_this_group_moved_to_msnand also you may want to look at this:http://techref.massmind.org/techref/pcb/etch/directinkjetresist.htm.At the time I was tempted to get a HP plotter for this but the pens were just to fiddly and dried out.I have not seen anyone do it but I wonder if it would be possible to do something similar with the cheap laser engravers coming out of Asia. My thoughts are get some bulk toner and somehow coat copper clad with it. "Engrave" your resist and then clean the board with something to remove the unfused toner. Finally etch the PCB. Not really sure if that has been done before but that would be kind of neat. Maybe someday I will try this out. Probably should build a fume hood first since that toner is not that good to inhale.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: February 28, 2017, 04:20:08 pm
content: Quote from: elecman14 on February 28, 2017, 04:06:21 pmYes, I had the same idea back in the '90s when I worked for a company that had many lasers. I was often involved with setting them up and I tried this method. I would spray the copper with Dykem and the attempt a laser burnoff of the ink. Unfortunately, there was not enough time to completely explore this possibility on company equipment, because the goal was to get the equipment into production ASAP. This equipment in the '90s was cutting edge and very expensive. On the few coppers that I had minimal success actually etched okay.I have not looked at prices for any lasers because I guess I was in the paradigm that lasers were way too expensive for this type of project, i.e. may as well setup as a professional PCB shop.

author: elecman14
author_rank: Unknown
timestamp: February 28, 2017, 04:39:31 pm
content: @tpowell1830 Thanks for the feedback on that. Do you remember if you were using the Blue or Red Dykem (or maybe another color, machinists have it good these days)? Also any idea how powerful the laser was?My thought was to use a DVD burner laser. A small engraver setup runs < $100 USD.http://www.dx.com/s/laser+engraverWould probably be useful for smaller PCBs and breakout boards.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: February 28, 2017, 05:56:24 pm
content: Quote from: elecman14 on February 28, 2017, 04:39:31 pmI had access to a machine shop which had the blue Dykem, fortunately. The lasers were varying type yag, CO2, hene, with varying power from 5 watts to 100 watts. The power was somewhat adjustable, so I didn't want burn into the fiberglass (which I did the first try). I am not sure how the power was adjusted, but I believe that it was in the speed of the sweep of the beam. The faster the beam swept across, the less power was applied. The beam output was a fixed power, so the adjustment was in the time spent on each surface area.If there is an inexpensive laser that has a movable beam, i.e. such as a moving mirror that can etch a pattern accurately and is strong enough to vaporize the ink, it could work. The mirror could dither for short distances, but an X-Y table setup would be needed to move the board under the beam for even small to medium size boards.I think the DVD laser may work, but would be slow and probably would not live long in that environment. Thanks for the info.

author: MLXXXp
author_rank: Frequent Contributor
timestamp: February 28, 2017, 06:25:30 pm
content: For removing large areas of copper, I suggest you route only around the edge of the area, then use a knife to lift an edge of the copper, grip it with tweezers or pliers and peel it off.