why not just shift g 56? i do this all the time to match moldlines etc , i think that the simplest solution is often best
PRIVACY NOTICE: Warning - any person and/or institution and/or Agent and/or Agency of any governmental structure including but not limited to the United States Federal Government also using or monitoring/using this website or any of its associated websites, you do NOT have my permission to utilize any of my profile information nor any of the content contained herein including, but not limited to my photos, and/or the comments made about my photos or any other "picture" art posted on my profile. You are hereby notified that you are strictly prohibited from disclosing, copying, distributing, disseminating, or taking any other action against me with regard to this profile and the contents herein. The foregoing prohibitions also apply to your employee , agent , student or any personnel under your direction or control. The contents of this profile are private and legally privileged and confidential information, and the violation of my personal privacy is punishable by law. UCC 1-103 1-308 ALL RIGHTS RESERVED WITHOUT PREJUDICES jeremy youngs On Thu, Aug 8, 2013 at 2:19 PM, Jan de Kruyf <[email protected]> wrote: > tangent of 1 degree is 0.0174550649282. > > So if there was a 1 degree error on your milling machine and a 1 degree > error on the cutting of the pcb, the offset from flipping would be > 0.0349101298564 inch per inch boardwidth. > > Just as an example. I am not saying this is the case at all, but at the > same time I would be very suspicious. > > I have made a similar error before in my life. I was doing acceptance tests > on a big machining centre and > the machine gave a few hundreds of a mm error compared to the calibrated > bar on the table used for checking. > > That is, until it dawned on me that it was summer and the workshop > temperature was in the 90's and the scale was glass (Heidenhain) and the > rod was steel. And a few quick sums on a piece of scrap paper relieved my > anguish. > > Good luck > > j. > > > > > > On Thu, Aug 8, 2013 at 7:29 PM, Troy Jacobson <[email protected]> wrote: > > > Gene, > > I've been starting to think about how I want to mill double sided pcbs, > and > > have been trying to figure out how to avoid problems like this. > > > > Is the size of your PCB blank causing an offset when it is rotated? It > > seems to me that the point around which the coordinates are rotated need > to > > be in the exact center of the PCB, or at centered between the two > relevant > > edges depending on the type of rotation/flip being done. If you were to > > drill a hole at that place, it should be half the board size away from > the > > edges of the pocket. > > > > When calculating the coordinates for a rotate or flip, are you using the > > same point for all files associated with the board? > > > > > > > > On Thu, Aug 8, 2013 at 10:53 AM, Jan de Kruyf <[email protected] > > >wrote: > > > > > Gene, > > > I would say, after reading through your code and looking at the > pictures > > of > > > your setup, that perhaps your table is not as square as you like to > > > believe; and at the same time the pc board you were trying to drill is > > not > > > as square as you believe. > > > Then when you flip it, it will not be in the exact same position on the > > > table, because the skewness that fitted perfectly into the jig first > time > > > around, causes a gap at the top or at the bottom (as you see it, along > > the > > > Y axis) for the bottom-up run. Or the other way round. > > > > > > With a perfectly right-angled pc-board that would not happen, but who > > makes > > > those? > > > > > > Try running a very thin feeler gage along the left edge with the board > in > > > both positions and see if it does not go in at the top or at the > bottom. > > > > > > To prove the squareness of yr table, mill a square or rectangular plate > > > (perhaps screw it down in the middle with 2 screws into the T-slot) and > > > machine a perfectly round hole in it somewhere (reamer?) perfectly in > the > > > middle would be nice, but again that is difficult to archieve. Then put > > it > > > in your jig, and clock on the hole with your fancy rotating probe and > > your > > > program. > > > Then flip the plate and clock again. I bet you will find the same > > > registration error as you find now. > > > > > > And here is a last thought: > > > After you have worked out the unsquareness of your machine you can > write > > a > > > kinematics routine to adjust for it, and then polish up the pcb jig so > > this > > > does not bother you ever again. > > > > > > Cheers, > > > > > > j. > > > > > > > > > > > > > > > > > > On Thu, Aug 8, 2013 at 12:05 AM, Gene Heskett <[email protected]> > wrote: > > > > > > > Hi all; > > > > > > > > I have a very small error, perhaps .010" in the top vs bottom hole & > > > > pattern placements. > > > > > > > > Unless someone can convince me that pcb2gcode has a built in error in > > > its Y > > > > calc's for the bottom of the board, the error is mine, darnit. > > > > > > > > Background: The eagle .brd file I was sent is arranged such that the > > > board > > > > is bigger in Y then in X. > > > > > > > > However, in building a pallet to hold the board I much prefer to have > > the > > > > board pattern laying long ways with the X axis. > > > > > > > > So, I wrote, and it has worked fairly well, for several projects > based > > on > > > > the first pallet I made for the lathes spindle encoder a holefinder > > > routine > > > > to establish a known location on the pallet, just off the upper left > > > corner > > > > of the board, a short piece of 1/8" brass tubing, superglued in place > > and > > > > connected the the LCNC probe input pin. Then I made, from a sewing > > > needle > > > > threader, a probe I can put in a 1/8" collet, with the wire shaped > > like a > > > > sharp speer. > > > > > > > > I have a .1 uf cap on the probe circuit which captures and holds any > > > > momentary contact the probe wire makes to the inside of the mouth of > > the > > > > tubing, holding it long enough for LCNC to grab it. The facilitate > > LCNC > > > > seeing the probe wire as a perfect cone, the spindle is running about > > > 1800 > > > > rpm while this probing is going on. > > > > > > > > Basically it lowers the spinning wire into the hole until first > contact > > > is > > > > detected, then raises the spindle 20 thou for clearance, then moves > > first > > > > the x, capturing #5061 into 2 vars as it moves to detect the tubing, > > > first > > > > left, then right. It adds those two, and divides by 2, then runs x > to > > > the > > > > mathematical center. Then it does the same with the Y axis, > captureing > > > > #5062 into fronty and backy vars, does the same /2 and runs the > mills Y > > > to > > > > that center. Once its done that, it applies the detected offsets to > > the > > > > G55 and G56 maps, which are then used by the rest of the code > depending > > > on > > > > whether its for the top (G55) or bottom (G56) of the board. The > bottom > > > > however has an offset added such that running the bot.drill file > should > > > > result in holes drilled halfway through the board that meet in the > > > middle. > > > > > > > > But, both G55 and G56 are also rotated with an R270 at the end of the > > G10 > > > > L2 P# statement in this code. > > > > > > > > What I am getting when I drill 5 thou into the board running the two > > > drill > > > > files from pcb2gcode shows a dead on registration has been achieved > > with > > > > the offset as applied to only the G56 map. > > > > > > > > The board is being flipped along the x axis, so the same end of the > > board > > > > is always wedged via the hold-down screws against the left side of > the > > > > milled pocket, so I can't see that as a source of error here. > > > > > > > > But, I have an offset of perhaps .012" in the drilled Y positions > after > > > the > > > > 270 rotation rotation to convert it to my mills real X axis. > > > > > > > > Could this be an artifact of a small error in the fudgex and fudgey > > vars > > > at > > > > the top of the file that you can see on my web page in the > > > > Genes-os9-stf/LCNC link? These are the actual locations of this > brass > > > > tube, with reference to the assumption that as I see it on the mills > > > table, > > > > of the exact 0.0, 0.0 upper left corner of the pallet's board pocket. > > > > Supposedly. On the previous pallet, I established a 0,0 location > then > > > > moved .2 left and .1 below and drilled the hole for the brass contact > > > pipe, > > > > this time I got ahead of myself and milled the pocket, then installed > > the > > > > pipe, unforch after the 0,0 had been lost due to re-homing the > machine > > > the > > > > next day. > > > > > > > > Because there is nothing to reference at that location since its an > > > inside > > > > corner, and I ran the mill making that pocket, out at the correct > angle > > > to > > > > serve as clearance for the sharp corner of the board, its not > > something I > > > > can measure and easily verify. > > > > > > > > I am ATM, fresh out of ideas, and somewhat confused in trying to > trace > > > the > > > > error because I am using the G55 and G56 mapping to rotate the > pattern > > as > > > > it is seen on the mills table. > > > > > > > > So if some kind soul could look at this "tholefinder.ngc" file at the > > > above > > > > link & suggest how to proceed in removing this error, I'd be most > > > > appreciative. > > > > > > > > Cheers, Gene > > > > -- > > > > "There are four boxes to be used in defense of liberty: > > > > soap, ballot, jury, and ammo. Please use in that order." > > > > -Ed Howdershelt (Author) > > > > My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! > > > > My views > > > > <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> > > > > I put up my thumb... and it blotted out the planet Earth. > > > > -- Neil Armstrong > > > > A pen in the hand of this president is far more > > > > dangerous than 200 million guns in the hands of > > > > law-abiding citizens. > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > > Get 100% visibility into Java/.NET code with AppDynamics Lite! > > > > It's a free troubleshooting tool designed for production. > > > > Get down to code-level detail for bottlenecks, with <2% overhead. > > > > Download for free and get started troubleshooting in minutes. > > > > > > > > > > http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk > > > > _______________________________________________ > > > > Emc-users mailing list > > > > [email protected] > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > Get 100% visibility into Java/.NET code with AppDynamics Lite! > > > It's a free troubleshooting tool designed for production. > > > Get down to code-level detail for bottlenecks, with <2% overhead. > > > Download for free and get started troubleshooting in minutes. > > > > > > http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk > > > _______________________________________________ > > > Emc-users mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > > > ------------------------------------------------------------------------------ > > Get 100% visibility into Java/.NET code with AppDynamics Lite! > > It's a free troubleshooting tool designed for production. > > Get down to code-level detail for bottlenecks, with <2% overhead. > > Download for free and get started troubleshooting in minutes. > > > http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > ------------------------------------------------------------------------------ > Get 100% visibility into Java/.NET code with AppDynamics Lite! > It's a free troubleshooting tool designed for production. > Get down to code-level detail for bottlenecks, with <2% overhead. > Download for free and get started troubleshooting in minutes. > http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
