cubeberg 540 Posted June 26, 2013 Author Share Posted June 26, 2013 Sorry for the length on this one (~3min) - but here's a youtube video of the plotter drawing the 43oh logo. abecedarian, spirilis, semicolo and 3 others 6 Quote Link to post Share on other sites
semicolo 39 Posted June 28, 2013 Share Posted June 28, 2013 Nice, the drawing is quite slow compared to the speed when the pen is up, is it because of all the small lines, or does it miss steps if going faster when the pen is dragging? cubeberg 1 Quote Link to post Share on other sites
cubeberg 540 Posted June 28, 2013 Author Share Posted June 28, 2013 Nice, the drawing is quite slow compared to the speed when the pen is up, is it because of all the small lines, or does it miss steps if going faster when the pen is dragging? Yeah - it's due to the small lines. Everything is interpolated, so there are thousands of commands coming from the computer. I'm going to try FTDI or another USB->Serial adapter and a higher baud rate - but I'm also going to probably add rounding in code as well to reduce the # of characters being transmitted. Removing the extra decimal places will cut transmission data almost in 1/2. I could probably try batching coordinates as well. I'll probably still have to play with stepping speed when the pen is down - I had some longer lines that I was drawing without multiple points and there were some skips in the ink. Quote Link to post Share on other sites
Fred 453 Posted June 28, 2013 Share Posted June 28, 2013 I was about to put your gcode through my CNC mill and mill the track-like logo onto a piece of copper clad board (after scaling it down by a factor of 100!). I got sidetracked. Anyway, it would have been a little unfair tempting your CNC addiction - like waving crack under a junkie's nose. ;-) Quote Link to post Share on other sites
cubeberg 540 Posted June 28, 2013 Author Share Posted June 28, 2013 I was about to put your gcode through my CNC mill and mill the track-like logo onto a piece of copper clad board (after scaling it down by a factor of 100!). I got sidetracked. Anyway, it would have been a little unfair tempting your CNC addiction - like waving crack under a junkie's nose. ;-) LOL - I've got my wife talked into a Printrbot when we get the money. I've been drooling over one of those for a while. Makerbots are impressive - but way too much $. I'd imagine a CNC wouldn't be cheap either Quote Link to post Share on other sites
davebranton 11 Posted July 1, 2013 Share Posted July 1, 2013 @@cubeberg Fantastic project, and impressive results. I wonder if you would be better off transmitting the co-ordinates in binary rather then text too? That might improve your bandwidth. I have a few questions if you'll permit me: 1) How much current do the motors draw? 2) How have you implemented the z-axis? 3) What kind of pen have you used? Have you experimented with others? Biro vs. a felt-tip for instance? Quote Link to post Share on other sites
cubeberg 540 Posted July 1, 2013 Author Share Posted July 1, 2013 @@cubeberg Fantastic project, and impressive results. I wonder if you would be better off transmitting the co-ordinates in binary rather then text too? That might improve your bandwidth. I have a few questions if you'll permit me: 1) How much current do the motors draw? 2) How have you implemented the z-axis? 3) What kind of pen have you used? Have you experimented with others? Biro vs. a felt-tip for instance? Dave, I'll check out the current draw tonight - I updated the C# code today to only provide whole numbers (so 4 characters per axis instead of 9 - XXXX.XXXX). I'm hoping to stick with g-code compatibility - increasing baud rate to 115200 will probably help. I'm thinking of using an bluetooth booster configured for that baud rate - I can set it up to be a build flag, or something that could be set at runtime - but I did consider it. Using hex values instead would be quicker - plus I'd save the time of converting from string -> integer. Yes - Z-axis is working. It's held together using poster-putty right now - so it's not the final solution - although it does provide a little give which keeps the pen in clean contact with the paper. I'm using a set of 0.3mm "porous point pens" - I'm hoping to look for some 0.1mm pens the next time I got to the store, and I'm planning on testing some others as well - pencil, ball point, etc. The felt tip bleeds a bit, but hopefully a speed increase will help. Minimizing contact time with the paper should decrease the size of the line. My wife is working on her book for the next week, so I will hopefully be posting some updates tonight! Quote Link to post Share on other sites
cubeberg 540 Posted July 1, 2013 Author Share Posted July 1, 2013 Also on order is a way to adjust the z-axis from the PC - right now it has to be set manually and then the MCU must be reset. Quote Link to post Share on other sites
cubeberg 540 Posted July 2, 2013 Author Share Posted July 2, 2013 Looks like they take about 2A - I saw some peaks around 2.1, but my multimeter - that's with all 3 steppers enabled, although I never run Z at the same time as X and Y. I was able to get bluetooth working @ 115200 - didn't seem to hugely improve step speed. It's capable of being fully wireless though, when I'm not updating code. I'll have to take a look at the MCU code to see if there's something slowing me down there. I could probably make my stepping speed quicker when the pen is down as there's a lot more going on there and calculations eat up some of the time between steps. I'm going to try to get some of this put into a more permanent setup - I've got a bunch of it on a breadboard in a box and I hook up the steppers when I'm read to test. I've got space under the setup though to house the electronics. Ready to do that now since the hardware is pretty much set. Quote Link to post Share on other sites
cubeberg 540 Posted July 2, 2013 Author Share Posted July 2, 2013 For those who are interested - the code is all available on Github now. I'll continue to post updates there. MSP430 - https://github.com/cubeberg/MSP430_3Axis C# Windows App (.Net 4.5) - https://github.com/cubeberg/430SerialGCodeTransmitter bluehash 1 Quote Link to post Share on other sites
cubeberg 540 Posted July 2, 2013 Author Share Posted July 2, 2013 Was googling about using pencils with plotters today - ran across this - http://interlockroc.org/2012/02/24/pencil-plotting/. Apparently they make self-advancing mechanical pencils. Might be a good way to get some really fine detail. I'll have to check Target to see if they sell these. tingo 1 Quote Link to post Share on other sites
Donny M. Carter 2 Posted July 3, 2013 Share Posted July 3, 2013 @cubeberg, very cool project! cubeberg 1 Quote Link to post Share on other sites
cubeberg 540 Posted July 3, 2013 Author Share Posted July 3, 2013 @cubeberg, very cool project! Thanks! Even better that it was almost free My kids think it's awesome since I've been making all sorts of things for them - the wife isn't overly impressed though Quote Link to post Share on other sites
semicolo 39 Posted July 3, 2013 Share Posted July 3, 2013 Yeah women that understand all the beauty of an axis moving thanks to a stepper are rare. cubeberg 1 Quote Link to post Share on other sites
semicolo 39 Posted October 4, 2013 Share Posted October 4, 2013 I'm finishing putting together my first 3d printer and attached a pen to make a test: http://youtu.be/t81QYGiyXX4 GeekDoc and cubeberg 2 Quote Link to post Share on other sites
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