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Robot Arm Printer Project — Parallax Forums

Robot Arm Printer Project

ercoerco Posts: 20,255
edited 2012-04-22 13:17 in Robotics
A strange little robotic project I hope to have finished for expo. 3-servo arm writes characters on a Post-It note. Goal is to let kids & grupps type in their name & print it out. Gotta keep up with the S2 printer boys, but low-tech. Just started programming tonight, drawing simple grids & boxes here. Double polar coordinate joints give a funky skewed look to printed material. I like it.
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Comments

  • ercoerco Posts: 20,255
    edited 2012-04-03 01:23
    Speaking of funky printing devices, check out this symphony of solenoids:
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-04-03 02:39
    Excellent work, Captain Erco!!! The skewed font for the arm printer adds a distinctive flair and it's a treat to watch it work!

    As for the typewriter hack, that's a total mechanical joy to behold. If you could "Charlie-plex" the solenoid matrix, it seems like that would be a piece of cake for a Propeller. The hardest part could be building a sturdy solenoid frame and then finding a typewriter. Oops, I mean something like that would be impossible to do with a Prop!
  • Martin_HMartin_H Posts: 4,051
    edited 2012-04-03 06:14
    Another neat project. The double polar gives it a Dali-esque aesthetic.

    Not to beat a dead horse, but inverse kinematics could convert from rectangular to double polar no problem. With only two joints that might be within the computational power of a BS2. Since the device is constrained to a narrow range of angles you'll avoid negative numbers which make trig on the BS2 much harder.
  • ercoerco Posts: 20,255
    edited 2012-04-03 08:25
    My printer is bipolar! Thanks for the good words.

    I'll leave IK to the Prop or coprocessor wizards. It remains to be seen how jaggy diagonal lines will be, moving both servos simultaneously. That may take some tweaking. I suspect this printer's strong suit will be the smooth "straight" arcs moving just one servo at a time, shown here. Besides, I need the simplest font and print routine. It's likely that the BS2's 2K memory will be chock full just holding data to draw 26 letters. Dare I dream of including numbers, too? :)

    Sample font shown.
    fontastic.JPG
    450 x 200 - 12K
  • davejamesdavejames Posts: 4,047
    edited 2012-04-03 09:03
    erco wrote: »
    Speaking of funky printing devices, check out this symphony of solenoids...

    I remember that!!!

    A perfect example of DWYGD!


    I will be looking forward to seeing the robo-arm at UPEW.
  • PublisonPublison Posts: 12,366
    edited 2012-04-03 09:18
    @erco,

    Massive kudos.

    You officially CAN quite you day job. :)

    Jim
  • doggiedocdoggiedoc Posts: 2,239
    edited 2012-04-03 09:23
    erco wrote: »
    Speaking of funky printing devices, check out this symphony of solenoids:

    Whoa! That's the ticket! I could have used one of those at Fort Benning back in the 80's!
  • ercoerco Posts: 20,255
    edited 2012-04-03 09:29
    Publison wrote: »
    @erco,

    Massive kudos.

    You officially CAN quite you day job. :)

    Jim

    Glad you like it. It has a left-handed look about it, huh?

    Once it's printing characters, we can make individual birthday videos for forumistas. 3 lines of printing are plenty to write out:

    HAPPY
    BIRTHDAY
    PUBLISON

    :)
  • ercoerco Posts: 20,255
    edited 2012-04-03 10:28
    I just ordered 100 badge holders for Expo on my dime, so...

    1) I gotta finish the print code before Expo, and
    2) Ninety-nine of you guys need to come by at Expo, print your name, and wear it as proudly as me! :)
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2012-04-03 10:40
    Ninety Eight left now.
    One is mine.
    -MattG
  • PublisonPublison Posts: 12,366
    edited 2012-04-03 12:20
    erco wrote: »
    Glad you like it. It has a left-handed look about it, huh?

    Once it's printing characters, we can make individual birthday videos for forumistas. 3 lines of printing are plenty to write out:

    HAPPY
    BIRTHDAY
    PUBLISON

    :)

    SWEET!

    Maybe you could do that over the video web link that we were promised. I'll be 3000 miles away. :(

    Jim
  • ercoerco Posts: 20,255
    edited 2012-04-03 12:21
    davejames wrote: »
    I remember that!!!

    A perfect example of DWYGD!

    I will be looking forward to seeing the robo-arm at UPEW.

    Stumped. I'm guessing DWYGD may be something what you get/got something ?
  • ercoerco Posts: 20,255
    edited 2012-04-03 12:23
    Publison wrote: »
    SWEET!

    Maybe you could do that over the video web link that we were promised. I'll be 3000 miles away. :(

    Jim

    Jim: You findum who has birthday during Expo, I printum heap big birthday card !
  • davejamesdavejames Posts: 4,047
    edited 2012-04-03 12:49
    erco wrote: »
    Stumped. I'm guessing DWYGD may be something what you get/got something ?


    "Do What Ya Gotta Do" as here:

    http://forums.parallax.com/entry.php?389-Of-Things-DWYGD...

    and here:

    http://forums.parallax.com/entry.php?509-Of-Things-DWYGD-2...

    :thumb:
  • bee_manbee_man Posts: 109
    edited 2012-04-03 13:06
    Is that arm made of wood?

    It looks like, dare I say, (insert puking sound) plastic.
  • NikosGNikosG Posts: 705
    edited 2012-04-03 13:16
    My comment in Greek: "Δεν υπάρχει!!!"
    rough translation: It is not exist!!!
    Normal translation: Awesome!!!

    Erco, can you use the coordinates of my alphabet in order to write leters? !!!!!
    Maybe you need a different excel file in order to create automaticaly the Bs2 code!
  • ercoerco Posts: 20,255
    edited 2012-04-03 13:57
    Wish I could use yours, Nikos, that would save me some valuable time. I'll need a very simple font as in post #5 and hope it all fits in the Stamp's 2K memory. Worst case, I may have to leave out the oddball letters. Apologies in advance to Quincy, Xander and Zachary! :)
  • ercoerco Posts: 20,255
    edited 2012-04-03 14:21
    bee_man wrote: »
    Is that arm made of wood?

    It looks like, dare I say, (insert puking sound) plastic.

    Hardboard bottom and plastic on top. Everything's a compromise these days, and I certainly appreciate you keeping me honest! :)

    "It's the wood that makes it good..."
  • bee_manbee_man Posts: 109
    edited 2012-04-03 14:53
    erco wrote: »
    Hardboard bottom and plastic on top. Everything's a compromise these days, and I certainly appreciate you keeping me honest! :)

    "It's the wood that makes it good..."


    I know what you mean. I've been playing on the DARK side myself lately, just finished a 3D printer.

    Jim

    Edit - It's an ORCA v0.30 but I made it out of 6mm Meranti Ply not aluminum, must remain civilized you know.
  • ercoerco Posts: 20,255
    edited 2012-04-07 10:36
    Progressing nicely, just a few letters left to code. Heckuva lot more work programming a simple vector font than I expected. The BS2 memory will be crammed full with all the data. I just love maxing out memory space.
    IMGP7826.JPG
    816 x 612 - 79K
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-04-07 10:39
    Nice looking font! I see "Quincy" is almost back on the roster!
  • ercoerco Posts: 20,255
    edited 2012-04-07 12:40
    All 26 letters in, EEPROM 100% full. Hoping to crunch a bit more so I can write EXPO 2012. ZOIZ just ain't doing it for me! :)
    IMGP7827.JPG
    612 x 816 - 85K
  • ercoerco Posts: 20,255
    edited 2012-04-07 19:54
    Finished! Step right up at Expo and print your own badge on erco's "poor man's printer". I made a PS/2 keyboard serial adapter so my laptop won't be required to use the printer. The keyboard plugs right in. This one's finished, so now on to work on my robot catapult ...
    IMGP7830.JPG
    816 x 612 - 87K
    IMGP7835.JPG
    816 x 612 - 103K
  • TtailspinTtailspin Posts: 1,326
    edited 2012-04-07 21:22
    That is just way to cool erco.:thumb::thumb:
    But, You are going to have to sleep at some point...Prefererably before UPEW..
    You will want to be alert for the full contact events...:)

    How fast will the poor mans printer write a four letter word name?

    -Tommy
  • ercoerco Posts: 20,255
    edited 2012-04-08 01:28
    Thanks Tommy. Just two words on print speed: painfully slow! Initially I had high/low speed control to help move things along faster. Moving one servo at a time can go quickly for straight (arced) lines, but coordinating two servos for diagonal motion (letter X, N, S, etc) required slower movement. In order to fit all the code in a vanilla BS2, I had to ditch the speed control commands and run everything on default SLOW. Letters take ~4 seconds each. Plenty of time to socialize while people print their badges! :)

    I hope to code a one-press macro to print "Parallax Expo 2012".

    Code attached here so I can access it at Expo when I forget to bring it on the netbook.
    bs2
    bs2
    printer12.bs2
    10K
  • Martin_HMartin_H Posts: 4,051
    edited 2012-04-08 04:03
    A well done project and it's neat to see the completely blue memory map in the IDE.
  • PublisonPublison Posts: 12,366
    edited 2012-04-08 07:45
    Sweet! That BS2 must be bulging at the seams!!
  • ercoerco Posts: 20,255
    edited 2012-04-08 08:49
    Martin_H wrote: »
    A well done project and it's neat to see the completely blue memory map in the IDE.

    Thanks Martin_H & Publison. I chopped it down to 99% by replacing a lengthy DEBUGIN with SERIN and combining a few letters together. Had to get creative: CDGOQ is a single routine that can make any one of those letters, starting out by drawing a C, then branching as necessary. Adapt & overcome!

    It's more typewriter than printer, as it prints "live", one character per keystroke, spaces and return included. No editing, no formatting, no LCD display. Makes you plan ahead and type carefully! Also, there wasn't any leftover room for a macro, so I loaded that into the serial keyboard adapter. Press 9 and it automatically parses "PARALLAX EXPO 2012" to the printer.

    Should be good for a few yucks at Expo.
  • Roy ElthamRoy Eltham Posts: 2,996
    edited 2012-04-08 10:01
    That's really neat, erco! Can't wait to see it in action Friday!
  • xanaduxanadu Posts: 3,347
    edited 2012-04-08 10:14
    Excellent work, creative and entertaining. I hope I can see a video of the printer in action soon.
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