McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.


Results 1 to 8 of 8

Thread: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

  1. #1
    Registered
    Join Date
    Nov 2017
    Location
    United States
    Posts
    4
    Downloads
    0
    Uploads
    0

    Default McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    hello im 1 month in teaching my self the art of cnc.
    I dont think i need to really explain step by step.
    whats the saying a picture = a thousand words.
    so this is my table top router. about (x)500 mm X (y)500 mm X (z)200 mm
    with the cheapest material i can find. so dont judge me on the cheapy look.
    i always fear the loss of performance and accuracy of somesort when i go the cheap way.
    i guess i have to see how it goes.





    *i made the little tiny cnc out of free cd drives i got for free from local computer repair shops.
    just to make sure id understood wth is going on before i invest i good amount of money in to this "educational project."
    once i got the little stepper motors moving with the arduino grbl shield with the universal gcode sender, i knew i was good.*



    i also made this pen holder for my first test runs. you can see the drawings in the first picture on the back of the cnc machine.
    (this is when the "cheapy" material i used first became an issue the x,y,z axis are not truely square).
    i gave the pen a little holder so it would slid up and down and then i added a rubber band for some down ward tension, and the
    tape would hold the pen in place so the the tension of the rubber band doesnt just make the pen drag and actually get picked up when the z axis lifts.
    harder to explain then expected lol



    so i was using inkscape to trace and create gcode using the plugin but i didnt like it. i wanted to learn legite cad/cam software. so i did some research
    and found out that auto desk offers 3 year demos for students so i found fusion 360. Spent the past week and thanksgiving watching youtube videos
    on how to create sketchs and etc. so i finally got it. somewhat....



    are my stepper motors to wimpy?
    or is it my settings?
    why is it skipping steps like this?
    i read somewhere that if you move the steppers in to small increments it loses its torque or something. so is it that? i have it cutting only 0.5 mm at a time.









    Electrical Specification:
    - Manufacturer Part Number: 17HD48002H-22B
    - Motor Type: Bipolar Stepper
    - Step Angle: 1.8 deg.
    - Holding Torque: 0.59N·m(84oz.in)
    - Rated Current/phase: 1.7A
    - Phase Resistance: 1.8ohms
    - Inductance: 3.8 mH ±20% (1KHz)




    Similar Threads:
    Attached Thumbnails Attached Thumbnails McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-fusion-png   McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-stepper-moter-jpg   McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-power-jpg   McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-shield-jpg  

    McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-pen-plotter-jpg   McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-failed-jpg   McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-cnc-jpg  
    Last edited by been_solo; 12-01-2017 at 06:48 PM.


  2. #2
    Member
    Join Date
    Apr 2004
    Location
    Oakland CA USA
    Posts
    4840
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    It might be an inductance issue. The motors have a lot of it at 3.8 mH; that means they really want 62 volts supplied to run optimally. But that grbl shield maxes out at what, 30v? What is your power supply putting out - 24v? You're right about the motors being wimpy, but if you don't give them enough juice you can't blame them for that entirely.

    Andrew Werby
    https://computersculpture.com/


  3. #3
    Registered
    Join Date
    Nov 2017
    Location
    United States
    Posts
    4
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    thees little motors can take 62 volts? Jiminy Christmas...

    so what driver and power supply is recommended?

    links?


    my end goal is to cut and engrave acrylic and or other soft plastics.
    and some wood here and there.

    ty





  4. #4
    Member
    Join Date
    Apr 2007
    Location
    USA
    Posts
    1876
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    Hi, perhaps the first step is to recognize what you have built and put it into the right "category" of machines.

    1) Pen Plotter
    - Before ink jet printers were invented, HP and Xerox sold "pen plotters" to print the output from cad systems.
    - They worked very much like what you have done - use a pen or so and it was moved around above the paper to draw the lines in the right places.
    - On most drawings of the time period, the lines were not all that complex so a lot of X/Y long lines and a few round holes. Very limited text and usually on D or E size paper (or larger)
    - Resolutions were on the order of 50 - 100 dots per inch, but since it was being drawn with a marker / pen, this sort of averaged out and you never saw these "dots" that were happening electronically
    - A common characteristic is unsupported rails (in other words, the rails are not attached to the frame along the entire length) and fairly low torque motors.
    - The machine stiffness and motor torque are suitable for moving a pen around and are not designed or intended for actual cutting
    - This is what you have built - and done a very good job of it



  5. #5
    Member
    Join Date
    Apr 2007
    Location
    USA
    Posts
    1876
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    2) 3D printers
    - Many 3 D printers are essentially cnc controlled hot glue guns, with the glue coming on a long string
    - It would be better if they were build with supported rails (rails attached along the entire length to a stiff frame) but the majority of them are unsupported rails like the pen plotters.
    - These designs force the 3D printers to work more slowly than they could if properly built, but it is a start and a learning process
    - Many customers are disappointed to learn that they cannot do "real machining" or even substantial engraving with these unsupported rail machines



  6. #6
    Member
    Join Date
    Apr 2007
    Location
    USA
    Posts
    1876
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    3) Wood cutting / engraving machines
    - cnc routers for wood, even small ones at this level of cutting should all be using supported rails, but they often aren't due to misunderstanding of the forces, cost, or frankly being scammed by the seller
    - An easy way to tell if a machine is stiff enough for cutting plastics, wood, or engraving is to take a piece of wood and push on the bit in the spindle. If you can see or measure anything moving on the entire machine, then it isn't going to result in useful cutting. It is a crudely simply and brutally honest test.
    - For a machine the size of yours, if you build it from wood, nothing should be less than a 4x4 post for framework - either built from a piece of wood or plywood - or use 2 x 4 steel tubes 1/4 inch thick
    - I know - sounds extreme, but engraving is a precision end result and the details are small / sensitive to errors
    - Motors should be in the 300- 500 oz - in range

    As you go through the forum and look at machines out there, you will eventually find that building anything with less stiffness will not work reliably. Yes there are many machines built with less stiffness, and they might work for short periods of time, but won't "hold" their tune. It is like having a piano that needs tuning every time you want to play it and then by the end of the song, it is not quite the same as in the beginning.

    As the materials and get larger and harder to machine, the requirements for stiffness, etc just keep rising.



  7. #7
    Member
    Join Date
    Apr 2007
    Location
    USA
    Posts
    1876
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    It is your first build and the majority of builders go through this stage on the first machine.

    I am very impressed with what you have done with it so far.

    If you want to try to stiffen it up a but, try adding some ribs in various places on all of the axes and under the table to stiff them up a bit.

    Some people have seen improvements by putting the unsupported rail under tension - sort of like tightening a guitar string makes it stiffer than when loose.



  8. #8
    Registered
    Join Date
    Nov 2017
    Location
    United States
    Posts
    4
    Downloads
    0
    Uploads
    0

    Default Re: McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

    thank you for your advice i finally finished building my all aluminum all supported rail system with 450 oz motors.

    McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-cnc-jpg

    Attached Thumbnails Attached Thumbnails McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.-cnc-jpg  


Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.

McBoxy Boxinator Build. Lead screw cnc. fusion 360. arduino grbl shield.