A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

Results 1 to 7 of 7

Article: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

  1. A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    6 Comments by James Newton Published on 11-20-2014 01:57 PM
    I see a lot of posts on the forums from people who say something like "I want to build a CNC router and so I bought this TB6560 driver really cheap on ebay, what should I do next?"

    :shudder:

    If it were possible, the first action would be to go back in time and stop yourself from throwing away money like that. Search the forums for all the people complaining about failures with those cheap TB6560 drivers, if you don't believe me. The TB6560 chip was never intended as a stand alone driver.

    But more than that, there is no point in buying the drivers until you know what motors you need, and you can't know what motors you need until you know what you are going to drive with them.

    The best possible order for building a CNC machine is:

    1. FIRST: Build the physical CNC machine: e.g. the router bed, gantry, z axis, lead screws, and so on.


    2. Measure the torque needed to move each axis and measure the weight being moved.

    techref.massmind.org/techref/io/stepper/measure-torque-rb.htm (this is for measuring a motor, but the exact same method works for measuring what the motor will move)

    3. Calculate the power (watts = amps times volts) needed to move that weight at the desired speed,

    techref.massmind.org/techref/io/stepper/estimate.htm

    4. Find
    motors have the necessary /detent/ (not holding) torque.
    techref.massmind.org/techref/torque.htm
    Some larger motors can be found in discarded office equipment:
    techref.massmind.org/techref/io/stepper/linistep/motors.htm

    5. Find drivers that match the amperage of your motors and can drive the necessary watts (=amps * volts) for the speed you want. E.g. 4 amp, 50 volt driver will drive 200 watts

    6. Find a power supply that can provide /peak/ power for all those motors and drivers
    techref.massmind.org/techref/io/stepper/power.htm

    7. Select software that matches your interest and will run on your PC. E.g. LinuxCNC doesn't run on Windows and MACH3 won't run a RAMPS/Grbl USB motion controller.


    8. Buy an interface board that works with those drivers and the software for your PC. E.g. a parallel breakout board (BOB) won't work if your PC doesn't have a parallel port.


    If you are working from a set of plans, or if you are good with mechanical design and you know about how much weight and torque each axis will need, then you can, perhaps, skip 1 and 2. But if you are just getting started, and you haven't done this before, please (please) don't spend any money until you have built the actual device.

    Similar Articles:

  2. Total Comments 6

    Comments

  3. #2
    Community Moderator Al_The_Man's Avatar
    Join Date
    Dec 2003
    Location
    Canada
    Posts
    22362
    Downloads
    0
    Uploads
    0

    Default Re: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    And also there are free sizing programs out there once the mechanics are decided on.
    Kollmorgan has one for e.g.
    Motor-load inertia ratio is a very important one.
    Electromate Industrial Sales
    Al.



  4. #3
    Registered gividen's Avatar
    Join Date
    Jan 2008
    Location
    USA
    Posts
    4
    Downloads
    1
    Uploads
    0

    Default Re: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    Thanks for that. I see what seems to be 100s of DIY plans but I cannot tell what plans are crap and which are great. Can you recommend an effective one?



  5. #4
    Registered James Newton's Avatar
    Join Date
    May 2005
    Location
    USA
    Posts
    1376
    Downloads
    0
    Uploads
    0

    Default Re: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    Nope, because it is too individual a choice. The question is which set of plans are best for YOU. In any case, start with the mechanicals...



  6. #5
    Registered gividen's Avatar
    Join Date
    Jan 2008
    Location
    USA
    Posts
    4
    Downloads
    1
    Uploads
    0

    Default Re: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    Can anyone else out there recommend a good set of plans for a 3 axis cnc machine based on MDF with home store parts? I have about 16 stepper motors from some old Bell And Howell industrial scanners. Building a 3 axis CNC seems like a fun way to recycle.



  7. #6
    Registered
    Join Date
    May 2005
    Location
    Australia
    Posts
    12
    Downloads
    0
    Uploads
    0

    Default Re: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    I've just settled on a ShapeOko, mainly as its a metal all over, has lots of modifications possibilities, comes as a kit that's cheap, is easy to assemble, can buy just the mechanics, or everything needed and can be expanded in size easily. V3 mechanical is available now and is stiffer than v2. I have a v2 under construction.



  8. #7
    Registered
    Join Date
    May 2005
    Location
    Australia
    Posts
    12
    Downloads
    0
    Uploads
    0

    Default Re: A Better Order Of Actions For CNC Builds: or don't buy the electronics first!

    I think people build the electronics first because that's probably the part that they are least familiar with. In my case I am comfortable with the electronics and that I'll get it working, but the mechanics are more difficult for me, so when ShapeOko mechanical kit came along I was very happy and started there. If their budget is less constrained then I'm sure people would follow the order James suggested.



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

A Better Order Of Actions For CNC Builds: or don't buy the electronics first!
A Better Order Of Actions For CNC Builds: or don't buy the electronics first!