543,873 active members*
2,345 visitors online*
Register for free
Login
Results 1 to 6 of 6
  1. #1

    Join Date
    Apr 2021
    Posts
    3

    Asymmetrical X/Y axis force

    Hi guys, this is my first post, I hope I'm giving enough information to help you to answer my question.

    I'm building a small 500mm^2 (I live in Tokyo) CNC machine that utilizes Oriental Motors Alpha-Step steppers and drivers. The configuration is a minimal gantry design, like a beefed up Shapeoko with 26mm (6mm lead X/Y, 10mm lead Z) THK ground ball screws and (real) 25mm Hiwin rails. All these parts were bought at a local factory surplus shop at excellent prices, so I have let the parts availability guide the design of the project. This has lead to some asymmetry in the capabilities of the different axis as far as motor sizes. Since the Y axis is driven by two motors, it already starts with somewhat of an advantage (of course it has to move the entire gantry, so there is some offset there) but the Y motors are also much larger in size, being based on the 90mm frame (AZM98MC-TS7.2U specifically.) While the X axis will use a smaller 60mm class, single motor (AZM66AC-TS7.2) and the Z uses a larger gear reduction version (AZM66MC-PS25) to take into account the lead difference and the additional precision I was shooting for. I'll link these motors below so you can see the spec's.

    My question is, given I will likely have more force available in the Y axis, does CAM software (Fusion 360) take this into account when generating GCode so that I can optimize the travel to take advantage of this, or do you just get crippled to the lowest common denominator even when the motion is traversing a single axis?

    Motors:
    Y: https://catalog.orientalmotor.com/it.../azm98mc-ts7-2
    X: https://catalog.orientalmotor.com/it.../azm66ac-ts7-2
    Z: https://catalog.orientalmotor.com/it...c/azm66mc-ps25

  2. #2
    Community Moderator Jim Dawson's Avatar
    Join Date
    Dec 2013
    Posts
    4879

    Re: Asymmetrical X/Y axis force

    The CAM software has no idea what your machine configuration is, short of writing your own post processor. In general the CAM software will assume that there is adequate power available to operate the machine at the feeds and speeds that you specify in the setup. In Fusion 360, there is Feed Optimization under the Passes tab that might be of some help to you.
    Jim Dawson
    Sandy, Oregon, USA

  3. #3

    Join Date
    Apr 2021
    Posts
    3

    Re: Asymmetrical X/Y axis force

    Interesting, am I wrong in thinking that each axis has independant feeds and speeds limits? Isn't that what I'm configuring in Fusion 360 when I'm adding a machine description?

  4. #4
    Community Moderator Jim Dawson's Avatar
    Join Date
    Dec 2013
    Posts
    4879

    Re: Asymmetrical X/Y axis force

    No, the feed speed is the interpolated RMS vector value, in other words, speed that the tool sees. So if your feed speed was set at 100mm/min, and you were cutting a 45 degree angle, the X axis and the Y axis would each be moving at 50mm/min, or a vector sum of 100 mm / min. Conversely, if the travel is exactly in the X axis, then the X axis would be traveling at 100 mm/min and the Y axis would be 0 mm/min.

    Fusion 360 machine configuration is just generic 3, ,4, 5 axis machines, with some manufacturer specific machines. You may be able to create your own configuration that takes your asymmetrical axis thrust into consideration. But this would also require a custom post processor.
    Jim Dawson
    Sandy, Oregon, USA

  5. #5

    Join Date
    Apr 2021
    Posts
    3

    Re: Asymmetrical X/Y axis force

    Okay, that makes sense as far as factoring in the cutting tool itself. I'm so used to thinking in the additive space, this adds a lot of extra factors. The main use case I'm thinking of is a simple clearing operation where we could theoretically bully through in the Y axis with a lot more load, doing our step overs in X which would not even need to be engaged with the workpiece during its travel, mitigating any force disparity and optimizing the whole process. It would have been great if the CAM was smart enough to take this into account, but I may be prematurely worrying about something unimportant. For all I know, the X axis may be able to exceed my cutting capability as it is, and all the extra force available on Y isn't even useable. I just worry that the two axis are disparate in total torque and if I should source a bigger motor for the X, or just try it with the current motor first (the obviously correct choice.)

  6. #6
    Community Moderator Jim Dawson's Avatar
    Join Date
    Dec 2013
    Posts
    4879

    Re: Asymmetrical X/Y axis force

    It is not often that the axis drives run out of power, it very common to have two motor gantry drives, but normally the X and Y motors are the same size. I think you'll be fine.
    Jim Dawson
    Sandy, Oregon, USA

Similar Threads

  1. Any way to force rotary axis to move only CW or CCW?
    By QuinnSjoblom in forum Mach Software (ArtSoft software)
    Replies: 0
    Last Post: 07-29-2019, 08:58 PM
  2. How to force A axis output on offset update
    By inthebay in forum Mastercam
    Replies: 5
    Last Post: 02-18-2016, 06:28 PM
  3. how to force M0 between toolpaths?
    By dwneumann in forum MadCAM
    Replies: 3
    Last Post: 02-11-2013, 11:42 AM
  4. How do you force an A axis move
    By dave281 in forum EdgeCam
    Replies: 3
    Last Post: 09-06-2010, 08:19 AM
  5. z axis requires more force than x to move (?)
    By forgetcolor in forum JGRO Router Table Design
    Replies: 5
    Last Post: 03-16-2010, 04:29 AM

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
  •