Welcome to Our Community

Some features disabled for guests. Register Today.

Setup issues

Discussion in 'CNC Mills/Routers' started by Cornerspace, Oct 1, 2017.

  1. Cornerspace

    Builder

    Joined:
    Oct 2, 2016
    Messages:
    24
    Likes Received:
    0
    Got the C Beam setup. Couple of niggling issues that i need advice on its likely cause and resolution.

    Noise - The machine is noisy. Been trying to identify the source of the grating sound, X axis seems to be running nice and smoothly when it suddenly decides to start making a grating noise. Turned off the mains to prevent damage. Maybe my stepper motor is too heavy and the existing supports are not rigid enough to offer sufficient bracing?

    Endstops - Set up the limit switches in a basic NC configuration. Hooked everything up as per the guide but nada. It still works when i manually trigger the limit switches. I am grounding the setup via the ground circuit on the stepper drivers (It is connected to the same ground as what is indicated on the guide for the endstop configuration on the GRBL guide. Did I miss a step? Do I have to configure and modify the config.h file to set it up?

    Heat - I know the stepper motors get hot, but what is acceptable heat levels? I have set the DM542 to 1/2 current at idle. My X axis get much warmer than the Y and Z axis.


    Cable management - What are your preferred methods on managing the cables on your machine?

    Thanks for your comments and advice. :)
     
  2. Cornerspace

    Builder

    Joined:
    Oct 2, 2016
    Messages:
    24
    Likes Received:
    0
    Tried modifying the GRBL acceleration setting. Works great for X and Z axis but Y axis is still having issues. The acceleration settings seems to have an effect on the X and Z axis but it does not seem to have any effect on the speed of the Y axis. I dialed the Y axis acceleration to 3,000 but to no effect. Any tweaks? :)
     
  3. Giarc

    Giarc Master
    Builder

    Joined:
    Jan 24, 2015
    Messages:
    523
    Likes Received:
    254
    Cable management: I have this one https://www.amazon.com/gp/product/B00AUB24VC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
    and this one: https://www.amazon.com/gp/product/B00AUB24VC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

    They are basically the same thing, but I did two different orders and the original one I purchased (second link) was not available. They both work well. On the Y axis, occasionally one or two of the nylon tabs that open to lay the cable will pop open where the bend is the greatest. They are filled with cable on the Y pretty much to capacity which is probably the reason. I plan to use a soldering iron to weld the offending tabs in place if it becomes a problem. So far after more than a year it has not. I have the 15mm x 30mm x 1 M.

    As for noise, the only time mine makes a grating sound, is when it is run real slow.
     
  4. Cornerspace

    Builder

    Joined:
    Oct 2, 2016
    Messages:
    24
    Likes Received:
    0
    Yeah. Got those on order. I was mulling over the best way to route the cables used for the endstop switches. It all over the place now. What is your approach to routing those cables? :)
     
  5. Giarc

    Giarc Master
    Builder

    Joined:
    Jan 24, 2015
    Messages:
    523
    Likes Received:
    254
    On the X and Z, they run from the switches into the cable chain and down to the controller. On the Y, they run in a slot on the underside of the 2040 V-slot that connects my Y 2080 to the aluminum plate pictured below. Sorry I do not have any real pictures available right now.
    [​IMG]
     
    #5 Giarc, Oct 2, 2017
    Last edited: Oct 2, 2017
  6. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder

    Joined:
    Aug 6, 2013
    Messages:
    775
    Likes Received:
    357
    yes, read the config.h and make the required changes.
    also read Home · gnea/grbl Wiki · GitHub which has pretty much everything you need to know. Note particularly the section on homing switches and avoiding electrical noise.

    all grounding should be to one point, what they call 'star grounding'. this avoids a lot of noise issues.
    if you can touch the motor for a few seconds it is fine. most motors are rated up to about 80C, which will burn you.
    you can always add PC fans.... an 80mm fan on 5 volts will run quiet but makes a lot of different to the heat buildup.

    setting to 1/2 current when idle will probably be ok on the C-beam. However, I would not do it on a belt driven machine since 1/2 current = half the holding power and then an idle axis may move under tool pressure.

    Keep signal cables (home switches) far away from power cables (stepper cables, power to the spindle).
    In particular, do not run them in the same cable tray UNLESS you have done everything right, shielded signal cables, star ground, opto filters on inputs etc. even the power cables should be shielded if they are to run close to signal cables..
     
    Cornerspace likes this.
  7. Cornerspace

    Builder

    Joined:
    Oct 2, 2016
    Messages:
    24
    Likes Received:
    0
    Turns out the mechanical grinding noise was due to my wheels being locked to tight against the C Beam. Redid the couplers and lock nut and everything is working fine. Well except for the end stops, keep getting a alarm signal. Tested the continuity of the end stop loom off machine and it works fine. :)
     

Share This Page