Networking two TinyGs

Home › Forums › TinyG › TinyG Support › Networking two TinyGs

Tagged: 

Viewing 10 posts - 31 through 40 (of 40 total)
1 2 3
  • Author
    Posts
  • June 10, 2016 at 4:30 pm #9786
    Splocal
    Member

    Alden, this is a bit off topic but along similar lines. I have a TinyG V8 and my setup runs two motors on the Y axis. What I would like to do is add an A axis to my current hardware. However all of my stepper motor drives are tied up. I would like to add an easy driver to say Port J17 and run both my Y axis that way. This would free up an on board motor driver which I could assign to my Aaxis. Will an easy driver work for this task in port j17 or j18? I an trying to avoid buying a TinyG 2 at this point until they have all the bugs worked out, also trying to go the least expensive route. I already have a Nema17 and easy driver I could use. Thanks for your help.

    June 11, 2016 at 7:08 am #9789
    cmcgrath5035
    Moderator

    Being unfamiliar with what you are talking about (‘easy driver’) I scanned

    for about 60 seconds.
    Quick observations:
    Relatively low current per phase from driver, compared to 1.2A from tinyG drivers. Don’t know much about your machine, this may or may not be important.

    It is not clear if the EN[able] interface is active high or active low.
    TinyG FW defines Enable signal as active low

    If your drive current requirements are low(compatible with this easy driver) I might suggest you simply drive you two Y motors from one tinyG driver. It has 1.2A total capability and much better heatsinking.

    June 12, 2016 at 6:01 pm #9794
    Splocal
    Member

    Hi cmcgrath5053 thank for the reply. Apologies on not providing more info on the easy driver. Looks like you found the website about it. Alden references the EasyDriver on the first page of this topic as a potential option for a 5th axis. I do not need this axis to be very tourqy just accurate and able to run a Nema17 for rotating a light cylinder to laser engrave. Is there another motor driver you might recommend if not the EasyDriver? I have considered running both my Yaxis motors on one driver but I have Nema23’s on Y axis and plan to do some aluminum cutting soon. I don’t want to burn out an irreplaceable driver on the TinyG board itself. I felt an external driver was a safer option and the driver could be replaced if it burned out.

    June 12, 2016 at 6:39 pm #9795
    Splocal
    Member

    Cmcgrath5035 maybe this one is a better option, it’s the bigger brother to the EasyDriver. https://www.sparkfun.com/products/12859

    Reading through the data sheet on this driver it seems that Enable can be set to work with either active high or active low. It can handle 2amp Max current and can be set to microstepping modes compatible with TinyG.

    https://cdn.sparkfun.com/datasheets/Robotics/A4988-Datasheet.pdf

    I greatly appreciate your help with this.

    June 13, 2016 at 7:17 am #9798
    cmcgrath5035
    Moderator

    OK, understand (I think).

    Either of these Easy drivers might be OK for your lite duty NEMA17 “fifth axis”.

    But my interpretation is that you need to drive one of your two higher current NEMA23s from the external driver to free up the fifth axis on your tinyG board. There 2A Easy driver might be OK there, although I would be a bit concerned about lack of driver device heat sinking.

    June 13, 2016 at 3:56 pm #9799
    Splocal
    Member

    Yes! Thank you that is exactly what I am trying to accomplish. I have my TinyG set up in a project box with constant fan air flow. However I have some small heat sinks and could add one to the driver if needed. I would assume I would see motor stutter or other issues if I was reaching those temps. The Big EasyDriver has an overheat shutdown as well so that could save the board from burning out if it got that hot.

    I looked closely at all the specs on Synthetos about external drivers and this seems to fit the bill. My main concern now is that in order to set the microstepping on the EasyDriver I have to have three pinouts set as either high or low. Since TinyG has limited I/O I am not sure how to do this. It defaults to 1/16 steps which is not an option for TinyG. I need to set easy driver to 1/8 steps.

    One other question you may be able to help with is that Synthetos recommends that the on board pot for the motor driver you are connecting the external driver to should be turned all the way down. Wouldn’t that essentially defeat the purpose of my goal rendering the on board motor driver unusable?
    Perhaps I need two EasyDrivers setup and not use the on board driver?

    Thanks again!

    June 13, 2016 at 7:14 pm #9800
    cmcgrath5035
    Moderator

    I believe the suggestion to turn pot all the way down assumes you are not still using the On Board driver.
    I suggest you try it with one on board(leave pots as is) and one off board driver first – if they are well synched, you should be OK

    You probably set the microsteps to 8 with wire strap or resistors – ?

    Yoru box with fans will probably work, but be aware that thermal shutdown of the drivers, on board or off board, will likely ruin a work piece and break a bit – there is no feedback to the tinyG that the shutdown event has occurred.

    June 14, 2016 at 1:59 am #9804
    Splocal
    Member

    Cmcgrath5035 you have been a tremendous help! I posted these questions in a few other forums and either got no response or people just didn’t know. It seems not to many people are exploiting this option. If I am successful I am considering doing a YouTube video to share this with others. I usually don’t do that but this is one of those things that I believe can be really helpful to others in the same boat. Thank you again for your time, I’ll be purchasing the driver soon and will post back here as well with an update.

    June 14, 2016 at 8:11 am #9806
    cmcgrath5035
    Moderator

    Good luck with your project.

    When you post back on results, I suggest your start a new thread – this one is long and some of what is at the top is not of direct use.
    And search is somewhat limited here, so Choose a topic such as (hopefully) “Running 4 axis 5 stepper machine from TinyG” so others will be able to find it.

    Provide a link (URL) to this thread and to any YouTubes you create.
    Your investigation/thought process is as important to many as your results.

    June 15, 2016 at 3:20 am #9810
    Splocal
    Member

    Will do, and completely agree a new thread is a better idea. By the way sparkfun got back to me on how to wire the driver for 1/8th steps. All I have to do is ground one of the pins! Super easy, I think I know exactly what I need to do now to get this 4th axis working, really looking forward to seeing how this pans out.

  • Author
    Posts
Viewing 10 posts - 31 through 40 (of 40 total)
1 2 3
  • You must be logged in to reply to this topic.