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.
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.
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.
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.
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?
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.
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.
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.
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.
This topic is from the original forum (June 2016). Your reply starts a new discussion linked to it.