Youpiee I’ve got my stepper motors.
I’m trying to build a small CNC router. After following many forums I’ve bought: http://www.aliexpress.com/store/product/Free-shipping-CNC-Router-4-Axis-Kit-TB6560-3-5A-stepper-motor-driver-interface-board-Nema23/323452_1460662161.html
It looks really cool but the documentation is not that clear on how to connect the steppers to the boards. It seems that you can connect them on several ways depending on your needs. Will what do I need and what is the proper way to connect it? Also what is the proper setting for the switches for the board ( current, decays ect) please keep in mind. I’m not looking to push the motors. I just want them to work.
Thanks @Peter_Fouche1 . Do you know what are the best settings for the switches in regards to max current, decay ect. I’m feeling a little lost here.
@Mark_Schouten
I have found that setting torque, and decay at 100% gives me the best performance out of my TB6560 drives. The higher step sequence mode selected the better the drives run too. So to sum up crank everything up if you want the most volume. I should add that my current sense resistors are selected to not exceed the current handling of my motors.
I do not know what sense resistors, or motors you have. You could do some run time testing with a current meter and only one motor installed to see where you are at with current. There is a way to statically calculate current settings too.
That is somewhat complicated, and I didn’t find it particularly accurate either. So if you want to do your static calculations get the information how to do that from the drive IC’s data sheet.
It is on page 10, sub section 6 of the data sheet I have titled, “Calculation of the Predefined Output Current”.
I’ll say it again though, just measure the current the drive is pulling. I found a large discrepancy between calculated current setting and actual current draw with my experimentation. Something like a 40% difference. Maybe I’m just really bad at math? I honestly do not know what is going on there. I do know it is far easier to just directly measure the current. I’ve more faith in the data from a meter too.
For the record I used an analog meter. A Simpson 260 to be precise. On the 10 amp scale is was pretty easy to differentiate between quarter amp steps. Which is close enough for this job.
I should close by saying measure your current through the range of your motor’s speed. All the way down to stopped, where current should be the highest, unless your drive has hold current reduction circuitry built into it. Then your peak current will be the point when that circuitry kicks out.
@Mark_Schouten i have bought from the same suppliers some time ago. this is a really good deal.
The one thing I read over n over again was not to unplug a motor while the driver was powered. I don’t know how true that is, but it’s something I’m glad I saw before I started playing with mine.
But on the current, being that the power supply is only 10 amps at 24 volts, I’m wondering what exactly do we calculate the settings on? Do we set it in this case to an actual (24v maximum) 2A (4 motors x 2A plus a 2A buffer), or should it be based on a calculation of 12 volts (the minimum) divided by 250 watts ( as in 4 motors x 4.5A)?
@Mat_Helm
Believe it about unplugging stepper motors.
@Bijil_Baji @Mat_Helm @Paul_Frederick thanks for all your feedback. I have loved to invite you all for a BBQ and build a CNC machine together, but since we all live too far from each other I have to forget about that one. Bijil Baji: I contacted the supplier after you pointed them out. So far so good Thanks. Paul Frederick: I’m using the ST330 while you are talking about the TB6560. Are they interchangeable? If yes, would you have a schematic on how to integrate the sence resistors? You seem to know what you are doing here, so I would love your input. Also one last question to everyone: I realized today that the old PC that I kept for this project is dead and not worth fixing. I know that the recycle shop has plenty of them, but is it worth investigating the use of an arduino instead of a PC with Mach3
Thanks
@Mark_Schouten Your driver chips are the TB6560’s. And yes, if we all lived close enough to @Paul_Frederick , we wouldn’t need to build one, we’d just use his… ;p
http://ecx.images-amazon.com/images/I/51W05LyF6WL.jpg
As I understand it, the arduino won’t work with mach3. Has it’s own little cnc eco system. GRBL…
Checkout diy cnc 2, I have listed several motherboards with parallel port that are still available, You may be able to do as I did and use that dead PC for parts toward building a new one. Also there is the intel D525 option that a lot of Linuxcnc types use. It’s a all in one board with a atom cpu…
@Mark_Schouten
Parallel port add on boards are an excellent choice for CNC. You’re better off using an add on parallel port than the integrated one with a PC. Then if you mess anything up you do not kill the whole PC. I had a look at your drive boards and I’ll say this, be very careful about the 5 volt source you power those boards with. It is kind of cheesy that they didn’t build regulators onto the drives themselves. It would have only cost them maybe 50 cents to have done so.
If it was me I’d build a dedicated little PSU out of a 7805 to supply all of my drives with the 5 volts that they need. It is a really simple circuit that you can power right off your high voltage input.
That would do the trick.
To @Mat_Helm and @Paul_Frederick thanks for all your feedback. I was able to make a working PC from parts laying around. Tonight I will be trying to get some motion. I have to say: the whole building thing it much more fun then I expected. Let’s hope the fun will double once I start cutting