Over the break I’ve been working on a driver board for the TBA6560, this is what I’ve got so far. It’s open source, although I won’t bother posting the files until it’s a bit more substantial, and I’ve made the PCB layout.
It’s a pretty simple circuit, the only tricky parts are figuring out values for certain parts. I got a lot of help form CNCzone, where there is an entire post on this chip. One of the important issues covered was that a low esr capacitor is needed across the 35v source. Setting the frequency is also a bit of a mystery.
I’ve spent most of the christmas break planning out a CNC setup. My initial goal is to complete the electronics set up, and then worry about making a gantry later. CNCzone.com has lots of information on everything CNC, the open source stepper drivers are of particular interest to me.
I have reviewed dozens of chips from multiple suppliers, and I have also outlined the features that I think are good to have:
– Drive bipolar steppers
– microstepping, to at least 1/8 step
– Chopper style stepper control
– Handle around 24V and 1.5A rms/3A max or more
– Easy to solder
– Easy to make a PCB for
Many drivers such as the EasyStepper that Sparkfun sells, and the drivers that run the MakerBot use SMT components, which are maybe a little to much for me to take on presently.
I looked through allegro’s site, and STM, and some others- somewhere too tiny, some didn’t microstep, some couldn’t handle the power.
LumenLab switched their drivers from EasySteppers to a design based on TB8435 which looked way more… well, beefy and tough. Don’t mess, you know? Its got easy to solder leads too. Too bad this chip is obsolete, and not made anymore.
Enter the TB6560! Its also made by toshiba like the LL one, but its still made, it looks tough, and there are some open source designs available on the web. I’m working on optimizing a design that suits me best, and then I’ll put it up here FTW!