3Step Stepper controller specifications
Specifications
What technical design or product description would be complete without some specifications?
Basic Design:
- 5A/phase Max Unipolar stepper driver
- 24V Max supply voltage
- Full or half step modes
- Enable input
- 12Khz Max step pulse rate
NOTE: Although the mosfets will handle 24V 5A steppers, realistically using power resistors to limit the current 12V at around 3A is probably the limit, although you can go higher if you have huge heatsinks and a small turbine for a fan. See the 'Power Resistor' comments on the building page for more detail.
Full Design adds:
- Estop latch
- 3x limit switch inputs
- Status LED
- Spindle relay driver output
Two Designs????
Err, well, sorta.
The circuit can be built in two versions, one has just enough bits to get three stepper motors moving, the second 'Full' version has the limit switch buffer inputs, and an Estop latch. Both circuit diagrams are online, or you can work from the full diagram and remove the bits you don't want.
Some nitty-gritty bits
The 3Step uses cheaply available components, which you should be able to find in most parts of the world.
The mosfets are IRFZ44's, which should be common in most parts of the planet.
The main chip is a PIC16f870 made by Arizona Microchip. It runs some software which you will need to program into it. You can either buy a programmer, or build one from one of the DIY ones you can find on the web. If you don't fancy doing the programming yourself, drop me an email and I might be able to find someone local to you who can get the job done.
As a last resort I could program the chip and sell you one for a nominal charge, but remember I'm in New Zealand, and the cost of the postage may be more than the chip is worth, and it wont be exactly a quick turn around if you live in North America or Europe.
At this moment in time I have not laid out a circuit board design for the stepper driver, but if someone with eagle is bored, I'd be happy to credit you with doing the layout.