The latest generation controllers I have built all use the same simple and cheap IC's. A pic 12c508 as the basic stepper driver logic and some H-Bridge chips that were originally meant for mundane things like tray loading motors on dvd players. I got a couple of hundred of these on ebay. The pic micros were from a guy that used to do mod chips with them but sold out his stock of unused chips really cheap.
I've used the cheapest parts I could find and still got great results with modest fine tuning. I used a dial indicator to see how bad my table was and it only varied .008 inches in depth from end to end. If I had used a surface planed board or aluminum plate that would have been better. I could always just mill a huge squared spiral pattern into the table to make it perfect
Step 1: Single Board or Multiple Board Modules
I've tried both ways and each has its advantages. I always keep the 110V SSR board separate. When using the single board approach I like to use an Arduino nano clone. when using multiple boards I use and arduino prototype sheild wired with a bunch of headers for the individual boards.
Step 2: Control Buttons
Step 3: 110V Solid State Relays
Step 4: Picking Motors
I use a simple driver that has no enable input but is really cheap to build and can handle 90W/per motor max (30V and 1.5A/phase). it does have overcurrent , overvoltage, overtemp protection though. I am writing an i'ble just on that controller. I like to use recycled power bricks in the 16-19V range.
that works well since I had a bunch of unipolar 12V steppers. I don't connect the common leads so I use an H-Bride bi-polar driver. this means the 12 coils on each phase are connected in series for a 24V coil. Running them at 16V keeps them cooler.
Step 5: Software
Step 6: X-Y Test
I worked by trial and error increasing the feed rate and acceleration until it lost steps then backed off a bit. In the real world I used a slower rate anyway so as not to break off the carbide bits.
Step 7: Z Axis
for all the axis' i used 1/4-20 threaded rod. To minimize backlash I used blocks of delrin to make the nuts
Step 8: Trivets
I used scraps of flooring, shelf boards and whatever else I could find laying around the shop.
to give the engravings more contrast I used some spray paint. I just gave the board a liberal coating and wiped it down with a rag sprayed with WD40
I then used mineral oil to give the wood a little protection
Step 9: Circuit Board Routing
So I decided to give it a try. I found a simple QRP transmitter design which I could use for an arduino project and tried to make a couple.
I built a 20M and a 40M board. They worked so well I’m going to route 2 more for 80M and 160M