Starting to design out my build, looking for critique

[AndyUK]

Will reply with a more detailed look at your spreadsheets when I get time, but to quickly answer a couple of points:

The weirdest one was not finding german stores that sell steppers. I could only find one real store, that sells for okay prices, but even that one only sells to companies. The general electronics sites here, only sell steppers for horrendous prices, and only around about 10 different models max.

As you're in the EU, pretty much any EU store is an option. CNC4YOU.co.uk is where I got mine, Zapp Automation also seem pretty good.

What that post also left open, is what the different types of support (like supported-supported) actually are. What would a ballscrew with its two bearing blocks count as? Supported-Supported?

So here you may need to read up on ballscrews and their mountings. Free means no support (an end which is floating in mid air), Supported means on a bearing but with no axial constraint (like a BF mount), and Fixed means a bearing that can take axial force (like a BK mount). Typical configuration is Fixed-Supported, with a BK at the motor end and a BF at the other. You'll need to know this when ordering your screws, as they need to be machined appropriately.

Another question concerns the other electronics. At this point i am wondering what I need in total. As far as I understood, the following is needed (mostly going off of Joe Harris' Build http://www.mycncuk.com/threads/4513-...0655#post90655):

• A PSU
• A Controller
• A driver per stepper
• A VFD
• A Water Pump
• A Spindle

Am I missing something here? Also, again, is there some kind of collection post of different options for this?

Oh wow. Theres like a billion different options. Finding a path is tricky! Ultimately, you need some way to turn GCode into motion.

That often starts with a PC sending the Gcode to a parallel port - but PC's aren't great at realtime and they're not often made with parallel ports these days, so some kind of motion controller is often used to simulate a parallel port and deal with the realtime aspect. Recommend ethernet variety. Then you may or may not need a breakout board depending on which controller you use - a UC300eth for example just gives you five headers with lots of pins, its nicer to have a board like the UB1 attached to output all those pins nicely and deal with a few other things like relays.

Next, the controller sends off pulses to the drivers. Depends on the motors you choose, but the Leadshine AM882/EM806s are popular around here. Nice to have a decent current range and voltage range that are applicable to your motors, and missed step protection is nice. As you point out, one driver per stepper.

PSU to power the drivers. Calculate the right voltage and current, then size appropriately. Some folks like Joe build their own, its not too hard. Other PSUs will be needed for the sensors and auxiliary components, you'll have to draw up a diagram to figure out what you need. Typically a 24/12/5V, or maybe even multiples.

Spindles and VFDs often bought together from China. Recommend ER20 or ER25 for the larger tooling. Water cooled will be a lot quieter. Some even come with a pump - to be honest, it doesn't seem like the cooling requirements are massive, an aquarium pump will probably do.

Other electronics - Circuit Breakers, Contactors, Switches, Relays, loads of wire, Limit switches, Home switches, fans.... the list is endless. Don't forget software, and somewhere to keep all these expensive electronicals.

Now, for a bit of a curveball... The problem I am currently running into, is that I am not going to be at the company I am currently at for much longer. They do allow me to use their hardware, however, which would come in really handy, building the machine. I am wondering now, if it would be okay to start ordering parts and building the frame/gantry now, while I still have access to the tools and the mechanical engineers willing to help, in parallel to getting the electronics planned out, or would should i wait to be done with that?

Up to you. If that was my situation I'd probably be making a start while I've got the opportunity to utilise the expertise, but be prepared to backpedal slightly more than if you've got a plan sorted from the start.