Hello Pete and welcome! I have looked for a Stand Alone 4th axis for the Shapeoko for over 2 years now, and still can't find something that fits my needs (Fit's below the X-Axis rail and is affordable). I am also hoping that maybe SOMEDAY Carbide3D will offer an updated control card with a 4th axis option. On my bucket list is to make a mini V8 engine block on the Shapeoko3...so I will keep looking. As it happens I am now starting to record a video about making long parts on a Shapeoko (good timing). I am making a 60 inch (5 foot, 1.534 meters) sign on my machine this week. I'll be posting a video using my EZ method soon.

Correct (Assuming your material is conductive)

+stirlingfromla Thanks! I'm thinking about getting the aluminum table anyway (as my MDF waste board has been soaking up cutting oil), but it's a hefty investment for that much tapped metal. Is it flat and true enough that the cutters don't ever scrape it, or do you shave a few mil off your maximum cutting depth to avoid it? Also, have you considered using a speed controlled DC motor? I saw someone using a 1500 watt Chinese one that he says is much quieter than the DeWalt and better for cutting aluminum because of lower speed (9000 rpm instead of 16,000). Curious what you think.

Thanks Mark for the questions. Yes, the $400 is a little pricy. You could source a 24x30 1/2" plate and have to ground, machined etc, but I think it would cost more. The S3 plate from Carbide3D is ground, anodized, drilled and tapped every 50mm, as well as bolt right in with no machining required. Is it flat? Yes. Checking this turns into a small problem since the X and Y Rails are extruded with no post machining and can vary from lot to lot, so checking can result in an error if the rails are not flat (which they are not). Anyway, I have never touched the metal table, since it is flat within a few 0.001" for my machine, so leaving a 0.010 thin skin under the cutter on a part that measures (say 6" x 6") will only vary 0.001". So yes, I raise the Z (usually) 0.010 to 0.020 so that it doesn't hit the metal table. Next, onto your spindle question. I don't like the water/air cooled Chinese spindles, and like you want a lower speed spindle (for cutting Stainless Steel, not aluminum, I want high speed (16k to 20k for cutting Al)) and have been very happy with the torque of the DWP611, that I will probably install a Super PID system this fall to reduce the speed and pray that it has enough torque. As far as your noise concern I find the DWP is very quiet, but remember most of the noise is produced at the cutter. (via cutting forces and chatter). FYI: Stiffening the motor place will reduce most of the chatter. Hope this long answer helps.

Well, yes and no, mostly no. Carbide motion likes to work in metric, let me explain its little quirk. I made a program in Imperial, Inch, SAE, what ever you want to call it, I even click on the Inch button in Carbide Create, but to sent the machine to a position, I see that the command NEEDS to be in Metric. I talked to Rob over at Carbide3D and he said that if I put a slash (/) before the command it overrides Carbide and talks directly to the GRBL board. (Sounded like it was more of a pain in the butt to remember this, so I continue to use Metric commands, and likewise, the dimensions for probing needs to be in metric as of today. There is a BIG update coming for GRBL and Carbide Create, as well as a really cool probing block. Whether or not it will change it I don't know. So We'll have to wait and see.

Thank you very much. I had a feeling it was metric only. Prish

Thanks for the question, but I do not use a tool change command in the middle of the program because of the disconnect problem that I and so many Shapeoko owners get when powering down the router. Meaning that if I write a part program that requires 4 different tools, I'd post it into 4 individual programs for each tool. Complete the program is the tool go back to the part's X0Y0Z0, and start the next program. Hopefully someday Carbide3D will fix the disconnect problem so that I can write a single program with multiple tool changes within it.