My Saturn Arrived Yesterday!!! Time to get busy
One of the design goals of this was to have a control cabinet that was clean with as few of components as possible, I will cover each component and the reasoning behind the choice to use it.
The learning curve behind all of this is very steep which is why I am creating this buildlog in case anyone wants to venture down the path of making their own control cabinet. If you don't want to use the Saturn maybe say a cheaper OX or R7 openbuilds based router this electronics kit would be a nice upgrade to those units especially the R7 that many seem to run into issues ywith.
I did a lot of research before deciding on the Saturn. The machine itself was $3500 but with all steel construction it was an easy choice over the aluminum extrusion machines in the same and even more expensive price range due to how rigid this thing is, I liked it even more than some machines being sold for $13,000. Although their website is not yet updated, the gauntry does now ship in steel not aluminium extrusion.
The unit can be purchased with a plug and play Nema 23 or Nema 34 control cabinets but they come with steppers and after reading several positive reviews from people who upgraded those kits to the Clearpath Teknic SDSK servos I was sold and so here we are. The Clearpath servos also have the drivers built in which means less components in the control cabinet and is part of the reason they are noise immune. To power the clearpath motors I went with the Teknic Amazon IPC 75VDC wired in 220v Single Phase (Optimal but can be ran on 120), This power supply has built in noise filter as well as working with the Clearpath servos which have the driver built in to the motor. This setup is noise immune and shielded cables are unnecessary, the OEM cables from Teknic are way too pricey so I just bought some Molex connectors and Belden wire saving myself a few hundred dollars.
A point to bring up about price, most people think oh no Servos are way to expensive when they compare a Clearpath to an equivalent stepper motor. I have to say that is just not true with Clearpath servos; there is a reason they call it the SDSK series (Step Direction Stepper Killer). You need to do an Apples to Apples comparison: 1) You need to include the cost of the drivers for the steppers 2) you do not need shielded cable for the Clearpaths 3) There is less footage of power wire and connectors $$ on the control cabinet for the Clearpaths because they are Daisy Chained together 4) you can buy a smaller NEMA enclosure because there are far fewer components in the control cabinet
When you take these things into consideration the Clearpaths come out the clear winner pun intended
Next up is the controller, after reading countless opinions on the different controllers and UCCNC vs Mach3 vs Mach4 software reviews I decided to go with the UC300ETH controller because it supports both Mach3 and UCCNC software. Many are transitioning away from Mach3 because it is end of life with no new bug fixes being implemented and this controller gives them an easy way to play with both Mach3 and UCCNC as they learn the UCCNC software. There is a UC400ETH but it does not have the features the 300 has and many regret going for the 400 after the fact. What about Mach4? Well it does not really have an end in sight of when it will be finished and the UCCNC software not only costs a lot less but is also actively developed and is preferred by many who have made the switch especially when using Ger21's (from CNCzone forums) Screenset.
For the BOB (Break out Board) I followed in Ger21's footsteps and went with the MB2, it was designed specifically for the Mach3 ESS controller but is compatible with the UC300ETH (not 400) to mount the UC300ETH you will need to 3D print a offset standoff board so the mounting holes can align. The only downside is the UC300ETH is powered via 5v (wish it was 24v) so for now a 5vdc power supply is required to power the UC300ETH and a 24vdc for the MB2 (This is not the case if using an ESS board with the MB2 but ESS is only compatible with Mach3). Both Ger21 and myself have been in contact with the manufacturer of the MB2 and he has agreed to create a version specifically for the UC300ETH so by the time you do your build the 5v power supply wont be needed and your install can be even more compact. Choosing the MB2 over other boards came down to the feature set, this board has a lot of built in functionality that can reduce the number of components needed as well as price for your build, I highly recommend it.
For DIN rail power supplies I chose the Micron Dinergy Series, these supplies come with built in noise filters (With a claim of better filtering than the competitors), again one of the design goals was a clean install with few components. They are a bit more expensive then other supplies but I did not price out what the other supplies plus cost of noise filter is so it might even itself out.
I also wanted to incorporate a low cost windows PC (for the UCCNC/Mach3 software) inside the control cabinet so all that was needed was a monitor and keyboard on a swinging arm, for this I chose the LattePanda 2GB ram / 32GB storage. One of the things that sparked my interest with this is the Arduino co-processor, I do not yet know what I am going to use it for, maybe sensing voltage and temps of the control cabinet, or find ways to incorporate it into the CNC process but its there for me to play with as I go. I recommend buying the version without a activated windows license if you have an extra windows 10 pro license key that you can use. You can use Blackbird on the home edition but it does not do as good of a job stripping the OS to bare essentials like it does on the Pro edition of windows. With that said, by using Blackbird to strip out all the windows 10 bloat (metro apps, background processes etc) the device is very fast and responsive. Just be sure to order up a couple packs of the copper heat sinks to keep it cool so it does not go into throttle mode. The LattePanda is also powered by 5v so this might not be something you want to do if you are building out a small enclosure with the new MB2 when available. Myself and another person have put in a feature request for the next version of Latte Panda to be variable power so it can be supplied by 5vdc-24vdc
I skipped using power distribution blocks or a ground star bar (Yes the build would be cheaper using them but my goal was clean, compact install). Instead I decided on using three level terminal blocks with P.E. ground (Phoenix Contact) which allows the ground to terminate on the same block as the power (get 4 level for 3 phase power). This keeps things tight and allows the ground to be twisted along with the power back to the source, It also means things are more compact with only one block per device. You will notice in the photo that one of the terminal blocks has a blue colored top, order these ones for any 120VAC connections, it makes it easy to identify which blocks have a Neutral instead of two hots. If using these you need to make sure that you mount your DIN rail properly since it becomes your ground bus. Don't drill and tap and do not use self tapping sheet metal screws, instead use self tapping "machine" screws, these are the only type of self tapping screws approved by code to make enough contact. There is also a press fit method but I do not have the tools for that so self tapping machine screws it is.
The fuse holder is a J-Class Finger safe fuse holder but you can go with a standard J-Fuse holder to save cost.
The SSR (Solid State Relay) is a 25A relay for controlling the power receptacle and switching on any devices you might need.
2.2KW Hitachi VFD Drive as recommended by many on CNCZone and a 2.2KW Water cooled spindle from BuildYourCNC (They have settled on this one over the years as the most reliable affordable option).
The only thing missing from the photo's at the moment is the Altech DIN Rail 15A GFCI branch circuit breaker for the 120VAC (on my enclosure this is to power a receptacle for a pond pump for water cooling but if not using a water cooled spindle you could use it to power on a router and/or a shopvac for dust collection).
I will update this post as I continue through the build, but that is what I have for now