CNC Build
CNC MACHINES:
Even "Desktop" CNCs can be enormous machines. Here's the smallest "desktop" model presently available from Laguna Tools (including an optional table):
We have a VERY confined space. Here's a turn-key solution whose X and Y dimensions would fit in our workspace:
You can see from the design of the above machine that it will do a great job at cutting "flat stock" such as plywood.
BUT the "vertical travel" (Z-Axis) is only 90mm (3.54 inches), and the "gantry" (the part that slides front-to-back) clearance is only 150mm (5.9 inches). So making 3D objects higher than 90mm is either impossible, or a major PITA.
Maybe there's a machine with more Z-axis travel? In 2021, the answer seemed to be no. At time of writing, it's the same answer: here's a snapshot of "Large Format" CNC machines from a Bing search (Source: Best Large Format CNCs in 2023 (Every Size) - CNCSourced):
You can see under the "Working Area" column on the right that the first item (Sainsmart Genmitsu 4040 CNC Router) has 3.31" of Z-Axis travel. The 2nd last item above, the "AvidCNC Benchtop PRO2424" has the most Z-Axis travel at 9". Here's what it looks like:
It looks like a lovely machine, but once again the gantry clearance is only 151mm [5.94 inches]:
[Vibration is the enemy of accuracy. Intuitively, suspending the Spindle motor on a gantry will be a bit "wobbly" and imperfect.]
So the author concluded that a traditional "CNC Machine" was designed more for cutting large, flat objects, but not objects that extend upwards much ("3D objects").
VERTICAL MILLING MACHINE
For a much improved Z-Axis, there is a "vertical milling machine", first created by Eli Whitney in 1818. The modern incantation is much bigger. Here's a photo from the current Wikipedia entry of a Bridgeport-style 3-axis machine (with my hand-written notes in Red):
Indeed, it's enormous. Per the internet, the typical weight of a vertical milling machine is 2,000 to 3,000 lbs. These machines are capable of extremely precise machining on very hard materials such as steel.
Intuitively, the vertical mill design does an excellent job of stabilizing the cutting tool. To achieve X, Y and Z-Axis movement, the "table" on which the workpiece sits moves instead.
The author is planning to make models exclusively from wood and soft metals such as aluminum, so there is no need for a full-size vertical mill made of steel, and we've found it to be a high-corrosion environment here. We don't have the space for one, in any event.
Here's a hobby-size vertical milling machine from the same current Wikipedia entry:
This design is making much more sense for making 3D objects. This one is a bit small, and the Bridgeport-style is clearly too large, but with a custom design, the author can attempt to optimize the working X, Y, Z axes within the confines of the limited workspace available.
For reference, here are some entry-level Tormach ones:
BC COVID-19 RECOVERY GRANT
As our Premier said in March, 2021, "We can't just leave bags of money in the street for businesses, because we're accountable to taxpayers for their money."
I took it as a challenge to make a long-term investment in my business. Instead of relying on third parties to make things and ship them to us, we can just make them ourselves.
A 5-axis machine can make incredibly detailed objects:
We have more ideas of physical things that we can make than we have time to make in our lifetimes.
DIY vs. Turn-Key Solutions
Turn-key solutions are EXPENSIVE. In retrospect, I appreciate how it makes sense when you want results ASAP. You would save countless hours of going down the wrong paths and wasted effort.
Building a DIY CNC Mill
This video has been the single greatest source of help and inspiration to my own build:
Sadly for the author, the efficient mag-drill process the maker uses is available for steel, but not aluminum.
Choosing Components
It seems that HIWIN brand components are among the most respected and high-quality ones in the world. So I started by looking at their product lineup in [March 2021].
When it came time to make decisions, my first mistake was choosing components that are MUCH larger and heavier than I was expecting. The numbers look great on paper, but when you pick up these components, made of solid stainless steel, they feel incredibly sturdy but also VERY heavy.
So the idea of using the IndyMill design was out the window.
The Corsair 4000D case can accommodate either 6 x 120mm fans, or 4 x 140mm fans. We want volume of airflow, normally measured in cubic feet per minute (CFM). RGB is a nice-to-have luxury (aesthetic only).
Training on YouTube
Choosing fans for the dedicated tower computer: (2463) PC Fans Types Explained... What is right for your setup? - YouTube. The video makes clear that ball bearings don't tend to deteriorate over time the way fluid bearings ones do (mostly due to dust imbedding itself into the lubricant). The incremental cost of ball bearings is about 25%, or about $20 upfront.
At time of writing, installing 4 x 140 mm of the following looks to be best performance per dollar of cost (with a whopping 169 CFM per fan):
It also happens to have addressable RGB, with an incremental cost of about $5/fan (Iceberg brand), or $20 total incremental build cost.
So this is the fan we are moving forward with (adding 1 extra as a spare).
Display/Keyboard/Mouse
We have an old touchscreen laptop (with no parallel port) that we'd still like to use for its display, keyboard, and touchpad to run Mach3 on the AMD computer.
In a sense, we want the AMD computer to be a server (with no independent keyboard, mouse or display) ("headless" in computer jargon, apparently).
We found the following videos very helpful (starting at ~5:15 for the first one):
We picked up an HDMI video capture device on Amazon for about $14:
To add a connector to an ethernet cable, we found this video very helpful:
TThe plot thickens on Mach3 running on Windows 10:
And yet, the current Mach 3 website itself suggests that Windows 10 should work:
Mach 3 continues with the following:
There is no definition of "external motion device". We had thought the BBC Breakout Board was such a device. As it turns out, no it's not.
After much reading, it seems that an "external motion device" such as the following will provide vastly better performance:
It's clear that the Ethernet SmoothStepper is the clear favourite for new builds.
Let's try the sole Canadian distrubuter (the pricing is lower in any case): DashX - Service and Retrofit of CNC Routers: Laserspec, Camtech.
The existing Ethernet port is connected to our Router, so we'll need to add another Ethernet port on the AMD Computer.
Mach 3
This one was most helpful on Feb-15-23, to make extra sure that the BBC Breakout Board instructions from MachDrives (and Stepper Motor Canada) we've been working with don't include any errors / troublesome settings [shortly before going live]:
Stepper Motors now working, but NOT POWERFUL enough. Ugh. Perhaps surprisingly, the Z (vertical) axis works reasonably well, as does the deep Y-axis, but the X-axis is quite sticky. I will attempt to improve it before installing the X-Axis Servo Motor.
It's clear that at current pricing the Servo Motors are quite reasonably priced, in the author's view. Servo motors have the built-in advantage of a position-sensing feedback loop, yielding superior results.
Electronic Control of Servo Motors
To leverage our knowledge of setup, let's try to control the 750W servo motors with a BBC Breakout Board (using section 6 this time, for Servo Motors), and ESS Smoothstepper. We will preserve the labour on the stepper motor electronics build for another build... likely a 3D printer of some sort, or maybe a CNC router with a larger table]
Problem: the Servo Motors need 24V control inputs. The BBC Breakout Board outputs much less than this (there is no information anywhere that I can find that provides the output voltage specifications). I've tried using a 2222 transistor to boost the signal to 24V, and I can get the Servo Motor to turn, but it's completely uncontrollable. I don't believe I have enough information to be able to engineer a reliable solution.
I re-reviewed the User Guide to my Oscilloscope to make sure I was using it correctly, but to no avail. Perhaps these devices are designed to make it difficult for a DIY-er?
The YouTube video ( ) using 750W Servo Motors successfully used an Eding iCNC600 Industrial CNC controller. I'm tired of things not working, so I think it's time to spring for one of those. I've tried all other options and despair is setting in.
The Eding comes with its own software, plus customer support.
To close the chapter with Mach3, I left a message with MachDrives that might engender a response (they ignored me previously):
...and this time a response was swift! David from Machdrives sent me a detailed, hand-written diagram of how to wire it (!)
Sadly, it does not work. I have checked and re-checked that my wiring matches the above EXACTLY, but I am not able to move the motors.
Servo Motor Upgrade
Machining Aluminum
We will try using isopropyl alcohol when machining aluminum, as per the following: (823) Does isopropanol make a difference? - YouTube In short, yes it greatly improves the finish.
Remote Control of Windows Computer
This is the only YouTube video that I found highlighting the need to first modify the BIOS: