Chinese 1610 CNC: a beginner's one week journey

Hi everyone.

I had a week of vacation last week. The plan was to work on the next DCS-BIOS version and answer forum questions about the current version. But no plan survives first contact with the enemy.

The enemy turned out to be eBay, which made me realize how inexpensive entry-level CNC mill kits have become. My apologies to everyone whose questions I have ignored all week, I was distracted by the shiny thing that arrived in time for my vacation:

The image shows a 1610 CNC kit I got for 185 Euros.

The work area is 160x100 mm.

The Z height you have to work with depends on the length of the bits and the thickness of the sacrificial board. With the 38mm long bits I ordered and a 7mm sacrificial board, I get about a centimeter of useable Z movement.

The machine comes with 10 cheap 10 degree engraving bits with a 0.1mm tip. On Warhog's advice, I purchased some decent quality engraving bits and end mills from a local supplier.

****-ups and fixes

The machine arrived three days before my vacation and came flashed with grbl 0.9, which is an open source CNC controller. The current version is grbl 1.1f, and whoever designed the control board ("Woodpecker CNC") did not bring out all of the pins needed for in-circuit programming.

...so the first thing I did was to solder some wires to it, and tried to update the firmware. That did not work immediately, and while debugging the issue I managed to short something out and fried the on-board ATMega328 chip. I ordered a replacement board just in case, then pried off the chip and attached an Arduino Nano (with current firmware) instead.

That worked, but I had some issues where the stepper motors would randomly do their own thing and crash the bit into the mill table. I found out later that this was caused by the probe cable being too close to the cable for the spindle power supply, but this issue made me switch to the new controller board (an Arduino Uno with a CNC shield).

The switch to the new controller board also meant that I am now running the steppers on 24V intead of 12V (I checked the part number on Google, they are rated for 12V to 24V operation).

After that, I managed to get the machine running.

I have mounted the old controller board (which I still use for the connectors and the MOSFET that switches the spindle power) and the new controller board in the case of a broken ATX power supply. The case came with a fan which draws about 100 mA at 5V, so I attached that to the Arduino's 5V line. The stepper drivers used to get pretty warm (not too hot to touch though). With the fan, I can hardly tell that the machine has been running after I turn it off.

The first thing I made was the small PCB. That proved that the machine can do what I bought it for: make PCBs suitable for SMD soldering of SOIC packages.

The second product was the small wooden box, which I designed as separate 2D drawings in Inkscape. That's where I found out that milling something like this can take quite a while (about 1.5 hours for this 5x5 cm box).

If you have a new tool, you will want to buy more tools

After making the small box, I knew I needed a faster way than milling to cut wood and acrylic. I also wanted some way to cut material stock to size before milling. After some research, I purchased a cheap scroll saw (73 Euro).

The Einhell TC-SS 405 E has an adjustable speed range from 400 to 1600 RPM. At low RPM, it was very quiet when I tried it at my parents house. Once I moved it to my apartment, it made the whole floor shake. I tried placing it on a piece of styrofoam, which had no effect at all. Then I tried placing it on a blanket (wrapped in a trash bag to protect it from dust). That works remarkably well. At low RPM, it now sounds like a sewing machine. If I adjust the holding mechanism so the 4mm plywood gets pressed firmly against the saw table, then even while cutting wood the vacuum cleaner is louder than the saw.

For the large box, I used the CNC mill to mark the cutting line and then cut the thing out with the scroll saw. I used the blade it came with, which was a bit too coarse for the job.

To design the large box (12x7x2 cm), I wanted to use a 3D CAD program. After trying FreeCAD and getting frustrated with it, I found SolveSpace.

SolveSpace is still in early development, so it does not have many features. That also means it has a clean interface that does not overwhelm a beginner. It does not support variables, but you can import one sketch file into another and then use "equal length" constraints against lines from the imported file. I used that to define the length, width, height and material thickness of the box once and re-use those values for all three sides. If I want to make a smaller or larger box of the same design or cut one out of a different material, I only have to modify a single file.

Unfortunately, I did not find a way to export just the outline of a face, so I ended up retracing two of the three sides in Inkscape. I'll have to look into this some more, there has to be an easier way to do this.

You'll spend more than $200 on a sub-$200 mill

All things considered, I spent close to 500 EUR on the mill, scroll saw and accessories. Here's a rough breakdown:

CNC Machine					185 EUR
New Controller Board	(Express Shipping)	 30 EUR
Drill Bits					 52 EUR
Scroll Saw					 73 EUR
Saw Blades
Cordless Drill				 70 EUR
Digital Calipers			 13 EUR
Feeler Gauge				 10 EUR
Materials					 50 EUR

Workflow and end mills

For anyone curious, here is the workflow I use:

I draw my plans with SolveSpace.

Some 2D exports require some post-processing in Inkscape.

The G-Code is generated and sent to the CNC mill with bCNC, which can also do autoleveling for PCB milling.

For PCBs, I use KiCad to draw the PCB, pcb2gcode to generate the G-Code and bCNC to send it to the machine.

The stepper motors are controlled by an Arduino Uno with a CNC Shield, running grbl v1.1f.

Review

The machine does what I purchased it to do -- it enables me to make single-sided prototype PCBs and is accurate enough to create 20 mil traces for SOIC packages.

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It does not come with any assembly instructions. Fortunately, someone has done a review of the machine and posted build instructions on his website. My machine was slightly different, but I managed to assemble everything in one day. The process can be a bit annoying at times, but it is not difficult.

I don't know how suitable this machine is for building a home cockpit. I'll probably find out soon enough. I don't have plans to build a simpit, but with the machines to do so now always available, I see some multi-function panels in my future.

Looking at this machine on my desk now, I realize that a 3020 would also fit on this desk. On the other hand, even when realizing this before, I probably wouldn't have spent $500 on a machine without knowing if I could get it to work beforehand.

Thanks for your post interesting.

This is great Ian, thanks for posting. I've never heard of SolveSpace before. I'll be downloading it for sure. My China CNC machine is still serving me well after a about two years. I use bCNC as well, but connected to a Raspberry Pi 3 + Arduino based motor controller for my X-Carve CNC. Works very well and the price is right.

I also think Vectric Software is pretty freaking awesome. A combined CAD/CAM. If you check out their tutorials, you can get a feel for how easy they make things. I don't have a background in CAD other than Autocad 30 years ago on DOS - LOL

And I tried like 8 or so CAD and CAM packages and settled on Vectric.