Sainsmart CNC 3018

Thread Starter

MrChips

Joined Oct 2, 2009
23,962
We got the Sainsmart Genmitsu CNC 3018 four days ago. It took my two sons and I about 3 hours to assemble and 3 hours of alignment spread over two days.

1610153861668.png

This model has been discontinued and has been replaced with the 3018 Pro. So far the quality appears to be excellent for the price with no complaints or issues. The reality is that this is an engraving machine and is probably not powerful enough to mill aluminum. It can engrave PCB prototypes on FR4 laminate but for the moment I have no intentions of doing so.

We are slowly taking it through its paces and have yet to make our first cut. Learning the CNC process and how to use Fusion 360 is our first step.
Our goal is to take our experience with this and build a larger and more powerful DIY CNC machine.
 

sagor

Joined Mar 10, 2019
469
They are handy tools, I've milled some plastic bezels and PCB with those.
Just a couple of comments:
1) The plastic housing that holds the motor in place may crack where the tightening screw closes the clamp on the motor. I had to drill and tap a regular screw after it cracked. Maybe it was too tight to start with?
2) The 45 degree support arms, if plastic, may flex a bit, causing some inaccuracy as the gantry can still flex a bit.
3) I added a mini-chuck to my motor, making the entire motor/chuck assembly a lot longer. Thus the vertical supports for the gantry were too short. I ordered new aluminum channels to increase the height. At the same time, I got proper 90 degree steel side supports/clamps to hold the vertical to the base better, to solve issue #2

Have fun with the machine...
 

BobTPH

Joined Jun 5, 2013
3,507
I bought one of these about a year sgo hoping to use to for PCB milling. No way. The spindle motor was way too slow for that. I replaced it with a far more powerful Dremel tool at 30000 RPM and still no luck. The problem is that the height mapping needed to get accurate depth was was useless. No matter what I tried, the depth would vary from not even scratching the surface to going several times deeper than the the copper layer. And, whenever ot gets too deep, the machine crashes, even taking out the USB on my PC requiring a reboot. Never got close to making a usable demo board.

Bob
 

sagor

Joined Mar 10, 2019
469
@BobTPH, did you run autoleveling in the software? That makes a difference in how it does the depth of the tracks. I've used bCNC software for running the machine. Yes, I've had crashes the odd time as well. Good ferrite chokes on the USB cable helped with that. It is too bad the machine does not have a "home" microswitch or sensor, so one could re-calibrate after a crash. The driver boards usually have sensor inputs for those.
 

Thread Starter

MrChips

Joined Oct 2, 2009
23,962
@BobTPH, did you run autoleveling in the software? That makes a difference in how it does the depth of the tracks. I've used bCNC software for running the machine. Yes, I've had crashes the odd time as well. Good ferrite chokes on the USB cable helped with that. It is too bad the machine does not have a "home" microswitch or sensor, so one could re-calibrate after a crash. The driver boards usually have sensor inputs for those.
So far I have been following what others have done with this machine.
The first thing I did was build a box for the electronics. It is handy having a 3D printer. Then I installed an E-STOP button.
The next thing will be to install limit switches on all three axes. It does come with Z-probe input.
And finally I will add a vacuum hose for dust collection to my central vac.
 

Thread Starter

MrChips

Joined Oct 2, 2009
23,962
What CNC software package does it use, or is it proprietary to the machine?
Max.
The controller board is a generic board powered with an ATmega328 executing GRBL gcode. It is interesting that they are using a USB-to-UART bridge instead of true USB. The data rate and volume is low enough that at 115200 baud this is still ok. I would imagine that implementing a USB stack is too complicated, at least it would be for me too.

I am running Autodesk Fusion 360 that can generate the gcode into a .nc file. It has a simulator so that you can watch the tool paths. The CNC control program is Candle. Both programs are free.
 

BobTPH

Joined Jun 5, 2013
3,507
@BobTPH, did you run autoleveling in the software? That makes a difference in how it does the depth of the tracks. I've used bCNC software for running the machine. Yes, I've had crashes the odd time as well. Good ferrite chokes on the USB cable helped with that. It is too bad the machine does not have a "home" microswitch or sensor, so one could re-calibrate after a crash. The driver boards usually have sensor inputs for those.
The machine did not have auto-leveling, or even manual leveling screws like my 3-D printer. I used a software height map, but that did not seem to help at all.

Bob,
 
Top