I got one of these from BangGood. As delivered and assembled it was fine for making simple wooden signs.
My goal was to squeeze the best accuracy out it and I did after 20 hours of rework, mods and tuning.
I really wanted to make accurate and high quality wooden gears for clocks and anything else.


Basic kit has all the raw material you need for simple sign making.
Aluminum extrusions are accurate and well cut
Stepper, leadscrews, bearing, electronics, cables, and spindle motor are adequate.

The BAD:

All 3D printed parts had very little interlayer adhesion so their strength was much less than wood.
The critical dimensions for the Y axis rails and linear bearing were off by a lot which forced the leadscrew into a permanent bow
The t-nuts are defective and unusable in any normal way. Because there is no friction element in the nut it cannot function properly and if you can get it to turn 90 degrees it only grabs a tiny part of the aluminum rail.
The antibacklash springs are hopelessly weak, less than 2 pound force, so this makes antibacklash a joke
All pockets were 0.018 inches too small


After fixing each of these problems I now have a great machine that makes very accurate high quality cuts:
** All antibacklash springs replaced by 7-8 pound springs.
** Great care was needed to align the Y axis leadscrew nut (required removing plastic from the mounting)
** All t nuts had to be carefully checked for seating and a new #2 phillips tip and a 90 degree driver was able to tighten adequately (this took a long time)
** Some screws were too long and had to be ground down so that they did not bottom out on the X aliminum
** ER11 collet system used,

WARNING do not even think about using heated assembly technique, it causes huge problems. It happens that the two materials to be joined stick and gaul immediately even when engaged slightly by hand so it is impossible to actually check the fit without lubrication.
What works here is to tightly clamp the rear stub of the motor shaft in a vise with the long motor shaft sticking up. Place the ER11 collet (good idea to bevel the sharp edge on this and remove grub screws) gently on the shaft, drop a few drops of machine oil down the hole.
Carefully turn the ER11 with a wrench on the flats and feel the degree of friction, if the friction is not too great then wind down the ER11 within 0.030 inch of the motor housing. You want moderate friction here.
If friction is a bit light then add grub screws with locktight tightening them moderately.
A point to mention here is that the motor is not capable of much torque and therefor the ER11 on the shaft can be a low force mount with no problems.
If the oil-and-turn method of install is too tight then use 800 emery paper to slightly dress the motor shaft, lube and try again. This must be done with the motor powered at 24 volts so roundness is kept.
** All of the 3D printed parts will fracture and split under light screw pressure. Fix this by making custom support plates from thickwashers to spread the load around and cause clamping against metal instead of air.
It takes no more work to make good 3D parts with good adhesion, just a temp setting that everyones knows about. It is unfortunate that this did not happen for my machine
** AFter fixing the three axis antibacklash springs and getting good alignment of axis, there is one more sloppy compaonent to fix. The Z axis linear bearing are the shortest and therefore have the most slop.
This is fix by by wrapping a strong elastic band around the two bottom hex head screws and up around the front of the motor clamp. This causes the bearings to always lean hard in one direction.

I hope this helps you. I had to figure all this out by myself over many hours and now I give it to you for free.

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