First trials of the 3018 CNC after z-axis upgrades show it is all moving in the right direction. The z-axis linear bearing rail size was incorrect in the original as bought condition. Correcting this has had a significant effect.
Increasing the spring stiffness of the backlash nuts on the X and Y axes has also helped. However, I have had to put grease on the leadscrews reduce the friction.
This small cnc machine can now engrave hardwoods very accurately. Although, it’s not that fast, glue-it.com machined in hardwood took me 1 hour 25 minutes.
- 22mm high letters, 4mm deep
- 1.3mm diameter end mill
- 0.5mm deep cuts
- Feedrate 200mm/min
The cutter was a low cost carbide bit that is more like a burr than a cutter. So, definitely some more research needed on very small router bits.
The 3018 CNC after Z-axis upgrades is significantly improved. However, the X and Y rails are moving quite a lot. The next upgrade is to change these rails from 10mm to 12mm diameter. Rails and bearings are available as upgrades from the USA, but come with a heavy postage. Other options are to find a local source for rails and bearings or to try something different. How about stainless steel tubes 14mm OD, 10mm ID and maybe fill the centre with sand? This would increase the stiffness and add damping.
Is this really worth it? Or do I look for a better machine? Can I find something as small as this though?