| It is a common problem for stone kitchen and | | | | line-buster to name a few which may result in a |
| bathroom countertop fabricators that their CNC | | | | better finish. |
| machine leaves visible lines after profiling the | | | | If you compare the hand polish process with the |
| marble or granite edge which results in a not so | | | | way the CNC machine works on a profile then |
| shiny finish as desired. | | | | you may recognize where this lines are coming |
| The lines are unavoidable on profiles with a large | | | | from and why it is hard to get rid of them. On |
| flat section like the 'T' profile but also on all the | | | | the CNC Machine the tool is spinning in the same |
| other profiles more or less. How visible the lines | | | | direction as the machine movement. There is no |
| are depends on different factors. One is the | | | | cross movement of the tools and the CNC |
| stone itself regardless if it is natural stone like | | | | machine movement. |
| Granite and Marble or manmade (engineered) | | | | Just see what happens when you hand polish, the |
| stone. The CNC diamond tools are another big | | | | tool spins across the movement you do by hand. |
| factor of the finishing result. With brand new | | | | That movement is what gets rid of the lines and |
| diamond tooling the lines are minimal but | | | | that is not possible with a CNC machine until |
| eventually they will develop lines that are | | | | someone designs a machine head which works |
| noticeable and unacceptable for most stone | | | | the same way as hand polishing. It is doubtful that |
| fabricators and their clients. | | | | this is even possible. |
| On some profiles and stones it is possible to limit | | | | You cannot really compare a "T" or "V" shape |
| the lines to a minimum by running the polishing | | | | profile produced on a CNC to a profile polished by |
| wheels forwards and backwards 3-4 times and | | | | hand or a line polisher machine. The profile from |
| changing the Z value up and down by a minimal | | | | the CNC is never as shiny and will need to be |
| amount (0.005mm) for every run, which might | | | | touched up by hand if you want a high quality |
| not be possible to do with every profile. | | | | finish. |
| Another option is to manually run a 400 grit pad | | | | TIP: If your CNC machine is equipped with a saw |
| after the CNC has run all the metal wheels and | | | | gearbox than you can get an adapter made to |
| before the polishing wheels. That helps to keep | | | | attach the standard magnetic draining-board |
| the polishing tools in good shape but it is extra | | | | polishing tools to run them on the T-Profile. |
| handwork which disturbs the normal workflow on | | | | Provided your CAD-CAM-CNC software allows |
| the CNC machine. | | | | you to program that correctly especially the |
| Dressing the profile diamond wheels on a regular | | | | entry and exit of the tools are critical, not to |
| basis with the right dressing stones will help to | | | | crash the machine. The result is almost perfect |
| keep the lines to a minimum. | | | | but the arris or pencil round still needs to be |
| There are also special tools called line-breaker and | | | | finished off by hand after. |