Chikonzero
1. Chipande chakachinjika hachina kupinza uye maviri akachinjika blade haana kuenzana-kumusoro.
2. Center point yekuboora uye shank concentricity haina kusangana nemaitiro.
3. Muchina uyu uri pamamiriro ekuti sipindle yapera.
4. Bhodhi yekugadzirisa (artifact) iri kufamba.
5. Spindle kutenderera uye kuchekwa kumhanya hakuna kufanana.
6. Iyo adapta concentricity yakaderera uye imwe data yehunyanzvi haisi kusvika pachiyero.
Chikonzero
1. Nzvimbo yepakati uye shank ndeyekukanganisa, kana nzvimbo yepakati haina kupinza.
2. Chigadzirwa chacho chiri kufamba panguva yekuchera.
3. Spindle kutenderera uye chishandiso chekudya nekukurumidza hazvienderane.
4. Iyo adapta concentricity yakaderera uye imwe data yehunyanzvi haisi kusvika pachiyero.
5. Iyo spindle yemuchina unofinha yakasununguka kana kukuvadzwa.
Chikonzero:
1. Mupendero weblade hauna kupinza, iyo drill bit inofanira kuchinjwa.
2. Spiral groove (chip groove) iko congestion iyo inozotungamira mukubviswa kwechip zvisina kunaka.
3. Artifact (material) humidity pamusoro pemuganhu kana kuti glue quality haina kunaka (kunyanya fiber board uye plywood).
4. Chishandiso chekudya chinokurumidza hachifananidzi nezvinhu uye kudzika.
5. Sarudza yakakodzera drill bit type yekugadzira zvinhu.
