Focus Distance 63 or 68? with z bed

[rushmore1305]

Hello I can't decide which one to get anyone have any insight.
What would be better
Botha are the znSe ones 20mm which fits in the air assist nozzle.
Both are 55$ or close. Just so not sure

[waltfl]

hi rushmore
just make the slope test .
greetings
waltfl

Hello I can't decide which one to get anyone have any insight.
What would be better
Botha are the znSe ones 20mm which fits in the air assist nozzle.
Both are 55$ or close. Just so not sure

[Tech_Marco]

Go for 63.5. You better not to use 68 as the laser tube comes with your machine is small power (35W or less)
The longer focus point you use, the slower the speed you need to adjust your machine to offset the power lost

Some K40 similiar machine even come with 38.5mm focus lens and that make it soley for engraving job. It may still do cutting but not a thicker object though. Probably good for 1~2mm cutting. Therefore, most K40 or smaller power laser machine use 50.8mm as it is most popular for handling decent engraving job and can cut up to 4mm without too much inclination issue.

If you use 63.5mm, you need to drop your speed by 15%~20% to offset the power lost. So, don't 'cry' when you find out that cutting is slower


Marco

[rushmore1305]

Go for 63.5. You better not to use 68 as the laser tube comes with your machine is small power (35W or less)
The longer focus point you use, the slower the speed you need to adjust your machine to offset the power lost

Some K40 similiar machine even come with 38.5mm focus lens and that make it soley for engraving job. It may still do cutting but not a thicker object though. Probably good for 1~2mm cutting. Therefore, most K40 or smaller power laser machine use 50.8mm as it is most popular for handling decent engraving job and can cut up to 4mm without too much inclination issue.

If you use 63.5mm, you need to drop your speed by 15%~20% to offset the power lost. So, don't 'cry' when you find out that cutting is slower


Marco

so when i am primarily doing cutting jobs what lens would you recomend