New Chinese Laser Help

[Rob Preston]

Hi everyone, what a great forum.Just bought a 50w laser from eBay
looking for some help please :
1: what is the correct height that the laser should be from the work that I am doing ? Using the template
2: how do I get the laser to stay in the top left hand corner ?
3: what sort of settings shall I use for engraving on 3mm ash ?
4: how do you do a dummy run without cutting or engraving ?
sorry for all the questions just a bit confused

thank you

[Clark Pace]

The model would help. But also I have seen two different almost identical models from the same company come with 2 different focal lens. You you will need to know that? Most machine are set for the upper left hand corner. On the dummy run, either run software simulator, set power to 0%.

[Rob Preston]

Thank you for the reply, this is a link to the machine : PRO 50W CO2 Desktop USB Laser Engraving Cutting Machine Cutter Engraver . Have you any idea regarding settings etc

[Bert Kemp]

To know the height from material you need to know the focal length of the lens your using. machine should have come with a height gauge

[Michele Welch]

Oh Bert, Bert, Bert! Really, a Patriots fan???? Just kidding, gonna be a good game in 2 weeks!!! Go SEAHAWKS!!!

To know the height from material you need to know the focal length of the lens your using. machine should have come with a height gauge

[Rob Preston]

Thank you for the reply Bert, I received with the laser a piece of acrylic 1cm x 4 cm. Unsure to use this vertically or horizontally? I am trying to cut 3 mm mdf or ash but not sure what settings to use ?

[Jerome Stanek]

Use the slant method to get your focal length.

[Rob Preston]

Can you explain please, and thank you for the reply

[Kim McIntosh]

Only a newbie myself Rob but I'd like to try and give a bit back. The piece of acrylic is your focal length gauge used horizontally. On one of the threads here it explains how to draw up a grid of squares with power listings down the side and speed settings across the top and then experiment with the timber you are cutting. I started off with increment of 10 (as in 10mm speed and 10% power) and then when I got close to the correct setting increments of 1. Hope that is of some help.
Kim

[Rob Preston]

Thank you Kim
I will keep that in mind , I thought I might have got a manual with settings for different materials along with the laser.

[Bert Kemp]

Rob theres several post here on how to get the correct focus height. one is to use the slant or slope method, assuming you have a 2" focal length lens basically you set a piece of anodized Alum or wood on a slope , prop it up on one end about a maybe a 1/4 inch high then program a straight line at low power make sure your laser head is not going to hit the material at any point and engrave a line the length of the material where your line is the thinnest is where you want to measure for your gauge. then cut a sq piece of acyclic that height and then you have a height gauged. Hard for me to explain mAybe someone else can do it better

[Rob Preston]

Thank you again Bert, not quite sure what you mean ? I have searched the forum but can't find another post. Thanks again

[Bill George]

Thank you again Bert, not quite sure what you mean ? I have searched the forum but can't find another post. Thanks again

Take a thin piece of finished sanded wood or other, prop one end up on the laser table about 3/8 inch or so, let the other end rest on the table. Set your laser head just high enough to clear the higher end of the slope. Set at a medium power and burn a line from the table end to the propped end. At the point where the line has the best looking cut and as narrow as possible, measure the distance from the end of the nozzle to the test piece, that is your ideal focal length.

The L shaped distance gauge with your laser should be flipped around so the bottom of the L is up and that end will rest on the top thread of the nozzle cone and bottom is on the work, adjust as needed. Your results will vary, if its not like mine