I have been cutting the same material for years , same settings but something is wrong.
Something is causing my Laser to cut wide at times, I now have to Resort to turning the machine on and off again to get it to start a clean thin line.
What is the main reason for this to happen. ? I Now have to do a Starter Cut to see if its going to be a thin cut or a wide ?
The Wide ruins the material quickly .
Please help
Might be a focus problem? Are you using auto focus or are you setting it manually? 
Putting in the depth my self and than using Auto focus , is there a better way. ?
Take a look at this post, plus the one after that… 
@coalakida: I should also point out that the point where the Glowforge does its focus is not where the laser cuts. It is slightly to one side. When the focus operation happens you can see a red dot flash on your material. If you are going to use auto focus, ensure that the red focus dot is falling on a place where there is material and not, for example, in a “hole” from a previous cut.
Where do i set the Focal Height , I only ever see the material height . or are you talking about what the camera registers. ?
@coalakida: Here is an example from a recent job here…
WOW thank you.
So let me see if I have this right, if my material is 0.5 and I also set the Manual to 0.5 it will not use Auto Focus but use the exact setting I have placed in the Manual. >?
@coalakida: I cannot comment on that. It may be true?
I believe that the material thickness calibrates the camera. Here is what the same cut that I posted shows when I click on the “UNKNOWN” material box and then select “use uncertified material”.
I’m sorry that you’ve run into some trouble with the kerf on your Glowforge. It’s great to see that you’ve already received some excellent information from our other community members. Thanks folks!
In addition to what’s been shared so far, you can learn more about manual settings including manually setting the focus height on our support page here: Working With Manual Mode.
Please let us know how your next prints go!
The Problem was the Auto Focus and the Browser sometimes getting really confused. I now know what to look for before I push the button , At this point I just have to close out of the Browser and start again, I also do a practice circle to make sure its on point…
You’ll want the values to be different. You want material thickness set to the actual (this is so the camera view is the most accurate), and then you’ll want the manual focus value to be slightly different - so .500 thickness and .499 focus.
We’ve recently announced that we’re switching the “Problems & Support” section of our forum to “Community Support”. Since you started this thread to have a conversation with our support team, I’ll be reaching out to you very soon via email so that you can continue to work with our support team directly.
