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StuartW Wilson
01-03-2016, 5:22 PM
Hi there I am using a Chinese 6040 laser at 98% speed is set to 180. The text should be black with no fade, all help appreciated. regards Stuart

Dan Hintz
01-03-2016, 7:53 PM
In your case, I'd say wood density. Is the pith near the center of the board? Notice how the "eye" near the right follows along the same path as the light portion.

Rich Harman
01-04-2016, 4:27 AM
That's a pretty straight line where it is faded on a curvy grained piece of wood. Also notice that the fading is on the interior of each letter while the edges are dark.

I'm guessing that you don't have an ammeter? Setting the power to 98% may well be overdriving the tube if it is not properly calibrated.

StuartW Wilson
01-04-2016, 5:49 AM
I noticed that the laser wasn't firing in the bare spots, would a chiller be the answere? regards Stuart

Dan Hintz
01-04-2016, 6:20 AM
Sorry, didn't notice the darkening at the edges of the letters on my small screen...

In that case, my guess would be something was happening with your cooling system around that time (minor kink in hose?). Has this ever happened before? Is it consistent? Another possibility is a failing tube/power supply, but it's difficult to narrow down without more data points.

Glen Monaghan
01-04-2016, 11:52 AM
Looking at an enlarged view, it seems to me that there are two bands, one much lighter and pretty straight across, just above center, and a second not-as-light band just below center that appears to follow the grain (especially noticeable on the last two letters, probably due to lighting there). The band above center is dark one letter edges but lightens in the middle of the letters while the band below center appears uniformly lighter across the letters, so I'm guessing the upper band was due to some laser power issue while the lower band is probably just natural variation due to the varying density with the grain.

Kev Williams
01-04-2016, 2:47 PM
It would interesting to see a closeup of the edges around the C in Shack, to see if the black edge is happening on only the leading-edge, the trailing-edge, or both-

StuartW Wilson
01-04-2016, 8:23 PM
328594 This is a close up of the issue, It stopped lasering in the light areas. regards Stuart

StuartW Wilson
01-04-2016, 9:28 PM
I tried engraving the image again, this is the result, I cleaned the lenses with no change it seams to have lost most of its power hardly engraving no depth, the water is cool I stopped this image 328596.I tried a different image which has come out very light.

Matt McCoy
01-04-2016, 9:36 PM
Can you try a piece of mat board, cardboard, or something similar?

StuartW Wilson
01-05-2016, 6:42 AM
328610This was supposedly engraved at 80% power speed 166mm/s on my 50 watt laser, I first tried at 98% power it was very faded this is on a sheet of A4 photocopy paper. The power seems to becoming worse.328611328612 I added these images maybe they show if the tube is broken to someone who has expertise in this area. Regards Stuart

Jerome Stanek
01-05-2016, 7:27 AM
Hi there I am using a Chinese 6040 laser at 98% speed is set to 180. The text should be black with no fade, all help appreciated. regards Stuart

What was the MA reading on your meter when you did that. At 98% it should be around 20 MA any higher and you are over powering it

Matt McCoy
01-05-2016, 10:04 AM
328610This was supposedly engraved at 80% power speed 166mm/s on my 50 watt laser, I first tried at 98% power it was very faded this is on a sheet of A4 photocopy paper. The power seems to becoming worse.328611328612 I added these images maybe they show if the tube is broken to someone who has expertise in this area. Regards Stuart


I suspect you need a new laser tube.

John Noell
01-05-2016, 11:46 AM
I suggest you search this forum on the subjects of (1) tube length and power (e.g., many "50 watt" machines are sold with what most of us would call 40 watt tubes, the length of the tube will tell you the true power), and (2) how much current (in milliamps) maximum your tube can handle before it self-destructs. For many (most?) of us, glass tubes should never be driven more than 90% power (but that depends on how your power supply is adjusted). At a guess, your are driving a 40 watt tube at 50 watts and it is in its death throes (i.e., rapidly losing power).

Dan Hintz
01-05-2016, 12:23 PM
328612

Is the tube on the right somewhat kinked as it passes through the floor of the sheetmetal? If so, you may not be getting enough water flow and burning up the tube.

Bert Kemp
01-05-2016, 12:55 PM
I can't tell for sure but it looks like your water lines are coming out the bottom of the tube. The water exit should be out the top of the tube so any bubbles can exit and not be trapped in the top of the tube. Check to make sure.

Scott Marquez
01-05-2016, 2:21 PM
I can't tell for sure but it looks like your water lines are coming out the bottom of the tube. The water exit should be out the top of the tube so any bubbles can exit and not be trapped in the top of the tube. Check to make sure.
I think Bert is all over it.
The air bubbles are hindering the flow of the cooling water to the output lense.
The tube may already be fried, but you might try rotating your tube so that the output cooling line is on to the top, then test again.
Scott

StuartW Wilson
01-05-2016, 8:14 PM
I have turned the co2 tube around so the water tubes are on the top to release the bubbles, the power has not changed there seams to be an arc on the lens end, when i press pulse there is nothing then maybe a bit later I try again it will fire. I hit the pulse a few times looking at the lense end there seems to be a lot of deviation with laser. Also there have been kinks in the the exit tube since the beginning which is about 5 months of use.328717328718

Bert Kemp
01-05-2016, 10:21 PM
I guess with the tube being over drivin, the water lined kinked and up side down we gonna assume your tube needs to be replaced:(




I have turned the co2 tube around so the water tubes are on the top to release the bubbles, the power has not changed there seams to be an arc on the lens end, when i press pulse there is nothing then maybe a bit later I try again it will fire. I hit the pulse a few times looking at the lense end there seems to be a lot of deviation with laser. Also there have been kinks in the the exit tube since the beginning which is about 5 months of use.:(328718

StuartW Wilson
01-06-2016, 3:42 AM
Thank you guys for your support, I can see where the power is been lost, there is an arc deviating and hitting the side of the lens randomly then returning to the center. This is causing all the fading and missing on my images. I am going to order a new tube which comes with a new power supply to suit,I will purchase a chiller at the same time. what should the max power setting I should run for long lasting of the tube? regards Stuart

Rich Harman
01-06-2016, 4:09 AM
I am going to order a new tube which comes with a new power supply to suit,I will purchase a chiller at the same time. what should the max power setting I should run for long lasting of the tube? regards Stuart

Use the ammeter to determine what the max power setting should be. If you don't have one, get one. An analog 0-50 mA meter is appropriate. Someone else here can tell you what the max current and suggested running current should be based upon the tube you choose.

You can't just use a certain percentage setting because there is variations in the power supplies. The ammeter tells you exactly how much power is going to the tube. The number you punch in does not.

StuartW Wilson
01-06-2016, 4:35 AM
Thank you for the reply, Is it an Dc ammeter? I obviously attache to the engraver what do I wire too. regards Stuart

Robert Schmiede
01-06-2016, 5:14 AM
Stuart, Google lens digital.com how to add an ammeter . If still unsure get a sparky.

StuartW Wilson
01-06-2016, 6:29 AM
Thank you for the information, Easy to do. regards Stuart