Bi-directional Engraving Offset

[Ztiep]

So after figuring out a Quick fix in another post I would really like to get to the bottom of my issue. I am having a problem whenever I use x-swing that it has a double image and after changing the Interval(mm) setting to .5 and running an engrave at 500mm/s this is the result. I have no idea what it could be, below is a list of everything I have tried and some issues I have had.

The machine is the Red and Black 60w

1. Checked all belts for being loose and from what I can tell none are loose.
2. Checked mirror alignment and all seems fine. No matter where you try to do the test engrave top corners or bottom or anywhere else you still get the same result. So does not seem like a mirror or lens issue
3. Tried setting the Backlash in the user setting after looking at post online from people saying this could be the fix, Problem I had with this is no matter what I set either the x or the y backlash it changed nothing about the engraver (I am not sure if i'm changing something wrong or there is another setting that override or enables this) I have tried writing the setting and then resetting the machine and reading both after a reset and a power reset. No matter what I put into here it makes no difference. I do know that it is at least listening to some of the settings because when I changed the scale setting from closed to open it changed it.
4. Have tried different images still have the same issue.

It works fine engraving in one direction but doing bi is when it has the problem, and from the picture with the Interval(mm) set to .4 you can see each pass easy. and can see that the left to right is offset from the right to left.
If anyone has any advice it would be great appreciated i'm kinda at a lose right now.

Also lowering the speed does make it lessen the distance between each directions pass. I have tried playing around with Reverse interval with some setting people said to try with no luck.


I used to have a k40 before this and even upgraded the controller to the LightObject DSP so this is not the first I have worked with a Laser Engraver, but this issue I have no idea what it is.

Similar Threads:

• Fanuc 31i bi-directional comp for ballscrews
• Directional issue
• Inkscape / GCodeTools - Engraving - offset ?
• 31i directional 5-axis indexing??
• uni-directional mold machining

[wmgeorge]

Back lash means play in your carriage when it moves. like play or movement in a gear train, usually its the X adjustment. I have never had to adjust on any machine I have owned. Are you sure the belts are tight, and are all the pulleys on the motor and other end tight? Use a allen wrench to check.
Did you physically check each mirror for play or just look? Same with the lens. Remove the lens and look at making a note of curved side up or curved side down. Gently clean and replace the same way it came out. Usually curve side up.
My other suggestion is check your wiring connections.

Scan Gap for a 300 dpi image should be around .06 - .08 do some testing to see which is best.

[Ztiep]

From what I can tell all the belts are nice and tight, I even gave some a shake to see if anything moved or was loose and nothing. I pulled all the mirrors out and they all seem just fine clean and solid in the housing. Will check again but pretty sure it is not the issue. Also from what I have known from my old k40, if it where a mirror issue it would change depending on the area of the machine you did the engrave in. Will def give the motors a check again because from looking at it, it would prob be the issue. Also as far as wiring what would you say that I need to check. Thank you for your response Also is there a setting that adjust the delay in when the motor changes direction? That seams like it would fix the problem if it existed.

[Ztiep]

Video of the problem in action if anyone would like to see, https://drive.google.com/file/d/0B81...ew?usp=sharing

[wmgeorge]

Those belts are not tight enough, the carriage only has one rail very sloppy construction. It was loose when you moved it and your scan gap is way to wide, IF that was suppose to be a solid letter. Pulley could be loose on motor shaft, did you tighten those set screws or just look??? Looking does not count.

[Ztiep]

Will check the sets screws again, but I would think if it where the set screws that it would not be the same result no matter where you do it on the bed. I would also think when the machine is on if I try to push the head in either direction it would move it is was a motor issue. The belt is a little loss in the video because I tried tightening them all the way with no luck to the fix. Also yes I do have the scan gap set high to allow me to see if the problem is fixed and see that it is the pass back that is offset, when you do it with a low scan gab it overlaps and just looks like two images right next to each other. I'm really thinking it is a software issue.

[wmgeorge]

Sometimes machine problems are a combination of several issues. I can offer no more help and suggest you contact the people who you purchased from for a fix or a refund.

[Ztiep]

Thank you for your help i'm going to keep tweaking and see that I can find, I contacted the seller and there advice was re install the software

[MFY]

Were you ever able to solve your problem. I have the same problem and am at witts end trying to correct it. it is just too slow going in one direction only most of the time. thank you.

[abyss]

I have tried playing around with Reverse interval with some setting people said to try with no luck.

Have you use for tests same speed as was declared in this option?

Say - try to do test at 200mm/s on same piece of paper, same place (move paper, not head)
next Add... value Speed:200 mm/s Reverse_Interval: 2.0mm Offset_repay: 0 mm
and next Speed:200 mm/s Reverse_Interval: -2.0mm Offset_repay: 0 mm
And compare results, probably best will be done one under previous to easily see effect. (wrote 2.0mm as it will be easily visible which direction is ok/wrong)

[KH0UJ]

I experience this kind of scenario every time the door is accidentally bumped hard, the issue is the alignment of the mirrors, I also checked everything back then from electronics all the way up to the software with no luck, align back your mirrors first and check (X0-X, Y0-Y) maybe we have the same scenario

and also I experience ghosting both X and Y when the tube is getting weaker, my remedy is to put additional O-rings on the lens focus to recalibrate it to a razor sharp point. to utilize the remaining life of the gas tube until it`s totally dull then replace it with new one.

[MetalArm]

I had this very same issue. Bidirectional engraving resulted in a clean image everywhere except the very right edge. Almost as if it was a backlash issue except the left side looked perfect.
The Issue/solution For me was Loose mirror/lens nozzle. The mirror would not move when the x direction moved back to the right. However, when it reversed direction to go left, it would move causing the beam to jitter. When I reset my mirror and nozzle, I noticed both were loose but hardly noticeable. The mirror(in the nozzle) was loose due to the jam nut not being tightened quite all the way against the oring. Once I reset my issue went away completely.