Strange alignment problem...

General Laser Usage Topics
Vicente Ferrando
Posts: 14
Joined: Thu Oct 29, 2020 10:47 am
Location: Quart de Poblet; Valencia
Country: Spain
Nickname: mcyv2
Laser Machine Make or Type: GWeike LC1610N
Laser Power: 130W
Laser Bed Size: 1.6m x 1m
Home Position: TR
RDWorks Version: v8.01.47
Ruida Controller: RDC6445
Accessories: Rotary device chunk, Rotary device rollers
Windows Version: 10

Strange alignment problem...

Post by Vicente Ferrando »

Hi everyone!

I'm unable to solve this alignment problem. I'm using a laser level to adjust the machine, but something happens in the middle of the machine. Both sides are perfectly levelled,  within them and with the floor, but when the laser is in the middle right part of the bed, it looses the focus. Could be the left guide twisted?
20210607_175019.jpg
These are a couple of videos I made moving the gantry. Any ideas?

https://youtu.be/C0Nccl97EaY

https://youtu.be/jDChfL5veQc

Thank you!!!

Edit:

Left side:
20210608_164500_1.mp4
You do not have the required permissions to view the files attached to this post.
Vicente Ferrando
Posts: 14
Joined: Thu Oct 29, 2020 10:47 am
Location: Quart de Poblet; Valencia
Country: Spain
Nickname: mcyv2
Laser Machine Make or Type: GWeike LC1610N
Laser Power: 130W
Laser Bed Size: 1.6m x 1m
Home Position: TR
RDWorks Version: v8.01.47
Ruida Controller: RDC6445
Accessories: Rotary device chunk, Rotary device rollers
Windows Version: 10

Re: Strange alignment problem...

Post by Vicente Ferrando »

Left guide is perfecty horizontal. See attached video.

This is what I get:
16231651762436211288578669501050.jpg
Any ideas?? Kind regards!!!
You do not have the required permissions to view the files attached to this post.
Vicente Ferrando
Posts: 14
Joined: Thu Oct 29, 2020 10:47 am
Location: Quart de Poblet; Valencia
Country: Spain
Nickname: mcyv2
Laser Machine Make or Type: GWeike LC1610N
Laser Power: 130W
Laser Bed Size: 1.6m x 1m
Home Position: TR
RDWorks Version: v8.01.47
Ruida Controller: RDC6445
Accessories: Rotary device chunk, Rotary device rollers
Windows Version: 10

Re: Strange alignment problem...

Post by Vicente Ferrando »

New test XD

To check if the left guide is twisted, I just did the following test:
Test.jpg
And I didn't get any movement at the end of the pole. So, the left guide is not twisted...
20210608_182312_1.mp4
You do not have the required permissions to view the files attached to this post.
Jeffrey Aley
Posts: 341
Joined: Fri Aug 11, 2017 1:08 am
Location: Folsom, California
Country: United States
Laser Machine Make or Type: Kehui
Laser Power: 50W
Laser Bed Size: 500mmx300mm
Home Position: TL
RDWorks Version: 8.01.24
Ruida Controller: RDC6442
Accessories: Spray bottle with water (for small fires)
Fire extinguisher (for big fires)
Windows Version: Win10 Enterprise

Re: Strange alignment problem...

Post by Jeffrey Aley »

Interesting. You've done some pretty thorough testing. I am a bit confused by the configuration of your laser. Can you provide an "overview" photo showing the rails and gantry, and where the tube and mirrors are located?

Also, I am unsure what your photo of the 9 pieces of paper are trying to show. You later show a piece of paper with 6 burns on it; how were those burns created?

Thanks,

-Jeff
Vicente Ferrando
Posts: 14
Joined: Thu Oct 29, 2020 10:47 am
Location: Quart de Poblet; Valencia
Country: Spain
Nickname: mcyv2
Laser Machine Make or Type: GWeike LC1610N
Laser Power: 130W
Laser Bed Size: 1.6m x 1m
Home Position: TR
RDWorks Version: v8.01.47
Ruida Controller: RDC6445
Accessories: Rotary device chunk, Rotary device rollers
Windows Version: 10

Re: Strange alignment problem...

Post by Vicente Ferrando »

Hi Jeffrey, thanks forvyour answer!

I'll show you:
20210610_095829.jpg
20210610_095829 (1).jpg
20210610_095829 (2).jpg
I hope this helps to figure out what I was trying to explain.

Kind regards!
You do not have the required permissions to view the files attached to this post.
Jeffrey Aley
Posts: 341
Joined: Fri Aug 11, 2017 1:08 am
Location: Folsom, California
Country: United States
Laser Machine Make or Type: Kehui
Laser Power: 50W
Laser Bed Size: 500mmx300mm
Home Position: TL
RDWorks Version: 8.01.24
Ruida Controller: RDC6442
Accessories: Spray bottle with water (for small fires)
Fire extinguisher (for big fires)
Windows Version: Win10 Enterprise

Re: Strange alignment problem...

Post by Jeffrey Aley »

Thanks for posting the photos - they help me understand a bit more.

From the videos, I think I see that the left rail is level, and the right rail is level, but I can't tell if they are at the same height because your video shows different targets. Have you confirmed that if you move the head to the left side, the red line strikes the head at the same spot as it does when you move the head to the right side? In other words, the rails are level; is the gantry both level and straight? Might the gantry be slightly curved?

What I still don't understand is the 9 pieces of paper and the 6 burn marks. You very clearly showed WHERE those locations are (thanks!), but I don't know what you did to produce the burns. For example, were the 9 pieces of paper located on the bed, or were they taped to Mirror 3? Why is there a white "X" of un-burnt paper on each of the 9? How did you produce them?

Similarly, you have a piece of paper with 6 burn marks from 6 places on the laser (again, thanks for the photo!). How were those marks produced, and what do we learn from looking at them. The 2nd mark from the left is slightly higher than the others. Is that significant? I don't know because I don't know where in the path of the beam you placed that piece of paper, nor how precisely you placed it. I imagine you placed the paper very carefully, but that's just an assumption, and assumptions will not lead to a solution :-)

Thanks,

-Jeff
Vicente Ferrando
Posts: 14
Joined: Thu Oct 29, 2020 10:47 am
Location: Quart de Poblet; Valencia
Country: Spain
Nickname: mcyv2
Laser Machine Make or Type: GWeike LC1610N
Laser Power: 130W
Laser Bed Size: 1.6m x 1m
Home Position: TR
RDWorks Version: v8.01.47
Ruida Controller: RDC6445
Accessories: Rotary device chunk, Rotary device rollers
Windows Version: 10

Re: Strange alignment problem...

Post by Vicente Ferrando »

Hi Jeff, thanks for your answer!

Sorry, I'll try to explaint better :) The nine pieces are shots using this in front of the third mirror:
Captura de pantalla 2021-06-11 085917.png
so, in some places laser seems to hit to the head higher than in others.

The six burns shows the same. I put the paper before third mirror, very carefully and, as you can see, at the front and the rear of the machine they are at the same height, but somewhere in the middle is pretty higher, specially on the right.

I also checked if the gantry is level and it seems to be. Maybe at the middle of the gantry it lowers half milimeter, but not at the beginning or the end.

I'll check if the gantry is curved, just in case, thanks for the idea!

Thanks you very much for your time. I hope I've explained all the burns a bit better now :)

Kind regards!!
You do not have the required permissions to view the files attached to this post.
User avatar
Gene Uselman
Posts: 1671
Joined: Thu Jul 07, 2016 3:18 pm
Location: Suburban Minneapolis, Minnesota, US
Country: USA
Nickname: Gene
Laser Machine Make or Type: AKL1318-2
Laser Power: 130W & 80W Reci
Laser Bed Size: 51 x 71
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: RDw .19 & Lightburn
Ruida Controller: RDC6445
Accessories: I have a combining lenses, pin tables [homebuilt], honeycomb tables , wireless remote, Modifed Ultimate Air Assist, home built non-powered rotary device, Prusa i3 MK3S and Mini Prusa printers.
Windows Version: Win 10 Pro

Re: Strange alignment problem...

Post by Gene Uselman »

Hi Vicente- I am just back to my machine after a fairly long road trip. I am working on a 1800x1300 machine after having a 1300x900 machine for 5 years and find that the large machines have a lot of, and different problems. I have a similar problem on this machine- I have checked and double checked everything, as I am sure you have. Have you checked your right hand rail for absolute straightness- they are normally shimmed in the middle and it appears the middle of your might be low/sagging? Russ [SarbarMultimedia videos] talks about a fourth corner problem with alignment in one video and that is closer to the problem I have. Gene
If the Help and advice you received here was of VALUE...
Please consider making a donation to maintain the RDWORKSLAB Forum.

BT48 Alpha Shopbot and 1300x1800 130W Laser

The days that I keep my gratitude higher than
my expectations, Well, I have really good days.

Ray Wylie Hubbard
Jeffrey Aley
Posts: 341
Joined: Fri Aug 11, 2017 1:08 am
Location: Folsom, California
Country: United States
Laser Machine Make or Type: Kehui
Laser Power: 50W
Laser Bed Size: 500mmx300mm
Home Position: TL
RDWorks Version: 8.01.24
Ruida Controller: RDC6442
Accessories: Spray bottle with water (for small fires)
Fire extinguisher (for big fires)
Windows Version: Win10 Enterprise

Re: Strange alignment problem...

Post by Jeffrey Aley »

Thanks for the photo of the apparatus with the copper wires - I've never seen a device like that.

It appears from the photo of the 9 pieces of paper that the right rail has an upward bow in it (higher in the middle; lower at the front and back).

I know you posted a video of the right rail moving with a laser level projecting a plane; that video does not clearly show (to me) the accuracy of the motion of the head when it is all the way to the right (the left-rail video is much clearer). If your right rail is shimmed as Gene stated, then perhaps it needs to have a shim removed. Or is it possible that the right rail is flexible, so you get different results each time?

Regards,

-Jeff
Martin Overberg
Posts: 6
Joined: Tue May 23, 2017 2:28 pm
Location: Herzebrock
Country: Germany
Nickname: Martin
Laser Machine Make or Type: China Red/Black
Laser Power: 60W
Laser Bed Size: 500 mm x 700 mm
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: 0.9.16
Ruida Controller: Other
Accessories: Rotary device
Windows Version: 10

Re: Strange alignment problem...

Post by Martin Overberg »

There is something like a light source mounted on the head. The weight of that part may twist the gantry when the head is in the middle of the gantry, which is the weakest position. I recommend to repeat the test with the light source removed.
Of course the gantry itself can be warped, too.
Martin
Post Reply

Return to “Laser Usage”