Laser alignment / beam issues

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di...@rlab.org.uk

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Aug 2, 2022, 3:19:51 PM8/2/22
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The laser is cutting badly - see picture

There is a secondary shadow cut, like the beam is getting split. Could be dirt on a mirror or lens?


IMG20220802180315.jpg

Mr E

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Aug 2, 2022, 5:40:08 PM8/2/22
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Erk.  I'd check for dirt clogging the beam tube (the red one - just disconnect the air tube at the back before taking out), Filth on the lens.  If you do take it out, you want gloves on, if you think about touching it - it's poisonous.  The methanol for cleaning with cotton buds is behind the monitor.

Otherwise I guess moving it around when we cleaned out the HT power supply has knocked it's alignment out.  If there's no improvement, let me know, I'll find time for a realignment.  We did some test cuts before we left and it seemed just fine.  Those were in the middle of the bed.  Where were you cutting it out of interest?

Rupert


On Tue, 2 Aug 2022 at 20:19, di...@rlab.org.uk <di...@rlab.org.uk> wrote:
The laser is cutting badly - see picture

There is a secondary shadow cut, like the beam is getting split. Could be dirt on a mirror or lens?


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Mark Morris

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Aug 3, 2022, 5:50:51 PM8/3/22
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Seems to be working this evening too

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Daniel Power

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Aug 4, 2022, 4:37:44 AM8/4/22
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Mark

 

Thanks for taking us through the router and the planer last night.

When will you be doing a session on the circular saws.

Dan

Mr E

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Aug 4, 2022, 12:57:48 PM8/4/22
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Ah good - Let me know if it happens again though.

Rupert


Tom August

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Aug 8, 2022, 8:36:45 AM8/8/22
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This issue seems to be back (or maybe never went away) but is more severe in parts of the cutting area. 

I was able to get by using the back right corner, in an area about A4 in size. Even here though the cuts were not pretty, leaving a noticeable 'shadow'. I countered this by using the rolls of masking tape, which prevented the shadow marks. 

I also noticed that the red tube is not straight. When I slide the 3mm focus block under the head, it passes part of the way under but not the whole way, suggesting the head is at an angle. 

When doing a preliminary engraving job I didn't notice the issue, it only reared its head when I started cutting. I have left a note on the machine so others are aware.

PXL_20220808_114128535.jpg

Mark Morris

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Aug 8, 2022, 9:07:27 AM8/8/22
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I'll try to pop in later on this evening and take a look


Mark Morris

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Aug 8, 2022, 4:00:33 PM8/8/22
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I've cleaned it as per Rupert's instructions but it's still not cutting well. I wasn't sure if I was meant to clean the actual lens, so didn't, just around the nozzle.

Attached pics before and after with a down the tube shot for diagnositics. 

The shadow seems most prominent at the front right, it cuts noticeably less well there, but the bed seems level enough.




IMG20220808204808.jpg
IMG20220808204223.jpg
IMG20220808204858.jpg

Mr E

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Aug 8, 2022, 5:12:00 PM8/8/22
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Thanks for looking at it.  That all looks fine.  I guess either the movement of it knocked it out, or it hit something at some point.

Sad to say, I think a realignment is on the cards.  I'd mark it out of order, as all that shadowing will just be the beam bouncing off the side of the nozzle, which will overheat it and cause more damage.

I'll make some time to do a full realignment, which is a bit of a long process.

Rupert


Mark Morris

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Aug 9, 2022, 8:59:02 AM8/9/22
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Thanks Rupert

I've marked it as do not use

If anyone can assist please reach out to them. 

Regards
Mark 

Richard Ibbotson

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Aug 12, 2022, 11:33:08 AM8/12/22
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Can someone do me an induction on the laser cutter?
I did the original installation and alignment, but that was with RDWorks and before recent modifications, so need to understand what has changed.
Once I am re-inducted and take a look I might be able to do any re-alignment/repair needed.
Cheers,
Richard


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On 9 Aug 2022, at 13:59, Mark Morris <di...@rlab.org.uk> wrote:



Mark Morris

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Aug 12, 2022, 5:08:27 PM8/12/22
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Update on the laser:

Still not fixed despite a few hours of alignment by Rupert and I (mainly him of course)

It is cutting well enough in the back right hand side of the bed, so it is ok to use if you just stick to that small area.

More investigation is needed but that won't be for a couple of weeks.

Richard - thanks for the offer of assistance. I'm sure Tony will do you an induction once it is back up and running properly.




Richard Ibbotson

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Aug 12, 2022, 5:58:08 PM8/12/22
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From the original fault reported it sounds like the problem was at the cutting head. However now if the problem is depending on bed position it sounds like the alignment efforts have now put the mirrors out too.

Fix the alignment from laser to the head first with a test target on the final Z mirror.

Then check the mechanical alignment of the head before fixing its optical alignment and cleaning.

I do have some spare heads but can't recall what focal length this laser cutter uses.

I am away until next Wednesday but could take a look after that

Richard

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On 12 Aug 2022, at 22:08, Mark Morris <di...@rlab.org.uk> wrote:



Mark Morris

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Aug 18, 2022, 11:51:59 AM8/18/22
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Hi Richard, the issue was always showing up depending on bed position.

We did check and clean the lens and head. Rupert suggested the next step would be removing the first mirror for further diagnostics/fixing but that is a full days task.

The people who have recently maintained it are Rupert who is away on holiday this week and James who I think is really busy at the moment. I think it might be worth you having a conversation with one of them. Alternatively I can walk you through what Rupert and I did (although I'm no expert)

I could make some time next week to meet up in person. Tuesday evening perhaps?

As it stands we have found that even the back right section of the bed is cutting poorly so we have marked the machine out of action.

Regards
Mark


Richard Ibbotson

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Aug 18, 2022, 12:21:03 PM8/18/22
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Hi Mark,
I am sure I can get down next week to take a look.
It does seem that it is best to now go back to a step by step setup from tube to head although time consuming.
Do you have spare mirrors and lenses if required. 

Are you using acrylic sacrificial targets for alignment? Do you have a stock?

Do we keep any old good targets, like the one from the final mirror?


Cheers,
Richard


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On 18 Aug 2022, at 16:52, Mark Morris <di...@rlab.org.uk> wrote:



Mr E

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Aug 22, 2022, 2:16:56 PM8/22/22
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Hi Richard,

It's mostly a question of rotten timing!  It happened just before I was going away on holiday for a week.  I did a very rough and ready realignment with Mark on Friday night, before I was off home to pack and leave the next day.  From the sounds of it, it's either an adjuster come loose or something else is up.

I'm happy to come in sometime this week to look at it.  We do have everything you mentioned aside from spare lens, but I don't think it's that.

All the best.

Rupert


Richard Ibbotson

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Aug 22, 2022, 3:17:40 PM8/22/22
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I will be down tomorrow evening (Tues) for the Electronics Meet-up. If you are around?
Richard


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On 22 Aug 2022, at 19:16, Mr E <excha...@gmail.com> wrote:



Mr E

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Aug 22, 2022, 4:54:54 PM8/22/22
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Sounds like a plan, I'll be there :)

Rupert

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