Big laser alignment

[pipi...@gmail.com]

I’ve realigned the mirrors on the big laser. I was cutting 1/4 acrylic at 3mm/s, now it cuts at 8mm/s. The cut is still not straight. DO NOT TRY YO CRORRECT THIS WITH THE MIRRORS. The entire lense assembly is crooked. I’m working on a way to fix this and to ensure the height is correct. One thing. The laser was set at 34 mA today. The limit is 28 mA. The tube is tired enough. Please spread the word not to do this.

[Brad Walsh]

Thanks. 

We should have some documentation posted around the laser. I think the max mA is pretty small and barely readable. 

Brad

On Sat, Mar 17, 2018 at 3:42 PM <pipi...@gmail.com> wrote:

I’ve realigned the mirrors on the big laser. I was cutting 1/4 acrylic at 3mm/s, now it cuts at 8mm/s. The cut is still not straight. DO NOT TRY YO CRORRECT THIS WITH THE MIRRORS.  The entire lense assembly is crooked. I’m working on a way to fix this and to ensure the height is correct. One thing. The laser was set at 34 mA today. The limit is 28 mA. The tube is tired enough. Please spread the word not to do this.

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Thanks, Brad

[pipi...@gmail.com]

Maybe a sharpie line on the gauge?

[Raven Abird]

so who is changing it,  and why?

On Sat, Mar 17, 2018 at 3:45 PM, Brad Walsh <bra...@gmail.com> wrote:

Thanks. 

We should have some documentation posted around the laser. I think the max mA is pretty small and barely readable. 

Brad

On Sat, Mar 17, 2018 at 3:42 PM <pipi...@gmail.com> wrote:

I’ve realigned the mirrors on the big laser. I was cutting 1/4 acrylic at 3mm/s, now it cuts at 8mm/s. The cut is still not straight. DO NOT TRY YO CRORRECT THIS WITH THE MIRRORS.  The entire lense assembly is crooked. I’m working on a way to fix this and to ensure the height is correct. One thing. The laser was set at 34 mA today. The limit is 28 mA. The tube is tired enough. Please spread the word not to do this.

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Thanks, Brad

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[Lorin Edwin Parker]

I haven't adjusted current on this machine.

Is it set with a potentiometer on the constant current laser supply, like most lasers? Is it set digitally? Or are we just talking about setting the % power and watching so that the mA meter does not exceed 30mA?

Regardless, the power supply should be constant current, and the maximum current should be set there and remain steady at 20-28 mA. I've seen that these lasers' supplies tend to be set too high by default (which I think Jon & Bill would have dealt with when we 1st set it up). Also, the current regulation can simply drift over time or change with a number of factors including heat, load, etc etc etc.

So, I'm wondering if the calibration at the high voltage constant current supply is set. If not, we should check.

Nancy, I think it's more likely that the laser went out of calibration due to time, errors, and normal usage / normal abuse. Unless of course the HV supply control is way easier to mess with than I am assuming (which would be really really dumb design).

Lorin

[pipi...@gmail.com]

Lorin,
There’s an adjustment in front the panel for percent power. Someone had adjusted it to 95%, which read on the meter as 34 mA. ~85% is where it reads 28mA. It’s certainly been done deliberately. It could be that whoever is doing it isn’t aware that they’re overpowering the laser.

[Brad Walsh]

Let’s put a sticker by the power meter that talks about what it should be set and how it is set. 

On Sat, Mar 17, 2018 at 9:32 PM <pipi...@gmail.com> wrote:

Lorin,
  There’s an adjustment in front the panel for percent power. Someone had adjusted it to 95%, which read on the meter as 34 mA. ~85% is where it reads 28mA. It’s certainly been done deliberately.  It could be that whoever is doing it isn’t aware that they’re overpowering the laser.

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Thanks, Brad

[Lorin Edwin Parker]

Ok, that makes more sense now. Thanks for the clarification.

I think a long term solution is to adjust the current regulation on the power supply. I can check this out. It is well documented that WEIKE lasers' supply regulator is often set too high at the factory. This would calibrate the maximum power from the supply to not exceed the limit, regardless of the % setting. Thus, 100% power on the panel would be 27mA or so. Makes sense, no? 100% power being 100% max current, not 125%.

Still, though, I think it's safe to assume that someone or some people simply did not know. It's good we're talking about this, and I sincerely believe that nobody is acting in bad faith here. 

Lorin

On Sat, Mar 17, 2018 at 9:36 PM, Brad Walsh <bra...@gmail.com> wrote:

Let’s put a sticker by the power meter that talks about what it should be set and how it is set. 

On Sat, Mar 17, 2018 at 9:32 PM <pipi...@gmail.com> wrote:

Lorin,
  There’s an adjustment in front the panel for percent power. Someone had adjusted it to 95%, which read on the meter as 34 mA. ~85% is where it reads 28mA. It’s certainly been done deliberately.  It could be that whoever is doing it isn’t aware that they’re overpowering the laser.

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Thanks, Brad

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