Author Topic: Some measurements of output power on my k40.  (Read 59 times)

Landbo

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Some measurements of output power on my k40.
« on: November 28, 2017, 04:00:50 PM »
Hi.

Max output just after the tube is 37.5 Watts at 22 mA.
The power measured after the tre mirror has dropped to 27 Watts, a loss of 10.5 Watts, which must give you a total loss of 100-(27/37,5*100)=28% in the tre mirrors (I hope my calculation is correct!). The loss is significantly greater than I expected. Has not measured the loss in the lens, which I do not expect is quite big as it do not appear to get hot during operation.

Next project will be measuring the linearity of the tube, which I expect has a strong crack about 50% of full output power.

The story continues.

Regards, Leif.
« Last Edit: November 28, 2017, 04:37:16 PM by Landbo »
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ggallant571

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Re: Some measurements of output power on my k40.
« Reply #1 on: November 28, 2017, 04:41:47 PM »
Please provide some details as to the tools and procedures used.
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Landbo

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Re: Some measurements of output power on my k40.
« Reply #2 on: November 29, 2017, 03:43:35 AM »
Please provide some details as to the tools and procedures used.

It's simple, I'm using a laser powermeter, which in its simplicity consists of an thermometer on which an metal block is mounted on the tip. When used, place the block in front of the laser beam for x number of seconds. Instead of degrees Celsius or Fahrenheit, the thermometer is calibrated in Watt instead.

Regards Leif.
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Zax

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Re: Some measurements of output power on my k40.
« Reply #3 on: November 29, 2017, 04:53:46 AM »
I only measured the tube output to final beam when the machine was new but the losses were less than 10%.

You must be losing partial beam from one of the mirrors, or it's not aligned with the final housing. If you put masking tape over each mirror in sequence is the spot centered?

You should see ~36W at the head, before it hits the final mirror and is directed down to the lens and then 34~35W once focused.

Landbo

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Re: Some measurements of output power on my k40.
« Reply #4 on: November 29, 2017, 05:28:44 AM »
I only measured the tube output to final beam when the machine was new but the losses were less than 10%.

You must be losing partial beam from one of the mirrors, or it's not aligned with the final housing. If you put masking tape over each mirror in sequence is the spot centered?

You should see ~36W at the head, before it hits the final mirror and is directed down to the lens and then 34~35W once focused.

I have checked that the beam hits approximately in the middle of the mirrors throughout the beam path. The mirrors are all cleaned. It must be the quality of the mirrors (the ability to reflect the laser beam) that is bad. This is probably the cheapest the manufacturer has been able to buy. My mirrors look like a plain mirror and are not coated with gold.

Has come to the end, it will be necessary to buy new mirrors if the machine is to be better and cutting.    :'(

EDIT: Forget and tell that the loss seemed to be evenly distributed across the three mirrors.

Regards Leif.
« Last Edit: November 29, 2017, 05:31:58 AM by Landbo »
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