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WTB LPM + Thank you Alaskan

Alaskan

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More power! Need to get you hooked on higher power lasers and you won't need a fog machine, but I do agree, if you are going to stay at such low power, a fog machine will make them appear to be much higher power :p
 

Hap

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More power! Need to get you hooked on higher power lasers and you won't need a fog machine, but I do agree, if you are going to stay at such low power, a fog machine will make them appear to be much higher power :p
Exactly haha.

This hobby is crazy though, I've probably spent over $1000 in the 1 & 1/2 years I've been here. Wow :can:

-Alex
 

vortish

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Alex I have a two bottles of lab grade glycerin that if you want one all you have to do is pay shipping and you can make about a gallon of juice for around 12 bucks to ship it to you
 

Hap

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Ha, I've spent 30K on laser stuff in 2 years.
Wow haha.

Also, yeah im not imagining things. I ran my 532 & 520 tonight & the 520 clearly has power issues. It's bright for a couple minutes then dims down to barely noticeable(and this is with the 3.7 cells). Common CNI....

Should I just contact CNI & ask for a new unit? I could try and send it to a member after all. *sigh*

-Alex
 
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I know I've seen an LPM for sale that was for low power, I think only up to 5 mW but I don't remember the brand or where, it's not something that would interest me. Most of our hobbiest grade LPMs drop off in accuracy at 20mW or less, at least I read that before here somewhere.

I don't know what kind is better at lower powers but you must be careful how you do it. Be sure there are no open windows, no fan, heater, AC, or ventilation running, the air in the room should be still, no heat source of any kind near the LPM. Do not hold the laser in your hand, even your hand can measure a mW or two, anyway the laser must be still and not moving, so put it in a tripod and point it at the sensor from 4 to 8 inches away, wait for the LPMs response time or up to a minute for an accurate reading. This can be a problem getting an accurate reading with high power lasers if they have a short duty cycle. All of you with an LPM already know this, I am just saying this for anyone who never used one. When measuring a class 4 laser being off by several mW may be unimportant, but at low power it becomes important.

Alan
 

gozert

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Return it to CNI and ask for a new one. Sending it to a member will most likely void warranty and it might not be easy to fix. This is the reason I try building most of my lasers myself nowadays. I don't have to rely on a company that may not test it's lasers well before shipping them, and I hate paying return shipping to China as it's way too expensive.
 

Hap

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Return it to CNI and ask for a new one. Sending it to a member will most likely void warranty and it might not be easy to fix. This is the reason I try building most of my lasers myself nowadays. I don't have to rely on a company that may not test it's lasers well before shipping them, and I hate paying return shipping to China as it's way too expensive.
Alright I'll try that & ask that CNI pay for return shipping. What is complicated is creating a label with FedEx. They ask so much information for customs like a signature of the company etc...I might need to driver over there so they can help me out.

PS: What is strange is CNI told me to turn off the laser after 1-2 minutes since that's it's duty cycle. Should 4mW of 520 really have a duty cycle?

-Alex
 
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gozert

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I doubt a diode running at such low power has a duty cycle at all and I doubt the driver is getting hot either. Especially since you have a 532nm too which you can run for long times without turning off, and those tend to produce more heat due to their pump diode.

I can imagine them charging you shipping costs both ways and say there is nothing wrong with it because it stays stable for the 2 minutes.
 
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Return it to CNI and ask for a new one. Sending it to a member will most likely void warranty and it might not be easy to fix. This is the reason I try building most of my lasers myself nowadays. I don't have to rely on a company that may not test it's lasers well before shipping them, and I hate paying return shipping to China as it's way too expensive.
That's right, building your own is the way to go. Except for my 3 pen type lasers I built the others. I know they are high quality and exactly what's in them, if one ever breaks I will know how to take it apart and figure out what's wrong and fix it. Some of the parts are made in the US, the power is stable, and the beam is straight. They also don't have to be the higher power lasers many of us build, I have seen some sources of low power LDs even <5mW and you can build these yourself too.

In China, most factory workers are very low paid and have to work very fast and there's little or no quality control. When you buy a laser made in China you are gambling. No one has to buy lasers made in China. We have members here in several countries (Israel, Norway, Belgium, US) that build and sell lasers or a parts bundle you can assemble yourself. There are members here who make hosts, heat sinks, and focus knobs (in U.A.E., Croatia, US), many drivers and battery contact boards are made in the US and G2 lenses are made in the US.

Alan
 
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Just this makes me build my lasers myself except for exotic DPSS. I absolutely hate angled beams.
HAHA I know what you mean, someone here recently in another thread said that they have never seen a straight beam. I can't understand any excuse for such poor craftsmanship.

Alex, the 520nm diodes are less efficient than others and do produce more heat, it is quite possible it really does have a duty cycle of 2 minutes. It is normal for it to start dropping in power as you exceed the duty cycle, it happens on my 520nm, I can see it if I measure it on the LPM, it is common to all solid state/diode lasers, there may be some that low power with no duty cycle but probably not a 520nm.

Alan
 

Alaskan

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I have a LaserBee A and although it isn't rated to measure down to a few milliwatts, I've been able to use it that low if I do everything Pi warned about, there cannot be much movement of air in the room, even breathing near the sensor head can change the power reading, or holding your hand close to the meter so keeping the laser pointer 8 inches away or more is a good idea too.

With my LaserBee, I first place the sensor on a small piece of folded paper towel to minimize the transfer of heat from its aluminum body to anything else and after touching it, let it sit for a couple of minutes so the heat from my hand drains off into the air. After the meter has stabilized, then I use the knob to zero the meter, or show all zeros but to do so takes some time; my meter seems to be reading a bit low, so I turn the knob until I see 0001, then back it off by turning the knob very slowly until I see 0000, turn it back up in tiny increments until I see 0001 again and then leave it there. Next I put the beam from the pointer on the sensor for at least 30 seconds to get a peak reading. The laser really needs to be completely still, holding it in your hand will cause differences in reading. Even with all of this the meter can be off from a half to a full milliwatt. I suppose that isn't so bad for a cheap laser power meter and doing so allows measurements far lower power than it is rated for.
 

Hap

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HAHA I know what you mean, someone here recently in another thread said that they have never seen a straight beam. I can't understand any excuse for such poor craftsmanship.

Alex, the 520nm diodes are less efficient than others and do produce more heat, it is quite possible it really does have a duty cycle of 2 minutes. It is normal for it to start dropping in power as you exceed the duty cycle, it happens on my 520nm, I can see it if I measure it on the LPM, it is common to all solid state/diode lasers, there may be some that low power with no duty cycle but probably not a 520nm.

Alan
Interesting. Alright, I'll take another shot at running it tonight & measure how long it takes before I see the drop in brightness and will report back!

-Alex
 

Hap

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Pm sent. A lasercheck just popped up on eBay.
Thanks for looking out GR3EN! I decided in the end to go with a fog machine, and pass up on a LPM for now :)

-Alex
 




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