Doing some very early testing of my new K40 and I heard some squeaking

Lasers
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#1

Doing some very early testing of my new K40 and I heard some squeaking noise start a few seconds after I start a job that sounds suspiciously like my laser might be arcing.

Give it a listen and let me know what you think? Normal, or do I have another fun project on my hands?

#2

My makes a similar noise when the laser is powered, at times. I’ve never seen any ill-effects so I’ve always just attributed it to the cheap high frequency power supply.

#3

@Gee_Willikers well, that’s a relief. Thanks. With everything that can go sideways with these, especially when you’re still learning, I just wanted to get opinions and make sure.

#4

What coolant are you guys using.

Even though they are cheap they should not squeal.

#5

RV antifreeze and RO/DI water. Which have both actually wreaked havoc on my pump.

#6

And now that you mention it that issue is ringing a bell…

#7

Just purified water for me so far. But then it’s only been a couple weeks. Best long term option I’ve seen so far is just a capfull of bleach and regular water changes.

#8

I suggest you change your coolant using distilled water and 6ml (.2oz) of Clorox and lets go from there.

If you have a conductivity meter I would be interested in the reading before and after changing it.

Anything else is highly suspect to be too conductive for healthy coolant.

#9

Purified water and distilled water are widely different in terms of conductivity?

I have a multimeter. Would that do?

#10

Also, since we’re on the subject, I’ve struggled to design a reservoir system that can be sealed to avoid contamination and evaporation. I was thinking of using a 5 gallon bucket with a standard lid and installing two bulkhead fittings with barb fittings for the in and out flows, but then the submersible pump power cord needs a way out and I’d rather not make anything permanent so I can swap parts etc which makes sealing that hole a challenge. So I thought next about using an external pump instead… and on down the rabbit hole I go.

@donkjr ​ what is your setup like?

#11

@Bob_Buechler like many others I have a 5 gallon HD bucket (orange).
Nothing special I hang my water flow switch tubes and cables through a slot I cut in the lid. The cover is not air tight but keeps the BIG stuff out. My future plan is to a fix fittings to the lid.

Prior to this discovery I was using tap water and not doing anything about algae growth.

Pictures under: flow sensor in this post.

#12

Thanks, @donkjr ​. I’d be curious to know the uS difference between purified water + 6mL of Clorox and distilled + the same. I don’t have a conductivity meter to test this myself, unfortunately. Reason being that purified (highly filtered) water is much easier to get and less expensive than distilled (evaporated and recondensed) water.

#13

@Bob_Buechler what exactly do you mean by purified? What would you buy?

#14

These are pretty common in my area (for example): http://www.custompure.com/Water-Quality-W24C7.aspx

#15

I noticed a funny click from mine, poor cutting. Changed the distilled water and seems fine.

#16

@BeenThere_DoneThat the distilled water stopped the clicking and improved the cut???

#17

Yes.

#18

@BeenThere_DoneThat Sweet yet another proof point! Thanks.

#19

Yours sounded like a whine, mine sounded like a crackle.

#20

Quick update. I’ve moved to a 5 gallon bucket and some bulkhead mounts with hose barb fittings, distilled water and 1/4 teaspoon of bleach per gallon of water, per @donkjr ​’s recommendations. I flushed the tube for about 15 mins so far.

I’ll do a few more test jobs and see if the sounds change.