Water temperature. How much of a differnce does it make?

[Ben Fenton]

Hey folks

Just wondering, my current 'cooler' starts off at around 19 degrees, but after a while climbs to as high as 28 degrees. Being the cw-3000, theres no option of making it cooler, and I think I can tell a difference in power as the temp rises. So, is it worth upgrading the cooler in the future?

Wont be for a while as its cooling down now, but just covering my bases : )

Cheers

[Peter Odell]

Yes it is worth it. You will lose some power the hotter it gets. I sometimes put my bucket in ice to cool it down. my big machine don't need it have a bigger chiller on it

[Dan Hintz]

Just make sure your water temp does not go below the dew point in your shop... water will start condensing in bad places.

[Dave Sheldrake]

Fat body tubes like the RECI and EFR start to degrade after 23 degree's, most of the narrow body tubes will run to 28-30 degrees but you will indeed lose quite a bit of power (as well as beam quality) due to the abberations caused on the internal tube mirrors by the heat. Warm is fine, cool is fine but fluctuations cause all sorts of issues.

Stable is the name of the game be that higher or lower temperatures.

I got asked the same question some time ago on my own forums and responded with the exact physics behind it ("what is the most efficient temperature to run a tube at") sadly a few people took it as THE temperature to run a tube and were calling the UK dealers asking for chillers that would provide that temperature.

Anything above the Cole figure up to the tubes max is fine, like Dan said though, condensation can be a killer.

cheers

Dave

ps: I use one of these and it keeps my 180 between 17 and 20 degrees even with ambients at 32 to 33.

269629

[Rodne Gold]

The cooler the better .. and as dave says , stability is key.
The CW 3000 is a POS... it is effectively a bucket with an small recirculating pump and maybe you get a fan blowing on the water surface or some mickey mouse radiator..no true chilling,
You can kludge a fix to make it more effective , that is to take a small radiator (like a heater core from a scrapped car or a transmission or oil cooler from an aftermarket car place) and run the flow thru that prior to running it thru the machine , strap on a computer fan on the radiator core to provide airflow. Be wares , you will never get better than ambient temp.
We lost a tube cos the 3000 we ran was low on water and getting hot , my guy put in ice cold water and the tube then proceeded to crack when it got the "cold" shock.

[Ben Fenton]

Hmmmm, interesting...

I had a feeling this 'cooler' was going to give me some grief when it was installed. As it happens, yesterday the temp climbed to 28 on the chillers display, it wasnt a hot day and was infact rather chilly. I'd say the temp in the workshop was around 17 degrees.

Half way through an engraving job, I noticed the machine had stopped engraving. The head was still moving, but nothing was coming through. After a little look, I noticed a little flaring coming from the back of the machine. It turns out the flaring was coming from the tube which no longer had a beam running down it, but just a spark near to the first water inlet. Hard to describe, but there is also a very visible burn mark inside the tube near where the sparking is. I suppose it looks similar to a burnt out light bulb

Somebody shoud be coming out to look at it today, and maybe replace the tube as I've only had the machine installed for 3 weeks, but do you think the water temp may have damaged the tube?

Its a 100w, even though the reci label on the tube states its rated to 120w. Does a higher wattage equate to more cooling needed?

Thanks a lot

[Dave Sheldrake]

Its a 100w, even though the reci label on the tube states its rated to 120w. Does a higher wattage equate to more cooling needed?

The CW3000 is rated for 50 watts MAX, using it on a 100 watt wide body will kill the tube. RECI's are supposed to be kept under 23 degree's :( There's a label on the back of the 3000 that says 50w max unless it's been removed by the vendor. If that chiller has been supplied by the vendor as suitable...it simply isn't.

The 120 watt rating is the kind of power it will deliver when it spikes up (first fires each time)

Bigger the output...the better the chiller you need.It sounds like the tube may well be dead :(

cheers

Dave

[Ben Fenton]

Thanks Dave

Thats good to know. I havent noticed the rating, but will certainly have a look when I go up to the workshop later. Its one of them things you just assume will be right when you buy a package. I'll try and print of a spec sheet now to show the engineer

I think your right though about it being dead. Cant say I feel guilty though as I was simply using what was provided and recommended by the vendor, so a new tube will be had : )

Is the cw-5000 a decent cooler for what I need? Or can you recommend another brand?

Thanks

[Dave Sheldrake]

I don't like the 5000 Ben, they have a dissimilar metals issue on the cooling ring that can lead to leaks....that alone isn't the main issue, it's the fact that if they do leak they cannot be refilled.

I use one of these

http://hpclaser.co.uk/index.php?main_page=product_info&cPath=2&products_id=10 (HPC is in the UK so you would need to find one there) it's not actually a CW chiller but was given that name to keep things simple for people who recognise the naming format. I don't know who it is made by but I have one fitted to a wide body 180 watt EFR and never have the slightest problem with heat.

Found the manufacturer

http://Shenzhen Sunrise Industrial Co., Ltd

http://dly-china.en.alibaba.com/productgrouplist-50225826/Laser_water_Chillers.html


If the vendor has supplied a CW3000 with a 120 watt rated tube then they have got it wrong, plain and simple and *should* provide you with another tube.

best wishes

Dave

edit: Found the manufacturer so added link

[Ben Fenton]

Thanks again Dave

Ive printed off the spec sheet for the 3000 and as you say it shouldnt be used with a 100w+ machine :s

Luckily, I'm UK based and have had dealings with HPC in the past. We had a laser installed at a college I worked at and they seem like a decent enough company.

Hopefully, the vendor will see sense and realise the mistake. Hopefully.

Out of interest, even though you seem to have a more poweful tube (kinky), could you take a guess at what speeds I should be able to cut 3mm acrylic at. Since install, the vendor recommended 12mm per sec at around 65% power (65% to reduce flares off the cutting bed). This works until the temp spikes, at which point a second pass is often needed, but I must admit I was expecting a little more speed. On the hpc 60w I used to use, the cutting was pretty much the same if not faster.

Cheers
Ben

[Dave Sheldrake]

Hiya Ben,

Chris@ HPC is a good friend of mine as well as being my chosen supplier, he likely knows more about Chinese lasers than any other UK company :)

3mm acrylic should cut (@ 75% power) (cast acrylic that is) at anywhere between 12 and 16mm per second on a true 40 watt tube. 60 watt will go to about 16 to 20, 80 watt from 18 to 26/27. At the other end a 150 (180 peak will do around 40 to 46mm per second at 80%.

Backscatter can be an issue on honeycomb beds, I use the rail beds for that very reason.

cheers

Dave

[Ben Fenton]

Thanks Dave

Quite worryingly, the engineer didnt turn up yesterday, so its still down at the moment. I've had a promise of Monday morning though, so not too worried at the moment. I took another look at the tube though and to try and describe it, when you test fire the laser, from what I can see in this vid, it should be firing a perfectly straight pink beam:

http://www.youtube.com/watch?v=03u-r1KW2LA&feature=youtube_gdata_player

Mine does not. Instead, it kind of looks like the wavy beam fired out by the ghostbusters. It almost coils around. I placed some card over the first mirror to see if anything is coming out. There was a burn mark, but it was fairly faint.

Then I realsied I dont really know a great deal about fixing lasers, so closed the lid and locked it up for the weekend : )

My diagnosis though... broken

[Ben Fenton]

Forgot to add, mine certainly does not cut at any where near them speeds for some reason. From them numbers, I'd say around 30 speed should be possible on a single pass. At 25 speed, I have to do a second pass. So maybe the tube has been faulty from the start.

Cheers

[Dave Sheldrake]

Hummmm Halo beams...there are three other things that can cause that, loose wires on the PSU, low gas pressure in the tube and on occasion the control Pad has the max power set low. Does it look more like one of those decorative Plasma Balls when it fires?

cheers

Dave

ps: what cooling water are you using? (does it have anti freeze in it) sometimes that can cause voltage leaks.

[Ben Fenton]

Hey

Yeah, I suppose it does look similar to a plasma ball now you mention it. Is that good or bad? : ) Max power is set to 85 on the control pad, and I suppose it could be a loose connection as it happened mid way through an engrave that could have loosened something via vibrations

When they set it up, I dont think they added any anti freeze

Thanks

[Dave Sheldrake]

That will be fine, (no anti freeze at the moment)

Have a look at the main PSU connections, they are usually just tiny screw downs that pinch the wire. Make sure you don't get near the main HV wire (the big red one) they can still contain quite a bit of residual current even after the laser has been off for some time. The TTL signal wire may be an issue...it can't hurt to make sure they are all nice and tight though :)

I have to say it again though...AVOID the HV wire...pokes from that hurt like hell :( earth the hand you are working with, worst case scenario you end up with a belt in your hand, better than across your chest for sure.

Halo fire is usually one of two things, the tube is dying or there is insufficient current to generate a stable arc. (can be a faulty PSU but those are *normally* pretty reliable.

cheers

Dave

[Ben Fenton]

Thanks dave : )

If the engineer doesnt show up on monday, i'll have a tinker. Should probably leave it to someone who knows what their doing though as i have a fairly none existent knowledge of anything electronic and a poor track record with electricity. It hurts.

I think the tube is damaged though because of the burnt area inside it at the base of the first water inlet pipe. I'll try and upload a pic tomorrow to show you

[Ben Fenton]

Hey

So, the tube was blown. Had a small crack in it. Replaced though and seems to be working fine. Still got the same cooler though, so i'm just going to have to watch the temps and stop any cutting above 25 degrees. Should only be for a few weeks until winter crashes in on us then I'll be asking for antifreeze advice :p

Ive been offered a cw-5200 chiller by the vendor for £450, which he normally supplies with 180w machines. Seem like a good price? Very closely priced to the cooler you suggested. He was 'unaware' of the specs of the cw-3000 and seemed genuinely concerned as he has had 2 other blown tubes, and has set up over 75 100w lasers with the same cooler :s

Cheers

[Dave Sheldrake]

Ive been offered a cw-5200 chiller by the vendor for £450

The 5200 is an excellent chiller.It can handle 180's with out trouble .


He was 'unaware' of the specs of the cw-3000 and seemed genuinely concerned as he has had 2 other blown tubes, and has set up over 75 100w lasers with the same cooler

If the end users aren't very careful he is going to have another 73 tubes go the same way.The chiller is rated for 50 watts MAX, fatbody tubes don't like anything above 22-23 degrees and will drop a LOT of their <10,000 Hr life if they go much above.

In particular this bit


He was 'unaware' of the specs of the cw-3000

Would give me considerable cause for concern. My rule of thumb is when buying, ask a couple of reasonably sensible questions about wavelength and lens materials, if the seller doesn't know then they are unlikely to be much use if it all goes tilt. As a retailer not knowing the specifications of equipment you are selling is in-excusable. I have a feeling I know who you are on about, check your PM's Ben ;)

Running a 100 watter on a CW3000 is a bad idea, even short term, the temps can spike in the mirror chamber and bust the tube well before the chiller gauge catches up.

cheers

Dave

[Zlatko Kursar]

Can anybody explain me how to set temperature on my CW-5000.
I can't find manual. I found some manual on web but it doesn't work for me.
270111

[Tony Lenkic]

Pozdrav Zlatko,

Check this video............http://www.youtube.com/watch?v=ND0rBX7Jybc

[Zlatko Kursar]

Hvala Tony,

but my controller is not same (this one have two buttons on left side and two on right side). I was tray all combination. I found this manual http://www.rabbitlaserusa.com/manuals/CW5000_UserManual.pdf and it doesn't work.