Laserwave 1 watt OEM V-S

[m0f]

It really does sound like inadequate cooling. Power will drop if the tec's can't keep up due to not being able to move the heat away. And especially with the red's and blue's getting hot too, it really does sound like a cooling issue.

Things to verify would be to make sure both surfaces are smooth as any gaps / warping / dirt could really limit the heat transfer. Also, did you use a good quality thermal compound between the laser and heatsink ? If not, that's something that can help immensely.

Make sure it's a nice heavy baseplate or heatsink, the more aluminum the better. Make sure it is in fact aluminum or copper.. Fans can help but not a substitute for good old mass.

If you can, post a picture of the setup. Can really help in diagnosing the issue.

[badger1666]

the problem with the oem-v its just to small for its own good.
the head gets to hot and can be difficult to get the heat away quick enough,the driver runs so hot by the three big resistors it dam near melts the solder(i see this being a bigger problem in a hot country). even one of the cables between the head and driver can get quiet warm.
also just fixing the head down to the baseplate can cause problems with warping the head ,and the shifts alignment of either optics or xtal a fraction and upsets power levels, and a lot of them just have a shit beam. and the grape vine says quite a few others have had issues with the oen-v , mine is complete crap.. i say more about it but it not going to be nice

now the oem-vs well thats just awesome a proper sized head that runs just so much cooler, great beam and stability, best laser i have ever owned so far , even the driver runs much cooler
thats my 2 cents worth

[m0f]

Hmm, good to know. I never realized there was much of a difference between the two models other than the beam specs. I wonder what the 4-5W area models are like. A lot more heat to dissipate, but I believe they're a bit larger too. Not sure on that though as can't find too much info on dimensions.

Anyone with first hand experience ?

[planters]

The OEM-V-S are not small. The head is nearly as large as the 2W and 4W models. The problem, when it develops after such a long time is almost certainly a heat removal limitation. Anyone who has received one of the Laserwave heads probably noticed the residual thermal compound remaining after the company performed QC testing on each laser. I have discussed this with them as it is rather a lot and needs to be carefully removed to avoid contaminating other surfaces. Nevertheless, the bottom surface of these heads is milled flat, but nearly all aluminum heat sinks are extrusions and their contact surfaces can be awful. They are often so far from flat that you can see it without a straight edge. A flat to flat interface is more important than thermal grease and if it is not present the grease will work very poorly. If well sink-ed the head's warmth should hardly be detectable and if not well sink-ed it can become painfully hot.

I suspect you have a flatness issue, but if your heat sink is low cost it may also suffer from a coarse fin density and so the surface area may be low as well.

While you are at it, feel the driver board base plate during operation. This can become hot just like the head and similarly needs good contact with a heat sink.

The Laserwave lasers are wonderfully compact and silent, but you must allow for the heat generated to be removed

[badger1666]

The oem-v i recieved the head and driver were far from flat, the head i had to lap in on a known flat plate .
The driver plate was warped enoungh that i had to make a new one.
The oem-vs that i have was better but not perfect ,but again the driver mounting plate was warped by 25thou ,that said i have owned several laserwaves now and the machining quality is an area they need to work on even if it puts the price up it would be worth them doing this as it would cut out some of the problems, but then as you said most people are just going to proberly bolt them down on as pissed base plate
So not much point in them improving the machine work

The OEM-V-S are not small. The head is nearly as large as the 2W and 4W models. The problem, when it develops after such a long time is almost certainly a heat removal limitation. Anyone who has received one of the Laserwave heads probably noticed the residual thermal compound remaining after the company performed QC testing on each laser. I have discussed this with them as it is rather a lot and needs to be carefully removed to avoid contaminating other surfaces. Nevertheless, the bottom surface of these heads is milled flat, but nearly all aluminum heat sinks are extrusions and their contact surfaces can be awful. They are often so far from flat that you can see it without a straight edge. A flat to flat interface is more important than thermal grease and if it is not present the grease will work very poorly. If well sink-ed the head's warmth should hardly be detectable and if not well sink-ed it can become painfully hot.

I suspect you have a flatness issue, but if your heat sink is low cost it may also suffer from a coarse fin density and so the surface area may be low as well.

While you are at it, feel the driver board base plate during operation. This can become hot just like the head and similarly needs good contact with a heat sink.

The Laserwave lasers are wonderfully compact and silent, but you must allow for the heat generated to be removed

[Diachi]

My employer heats the baseplates of our lasers at all times, even when "off" and runs the crystals in heaters at ~50' C, Type II SHG.
Does not matter if its a small laser, or fills a 4x8 optical table, its heated. Of course the drivers and fiber coupled diodes are in racks, so they are cooled, but the principle still applies.

Steve

Steve, what's the best way to heat an Al base plate in a projector? Some heating elements bolted on to the bottom with temperature control? I'm looking into doing some work here but winter temperatures up here north of 60* often reach -50*C (Though usually it's around -35*C).

Thanks,

[carlos3621]

Planters, what laserwave powers are u stocking now?

[planters]

Carlos,

I have 1W,2W and 4W greens.

Diachi,

What exactly are you trying to do at your "usually it's around -35*C" temperatures?

[dnar]

The OEM-V-S are not small. The head is nearly as large as the 2W and 4W models. The problem, when it develops after such a long time is almost certainly a heat removal limitation. Anyone who has received one of the Laserwave heads probably noticed the residual thermal compound remaining after the company performed QC testing on each laser. I have discussed this with them as it is rather a lot and needs to be carefully removed to avoid contaminating other surfaces. Nevertheless, the bottom surface of these heads is milled flat, but nearly all aluminum heat sinks are extrusions and their contact surfaces can be awful. They are often so far from flat that you can see it without a straight edge. A flat to flat interface is more important than thermal grease and if it is not present the grease will work very poorly. If well sink-ed the head's warmth should hardly be detectable and if not well sink-ed it can become painfully hot.

I suspect you have a flatness issue, but if your heat sink is low cost it may also suffer from a coarse fin density and so the surface area may be low as well.

While you are at it, feel the driver board base plate during operation. This can become hot just like the head and similarly needs good contact with a heat sink.

The Laserwave lasers are wonderfully compact and silent, but you must allow for the heat generated to be removed

Before lasers (lol) I was heavily into computer over clocking in a big way (at one stage I had an OC rig that ran almost twice factory speed). One of the key elements in achieving such punishing and on the edge clocking is the interface between CPU and cooler (water cooled). The "normal" way was with what we called "factory chewing gum" placed on the heatsink that melted into a final position between CPU and heatsink on first use (read agricultural).

The ultimate solution was a combination of silver impregnated compound (Arctic Silver) and a hand lapped heatsink. Lapping involved gently massaging the heatsink over wet and dry paper placed on glass (dead flat)in figure of 8's. Get it right and you removed all matching marks and resulted in a dead flat mating surface, get it wrong and you had a heatsink or water cooling block that wobbled on top the CPU.

What I learned from this uber-anal subculture was that mirror finished surfaces require very little heatsink compound, the less the better. I would place the compound on the aluminum surface and spread it evenly with a razor blade. The perfect surfaces require NO compound, but such surfaces only exist in uber-topia, so a small amount is required. The purpose of such compound is to fill the voids between 2 imperfect surfaces. In the electronics industry I note most applications are a liberal slathering of compound applied as if jam on toast, which is not ideal! In fact, for general electronic applications I just hate the stuff, especially the white silicon based "Gensil" stuff as it's an evil product that always manages to migrate from product to your fingers and then it gets plastered on everything you touch before you realize.

I used sheets of silicon rubber thermal material on a job once, between microwave video modules and chassis that was great, although I am not sure how this would go under laser modules.

EDIT: DHL tracking states my custom V-S module is in the van for delivery, time to go sit at the front door in shear anticipation!

[planters]

The silicon thermal material should work well below a driver board because strict rigidity is not needed here and if the thermal conductivity is a bit of a compromise it matters little if there is some temperature gradient here. The transistors will work fine a few degrees above ambient and this material's compliance will avoid the risk that an unnoticed thermal barrier will allow a temperature run away.

We have a side interest here that is much like yours and I am working on a design that uses LN2 and gallium based "liquid metal". Do you have any experience with this mercury-like stuff? It would seem to me that it might allow nearly the same performance with poor surfaces as with nicely lapped surfaces.


Badger,

The driver base plate is stock and far from flat, but I'm surprised the underside of the head was un-flat. There are obvious tooling marks on the one I have with me and I will check the others tomorrow. If this is true, I think that is a problem and could contribute to the thermal problems manlie was having. If necessary, I will fix this.