GB laser barrels

Re: GB feeler laser barrels

Kenom, please put me down for 1...
Thanks,
Jay

Re: GB feeler laser barrels

I might be interested in these as well, preference for CR123 powered and a good amount of room to mount my own driver in.

However:

The barrels will look like a Sonar case on http://www.wickedlasers.com/lasers/SONAR_Blu_ray_Case-58-11.html
the one exception being there won't be any indents on the barrel. the barrel is totally smooth and finished smooth and shiny

Click to expand...

I would really recommend working some ridges into the barrel on the output end, increasing surface area and hence cooling ability. Cooler operation really improves laser performance, and it shouldn't be that hard to do when you are building from scratch anyways!

Re: GB feeler laser barrels

Benm said:

I might be interested in these as well, preference for CR123 powered and a good amount of room to mount my own driver in.

However:

The barrels will look like a Sonar case on http://www.wickedlasers.com/lasers/SONAR_Blu_ray_Case-58-11.html  
the one exception being there won't be any indents on the barrel.  the barrel is totally smooth and finished smooth and shiny

Click to expand...

I would really recommend working some ridges into the barrel on the output end, increasing surface area and hence cooling ability. Cooler operation really improves laser performance, and it shouldn't be that hard to do when you are building from scratch anyways!

Click to expand...

Now Ben, I would tend to agree with you and I'm not going to argue that adding circular cuts around the diameter is not going to increase the cooling effeciency of this. IT WILL. However, since the head is constructed out of one piece of aluminum and there is a large amount of metal in the head by itself, I don't see heat being an issue for this. I have considered putting some cuts in the barrel to increase surface air circulation and heat removal. Like the Sentorch. I'm not tossign this idea out completely, but I want to see how well our beloved GB diodes do without the need for em first. Lets hear what everyone thinks about this.

My Dorcy Mini's that I'm building incorporate a spacer/heatsink around the module and NEVER has my spacer heated up more than 80 degrees f. This temp was taken right next to the laser diode. so the heat would have been hotter there than anywhere else. with the exception of the diode itself being the heat source. We'll see what everyone thinks.

Now I'm trying to incorporate everyone's preferences and wishes. However I cannot fulfill everyone's wish and won't even try. If you have a sugestion you would like to see incorporated into this design don't hesitate to give me a PM or post it here. Although don't feel offended if your idea isn't chosen. LOL oh and I won't even be nice and say I'll be fair. cause I won't! LOL it's my design and I'm doing it my way doggone it. LOL Kidding. I will reserve the final approval of course!

Re: GB feeler laser barrels

i think adding a notch inside of the unit that will stop the batteries would be quite a good idea also. the sonar case was a pita to get something in there that would stop the batteries but still hold up to the tension of the spring

Re: GB feeler laser barrels

busterhax said:

i think adding a notch inside of the unit that will stop the batteries would be quite a good idea also. the sonar case was a pita to get something in there that would stop the batteries but still hold up to the tension of the spring

Click to expand...

Already part of the design. Great idea!

Re: GB feeler laser barrels

Kenom,

I'm thinking a modular design, made in 2 parts, perhaps 3.

The end part: a huge heatisink with space for the diode and lens. Common to all combinations.
The middle part: Space for a circuit (from DX if suitable) or enough space for a custom driver.
The bottom part: Battery compartment, so many different types could be made for different holders. e.g. AA's AAA's CR123 etc....

Then, they all press together into one tube, the same diameter.

This would be alot cheaper to produce than a complete unit, + it's more flexible with circuit sizes and battery types.


What do you think?

Dan

Re: GB feeler laser barrels

However, since the head is constructed out of one piece of aluminum and there is a large amount of metal in the head by itself, I don't see heat being an issue for this.

Click to expand...

Heatsinking ability relies more on surface than it does on mass, though many people think otherwise. A solid block of aluninium has the exact same thermal resistance tpwards ambiant as a hollow cube of equal dimensions. Internal heat conductance is another thing, but only becomes limiting with a really thin shell.

However, lets just stick to real world performance. For the sony diodes, running at, for example, 25 versus 40 degrees results in a power loss of around 10% for a given current. It will probably also have an effect on diode life, though i have no hard data on that.

It's totally up to you if that's worth machining a larger surface area... i'm interested either way though.

Re: GB feeler laser barrels

Benm said:

Heatsinking ability relies more on surface than it does on mass, though many people think otherwise. A solid block of aluninium has the exact same thermal resistance tpwards ambiant as a hollow cube of equal dimensions. Internal heat conductance is another thing, but only becomes limiting with a really thin shell.

However, lets just stick to real world performance. For the sony diodes, running at, for example, 25 versus 40 degrees results in a power loss of around 10% for a given current. It will probably also have an effect on diode life, though i have no hard data on that.

It's totally up to you if that's worth machining a larger surface area... i'm interested either way though.

Click to expand...

I agree with you, but only for longer runtimes. For a short duration the heatsink is just a thermal flywheel absorbing the thermal energy from the diode and radiating very little. Hence a large mass is a large flywheel.

I don't know what the specific heat of this Al alloy is, but if memory serves pure Al is .215 cal/g-°C. Multiply by 4.184 J (or Watt Seconds), and by let's say 28 grams of Al = just over 25 Watts for a duration of 1 second to raise the temp of the block to an average of 1°C higher that before.

Even if all the power I'm putting into this LD were dissipated as heat, that would still be only .87 Watts, so a 1 minute run should raise the average temp of the system by less than 2°C

It's been some time since I've taken any physics classes so someone please correct any mistakes.

Personally, I'd rather see the OD of the head Kenom designs be round and some standard Dia. as to be easily threaded by a standard tap and die set. That way I can make a heatsink, drill and tap it, thread the laser body and screw it on for 100% duty. or leave it off for a smaller (pocket) size.

Re: GB feeler laser barrels

@pyro - why are you multiplying by the specific heat capacity of water??? :-?

I might make some CAD designs and post them up, but I'm quite busy this weekend, so might not get chance. However, when I do, feel free to comment on the design to add bits or changes bits/dimensions. However, please take into account the time, and then hence cost, of a small change in the design. I.e. to have a threaded part may take an extra 5 mins per unit to make, x100 = an extra 8 hours min, which could raise the price by £20 (per hour) = £160...

Not that I have anything against people suggesting things, I'm just commenting about the impact some changes could incurr.


Dan

Re: GB feeler laser barrels

danielbriggs said:

@pyro - why are you multiplying by the specific heat capacity of water??? :-?

Click to expand...

Unless my memory is faulty, Specific heat of water near room temp is about .998 cal/g-°C whereas Al is .215 cal/g-°C

danielbriggs said:

I.e. to have a threaded part may take an extra 5 mins per unit to make, x100 = an extra 8 hours min, which could raise the price by £20 (per hour) = £160...

Click to expand...

Good point, press fit for most connections, and threaded just for the back of the battery tube. So long as it's a good tight fit there's no need for all that thread work. But i'd still like to see the outside of the head be round and a common size so that I could thread it if I wanted to without having to have someone turn it down first.

Re: GB feeler laser barrels

a_pyro_is said:

Unless my memory is faulty, Specific heat of water near room temp is about .998 cal/g-°C whereas Al is .215 cal/g-°C

Click to expand...

Ahh... I didn't see the units, I forgot you USA people use calories. Sorry!

a_pyro_is said:

But i'd still like to see the outside of the head be round and a common size so that I could thread it if I wanted to without having to have someone turn it down first.

Click to expand...

I totally agree! I think for my design I'll use the min size needed, and then round it up to the nearest 'nice' or 'die friendly' diameter.
Also, when I buy some bar stock, it make it a HELL of a lot easier in the long run!

Re: GB feeler laser barrels

a_pyro_is said:

It's been some time since I've taken any physics classes so someone please correct any mistakes.

Click to expand...

IIRC That stuff was Thermodynamics... which I painstakingly took (had to).

The fact that the heatsink is a 'block' means that it can take heat away from the diode and store it in until enough heat dissipation into the environment has taken place to bring the block back to cooling temperature... and then it will work as a heatsink again. Otherwise... it's a heat suppressor. The reason heatsinks are usually finned and very thin and light and have all these mm-thick pieces pointing in every which way is because the point is to keep the heat source at room temperature... the more surface area you have the more heat dissipation you can create... and the more you can keep the internal temperature at room temperature because the body of the heatsink itself will not hold the heat in itself.

it is true that it would be better to have a nice finned design for applicability and duty cycle, but IMO, a sleek polished barrel looks much nicer and quite attractive... it's the kind of thing you'd get asked about

Considering this is the preliminary run, any result is better than nothing, there is honestly no way of making it any better unless we have the unit and then come up with better things later on

--DDL

Re: GB feeler laser barrels

a_pyro_is said:

I agree with you, but only for longer runtimes. For a short duration the heatsink is just a thermal flywheel absorbing the thermal energy from the diode and radiating very little. Hence a large mass is a large flywheel.

Click to expand...

True, on the sort term the termal mass is important.

I guess it depends on what you actually want to use the laser for. IMO a 200 mW-ish red laser is not a device to be used for pointing at sheets during a presentation, but more something for the enthousiast to do experiments with. In that case continous operation would be desireable.

Don't worry about it though, it's something that could easily adapted in a second or additional version. Getting a purpose-built barrel of good quality that fits the LD, optics and batteries well is difficult enough as it is

Re: GB feeler laser barrels

so whats the news? i'd REALLY like some of these, and i wanna make myself a nice bluray. this seems like the right housing!
so yeah Kenom, howsit coming?

Re: GB feeler laser barrels

well, blue if you look up at the second post you will see a running tab of how many we've pre-ordered.  When we get to 60 pre-orders, I'll let everyone know that we've reached enough and ask for the money for the barrels.  I will then take the rest in my finances and go have the barrels designed, cadd'd and turned.

Or provided I can learn how to use cadd software quickly, I'll put together a design myself, send it on to Danielbriggs and have him turn the one's that have been pre-ordered already. The cadd software is pretty complex and may take me a while to learn. I'm also gonna sit down and hand draw some designs. (donno how well that's gonna work) Daniel looks like he is fired up and gonna make some barrels regardless so I'll probably work with him closely LOL. No stealin my idea's daniel! lmao

Re: GB feeler laser barrels

You dont have my 1 down. Can you add me to the list?