Fan or Peliter??

[andy_con]

ok now heres my scanners which i re-box today

http://www.laser-man.co.uk/2006/inde...id=14&Itemid=6

the laser is getting pretty hot, fan or peltier to cool it??

i have this peliter and heat sink

http://www.laser-man.co.uk/2006/inde...id=22&Itemid=6

[MechEng3]

The TEC is a very good way to keep things cool if you have a controller of sorts to make sure you can stabilize the temps. Or a large sink with a fan will do in a lot of cases where size is not important.

[andy_con]

my peltier is tiny so i dont think a fan and heat sink is need. just a heat sink should do

[dave]

The TEC is a very good way to keep things cool if you have a controller of sorts to make sure you can stabilize the temps. Or a large sink with a fan will do in a lot of cases where size is not important.

Ummm,

You will still need a heatsink for the hot side of the tec.

[Banthai]

Hi Andy

as dave says... if you use a TEC you will have to bond it to a heatsink

the TEC is just the same as silicone paste / heatsink compound but transfers the heat a lot faster, it has 2 sides .. a cool side that you bond to the item that you want to pull the heat from ... and a hot side this is normaly bonded to a heat sink in ambiant air ( outside of an enclosed case ) this the dispates the heat ... without this the peltiers hot side will overheat and burn up

The photos of the new case look good on your website, just one recomendation, fit an aluminium baseplate to disipate the heat from the scanners, DPSS, and power supplys, as that foam liner will act as an insulator and all the components will overheat very quickly ...
even if you fan cool the case, ... oh and it may be a good idea to remove as much of the foam as possible.

Good luck with the build


all the best .. KARL

[The_Doctor]

What are you trying to do? Remove heat, or get the scanners to a low temperature? There is a difference. Use a fan.

Scanners aren't designed to run at very low temperatures, and the only point in using a TEC to reach moderate cooling of a small object is to control the temperature precisely, and you don't need to do that.

The misconception is that a TEC will somehow couple to a small area to drag heat out of an object ruthlessly in a way that ordinary thermal coupling won't manage. If you need that object to run at temperatures much lower than ambient, this is valid, but you don't, a scanner will probably be damaged if you try to run it at temperature far below spec, the lubrication will stiffen, the load will rise HARD, making more heat, and wear which will cause early failure.

Use a fan.

You can always stop air from a fan blowing gack over the mirrors by making the heatsink a part of the enclosure. The simplest way is to bond the scanner thermally as well as physically, by a heatsink block on the baseplate. If your scanners don't have that, and were not designed to need it (see WideMoves, for example), but are still getting too hot, you're running them in too hot an environment. Divert the hot ambient air away from them somehow. Use a fan!

[andy_con]

thanks for your replies people.

right i want to cool the laser module not the scanner/galvo's

and i know i have to use a heat sink on a peltier.

the question is, to cool my laser fan or peltier???

and karl you recon to remove the foam??

cheers

[yaddatrance]

Fan... A peltier will create MORE heat which you'll also have to remove with a fan.

A peltier with only a heatsink will operate for about 15 minutes better than a heatsink, but once the hot side heats up, the peltier will slowly heat the cold side until it's worse than not having anything at all.

[carmangary]

Looking at the picture, I see the laser module sitting in the corner totally out of the air flow path. Most likely, the laser module has been designed to adequately cool itself as long as you maintain a decent ambient temperature for it. It doesn't look like you are giving it enough air flow. I suggest fixing that problem first. A heatsink or peltier without proper airflow will just compound the problem.

[andy_con]

i have just installed a fan, which takes air from outside and blows it onto the fan within the laser, ill see how this goes