Somethings moving

[andy_con]

oh sorry everyone calls you alan so I just assumed...

[Insanity]

Thanks for the responses guys...

I am hoping Chris or Steve Milani are right and it is one of the screws holding the module together. I never thought to look at them which goes to show how valuable these forums are... The modules are only a few weeks old so hopefully it's nothing internal...

Al: the slots for the screws are 7mm and I am using M3's to give me loads of adjustment at the module end, as the dichro is small and has very little room for adjustment... I don't see this would be a problem as A) the other two are not exhibiting the same issues and B) even with a good yank I can't move it more than a couple of 10ths...

Dan: I always had a screw loose...

Steve-O: Well spotted, eagle eyes indeed... But if I show you the module from a different angle, you can see that the wires go to TEC's sandwiched between the module and the module foot. I am hoping as Chris and Steve say that the screws holding these two parts together are loose... everything points that way, as they move on their own as the laser runs for longer which indicates heat. And the beam shape never seems to change..



I'll have a look at those screws tomorrow and let you all know the result...

Thanks again for the great feedback
Mark

[andy_con]

hope you get it sorted marc

[norty303]

Get some sprung washers on those bolts, and fix the foot and and module in place with hot glue. If that stops it, you know you can always look for a more elegant solution.

[dilbert]

Mark, are you sure the top of the module (above the TEC ) isn't moving? The base might be solidly mounted but the temperature difference between the two parts may cause movement in the mountings..... Can you tighten the TEC sandwich a little?

[steve-o]

hi mark
look like the 4 little bolts on the underside of the laser, that sandwich the base/tecs to the laser need a tweek up
they are proberly just not tight enough and allowing the base or laser to slide on the tecs
thats all i can i think of

Just noticed.. Badger 1st suggested in post #2 what some other people and I are saying .. the laser head might be loose from the base in the "TEC sandwich" area ..
I might suggest tho don't torque it too tight .. I know (from experience) that over torquing a peltier junction plate can be a 'crushing' experience lol .. They're fairly fragile to screwing 'em down hard .. <crunch> argh .. <sigh> ..

[Insanity]

Badger, Dilbert and Steve M were all right... These four screws on the TEC sandwich were all loose and I tightened them last night, which fixed the drifting problem.... Thing is, I now have a nasty beam, so I now have to find out which of the screws is causing this and shorten it... Have to say, I am becoming less and less impressed with Laserwave and their poor quality control....
I have PM'd Bridge, but he only seems to reply when you are buying something. He was very quick to reply and tell me the problem was with my optic mounts, but when I proved to him that it wasn't, he buried his head in the sand...