Arc LS optic centering help needed

[bhds]

Anybody have any tips on centering a fraen lp in a arc ls? I have done 3 already and was able to get them centered mostly through trial and error. This one I'm doing now is driving me up the wall. Im suprised I havent stripped out the threads as many times I have had it apart /ubbthreads/images/graemlins/mad.gif.

Thanks,
bhds

 

[mahoney]

It may be that the emitter is not well centered on the board. I had one that had this problem. You can carefully pry the emitter up off the double-stick heat transfer tape and move it a bit without having to unsolder it, but be very carefull, the leads to the emitter are fragile and if you break one and then power up your LS, you will destroy the chip in the power supply. I learned that one the hard way. Un-soldering the emitter to move it is a bit safer, if a bit of a pain.

One trick I did find usefull was to place the board in my LS with the retaining ring barely tight. Get a battery holder for 3 volts worth of batteries and a couple of alligator clip test leads. Clip negative to the head and positive to a pair of needle nose pliers. Grab the positive contact on the board and you can spin the board and see the effect at the same time. Of course when you tighten the ring the board will spin but once you know where it needs to end up, it's not too hard to compensate for the amount it will move when you tighten the ring.

 

[gadget_lover]

I tried a different trick, and it's worked on a few cases.

I carefully lifted the emitter from the tape and left the leads soldered. I positioned it using a wierd tool that I picked up for finding the centerline of pipes. It's a 60 degree anvle bisected by a ruler coming straight out of the V.

With the LED roughly in position and still not touching the tape, I put the assembly in untill the LED was in the cup of the Fraen. The cup pushed the led down onto the tape in the right spot.

I haven't done this enough to say if it's a good trick or not.

Daniel.

 

[bhds]

[ QUOTE ]
mahoney said:
One trick I did find usefull was to place the board in my LS with the retaining ring barely tight. Get a battery holder for 3 volts worth of batteries and a couple of alligator clip test leads. Clip negative to the head and positive to a pair of needle nose pliers. Grab the positive contact on the board and you can spin the board and see the effect at the same time. Of course when you tighten the ring the board will spin but once you know where it needs to end up, it's not too hard to compensate for the amount it will move when you tighten the ring.

[/ QUOTE ]

The needle nose plier trick helped a lot! Before I was using an alligator clip to the body and a probe touched to the positive contact to check after every adjustment. Using the pliers allowed me to get it pretty darn close before the final tightening and tweaking. I just need to get some heat shrink to insulate the upper part of the pliers/ubbthreads/images/graemlins/ooo.gif /ubbthreads/images/graemlins/ooo.gif

Thanks Mahoney /ubbthreads/images/graemlins/thumbsup.gif

 

[bhds]

[ QUOTE ]
gadget_lover said:
With the LED roughly in position and still not touching the tape, I put the assembly in untill the LED was in the cup of the Fraen. The cup pushed the led down onto the tape in the right spot.

Daniel.

[/ QUOTE ]

Hmmm. Never thought of using the optic and body to center the emitter on the board. Will have to try that on the next one I do. So far I have been pretty lucky /ubbthreads/images/graemlins/grin.gif