Internal LED light ring for sight glass

[coppercreature]

Y'all got me thinking, partly because I wanted to add a 1 1/4" sight glass to my 2" VM. I figured a 1 1/4" sight wouldn't really let in enough light to see anything. SO, here's my idea:
McMaster, ColeParmer, and a bunch of other places sell 1' lengths of borosilicate glass tube in standard diameters (3/8" maybe?) Use a torch to pinch the end of the tube, then form it into a loop that would fit around your sight glass (in my case, 1 1/2" diameter.) Leave a tail at 90 degrees from the loop. The tail will go through a stainless or brass compression fitting to the outside of the column. (I usually drill and tap for 1/4" NPT and solder in the cleaned brass fitting.)
Digi-key sells some nice Axial lead LEDs (http://search.digikey.com/scripts/DkSea ... 16-1410-ND) that have a wide angle and should fit in a 1/4" ID tube. Solder a few in series, add some thin leads, and insert the string into your glass loop. Use the calculator here http://led.linear1.org/led.wiz to find what size resistor you'll need for your power supply.
If the loop seems to fiddly (aligning the LEDs to point out might be a PITA,) then use straight tubes to illuminate an area. I'm not sure how much the ID of the tube will distort when bent (like copper?) so getting the LEDs in there might also be pain in the ass.
For flute designs, where the sight might be directly adjacent to the plate, maybe we could use a single, extra bright, wide angle LED inserted into a short piece of glass tube held in place with a single compression fitting just above or adjacent to the sight glass? Just gotta figure out how to seal the end of the glass tube without blocking all the LED's light...
Thoughts? Anybody want to give this a try?

[bgrizzle]

I highly doubt this would work. I own a company that sells LED products. I think that the environment is too hot for the capacitors, rectifiers, and the LEd chip board. LEDs require proper heat sinks to dissipate the heat. HEAT = DEATH for an LED.

[bgrizzle]

One more thought... why LED?

You could use a tiny 12V g4 bi-pin. 5W would be plenty. I think my oven has 2 5W bulbs to light it up... its not going to take much light to illuminate inside a column...

good luck

[coppercreature]

Good to know about the thermal limits for the LEDs - checked some data sheets and 90 deg. C is about the max. I think the bi-pin idea would work better - not as sexy, but much more functional in terms of illumination angle and environmental conditions. Might not even need a socket - press fit in a hole in the column to act as a return, and have a single wire to do the switching. Back to the drawing board....

[bgrizzle]

I would not use a socket. The tiny springs inside the socket would detiorate in no time. I would solder wires to each pin on the bulb. The real question is to put the bulb inside the column and keep the vapor and liquid from hitting it!

[olddog]

I don't consider lights in sight glasses necessary, while it might be difficult to photograph whats going on for posting purposes, it's quite visible to the naked eye o see what's happening without extra lighting


OD

[coppercreature]

So I guess the spinning disco ball idea I had for inside your flute isn't gonna fly either?
Maybe I'll just get the basic build done first, and bling it out later....

[tafinaf]

How about TWO sight glasses? One to let light in and one to look through.

[Braz]

How about TWO sight glasses? One to let light in and one to look through.

Yep, KS already did that with the sight glasses set 90 degrees from each other.

[Kentucky shinner]

Yep it worked out really well. What about 2" sight glasses 180 degrees apart.

[coppercreature]

Got it. 2 sightglasses, 180 degrees apart, and the disco ball in the middle that spins when attatched to the turbo blades in the deflag....