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View Full Version : How to LED gauges work?



4thgenceli
05-24-2010, 10:48 PM
As in for the display?

I'm about to finish the gauge in cluster mod, but need to affix the gauge so it doesn't move around. I'm wanting to use some epoxy or hot glue sort of stuff to glue it to the back of the bezel.

Would this work, or can I damage the LED gauge?

Shadowlife25
05-24-2010, 11:56 PM
Hot glue will be fine, but if anything breaks, good luck.

4thgenceli
05-25-2010, 12:00 AM
Upon closer inspection of the gauge, there's the LED portion and then the gauge face. Hot glue/epoxy would be EVIL.

I poked around the garage and found some clips that I can use that will do what I need. I'm going to glue them to the back of the bezel, and then use zip ties to hold the gauge to the bezel.

klapa
05-25-2010, 12:27 AM
Just saw this thread. That's probably a good idea.

The LED's I deal with are the "high brightness" types used for lighting - not those used for displays like yours.

Yet for the types I come in contact with - they are VERY susecpible to "out-gassing" which results in the lens that covers them cracking and ruining them. The prescense of certian chemicals - most especially epoxy or "super-glue" is strictly a "no-no" with these - as these vapors can somehow be absorbed into the plastic lens material that is molded into the part at the top of the die.

They are in fact so "particular" - that on one of our newer very hot products, and exterior "are light" (essentially a small street light for example used in parking lots) we even need to be careful what gasket material we use.

Again - such a light has LED's which generate a large amount of heat - which causes these other material to make the offending vapors. The display type of LED's your gauge has probably does not generate such heat.

In nearly ALL cases - it is always safe to use silicon - either the silicon glue or gasket material.

Shadowlife25
05-25-2010, 12:32 AM
Why would you glue the face of the gauge?

I thought you were just going to bead around it to retain it from the back.

klapa
05-25-2010, 01:54 AM
Why would you glue the face of the gauge?

I thought you were just going to bead around it to retain it from the back.

I think that is what he said but he noticed the actual LED elements are on the back-side of the PCB.

4thgenceli
05-25-2010, 02:06 AM
I think that is what he said but he noticed the actual LED elements are on the back-side of the PCB.
Correct.

I'll try to get a better picture of it, but there's the board, then the LEDs, then the faceplate. Not a lot of material to use to bead to.

I figured something out... :P Super glue & zip ties FTW!!

klapa
05-25-2010, 02:50 AM
I would recommend RTV/silicon - you can't go wrong with that in my experience - and it would not only hold well but do better to isolate the instrument from vibration..

Zip ties are fine - superglue IS a risk - it has very reactive vapors - not only for LED's but any plastics in general.