DIY LEDs - The write-up

[g8gxp]

I don't know about 8-32 but i was trying to do 220 holes of 4-32. After about 5 of them and 2 broken taps i went the easy route.

I have drilled & tapped over 350 8-32 holes in the 1/8" Al channel & the heatsink USA stuff.

I have broken ONE tap, and that is because I bolted the channels together first and hit one of my bolts while tapping.

Oh, and my 12 year old son did about 50 of them.

You guys must be doing something wrong.

After EVERY hole, I clean off the tap, inspect for any Al stuck in the teeth & re-oil.

I did 48 holes in the 2" fin heatsinkusa stuff drilled & tapped ( all the way through ) in less than 2 hours.

Stu

 

[HeneryH]

A 4-x tap is going to be thinner than a 8-x tap so that might be one problem.

I now know my problem was not oiling the tap. I can report on my success rate tonight after correcting my technique.

 

[TheFishMan65]

If with about tenth inch aluminum and a 3/32 hole I could screw in a stainless 4/40. Works, but only use the screws once for tapping. The few I did break the head came off and Vise grips were able to get the screw out. Just a possible option for some.

 

[stugray]

"I could screw in a stainless 4/40. "

For all of you guys using the self-tapping screws....

Are you using a screw-gun directly over these expensive emitters?

Stu

 

[TheFishMan65]

I did not use self tapping, but it is on 1/10 inch or so. But ro answer your question, No regular old phillip screw driver #2 I think.

 

[bstohrer]

I wonder if some are drilling holes too small for the tap??? I bought a matched drill & tap set from Lowes along with tapping oil. I drilled all 200 of the holes in the 1/8" channels and have tapped about 50 holes so far. I used my cordless, variable speed drill to tap (at low speed). I oiled the tap between each hole and have had no problems. It takes about 5 seconds per hole to tap.

Bob

 

[TheFishMan65]

I think part of lesson here maybe that thinner aluminum is easier to tap. Not that I am surprised.

 

[bstohrer]

Yes, the thinner stock is easier. Another reason I went with channels.

 

[laverda]

I hope you guys are cleaning the oil off thourghly and deburing the holes after taping them so your stars sit flat and make good contact.

 

[bstohrer]

I hope you guys are cleaning the oil off thourghly and deburing the holes after taping them so your stars sit flat and make good contact.

Yes, both are important. Also, to keep oil and aluminum chips out of the tank.

I normally add a small amount of oil then blot excess with a paper towel. Tap, debur and then wipe down with isopropyl alcohol to clean last bit of oil off.

Bob

 

[Jepjep13]

Hey I'm sure this has been asked but if I can check one led with two double A's can I test a string of 3-4 led's with a 9 volt?

 

[kcress]

Probably yes.

 

[TheFishMan65]

Since I started the summary I have been thinking more about the parallel configuration.

As a general rule we have been saying avoid parallel configurations. After thinking I wonder if the Meanwell's are meant to driven in parallel. The advice was to ignore the internal voltage setting potentiometer. But if we set the voltage to the measured voltage when running at the desired current then when a string is lost the Meanwell us unable to increase the voltage to get the additional current out. I don't think any additional safety precautions are needed.

I think this was mentioned before, but just did not sink in for me. So where is the problem if both internal adjustments are PROPERLY set with running parallel strings?

 

[kcress]

The problem is shorts in a string.

With a short the required voltage of the string drops and the current increases, a vicious circle.

All the streetlights and signal lights run parallel with no protections and the strings all burn out eventually. I was just noting yesterday that about 1 signal light in 3 has failing LEDs showing. My town embraced LED signal lights the minute they came out. So what, 6 or 7 years? And now failures are starting to occur. If you are fine with retooling your fixture in that period it will probably work fine to parallel with no added protections.

 

[TheFishMan65]

Thanks I forgot about shorts. We have a lot of LED lights around, but I have yet to notice that the lights are missing. I think the northern Virginia area were some early adopters also so I will have to keep my eyes open.

 

[tahiriqbal]

Bargin hunt.... Well, I bought these heatsinks from ebay, all in all 9 heatsinks with 200 x 160 x 40mm dimensions for £45.

and rest of family including some aluminum profiles for housing.

 

[CJO]

Any idea what happens if you give the Meanwell ELN-60-48D a voltage signal over 10 volts? I've looked around and I have a varied group of power supplies including 5V, 6V, 9V and 12V. I thought I was good with the 9V, but when I actually measured it, it puts out over 15 volts!

Thanks,
CJ

 

[kcress]

Most wall warts are garbage. What you measured is more the rule than the exception.

You may damage the MW if you go much over 10V.

 

[TheFishMan65]

I think someone contact meanwell and the magic number from them is 10.5 IIRC. I also think I read of people doing more with no apparent damage - no I don't recommend it I am also not sure how long they did it for.

 

[CJO]

I caught mine after a few days with no apparent issues. I'm heading to radio shack with a multimeter after work to get one in range.

Thanks,
CJ