electronics soft soldering joints arent very good in terms of taking mechanical stress.

From what I have seen regular soldering isnt used for these kinds of tools.

I took apart a 230V power drill some years ago with some kind of TRIAC drive PCB inside the handle, very miniaturized. That had 800 Watts eventually. just curious how it looks like.

 

I've been working on a drill recently, and I can't desolder the diode mounted in the trigger.

My everyday solder melts easily with my iron, but this stuff is practically welded.
I even tried my big gun (100 watt I think), and it wouldn't budge.

Braising has a different color I think, but this stuff looks like solder, but it doesn't melt.

Would that be a requirement for a 600 volt diode, because of the heat generated?
It's mounted near plastic (so I don't think it's a heat issue)

The trigger is in a 19.2 volts cordless hammer drill.

Any insights welcome.

Even flux did not help?

 

View attachment 77951 View attachment 77952
Makes sense about the vibration issue.
Here are two pictures of the switch.
The old broken diode has been cut out with dikes.
I expect the replacement diode to be here in a few days
I will post back with results.

Thanks for the feedback.

If you cut the old leads close to the diode body, that leaves the stalks set in the old unmeltable solder.

Fitting the new diode by forming loops to go on the old stalks, you can crimp the loops on to make them fit tightly - then you will probably have a secure enough mounting even if you use regular solder.

 

I re-worked my Weller 8200-N, and today, it's melting the solder much better.
I think it should work once the part arrives.

New question, why do Weller and other guns have such a long snout of copper?
Wouldn't it work better, especially in cold weather to have a much shorter snout?

Maybe snout isn't the right word...............

 

I re-worked my Weller 8200-N, and today, it's melting the solder much better.
I think it should work once the part arrives.

New question, why do Weller and other guns have such a long snout of copper?
Wouldn't it work better, especially in cold weather to have a much shorter snout?

Maybe snout isn't the right word...............

View attachment 78004 View attachment 78005

You can make your own shorter tip from a piece of solid copper wire which would get it hotter. It is forming a short circuited loop of high current and very very low voltage. I suppose using thinner copper wire would also make more heat.

What is the voltage on the tip?

 

I hadn't thought to check temperature of the tip.
I'll do that.
I'll try a shorter tip also.

Anyway, the Diodes arrived, and I figured out how to securely mount and solder one in place, to and thru the stalks, and
"Success", a nice drill has been pulled back from the jaws of the scrap yard.

I'll post some pictures next time it's warm enough to go back out in the Garage.
The high tomorrow is supposed to be in the mid 30's F,

I've wondering if the hard solder, and thick wire ends on the old diode caused the old diode to take more of a beating, than if it had been a secure soft mount, with slightly thinner Diode wire. The new diode wire was more easily bent, and easier to conform around the stalks.
Once it was wrapped thru and back over on itself, it took solder very well and looked secure. I would say it appeared to be under less stress than the original. So maybe it was over engineered? Any thoughts on that theory?

Thanks for the help.

Gary

 

Is there room to tie the diode to the board with a dot of hot glue or 5 minute epoxy? To keep it from moving with the vibration.

 

Many forget that those Weller solder guns usually have two trigger pulls, the first is the Hottest, (notice the two power ranges?) the tendency is to pull full on, also after use the copper tip relaxes where it is clamped and the resistance goes up, it does not take much as there is ~100amps flowing!
Max.

 

Say what?
Now that is news to me!

Thanks Max, I think you've solved a mystery for me.
I've always pulled the trigger full on, and never even thought about it having two power ranges.

Talk about a paradigm. Thanks a million.

I'll give that a try today when I get home.

Now that's awesome.

shortbus,
I was able to solder the new diode in place.
I don't think there was room enough for a hot melt application.
Anyway, it's reassembled and working now.
If it fails in the future, and if I have access to it (it belongs to a friend), I may give that a try.

Thanks all,

Gary