Soldering Iron: Cheap temperature control?

[sam_sam_sam]

Re: Soldering Iron: Cheap temperature control?

Thanks

[Agent24]

Re: Soldering Iron: Cheap temperature control?

Making some progress... got pretty much everything now I just need to wire it all together.. ordered some crimp terminals for the switches from Farnell, had to buy 100 of them, but it's not too bad, at $9.80 for 100 it's better than the $6.50 for 10 at a local hardware store.

[Agent24]

Re: Soldering Iron: Cheap temperature control?

Got the crimp terminals yesterday, decided to build the thing this afternoon.

I also changed the schematic to add some LEDs for indicators (note in the schematic I am using only LEDs, but obviously I added dropping resistors etc in reality as well)


The thing seems to work (tested with lightbulb so far, but not iron yet)

Only problem is that the LEDs don't work - well they work, but they BOTH light up.

It seems like the dimmer works in both directions (I had not counted on that). I can dim the indicator LEDs alternatively with each position of the switch


I guess it won't hurt like that, so I think I'll leave it as-is since I can't see any easy way to fix the damn thing.


Will report back on the actual temperature control once I test it out properly.

[Agent24]

Re: Soldering Iron: Cheap temperature control?

Well, tried the thing out and if anything it seems worse, though that might not be entirely the fault of the controller

The tip even after one use has become quite pitted and damaged even with the layer of solder (really cheap shit tip?) and I can't see anywhere to get a new one to try

If I find a new tip I might give it a new test but for now I think this idea isn't a great idea.

Oh well, maybe time to start saving up for a decent high power soldering station?

[TonyTheToolGuy]

Re: Soldering Iron: Cheap temperature control?

Just thought I would pipe in with my solution to temperature control of Harbor Freight's 80 watt plastic welding iron (essentially just a soldering iron with a female 5.1 metric thread in its end to receive the threaded brass flat triangular welding tip for plastic. This iron is available on sale for $15, rarely, even less with Inside Track or coupon).
Burning plastic is no good. When melting any plastic, one wants to just melt it, any extra heat breaks down the plastic molecules and weakens the joint. So...
One simple improvement is current control with a triac, as in a dimmer or router speed control... but I wanted temperature control, I want feedback, I want control!!!

The solution is at your local thrift store, or Walmart, in the form of temperature controlled curling irons. You get a nice handle with all the electronics in it, a dial potentiometer for temperature setting or sometimes even electronic settings with displays, and as an added bonus, all curling irons have swivel cord connections to the handle so the cord never gets twisted.

I tore my Harbor welder apart and mated the metal housing heating assembly to the curling iron handle. I had to drill a small hole in the back of the welder's copper/brass heating body to receive the curling iron's temperature probe and I had to change a resister on the circuit board to adjust the temperature control upwards as curling irons aren't designed to go to 500+ degrees, or they'd melt A LOT of hair!

A cheap pen type temperature probe and a couple guesses on resistors later and I got my unit to top out at 800 degrees and hold any temp quite well. It doesn't burn plastic anymore and makes for a pretty nice high wattage soldering iron.

The real nice plastic welding tips at Urethane Supply have 12-24 threads so I modified one of my plastic welders by drilling it out with a #16 bit and tapping it with the 12-24 thread. I also have found that copper grounding wire pounded with a nice BFH (that's a Big F'in Hammer) makes for great custom welding and soldering tips.

12-24 threads are 0.215" OD and 3AWG is 0.2294 OD while 4AWG is 0.2043 so with a 12-24 die, I, and you too can make your own custom welding tips for this iron out of copper grounding rod.

[momaka]

Re: Soldering Iron: Cheap temperature control?

Nice project!
I had someone bring me one of those curling irons for repair, but I never thought of making this. I did thought of making a hot plate out of it for putting balls on BGA chips. The ceramic heaters wouldn't have had any problem reaching those temperatures either. I had quite a few projects at the time, though, so I never really looked more into this and I no longer have the curling iron.