MadModder

I've ordered a a set of 6 20mm 275VAC MOVs. : $9.19.

Adding up the costs

The 100A SS Relay cost $19
Timer (1/2 x 13.99) cost $7
MOV (1/6 x 9.19) cost $1.50

Total $27.50 for electronics.

I'll need a utility box, and I want to add a foot pedal and a couple switches. I have most of that stuff, anyway, but that might add to the cost for someone else.

I went at the bottom of the circuit board with the multimeter, and this is what the relay pads test out to be on mine. Don't take this as written in stone for these timers as there are often variations in circuit boards and circuitry.

Since I have two timers for my $14, I'm going to just jump right in and de-solder the existing relay in order to substitute the 100A SSR. If I kill the first timer, I have a spare.

  [ You are not allowed to view attachments ]  

I did another set of consolidation melts today. I'm trying to get more room in my shed, so melting stuff down kills two birds with one stone. Plus it's fun. I thought you all might like to see the results from some other scrap types. Result, about 30 half pound ingots.

  [ You are not allowed to view attachments ]  

Stock: I melted down a light aircraft wheel hub, a small Tecumseh engine, and a bunch of thin architectural extrusions, plus small odds and ends.

The Tecumseh engine was probably about 4 hp horizontal, which I removed most of the steel and iron from. Actually, see my Avatar up left? Well that's it! You're seeing an exhaust and intake port view of it. It's been hanging around in storage for many a year. It had thrown a rod, so not much use.

I don't know where I got the aircraft wheel hub from. It was conical shaped with internal ribs. I think that was its use.. not totally sure. 

The thin extrusions looked like window molding stuff.

Anyway here they are as muffins. The motor made beautiful shiny puffy versions with fine grain. The wheel, meh, not as nice, but usable, fairly coarse grain fair amount of shrinkage.

And the mixed scrap and extrusions turned out pretty good, considering. Maybe just a little better than the wheel aluminum, finer grain for sure.

  [ You are not allowed to view attachments ]  

I've taken to marking muffins now for future reference when mixing, and matching for purpose.

Another way not to hate casting aluminum!

Endnote: BTW I test every major piece of casting material before melting, by taking a small sliver off of the piece, and subjecting it to my MAPP torch. We don't want to mistake magnesium for aluminum! Magnesium burns with an intense white flame. And as I found out a few years ago upon doing the same test, the nice big VW bug engine block I was given was made of magnesium. Darn!!!! that had a lot of material in it.

And this time I was glad I did, as well. An old carburetor found half buried in the ground from some ancient vehicle seemed suspiciously heavy. A little piece of it turned yellow in the torch flame -- zinc based pot metal. Not good to mix with aluminum. In fact I do wonder if the casting defects seen in Ironman's video were due to zinc contamination. Zinc has BIG shrinkage, and coarse crystalization, not unlike the appearance of those castings.

Thanks Andrew! 

Guess I'll try it on a lightbulb load, at first.


If it checks out, I think I'm going to completely remove the switch wiring in my HF spot welder, which is a little, um, what's the expression..sketchy? Also some additional sketchyness in the fact that you have to squeeze your hand hard on the metal handles while twiddling the sort of homemade looking unencased 220 V switch at the front -- with its paper insulation. I can imagine several non-pretty failure modes ....involving an unreleasable handshake. 

It does make me wonder about the expression "lifetime guarantee."  How exactly does that work?

I'd like to make an interval timer for my Harbor Freight 220 volt spot welder.  I have a couple of timers coming in the mail. They use mechanical relays. Here's a pic:

  [ You are not allowed to view attachments ]  

Specifications:
 Operating voltage: DC 6V - 30V, supporting micro USB 5V power supply
 Operating current: 50mA, static current: 20mA
 Working temperature: -20—60℃
 NO maximum load: < AC 250V/10A, < DC 30V/10A
 Size: 6.4*3.8*1.7cm

HOWEVER:

I'm guessing that triggering the inductive load of the 220V line of the spot welder might be too much for the relay, so I was going to add a second solid state relay, which would be triggered from the timer's relay. Maybe this one....

  [ You are not allowed to view attachments ]  

Twidec/Output Single Phase SSR Solid State Relay
100A
3-32V DC to
24-480V AC
SSR-100DA

BUT, I was wondering if I could eliminate the middle man (the timer's mechanical relay) maybe desolder it and then just hard wire the relay coil's lines to the inputs of the 100 amp solid state relay?

Thanks