I ended up throwing that away before reading this, it looked like a very crumpled mound of tin foil with some black patches and even a white looking patch, definitely nothing pretty like in the “How To” section on soldering.
@Athrx
Realistically how long should it be taking for me to heat up the connector to tin that part? I hold it on there for awhile, long enough that my tip ends up oxidizing badly, but it never got to the point where solder would flow on to the connector
Okay, here’s the deal. The reason for all my questions the past two days is I want to somewhat duplicate Moe’s setup with belt drive. I’m particularly interested in the Mamba XLX and the SSS 5694 motor (800 Kv and 200A max current) he uses. What I can’t duplicate is his 11/67 gear drive and 155mm wheels.
Dual 5694 800 Kv (200A Max)
Dual Mamba XLX
8s 30C lipos @ 16 Ah
14t/44t pulleys (1:3.14 gear ratio)
110 mm TB wheels
I’m not trying to go above 30mph (esk8 calc. indicates 87 mph loaded speed).
Is acceleration going to be awful because of the gear ratio or can I overcome that with high current from Mamba? Am I going to blow something up? What are the fatal flaws?
Holding a dry iron on the connector will take forever to transfer enough heat to bring the connector up to temp. You’ve gotta have a small amount of solder on the iron tip already to act as a thermal transfer medium. Basically mash some solder between the iron and the connector and let the melted blob conduct the heat into the connector.
For me, with an 80W directly-heated iron tip at 450C, I can solder a piece of 10AWG wire to an XT90 in about 30 seconds from touching the iron to it being done.
Sweet thanks, let me just back brief you on this to see if I have it straight:
Basically I get a little bead of solder on the tip, press that bead to the bottom of the connector to heat the whole thing, then apply solder to the open top to tin it.
What I did for that demo photo was:
A: Tin the wire.
B: Tin the connector. Leave some solder on the iron (E.G. don’t wipe it off.)
C: Put the wire in the connector, add a little extra flux.
D: Start stopwatch, mash iron against wire-in-connector hard to get good thermal contact.
E: Wait about ten seconds for heating, then dab some extra solder on the iron where it touches the wire-in-connector.
F: Continue to add heat and solder until it looks like the picture: A nice shiny fillet all around with no pucker or gap between the wire and the connector.
G: Stop stopwatch, remove iron and solder.
There are a LOT of different solder alloys, many of them lead-free. They all have different properties such as strength, ductility, melting point/range and cost.
The most common lead-free alloys are SnAgCu (3% silver, 0.5% copper, 96.5% tin) and SnCu (99.7% tin, 0.3% copper). They have melting points of 228 and 217 degrees C, whereas standard Sn63/Pb37 is much lower at 183C, and is generally cheaper than lead-free alloys, especially ones with silver in them.
Generally lead-free alloys can have a higher tendency to creep, become brittle from thermal cycling, form tin whiskers, or otherwise misbehave under some conditions. Different alloys behave differently, and have different compatibility with platings/coatings like silver and gold.
Here’s a Wikipedia excerpt about SnAgCu alloy SAC305: Dull, surface shows formation of dendritic tin crystals. Weakens at thermal cycling, concern of whisker growth, large Ag3Sn intermetallic platelet precipitates causing mechanical weakening and poor shock/drop performance. Tendency to creep.
Ah okay, its a saying that’s popular in the military but I didn’t realize it was that much of a niche, I’m guessing Alanson spent some time in the service and wrote that line for a character
