Hey guys, I’m changing the crappy stiff wires on my SK3 to 12awg silicone wire and thought I might as well document the process. @whitepony also documented bits of this process in this thread http://www.electric-skateboard.builders/t/sk3-silicon-wire-mod/3061 but I’ll do a step by step here.
(@mods: please fix a howto/guide-category where we can stick all guides and howto’s so they don’t get buried in build threads etc.)
Note: all pictures are from me testing this so that’s why the wires aren’t cut closer to the actual motor.
Step 1 Take a look at your otherwise great motor and cry a bit over the fact that the original wires sucks when trying to use the motor on a skateboard. They are really stiff and easy to break if you bend them in different directions often.
Since the motor is magnetic it will attract small metal scrap that you might have on your workbench if you’re sloppy like me. So a good thing to do is to wrap the motor in a plastic bag or similar for protection. I used a rubber glove where I snipped a hole in one of the fingers.
Cut the current motor wires wherever you like, preferably as close to the motor housing as possible and strip about 10mm of the cable cover. However, if you cut to close it might be hard to work on the wires without opening the motor. It’s really your own decision. When you strip the wires you’ll notice that they are covered in an enamel which has to be removed or else the soldering tin won’t stick.
There are several methods at hand to strip the enamel (google “strip enamel wire” and it’s up to you to decide which method you want to use. I tried three different methods: knife scraping, sandpaper and the aspirin method. I would have tried the NaOh-method as well but I couldn’t find a good way to heat it up in my apartment. The aspirin didn’t work at all, probably because I had the wrong brand. I then tried scraping with a knife, but I found it rather hard. It’s easy to accidentally cut the copper strands beneath the enamel.
The method I ended up using was sandpaper and a flat head plier. With the plier I applied some light pressue to the enamel and it started to crack. After that I used the sandpaper to remove it completely.
Again, this is just me testing so don’t mind the crappy stripping on this particular wire…
Step 4 Get your awesome silicone wire and cut it to your preferred length and strip about 10mm of the cover. To join the original wire with the silicone wire I will use a method called ‘butt solder joint’. There are other methods, but I like this one because it’s not so clumsy. Dilate the strands on the silicone wire a bit and then just press the two ends together and give it a light twist.
Step 5 Next, get a scrap copper cable and pull out a copper strand that is about 100mm in length.
We will use this strand to do some looping over the two joined ends so that the joint gets real tight.
Step 6 We’re now ready to solder the two cables together. Use your soldering iron to apply an even layer of soldering tin all around the joint. However, don’t use to much tin, because the silicone wire will actually suck tin into the cable and it’ll get stiff, which we don’t want.
Step 7 Apply your heat shrink and make sure that it’s well done because if two phase wires touch while connected it will blow your VESC.