From: bretcahill@aol.com   
      
   > > The power wires for a 500 watt ebike motor go through the board. It there   
   any off the shelf insulator designed to protect the caps and other components   
   only 13 mm away? This is asking for a torch.    
      
   > Try Chip Quik. It's a bismuth alloy that should make the high-melting    
   > solder lower-melting.    
      
   I tried some with an 85 watt Weller and it didn't do much.  I bought a used   
   260-200 watt Weller and it worked after multiple applications.      
      
   I was wondering if this hack is common:  Since I didn't want to cut off more   
   than a few millimeters of wire for a nice clean packed end I was stuck getting   
   about 40 kinked strands, bits of solder still clinging to them, 3 mm effective   
   diameter,  back    
   into the 2.5 mm hole in the circuit board.  I wouldn't be surprised if there   
   was a dedicated tool -- they got a lot of cool time savers in electronics --   
   for crimping all the wires into a nice tight round bundle.  I was going to try   
   an insulation    
   stripper tool but maybe it was in the storage locker.  It's really frustrating   
   to have a tool, especially one that probably won't work, and not be able to   
   find it.  It's like wasting time^2.  I was still feeling unlucky when I got   
   some nylon thread,    
   wrapped it around the frazzled copper about 15 - 20 times for mechanical   
   advantage and pulled, tourniqueting them to hexagonal close packing.  _It   
   actually werked_!   
      
   Anyway gearless high torque hub motors shouldn't be used on hills.  When the   
   axle reams out the torque arm it spins, reeling up the wires, yanking them out   
   of the circuit board.  I can't read any markings on the wires but I measured a   
   strand at 0.3 mm    
   dia.   40 X 0.07 mm^2 = 2.8 mm^2 for one wire.  (This is a 38 volt system.)     
   Ultimate yield strength of copper is 210 MPa or 210 N/mm^2.  The force on the   
   board when each power wire ripped out could have been up to 600 Newtons ~ 130   
   lbs.  It's hard to    
   tell what actually happened -- the bike mechanic was trying to resolder the   
   wires in the inlet side next to caps, not through board -- but that's one   
   rugged circuit board!   
      
   I'll add some safety features:     
      
   An easy disconnect between the plugs.  The wires are two short now anyway.     
      
   An easy disconnect shear pin for the torque arm on the chain stay to preserve   
   the axle.     
      
   A lower pedaling gear, 13 t instead of 12t.   
      
      
   Bret Cahill   
      
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