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Re: (ET) BB600 status and some failures.

Will give that a shot. In the meantime I dragged the hulk of the E15 over to the shed and took a look at the battery pack: Every single battery was wrecked, melted cases, holes in cases, the whole nine yards. So 30 cells now need to go to the recycler. Sigh.
I'm thinking about fixing up the hulk again; this is the one that was buried in leaves and crap for 20 years or so, with the frame that was so rusted in the rear that I had to weld on new angle-irons to support the transmission (it worked). I have a spare right side front panel, think I will buy a left side panel and replace both of them. That plus new decals and a new charge controller should make this thing worthy of a new set of BB600's. 

Moral: Don't try to charge the BB600's over 42-43 volts.

C


On 3/5/2017 8:32 AM, RJ Kanary wrote:

           Left hand twist drills might be an option to consider.
You/MIGHT /snag the offending piece of twist drill and back it out. :)


RJ


On 3/5/2017 7:55 AM, Chris Tromley wrote:

On Sat, Mar 4, 2017 at 4:31 PM, Christopher Zach
<cz alembic crystel com <mailto:cz alembic crystel com>>wrote:

    By grinding the bolt flush with the post and using a 10/32 tap and
    drill set I was able to get four of the cells drilled, the old
    bolt drilled out, and new threads tapped. Of the other three one
    had a drill bit in it already, and I broke two bits trying to
    drill out the remaining two. So now I need to drill through drill
    bits. Not fun.


​Not familiar with BB600s, but drilling out drill bits will be tricky
business.  I've never had to do it myself.  If presented with that
problem, I'd hope that the drill I broke off was made from high-speed
steel (the most common type).  Then I'd go to McMaster-Carr or some
othe​r industrial supply house and get some carbide drills.  Not sure
if carbide is hard enough to make that work. Maybe search on what
you're trying to do first, and you'll likely get some hits on
machining discussion forums.

Typically you remove a broken drill bit by EDM.  But that requires
immersing the BB600 in a dielectric liquid, which would likely be hard
to keep out of the plates.  Or not?

Good luck,
Chris


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