Re: stiff bearings [TANKS]

[Frank Pittelli <frank-at-rctankcombat.com>]

Doug Conn wrote:
> I just bought some flange bearings from the RC Tank Combat Superstore 
> (aka www.surpluscenter.com <http://www.surpluscenter.com/> ). I tried to 
> save some money and got cheap ones. They came today. When I turn them by 
> hand, the bearings are very stiff. They’re certainly turnable, but they 
> don’t really rotate easily.

Oil them and break them in a little (slow RPMs for an hour or so) and 
then see how they turn.  Given that we don't really run our tanks that 
many hours per year and the drive shafts are running relatively slow, I 
wouldn't worry too much at this point.  You can always put in more 
expensive stuff, but why bother until you absolutely have to.

The overally key to success in this hobby is (get your pencils ready to 
take notes) .... get it running and let the battlefield tell you where 
you need to improve things.  In our world, iterative refinement is a far 
better design strategy then trying to optimize things in the beginning. 
  Not only is our environment harsher than most can imagine (1/2" 
stainless axles bend!!), but the number of variables is large enough 
that no simple model can be used to base optimization decisions.  Your 
understanding of the problem will jump an order of magnitude after the 
first battle. Everything is a trade-off and you really need to see 
things in action (multiple times) before the "right" answer pops out.

        Frank "Build It, Break It, Analyze It, Repeat" Pittelli