[NSRCA-discussion] Proposed rule change-weights

[Bob Richards]

Jerry,
   
  Thanks for writing. That is VERY useful and pertinant information.
   
  I did not know the AMA had a 42 volt limitation. I do not see why it could not be 48v, your argument makes sense to me.
   
  Bob R.
  

Jerry Stebbins <JAStebbins at worldnet.att.net> wrote:
          Two years ago I was told we could not make a kit that would make the electric weight. I did not believe that, even though I was appalled at the "gram counting-corner cutting- un-safe construction" I was seeing people using just to make the weight.
  A year ago we took our glo Aggressor, and with minor changes made an Electric that flew at 10 lbs 5 oz. Minor changes being --no pipe tunnel, a minor change in chin layup, and no firewall. We installed the Pletty30-10, and later the Pletty30-10EVO  in the spinner, and used Falcon 5s2p 5300 10c batteries. I decided I wanted to go with an outrunner instead of a geared system. Our only problem was being committed to only three prop configurations available that were not that good in very high winds. After about 80 flights on the batteries we switched to the EVO and had our first electric problem. The new EVO controller was not tested to an Airtronics Stylus for throttle settings, and guess what-we drained the batteries and lost one set. Our fault, we should have measured the top end before we flew on the new setup, but we did not and had a max top end of 89 amps. We reset the transmitter curve and now things are fine.  Since then we have tried (on loan) several types of
 batteries and the weight has gone down, and the performance gone up (20 to 50 C versions).We are now converting to a normal fiewall installation to be able to match props/ conditions better.
  So much for "weight being an impossible problem", and others have confirmed their similar experience with nominal costing kits. You DO NOT have to buy $2500 kits to make the weight-matter of fact the way some of them made the weight was lousy engineering/fabrication, and then they came apart very easily.
  COSTS- more-yes, if you already have all the glo stuff -you have essentially a duplicate expense to what you have spent already, assuming you are flying a DZ or a large two stroke. I do not believe you can use electric "cost" as a justification for a rule change--as others have so aptly stated! Competitive people will strive for the best -no matter what the Sport. And you also can get very good motor performance now days for less than half what it was a year ago.
  Therefore I see NO logical, or substantive reason to change the current weight rules.
  Now from a safety standpoint I do see some logic behind making a minor change to the rule on allowable voltage. Increase it to maximum of 48 volts  using the Manufacturer's rated cell voltage. 
  The current AMA rule stating 42 volts nominal ( I do not know whether that precisely means --designated cell voltage, or fully  charged voltage). Our 5s batteries are sold at (marked) as 18.5v. Yet we know when fully charged they are 21v give or take. One more cell would reduce the current needed for the same power, and therefore be somewhat safer. I know there was a 48 v limit in the National Electrical Code, and why it was  there, and see no reason why it should not be used.
  Also, with the new LIPO cell chemistry and associated cell voltage changes, they would become more attractive, even with a minor weight penalty. They also would be more user friendly,(charging) and safer, than the current LIPO's.
  HMMM-maybe I should think about working a proposal up on that--any thoughts from the gallery?
  Jerry 
_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20070626/726ca33e/attachment-0001.html