REFLECTOR: Static RPM

[Brian Michalk]

I have seen acme screw damage from the spool on the IVO system.  The 
problem is that the thread lands were not dressed up, and "cleaved".  I 
don't know what other word to use to describe it.  The end result was 
that the spool acme threads in the spool tended to cut into the rod 
threads under load.  This resulted in a small ridge on the rod threads 
that was visible.  Over time, when the spool was under load, it would 
bind up and not go to full fine pitch.

The acme threads should be nice and smooth.  If they have ridges, you 
may be having this problem.  If you have the prop apart anyway, I 
suggest taking the spool off and make sure the thread lands are free of 
defects.  If not, get the Dremel out and dress them up.


On 10/29/2011 06:11 PM, Michael Watson wrote:
> Hi John,
>
> Thanks for the response. Today I dismantled the prop and found that 
> while the plane was being repaired at Velocity,
> they placed 3 washers on the fine pitch side and one on the course 
> side. I originally had one on the fine pitch side and
> 3 on the course side. After correcting the problem and reassembling 
> the prop, I now get 2500 rpm static, that's a 150
> rpm increase. On the ground, engine off my prop has never stopped 
> abruptly to fine pitch, It always sound as if it's straining to a stop.
>
> BTW, where did you get the stronger spring for the motor brush. Even 
> with the new springs and brushes from IVO, I'm
> still having problems reducing the rpm if it's over 2550. Have to 
> reduce power, adjust, then increase power.
>
> On Sat, Oct 29, 2011 at 10:41 AM, <aminetech at bluefrog.com 
> <mailto:aminetech at bluefrog.com>> wrote:
>
>     Mike,
>     Are you sure you're getting full fine pitch travel?  The only time
>     my static was reduced was when the motor was a bit weak.  You can
>     check for this in 2 ways.  The current draw is normally 2-3 amps
>     and should spike to 8-10 if the travel limit is reached.  If you
>     aren't reaching full fine pitch, the amps will go to 0.  Also, on
>     the ground with engine off, you can listen to the motor when
>     adjusting for fine pitch.  It should stop fairly abruptly.  If it
>     gradually dies out, then you may not be reaching full fine pitch.
>     John
>
>     --- mikewatsspg at gmail.com <mailto:mikewatsspg at gmail.com> wrote:
>
>     From: Michael Watson <mikewatsspg at gmail.com
>     <mailto:mikewatsspg at gmail.com>>
>     To: Reflector <reflector at tvbf.org <mailto:reflector at tvbf.org>>
>     Subject: REFLECTOR: Static RPM
>     Date: Fri, 28 Oct 2011 19:11:58 -0400
>
>     To all Franklin /IVO  drivers,
>
>     What is the maximum static RPM you are seeing before brake release
>     on  takeoff?
>     This is with prop set to maximum fine pitch, throttle full forward.
>
>     I used to see 2475 RPM but of late, it is has dropped to 2350 RPM.
>
>     -- 
>     Mike W.
>     1997 Velocity Elite RG
>     Franklin /IVO Electric CS
>     Dual GRT EFIS HX Synthetic Vision
>     _______________________________________________ To change your
>     email address, visit
>     http://www.tvbf.org/mailman/listinfo/reflector Visit the gallery!
>     www.tvbf.org/gallery <http://www.tvbf.org/gallery> user:pw =
>     tvbf:jamaicangoose Check new archives: www.tvbf.org/pipermail
>     <http://www.tvbf.org/pipermail> Check old archives:
>     http://www.tvbf.org/archives/velocity/maillist.html
>
>     _______________________________________________
>     To change your email address, visit
>     http://www.tvbf.org/mailman/listinfo/reflector
>
>     Visit the gallery! www.tvbf.org/gallery <http://www.tvbf.org/gallery>
>     user:pw = tvbf:jamaicangoose
>     Check new archives: www.tvbf.org/pipermail
>     <http://www.tvbf.org/pipermail>
>     Check old archives:
>     http://www.tvbf.org/archives/velocity/maillist.html
>
>
>
>
> -- 
> Mike W.
> 1997 Velocity Elite RG
> Franklin /IVO Electric CS
> Dual GRT EFIS HX Synthetic Vision
>
>
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20111029/04abf690/attachment.htm>