Jos I suspect you had your mind on other things! Carl Pattinson has been
requested by the LAA to modify the mechanical end stop of his prop to stop
it being able to go into reverse. He has the prop from William Mills
aircraft, which happens not to have been on William's plane when he crashed.
It is one of the earliest SR3000s. Carl has recently dismantled it and the
mechanical end stop is there, taking the form of a stud sliding in a
groove, with the length of the groove determining the mechanically possible
pitch range.
Regards, David Joyce, G-XSDJ
----- Original Message -----
From: "josok" <josok-e@ukolo.fi>
Sent: Wednesday, March 25, 2009 7:13 PM
Subject: Re: Europa-List: Woodcomp Propellers
>
> David and All,
>
> Probably i am the only one who has ever opened an SR 3000 hub. There are
> no mechanical endstops. Not on the end of any travel movements. Maybe
> added later, that i don't know.
>
> The micro switches are not suitable for outdoor use. That point is left
> out.
>
> The rating of the micro switches, if 16A? is probably for AC. DC ratings
> are usually 1/4 to 1/3 of that. Left out. Why two in series? Doubt about
> the quality? Left out.
>
> If the normal working current range of the motor is 4 A, the stall
> current, or startup current, is about 5 times higher. That stall current,
> startup current probably is over 20 A for a very short period.
> Specifications of diodes are for peak currents too. Peak current, even
> glitches break semiconductors. So any time the (fine) endstop micro
> switches are opened, the reverse current, momentarely up to 20 A will fry
> a 5 A diode easily. Left out.
>
> If the diode is short circuited, there is no electrical endstop working.
> If there would be a mechanical endstop, the motor could fry because it
> would be blocked. Left out.
>
> So David, please ask some more questions? I do very well understand, that
> you are not an outsider, as the person who got the first SR 3000 approved
> by the PFA. I am not either, so that could balance things out. Your
> interest seems to be to flatten issues with the Woodcomp SR3000, mine is
> to warn about the product, and maybe save lifes.
>
> Regards,
>
> Jos Okhuijsen
>
>
> Visit - www.EuropaOwners.org
>
>
>
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