dunc
Active Member
- Joined
- Aug 1, 2016
- Messages
- 255
- Location
- Crawford, CO
- Aircraft
- AR-1C 915is, RAF/SH/SC
- Total Flight Time
- 5000
Although my pulley bearings have a "tight" fit into the pulley, there seems to be a few that suggest that the pulley be machined for a steel sleeve be installed to prevent possible wear and dissimilar metal corrosion between the outer race and the pulley. These include:
Mike Burton: https://www.rotaryforum.com/forum/k...sparrowhawk-gyroplanes/24068-sh-psru-upgrades
Brian Willis: https://www.youtube.com/watch?v=CYXftOzQ-AU
This seems like a good "preventive" measure and I am likely going forward. However in the video, a external sleeve is stalled for strength for the internal bearing. My SH pulley shaft is tapered, per the attached rough sketch, making this external sleeve problematic for the interior bearing area. Of course the taper could be machined to square for adding the external steel sleeve, but this would weaken the aluminum assembly and possibly make a stress riser. A good view of a RAF pulley is seen at 2:02 into the video. This looks like the RAF pulley shaft is square throughout, and possibly welded to the pulley wheel portion?
??? My question to your gyro experts is whether this is another difference between the SH and RAF pulleys. Your overall opinion on this sleeving modification is also requested.
Mike Burton: https://www.rotaryforum.com/forum/k...sparrowhawk-gyroplanes/24068-sh-psru-upgrades
Brian Willis: https://www.youtube.com/watch?v=CYXftOzQ-AU
This seems like a good "preventive" measure and I am likely going forward. However in the video, a external sleeve is stalled for strength for the internal bearing. My SH pulley shaft is tapered, per the attached rough sketch, making this external sleeve problematic for the interior bearing area. Of course the taper could be machined to square for adding the external steel sleeve, but this would weaken the aluminum assembly and possibly make a stress riser. A good view of a RAF pulley is seen at 2:02 into the video. This looks like the RAF pulley shaft is square throughout, and possibly welded to the pulley wheel portion?
??? My question to your gyro experts is whether this is another difference between the SH and RAF pulleys. Your overall opinion on this sleeving modification is also requested.