Tom_McBride Posted July 5, 2011 Share Posted July 5, 2011 Noticed on a pre flight check that I was starting to get more movement in the prop hub on my Macro. Not a great deal so I decided it was ok to fly but I would replace the bearings anyway. Ordered the bearings £11.50 Each ! When I took it all apart yesterday I discovered that the rear bearing had seized solid probably due to eating the seal, the bearing has spun and mangled the bore of the hub hence the increased play! (and probably explaining in part why I have been burning so much fuel!) Had to grind off the old bearings, but have now fitted the new ones to the shaft with new circlips. I am going to modify the hub and turn a stainless steel centre section as a new one is £130! hopefull get it sorted for the weekend! Good pre flights are essential! Tom Quote Link to comment Share on other sites More sharing options...
Tom_McBride Posted July 5, 2011 Author Share Posted July 5, 2011 The bearings are 6004-2RSH/C3 for anyone else changing theirs you can get them cheaper Quote Link to comment Share on other sites More sharing options...
stuartasutherland Posted July 11, 2011 Share Posted July 11, 2011 Hi Tom, did you experience vibration before looking at the bearings? I've been suffering with high frequency vibration since I bought my second hand motor. I thought it was the prop first but got Pete B to check and re-balance that. Still quite uncomfortable though. I've now pulled the driven pulley apart like your pictures and the bearings dont have any lateral movement but do feel a bit rough. I will change these today. I hope this sorts my problem. Stuart Quote Link to comment Share on other sites More sharing options...
trm8620 Posted July 15, 2011 Share Posted July 15, 2011 Stuart, Apart from having to use more revs to sustain level flight I noticed no change what so ever. However now I have changed the bearings and made a stainless centre section for my prop hub (slight weight penalty ) I have a massive increase in thrust (30 % approx !!) Hopefully I will be slightly more fuel efficient now Tom Quote Link to comment Share on other sites More sharing options...
trm8620 Posted August 1, 2011 Share Posted August 1, 2011 Well I used just over a litre in 20 minutes so massive improvement in efficiency!! That bearing must have been dodgy since I've had it hardly any revs to sustain level flight too! May be worth adding it to your 5/10 hour check, Take the belt off and spin the prop to check for resistance (not trying to teach granny to suck eggs here!! ) Tom Quote Link to comment Share on other sites More sharing options...
Guest Posted August 1, 2011 Share Posted August 1, 2011 I normally replace my bearings every year. If you allow any minor slack to stay, it will continue eating away at the hub. For £22 a year. I am happy to jut bang a new set in. Stuart, I can 100% say that I was not aware of the existence of this problem when I sold you the unit dude. Maybe it has built up over time thus making it harder to notice? Also, as I say... I change the bearings often... Not sure when I did the Macro but they would not have been 12 months old when you had it... Sorry your having niggles with it. SW Quote Link to comment Share on other sites More sharing options...
trm8620 Posted August 2, 2011 Share Posted August 2, 2011 I think I will be doing the same. Quote Link to comment Share on other sites More sharing options...
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