I have a windy 750 with wind grabber blades for about one year and the last couple of weeks it has needed more wind to get it going. Recently I can hear the motor whining when spinning and assume a bearing is going. Is this common and what are my options for getting this rectified? How often does this reoccur under normal operation?
It is not common. My 500 watt has been up for a year with no problems. I can tell you that alot of the ball bearing type bearings do not come with a whole lot of grease when new. The last set I took the seals off of there was only about 4 dabs of grease on the bearings. If you need to replace the bearings I would pop off the grease seal on them and clean them out and pack only half full of disc brake grease and put the caps back on. You can not pack them full and get the seal back on. I flattened out an end on a paper clip and popped the seals off from the outside edge. Do one bearing at a time my seals were not interchangeable between two bearings from the same company.
Check the back seal where the wires come out. If the seal somehow came loose, then the possibility exists that water entered through this hole and got to the bearing. You can undo the bolts on the generator and remove the stainless steel caps. Open up the seals on the bearings and re-grease them. There are lots of tutorials online that will walk you through the process of re-greasing bearings. If you are handy, you can replace the bearings but I think re-greasing should do just fine. Normally the bearings should last ~5-7 years until they are recommended to be replaced. They will probably give you 10+ years before they really need to be replaced. But if water somehow did get in, then the bearing is probably starting to seize.
I have a old 500 that cooked the grease out on one of the old geared towers before it fell due to non furling tails and overspeed.Its still all over the case .I will cleane it up with acetone once I decide what to do with it. I would like a proper tear down video so we could see the careful way for this kind of maintence without worry of breaking that investment.
If you are going to go through the trouble of opening it up, it might be better to replace both bearings. They cost about 2-3 bucks each. If you do not have the equipment, take the rotor to your car mechanic with the two new bearings. They can pop off the old bearings and put on the new ones quickly. They have the proper equipment. The reason I say this is because it is time consuming to open up the PMA and re-close it. If you are going to put in the time to do this, you might as well put on two new bearings.
