Setec Astronomy
Well-known member
gonz0 said:Actually the PM of the Flex sounds quite legitimate and reasonable to me. Now as far as documentation of said PM, it would appear as if that is lacking from the manufacturer. The design itself I'd call sound from the description (I've yet to hold one in my hand). The needle bearing is a good design for quiet, smooth and consistent operation, but comes at the cost of needing lubrication and maintenance. Brass bearings would work but they'll still wear over time, requiring replacement, just the interval will be extended (with all other constants remaining) but during that time the vibration and noise will be higher for the tool. Now a reasonable solution would be a service port for grease, but maybe the position of the bearing doesn't allow for such an opportunity, again, I've yet to handle one so I cannot comment.
I also prefer rolling-element bearings, and it seems like the logical choice for this application. And if the other gentleman is using this machine 8 hours a day/5 days a week, then he's lubing it at 1000 hours, which also seems like a reasonably long lubrication interval. If that's the case, I'll be dead before I have to lube mine, so it's all good. Usually I try to design/select components to reduce/eliminate maintenance for the expected life of the equipment, largely because that is what customers demand today. I mean, you don't see any grease fittings on HVAC fan motor bearings anymore, because they used sealed bearings that are lubed for life...OTOH, I just had a fan motor burn up that was only 2 years old...and of course a needle bearing is a different animal.