Re: Older Rongfu RF-115 bansaw details required
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Does the gearbox output shaft assembly look correct? - Yes & No Yes its that short. Think from memory just under 1.5" overall between the outsides of the ball races. One of the many failings in this gearbox design, but it is what it is.? No The order of the oil seal and spacer is wrong, Inner bearing, then seal (spring around the seal lip toward the gearbox), then there should be am 8mm long?steel spacer which is a sloppy fit in the casting but still bears against the outer diameter of the seal and the outer bearing, Lastly the outer bearing.? To improve lubrication of the outer bearing, which is the main cause of failure, prise off any inner seal with a seal pick and half fill the void between the seal spacer, ring and inner face of the bearing with some thin moly grease. Just so we're on the same page; when you say "...main drive pulley.." I think that you mean?the bandwheel on the gearbox output shaft which?drives the sawblade around, not the pulley on the gearbox input shaft. Am I right? Assuming I'm right, and you are not experiencing any radial movement in the drive bandwheel because?you say "...I took care of that..." , then the movement you are talking about is axial, i.e. endfloat in the shaft.? Am I right in assuming this? There should be no endfloat in either shaft.? If you are experiencing this then the bearing outer is not as tight fit in the casting as most people have.? This is just a manufacturing tolerance issue and no big deal so long as you have the bearing retainer ring in place (It's screwed onto the outside of the gearbox casting where you can see it behind the drive bandwheel) AND the spacer that goes in between?the outer output-shaft bearing.? Most people don't?need that spacer as the bearing outer ring is too tight a fit in the casting but in cases where its not then the spacer is what prevents the whole output shaft from migrating back into the gearbox and the following?all happens:
?I've measured this spacer as between 0.260" to 0.280" long on RF115/ RF128's. Cut one from a piece of 5/8" ID conduit if yours is missing, plastic or metal as there is very little force on it.? The actual length really needs to be determined from wherever the drive bandwheel sits on the output shaft when the blade tracks properly (back of the blade hits and misses the rim of the drive wheel when blade is at the proper tension). That's a whole other story which we can go into if your blade doesn't track properly after you've rebuilt the gearbox? I don't think a 3rd bearing would take any load,? the way the shaft flexes, But you may have a point.? Unfortunately the rubber seals on a 6202-RS bearing are only there to retain grease and are not supposed to be effective in sealing in oil and you definitely don't want oil leaks. Three bearings all with a single seal on the outside might well be a better and sealed bearing set, however I've not tried it.? The seal drag would be lots higher than standard, because Its way higher with just a 6202-2RS outer bearing (std is only a shielded? 6202-Z) - jv On Thu, May 11, 2023 at 6:24?AM Hettie Chom <hettiechom@...> wrote:
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John Vreede