PDA

View Full Version : Vigor Crown Gear Runout Solution


Ivan
07-04-2004, 09:44 PM
I was trying to figure out why the crown gear has so much runout, even after the installation of the SGP support on my vigor.

Looking at the whole situation, and noticing that the gear had absolutely zero runout wuth the two hub bolts loose, and probably close to .040" with them tight, I surmised that there must be something warping when the bolts are tightened.

I fiddled arond with it (a highly technical process) until I found that the second bolt that clamps teh hub to the main shaft was culprit.

When the clamp bolt is tightened, it compresses the hub via the slot that is cut in the top of the hub flange. This makes the diameter of the top of the flamge smaller than the diameter of the bottom, and offsets the top of the flange away from the slot, causing the gear to be high on that side.

My solution was to drill an appropriately sized hole opposite the slot near the top of the hub, and thread it for a 3mm setscrew. After some trial attempts at balancing the tightness of the setscrew with the tightness of the clamp bolt, I was able to keep the runout near zero with everything tightened up. Farhter experimentation indexing the gear to the four different positions on the hub may yield a perfect setup, with the exact amount of runout all the way around. For now I am very satisfied with near perfect.

Let me know what you Vigornauts out there think of this, I like positive input :glasses2:

Ivan

choas227
07-19-2004, 04:10 PM
I have the SGP gear support as well. I have No runout. Well..... maybee just a little... and I mean... very,very,very little. When I tightened the bolts on the crown gear I tighed the one that went throught the shaft first... then the clamp bolt. Now wiether that makes a difference, I dont know... but so far I havent had mod that area....... Now the head.... thats a different story.. :arggg:

wolfdad
09-01-2005, 12:47 PM
Ivan,
Try taking a look at how Mark Christy (http://www.rotarsoft.com) designed his bevel gear support plate and how he designed the unit with dual pull-down bolts on the main rotor shaft...keeps that run-out from jumping up again and the bevel gear is installed on the plate without any mods to the gear. The SGP design is good, however I think Mark's is a bit nicer.

wolfdad sends...