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Old 04-07-2011, 09:55 PM   #47
mejmea
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Join Date: Nov 2010
Location: Chicago Area
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Quote:
Originally Posted by Ampdraw View Post
Got my B grips and head.

Bearings are not moulded in....only difference is the central plastic comes toward the feathering shaft more and supports the inner race of the bearing.

Loktite was used on the feathering screw but not enough that I couldn't take it apart...ie screw head didn't shear off.

Interestingly mine came with the outer bearings brass shield toward the blades, ie facing outward and the inner bearings were the other way around with the brass facing the head??

Anyway, b grips, spectra 50Lb tether (incase the screw head shears) and all good for indoor inches from face inverted imo. If I dumb thumb it I may get a crazy 2g blade gash. I can blame myself and point the finger toward the mirror. Been running a tether from day one though as I like to fly this heli close and well...things can happen.

Crashed my Spek 2s 4g6 into myself before spinning 4800 rpm and sure it stung like an angry bee and broke the skin but no big deal.

Good job HH. This is the perfect lounge cp for me.

Amp
This seems logical to me. These bearings only have a 1/2 cage, i.e. the cage does not totally surround each ball. Picture a tiny little crown that sits in the bearing and each of the eight balls is captured in one of the valleys of the crown. The bearing cage is inserted from the opposite side as the brass colored seal.

With the old grips I think one of the potential failure modes was that the bearing cages could come out which leads to bearing failure (I had this happen with two bearings, one brass side out and one silver side out - I happened to catch both in the act before they blade actually went flying). This could happen due to impact or possibly in conjunction with the centrifugal forces as well. The original recommendation was thus (IMO) to have the brass/shield side of both bearings face the blades so that the cages were not exposed to both possibilities at the same time.

In the ideal world, however, the brass seals would face outward for each bearing just as you say that they are in the new grips. (They are intended to keep junk out of the bearing so why would you have them face the inside of the grip, right?) With the new design the additional plastic in the middle retains the inner race and the bearing cage of the bearing closest to the hub so that bearing can now be flipped and put in the proper orientation with the seal facing the hub. The outer bearing retains it's original seal facing out orientation because that makes sense both from a "retain the cage" as well as a "keep the dirt out" perspective.
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mCPxs,Trex 450 Pro, Blade 300x, Rotormast V-22 Osprey, Blade mQX, Helimax 1SQ
Planks - Super Cub w/floats, PZ T-28, PZ UM Sbach, PZ P-47 w/ retracts and flaps, GP PBY Catalina, HL F9F Panther EDF
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