Hi
#1
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Hi
Greetings to you all heli experts:
Question one: Is a brand new main rotor shaft true 100 %(no wobble) from lower bearing end to the rotor head end? Any heli basically.
Question two: What should be an acceptable wobble in thousandths of an inch form lower bearing to the rotor head?
For example if one end of the shaft is placed in a lath chuck and the other end is measured with a dial gauge, what should be the max
variance that these helies could tolerate?
Thank you one and all
Question one: Is a brand new main rotor shaft true 100 %(no wobble) from lower bearing end to the rotor head end? Any heli basically.
Question two: What should be an acceptable wobble in thousandths of an inch form lower bearing to the rotor head?
For example if one end of the shaft is placed in a lath chuck and the other end is measured with a dial gauge, what should be the max
variance that these helies could tolerate?
Thank you one and all
#2
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Location: FromeSomerset, UNITED KINGDOM
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RE: Hi
hey JH!
i'd check any shaft before i fit it (justin), if there is any wobble the key is not to fit it! if it is new, try taking/sending it back to where it it was purchased!!
even the minutist variance from straight will have a detrimental effect which will get worse sooner! the speed the heads are turning at, it is not worth the sake of a few bucks to skimp on something that is not straight! you'll also find that you will wear the bearings out quicker (just like any rotating thing!)
hope this helps (i haven't measured any of mine in that detail so i can't give you any figures)
Matty )}}}}}]@>
i'd check any shaft before i fit it (justin), if there is any wobble the key is not to fit it! if it is new, try taking/sending it back to where it it was purchased!!
even the minutist variance from straight will have a detrimental effect which will get worse sooner! the speed the heads are turning at, it is not worth the sake of a few bucks to skimp on something that is not straight! you'll also find that you will wear the bearings out quicker (just like any rotating thing!)
hope this helps (i haven't measured any of mine in that detail so i can't give you any figures)
Matty )}}}}}]@>
#5
RE: Hi
Steel shafts are almost never 'bent' when new, so you should be fine.
If you want to check a shaft just roll it on a supported piece of glass and look for spaces at the points of contact as it rolls.
BTW- People interpret a wobbling heli must have a "bent" shaft... Not always the case. An unbalanced main blade set, mis-aligned flybar, a slightly longer feathering shaft causing the feather shaft to slide laterally (Trim it OR use shims if need be), unbalanced paddles, main blades TOO tight in the grips (keep them loose to pivot freely) or a rotor mast hub not properly seated WILL GIVE THE ILLUSION of a bent main shaft.
Avoid chucking a shaft into a lathe or drill, some chucks will scratch a shaft.
If you want to check a shaft just roll it on a supported piece of glass and look for spaces at the points of contact as it rolls.
BTW- People interpret a wobbling heli must have a "bent" shaft... Not always the case. An unbalanced main blade set, mis-aligned flybar, a slightly longer feathering shaft causing the feather shaft to slide laterally (Trim it OR use shims if need be), unbalanced paddles, main blades TOO tight in the grips (keep them loose to pivot freely) or a rotor mast hub not properly seated WILL GIVE THE ILLUSION of a bent main shaft.
Avoid chucking a shaft into a lathe or drill, some chucks will scratch a shaft.
#9
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RE: Hi
I have also posted questions on the bent shaft problem on the Blade copters. (Blade and Pro) I have been able to straighten them on a cast iron saw table by gently tapping them with a hammer. I backlight the sawtable so the imperfections will show while rolling the shaft along the edge. The blade helis have the main gear swaged on to the shaft so the glass rolling doesn't work to well. I also check them by using a tool shaped like a screw driver that has a hollow shaft. It is the same diameter as those shafts. If I put the shaft in the tool and it spins freely, it is straight. When it does not spin freely it needs work.
I have attempted to use a press like I use to straighten the shaft on the AXE but that does not work as well on the Blade shafts. On either one, you need to make sure to deburr around the holes in the shaft.
Would it work to take a small block of mild steel and drill hole in the solid block and push and almost bent shaft in to it? Would it straighten or just bind up? How about having a small steel block say 2x6x3/4 to sandwich the shaft between the block and the cast iron table? Roll the block over the shaft on the table, back and forth. Would that straighten the shaft?
I have attempted to use a press like I use to straighten the shaft on the AXE but that does not work as well on the Blade shafts. On either one, you need to make sure to deburr around the holes in the shaft.
Would it work to take a small block of mild steel and drill hole in the solid block and push and almost bent shaft in to it? Would it straighten or just bind up? How about having a small steel block say 2x6x3/4 to sandwich the shaft between the block and the cast iron table? Roll the block over the shaft on the table, back and forth. Would that straighten the shaft?