How tough should it be to spin the main shaft by hand?

[bleomycin]

Hi everyone,

I'm a bit worried something isn't quite right. I have the whole heli completely assembled pending some final wiring, but when i spin the main shaft engaging the auto hub only there is a significant amount of resistance. Should i be able to start spinning the head and have it continue under its own force or should it pretty much stop instantly? The reason i ask is because i was at the LHS today and spun the head on a trex 700 and it moved effortlessly, spinning the main rotors and the tail under its own force with no resistance at all, far different than mine! Thanks!

[curmudgeon]

Highest in the differential diagnosis is the 610-151 Auto Hub Delrin Shim (page 26), specially the upper one.  I reduced the thickness in mine with sand paper, and it made a drastic difference.

Second is OWB lubrication.  Make sure not to go cheap with the TriFlow.

Many other possible causes, but those two are at the top of my list.

[RichL]

From your description it is hard for me to know how much resistance you are experiencing.  Preform this test, install the blades, level the swash plate zero pitch and give the blades a good hard spin.  If you get two or more revolutions I wouldn't worry because it is going to loosen up after 5 or six flights.  If you were unable to get two revolutions with the blades then something may be binding a bit.  Let me know what the results of your test are.
I also had to lightly sand my Delrin shim.
Rich

[Greg Jackson]

I found it sort of tough at first to spin without the blades, but with the blades on it moved pretty well.  As Rich said, after a couple of flights things seemed to settle in.

[flyalan]

Did you lune the one way?  Oil only no grease!
Greasing will cause some resistance.

Cheers
Alan

Alan Butler
Team Synergy