Screw on bottom of main shaft

[moparherb]

I've built quite a few larger Trex helicopters and they always had an auto rotation gear (also drives the tail). If you manually spin the blades in the correct direction the motor does not engage and they kind of free float. Reverse direction makes the motor move. Now I'm building an Align 250 Pro DFC and I have gently snugged the screw with washer up on the lower main shaft. So now if I rotate the blades in the correct direction the motor does not engage and the blades do not free float and there seems to be a little drag. When turned in the reverse direction the motor engages. Is this correct? I realize that this heli does not have an auto rotation gear so I guess I'm having a hard time wrapping my head around this idea. How tight should the lower screw be? I have not finished the build enough to activate the motor yet but I just was hoping to get some experienced ideas. Any help is appreciated.

[HankAz]

https://www.helifreak.com/showthread.php?t=417031

[jbilliter]

This post has a lot of discussion:
https://www.helifreak.com/showthread.php?t=417031
Basically you can locktight it and dont tighten the screw completely, or find a washer that will allow you to tighten the screw without pinching the OWB.

[moparherb]

Thanks for all the reply's and links. But my main question is when the blades are rotated in a forward, clockwise direction should there be a little drag or is this supposed to be almost free floating. When I turn the blades backward the motor engages and every thing seems normal. I guess I need to know how much drag if any is correct when the blades are manually spun forward

[Besen]

There should be very little drag. If you loosen the screw is there still drag? If there is you have a problem with one of the bearings in the main gear hub. If not, it will be worth your while to read the thread posted above.

[vtown nick]

Originally Posted by moparherb

Thanks for all the reply's and links. But my main question is when the blades are rotated in a forward, clockwise direction should there be a little drag or is this supposed to be almost free floating. When I turn the blades backward the motor engages and every thing seems normal. I guess I need to know how much drag if any is correct when the blades are manually spun forward

Take the main blades off so you can get more of a feel for how tight it is. Using loctite on the lower Jesus bolt only run it down till it very lightly touches the main gear hub and there is no up and down play in the main shaft. The goal is to get a very smooth rotating main shaft clockwise. It should be smooth and have next to no drag at all. When you land and shut the heli off the main blades should take quite some time to stop rotating if it's set up right. No autos with this baby at all.

[ahahn]

Originally Posted by moparherb

Thanks for all the reply's and links. But my main question is when the blades are rotated in a forward, clockwise direction should there be a little drag or is this supposed to be almost free floating. When I turn the blades backward the motor engages and every thing seems normal. I guess I need to know how much drag if any is correct when the blades are manually spun forward

There is little drag when you rotate the blades in the correct direction, but it isn't zero. This depends a little on what lubricant is in the one way.

This is the one way bearing (attached to the main gear) disengaging from the main shaft. Turn it opposite and it engages the motor.

I don't think you have anything to worry about.

The bolt on the bottom should be snugged up and locktited as shown in the directions. (I assume you have the directions).

[moparherb]

Yes I have the directions and tonight with the help of a second well placed washer on the Jesus bolt it turns much freer than before now it see wher it touches and I'll loctite it and call it good. Thanks for all the help.