How free should the OWB be?

[jasumx]

Hey folks. I have (yet another) noobish question regarding my E6 build. The kit I have was pre-assembled and used. I disassembled the transmission and found that the original owner had greased the one-way bearing. Because of this (I think) there is a noticeable drag when turning the sleeve in the bearing. When spun in the other direction, it locks up immediately, but I am concerned that drag will stop the heli from being able to auto. With the transmission/head fully assembled I can spin the head (blades off) and it turns fairly freely (2-3 revolutions with a hard push). When I hold the main gear and spin the head again I only get half a revolution at best.

I have tried soaking the auto hub in iso alcohol for hours, scrubbed the pins with a toothbrush soaked in alcohol, and spun the sleeve inside the owb while submerged in alcohol, dried the bearing, and then liberally applied tri-flo oil. Unfortunately the head only turns slightly more. Is this normal, or should I be looking to replace the hub?

[Chris Sexton]

I would oil it up and fly.  When the head is assembled and swinging blades, there is substantially more mass and inertia present. If it free wheels at all and isn't locking up completely, I say it is fine.

[Brandon Bartolomucci]

+1. Just make sure to grease or oil it up well now that you've got alcohol in there and soaked it. You don't want it failing from being too dry.


Regards,
Brandon Bartolomucci
Sent from my iPhone

[okanor]

With blades on it spins for quite some time.  My guess about the difference you see is from the weight of the gear allowing it to spin longer vs not having that mass to keep it rotating.  I would try some blades on it and manually spin them to help reassure yourself. You will see how smooth this setup really is then.

Sent from my SPH-L710 using Tapatalk 2

[stevehof]

Does your ship have a Torque tube or belt?

[Kevin Dalrymple]

The is a tip trick Matt posted on this forum about the one ways in the E6 and E7 kits. It has to do with the washers and spacers. I would just check that since you are there.

Kevin

[stevehof]

The is a tip trick Matt posted on this forum about the one ways in the E6 and E7 kits. It has to do with the washers and spacers. I would just check that since you are there.

Kevin

((If your ship is set up with a torque tube)). Make sure the two Delrin spacers are both BETWEEN the auto rotation spur gear and the main gear. If they are in there, take them out to check the auto bearing.

Reassemble the two gears outside the ship with just the bolt, no nut. The spur gear should be free and easy to turn, almost free spinning without the two spacers. If it is not, something is wrong with the bearing. If the auto spur gear is easy to turn without the spacers, the bearing is probably fine. Put the two spacers back in and reassemble the two gears with the bolt. If the spur gear is now tight, you will have to make one of the spacers thinner. Sand one spacer down a few thousandths of an inch and try the fit again. Just lay the sand paper (320-400 grit) on a flat surface and make little figure 8's with the washer on top of the sand paper.

The other issue that can cause a stiff free spool is a tight fit between the auto spur gear and the gear that drives the TT transmission. The most common cause of this is the boom being a bit too far forward and pushing on the rear of the TT transmission. This situation can push the driven gear into the spur gear (no gear lash at all).

[jasumx]

Thanks for all the tips everyone. I really appreciate the quick responses   

My heli still has the good ol belt drive, and I actually have the boom removed with the belt just hanging out the ass end, so there isn't any resistance from that.

I'm going to strip it down again tonight, give it another quick soak, and re-oil it. That will give me a chance to check the brass washers and make sure they're secure.

I'll give it a spin with the blades on when I'm done.