master111400

I know this is an issue many people are having. I have looked for a few weeks now for a "true" main shaft for my Belt CP. I cannot seem to find one anywhere. The only thing I can find is the Esky replacement main shaft. Can anyone help me with this please?! I work in Army Aviation, so if the answer lies in making my own shaft, can anyone tell me where I can find the steel stock or titanium stock thats the right size? Any help is greatly appreciated. I have been having very bad vibs on start up every time. When I get it into flight it seems fine. I can fly around with hard banking and have no problems. I am wanting to try and start 3D flights but I fear that the main shaft issue will cause problems when I attempt inverted flights. Thanks for the help.

blk822

The vibration on initial start of spin up is normal, the blades are getting in alignment and when the shaft first starts to spin the blades move back alittle then have to be spun back out into proper position by centrifical force. It takes some time and head speed to do this. A bent shatf will make you tail shake when flying.

DirtyBrad

I always shake my tail when I fly.

nitrofreak06

My Feedback: (17)

lol? was that a joke

tom dubya

I use the align main shafts on my belt. All you have to do to make them work is install them upside down. Also you should gind a groove for the collet ring since when you flip it upside down its no longer in the right position.

sunbuzz

I use an align shaft aswell, but I also installed a 4mm thick bearing (instead of 3mm) in the bottom, and took 1mm off the ring that slides thru the auto rotation gear and out in the bottom.
this way the align shafts sits much better in the bottom bearing.

I don't think you HAVE to do this, but without it, the align shaft just bearly goes in to the bottom bearing, like 0.5mm.

// Sun

onehot69stepside

where do u get that bearing?

planepounder

Hey, I just got a pack of 2 Belt main shafts from BP Hobbies. They were Esky OEM. I put them in my lathe to check run-out and they were absoutely true. These were black oxide finished the one in my bird was raw metal. Maybe Esky has addressed the bent shaft issue, or I lucked up and got 2 good ones in the same pack.

sunbuzz

A swedish bearing supplier [link]http://www.kullager.se/sv/article/402/kullager_smr_105_zz[/link]

But you should be able to find those at any good bearing store...

// Sun

Cigarette38

I thought abou making them myself to. But I found I can true them with some V blocks and a dial indicator using my drill press as a press. Works great and is fast.

master111400

Hey thanks for all the help. I am sory I havent written back in a while. I am deployed and was away on a mission dealing with some b/s. Im back in business now. I know that some vibes are normal on start up but my heli started to hop around on start up. It hopps so much that it causes the heli to spin when starting. I was told about the shaft problem. When I started to look at things I noticed that my swash plate and drive gear are actually closer to each other on one side and farther apart on the opposite side. I decided to investigate and found that the main shaft I just replaced is bent to hell. I then put the other shaft that I crashed already back in. Now it is better but it still shakes some. And to address the shaking of my tail in flight...i like her to shake her tail...it still does it. Not that bad but it still does. I want to get a good "shaft" so that I can fix this issue. What align shaft are you running? For what heli?

tom dubya

the align shaft for the trex 450 size.