Up & Down play in main shaft

[Mizark]

I have read that others have also got up & down play in there V90 main shafts but have tightened the lower jesus bolt to remove it. I have tightened mine down (so much that I actually cracked the plastic on the auto hub) but I am still not happy.

Is anyone else feeling this way? I dont belive tightening up the lower jesus bolt is a perfect solution as it could still move in high loads.

I like the idea of the movable lower bearing block instead of a standard mast collar but the play in the lower jesus bolt hole makes it hard to get right. The auto assy should be bolted to the main shaft like some other helis (such as MA) to make the movable lower bearing block idea work properly.

Im going to source a mast collar but before I do wanted to see if anyone else has came up with any ideas about it all.

[raptorheli2]

doesn't sound right to me. i just finished building mine and i didn't have this issue. perhaps one of your parts isn't quite bang on causing this.

looking at the room left on top you could fit a collar though i think.

cheers

[Mizark]

I also didnt see an issue when building it, only after a couple of harder flights did it come apparent.

Yeah there is enough room for a collar so thats no problems I reckon.

[deldeb]

I think you can lift the bottom bearing carrier to take out the play.
Cheers Del.

[Mizark]

Yep thats right but if you read I am not having issues with that, its the lower jesus bolt allowing minor up & down movement in the main shaft.

The bearing block just pushes up & supports the main gear/auto unit, no the actualy shaft.

[raptorheli2]

i just put my 2nd vel 90 together and it doesn't have this either. one of your parts has an issue there.

cheers

[RotaryBliss]

One would think that if the jesus bolt is allowing any movement, the hole in the oneway sleeve or the hole in the shaft is somehow wrong. My lower jesus bolt fit through the gear/sleeve/shaft hole rather snugly, there shouldnt be much if any slop there. Unless of course it was run loose and it somehow got out of shape during flight.

[Mizark]

Well the only thing I can think of is either the bolts shank is not beefy enough or the hole drilled through the main shaft if slightly over sized.

Can I stress guys that the play is minor but it is still there.

I will take the main shaft & bolt to a fasteners shop & see if I can get a bolt that is a tighter fit.

[Foxden]

Originally Posted by Mizark

Well the only thing I can think of is either the bolts shank is not beefy enough or the hole drilled through the main shaft if slightly over sized.

Can I stress guys that the play is minor but it is still there.

I will take the main shaft & bolt to a fasteners shop & see if I can get a bolt that is a tighter fit.

I've got the same thing here but I have a pair of Prototype Vel 90's, I re-adjusted the lower bearing block yesterday before heading to the field and I noticed the tiny bit of play between the lower Jesus bolt and the main shaft hole, I tightened the bolt a tiny bit more and removed all the play, but you are correct it would appear the hole in the main shaft is slightly larger than the shank bolt, after tightened down on the bolt Steven flew the pooh out of it for a couple of flights, the bolt didn't loosen nor did the play return and it didn't seem to have any effect on the flights.

[Mizark]

Originally Posted by Foxden

I've got the same thing here but I have a pair of Prototype Vel 90's, I re-adjusted the lower bearing block yesterday before heading to the field and I noticed the tiny bit of play between the lower Jesus bolt and the main shaft hole, I tightened the bolt a tiny bit more and removed all the play, but you are correct it would appear the hole in the main shaft is slightly larger than the shank bolt, after tightened down on the bolt Steven flew the pooh out of it for a couple of flights, the bolt didn't loosen nor did the play return and it didn't seem to have any effect on the flights.

OK great. I will go & try to get a bigger bolt first then & lock it right down.

I will also buy a collar to have sitting here in case.

Thanks heaps for your response

[Tim Tompkins]

Beware of taking advise from Clyde. He sometimes starts a fight. TimT

[tS8103]

I have a new flybarless 90 kit and have the same vertical play after a couple of flights. The bottom bearing is tight and the play seems to be within the auto hub, because although the main shaft has small vertical play, the gears and auto assembly did not. I really tightened up the bottom Jesus bolt and it removed the play on the bench, but I will let you know if it comes back this afternoon.

Tone

[DominicD]

Originally Posted by Tim Tompkins

Beware of taking advise from Clyde. He sometimes starts a fight. TimT

And he will "polish the floor" with ya

[Mizark]

Originally Posted by tS8103

I have a new flybarless 90 kit and have the same vertical play after a couple of flights. The bottom bearing is tight and the play seems to be within the auto hub, because although the main shaft has small vertical play, the gears and auto assembly did not. I really tightened up the bottom Jesus bolt and it removed the play on the bench, but I will let you know if it comes back this afternoon.

Tone

Yup thats what I had Tone.

I actually modified a Quick UK Raptor 90 collar & its working well. The problem is that is it rather large & blue :p

I have a Rave ENV collar coming today that I think sould be a much better fit. It also uses pinch system instead of the set screw one I am using now. I rather the pinching method, I belive it holds tighter.

I will post some pictures up a bit later.

[Mizark]

Well I was wrong, the Rave ENV collar is too big

The Raptor one is working so I will continue using that until I get a new main shaft in that hopefully has a smaller hole. The Raptor collar just hits the swash at max's but it is fine.