Main gear warped.

[FLYGUY 11]

Started my build today and after installing the main shaft, gear and pully with the shims specified in the manual, my main gear would rub on the bevel gear from the gear box. I noticed the main gear has a nasty wobble. Took it apart and removed the one way from main gear, put it on a glass surface and determined that the gear is warped. I re-assembled with an added 1mm shim(as well as the .5 shim) above the pulley and removed the 1mm shim from between bottom bearing block and gear.
This gives me clearance from the gearbox gear.
I'm concerned about motor gear mesh with this wobble.
Anyone else experience this?

[10pilot]

I wouldn't use it. My experience is the mesh has to be as close to perfect. Especially with the pinion support now, I believe the chances of stripping the gear or wearing out a bearing prematurely would significantly increase. Don't do it....

[JamesGreen]

Originally Posted by FLYGUY 11

Started my build today and after installing the main shaft, gear and pully with the shims specified in the manual, my main gear would rub on the bevel gear from the gear box. I noticed the main gear has a nasty wobble. Took it apart and removed the one way from main gear, put it on a glass surface and determined that the gear is warped. I re-assembled with an added 1mm shim(as well as the .5 shim) above the pulley and removed the 1mm shim from between bottom bearing block and gear.
This gives me clearance from the gearbox gear.
I'm concerned about motor gear mesh with this wobble.
Anyone else experience this?

I had the exact same issue, and did the same thing to resolve. just trying to get rid of a little tail wobble now.

[FLYGUY 11]

I have a pic and vid but having trouble uploading for some reason.
I will post them as soon as I can.
Never expected to have such a warped gear!
I have had this with my 600se before but not nearly as much as this.
I can't convince myself to use this gear and I'm a bit upset.
I guess I will order another NEW gear and continue the build once I get it.
I feel I should contact mikado.

[FLYGUY 11]

[ame]http://www.youtube.com/watch?v=qUhR6CqXgt8&list=UU6ML7EGtB4-8WliIMJd0bRw&index=1&feature=plcp[/ame]

[NTM]

You can true the gear up to a certain extent by using threadlock on the gear to hub bolts and tightening them progressively until you have no runout.
Exact same thing is done with the logo 600 gear, there are detailed instructions in the 600 forum.

The recommended shimming order didn't work for me either though, even with a trued up main gear. If I put any shim at all between the one way hub and the third bearing block, the main gear would rub the tail drive gearbox pulley.

[FLYGUY 11]

I know the procedure for fastening the one way as I have used mikado for a while now.
I have tried re-installing the hub 3 times now and end up with the same wobble every time. You can see it even with the hub removed from the gear.

[JamesGreen]

post on the mikado xxtreme forum, see what they say.

[OICU812]

Herringbone pinion will keep that gear surprisingly level. Hook on motor and pinion you'll see. Being a triangle the force is across the entire surface.

[FLYGUY 11]

Yes, I realize the pinion will keep it level but they do fight each other where the gear is warped.
I would feel better just ordering a new one.

[OICU812]

No problem, it doesen't really "fight" at all, it centers it with ease Like I said you can mount motor and pinion and turn by hand or power with blades off and see for yourself as well.

[Stolla]

Sure it will centre when turn by hand but totally different story at 2000 rpm under load, from an engineering point of view its looking for disaster, espescially heringbone where once the v is damaged gear is gone, i really dont get it why a company like mikado cant get it right with the gear, on the 600 they were never round, so you had a high and low spot. Now i know many blame it on being a molded gear, thats also rubbish, even my e720 gear runs as true as a machined delrin gear. Reason its not straight, either their mold is rubbish in which case all would be warped or the parts were removed from the mold too early or handled before they settled, just plain bad qc, seems now everything made in China! They should replace the gear no questions asked

[sandro12321]

I would try the old Trex remedy, put the gear in boiling water for 5 minutes, pull it out and onto a flat surface and put a flat surface on top and some weight, once it cools it stays in that shape. Not sure if it works on Mikado gears but always worked on my trex's

[OICU812]

He'll be taken care of and I never said it was acceptable. What I was saying is it actually won't harm anything I've ran ones way worse on other sizes etc on loaded disc at flying rpm for many many flights with no abnormality in flight or wear, if it were a straight gear or helical it would be more of a concern, herringbone don't care, and trust me I understand the engineering angle very well.

And NO the gear is not made in China and my TT E720 gear wasn't perfect either so why we're pissin on about that comparison not sure.

[OICU812]

Originally Posted by sandro12321

I would try the old Trex remedy, put the gear in boiling water for 5 minutes, pull it out and onto a flat surface and put a flat surface on top and some weight, once it cools it stays in that shape. Not sure if it works on Mikado gears but always worked on my trex's

That works on pretty much all gears out there yes. And it also can take out small bubbles like it did on my TDR gears. Acts abit as a strengthening process to, many RC cars guys do this.

[dahld]

I've seldom had perfect gears, but on the other hand, they've never caused us any trouble. But still, nothing as bad as the one in the vid. I bet if you ask, they'll replace it (start by asking RH if they'll replace it, and they'll pass the hit onto Mikado...or something like that). Won't know until you ask.

At any rate, about the China remark. I've been to where the gears are molded, and I've been to the machine shop where the molds are created. Everyone there spoke German

(-: Dave

[Stolla]

Good to hear Dave, was getting worried here!, maybe they should look at China lol,
Shawn relax my comment wasnt directed towards you, just based on my experience with mikado gears, on the herringbone a warped gear is worse than straight gear because a straight or even helical gear can deal with frictional movement between gears much better, on a herringbone the mere fact that the V now have take the strain of straightening the gear on every rpm places undue stress on the gear.
Botom line for me is when you buy a German product from a upmarket company like mikado you should not accept a remedy to cook gears, except off course if you have a decent sauce to go with it
Oops sorry, almost forgot JUST MY OPINION!

[10pilot]

Dude, you're flying $3500.00!!! Are you seriously considering, even remotely, using or fixing a piece of equipment that could make it a $5000.00 investment? Let's see, $1500.00 crash or you could take my initial advice and don't do it. My experience is filled with wishes of not pushing a bad position. Crappy deal you got a warped gear, my friend. But don't let impatience cloud your judgement. Just sayin'. Unless you actually engineer main gears for a successful RC Heli company, just get a new one. Stolla, good advice!!

[FLYGUY 11]

Thanks for the replys gents.
NO, I have no intentions of using this gear! These big high powered machines are not worth risking a crash or injury.
I have sent Mikado an email yesterday and waiting on a reply. I hope they understand my situation especialy after paying aprox 2700 bucks for this beautiful machine.
I will post again when I hear back from Mikado.

J

[EO19]

Originally Posted by FLYGUY 11

Thanks for the replys gents.
NO, I have no intentions of using this gear! These big high powered machines are not worth risking a crash or injury.
I have sent Mikado an email yesterday and waiting on a reply. I hope they understand my situation especialy after paying aprox 2700 bucks for this beautiful machine.
I will post again when I hear back from Mikado.

J

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