Main gear wear

[Anthony Oxlade]

Hi guys,

My e7 main gear has had about 90 flights now. In the last 5-10 flights i have noticed a large quantity of delrin dust collecting on the gear and motor pinion, as well as the surrounding areas. I can see and feel with my fingernail that the shoulder of the motor pinion has started to wear a lip in the top surface of the main gear. I have cleaned it repeatedly but the dust keeps building up so the gear must be continuing to wear. I didn't have any issues in the first 80 flights so i'm wondering if anyone has seen something similar and found the cause?

I checked over the heli carefully and tightened the lower jesus bolt below the belt gear. This has removed some slop from the collar that sits above the auto hub. The vertical play in my main gear is about 0.5 mm which is pretty typical from what i've heard.

[Matt Botos]

With helical gears you can use grease to minimize wear. Helical gears have more of a "swiping" action than straight cut gears. I personally use a high pressure synthetic grease to keep the gears cool, quiet, and minimize wear. I use a tooth brush to brush the grease into each tooth.

The E7 main gear is virtually bulletproof in flight and most of the time does not even strip in hard crashes. However, I believe helical gears do require a bit more maintenance than straight cut gears.
This sort of thing is some what of a compromise, either you have quiet, smooth, strong gears that require a little maintenance or you have noisy, weak, vibration prone gears that do not require any maintenance. While designing the E7 I wanted a stronger/smoother main gear so I went with the helical cut gear.

Grab yourself a tube of Boto-Lube and grease regularly.

Hope that helps!

Thanks,

Matt

[Darren Lee]

+1 for everything Matt said.

I used to have a problem with main gear wear also.  Since I replaced the gear and started greasing every 20 flights or so, it's silky smooth and quiet with no visible wear.

[Anthony Oxlade]

Thanks for the tips Matt and Darren.

I just had 5 flights on the gear after lubing it with a high pressure grease and there are no signs of further wear.

[steffgiguere]

They are almost indestructible, I have over 400 on my E6 and 406 on my E7, still original main gears. Have not even greased them. Is you mesh really tight?

[Anthony Oxlade]

They are almost indestructible, I have over 400 on my E6 and 406 on my E7, still original main gears. Have not even greased them. Is you mesh really tight?

No my mesh is on the loose side. It is possible that my loose auto hub lock collar was allowing excess vertical movement of the main gear but i can't really be sure. Since tightening the jesus bolt and applying grease my pinion has stopped wearing a lip in the top surface of the main gear

[RyanW]

I had the same thing happen. It was the canopy. It made a small chamfer on the top edge of my main gear. I swore it wasn't the canopy, but sure enough there were two tiny dark marks on the inside where it was touching the main gear occasionally. It doesn't take many brushes with the inner fiberglass to sand it down!

[Kevin Feil]

  Ryan,

 One alternative is to add tail blade spacers inbetween the canopy mount and the frame. This will kick out the canopy enough to clear. shouldn't be any more issues.


Kevin

[RyanW]

I did that and it cured it. Just thinking of things to help this guy.