Atom 5.5: too fragile Main Gear?

[ARM_Coder]

Yesterday I had, for the second time, my 5.5's Main Gear sheared while trying to recover from a poor auto by engaging the Bail Out. Fortunately I managed to land the heli smoothly both times!

I can, of course, reduce the Bail Out speed, but this will make it almost as slow as the regular spool-up.

Maybe the 5.5, as floaty as it is, doesn't need Bail Out at all. But my impression is that in the 5.5 the Main Gear is working very close to its limits!

Does anyone else has such an impression?

Cheers!

[aburkhardt]

I chewed up 2 main gears recently. I called Tony and he said the yellowish gears are better than the snow white gears. It's been colder here in Ohio and maybe I've been getting better. But yes, I think we got a bad batch of gears. Hopefully compass will fix the next batch but I doubt it. Just stock up and keep flying!

[cyclo]

Originally Posted by aburkhardt

I chewed up 2 main gears recently. I called Tony and he said the yellowish gears are better than the snow white gears. It's been colder here in Ohio and maybe I've been getting better. But yes, I think we got a bad batch of gears. Hopefully compass will fix the next batch but I doubt it. Just stock up and keep flying!

I am still using the original yellowish gear but I do think the Atom 5.5 is definitely harder on the gears than the regular Atom. When mine was new, I noticed white plastic residue accumulation in the CF around the pinion area every 5 or so flights. I did not notice this on the Atom 500 with the same gear. I fixed the issue by using White Lightning Wax based bicycle chain lube on the main gear. I am using the stock 9T pinion on my Atom 5.5.

[ARM_Coder]

I rebuilt my 5.5 yesterday, but all 5 gears (now 4) I have in stock are the "Snow White Edition". So no abuse is allowed.

I don't think temperature plays a role here, because it's summertime here in Brazil. Although an untimely cold front arrived and cooled the weather a bit, it's still balmy here.

I'm using the 9T pinion and Rotortech 515 blades. The pinion may play a role here, since the 5.5 upgrade kit brings a 8T. Perhaps the guys at Compass realized that the stretch kit was too hard on the gear, and opted to alleviate this reducing the pinion. But the HS yielded with the 8T is too low for my taste, and I suppose that's true for most.

The 5.5 is a kit that definitely demands a black helical gear IMO. Just to compare, the Trex 500L has such a gear, in a diameter bigger than the Atom's, and a higher KV motor to make up for the larger diameter. In this sense, the Atom is really dated.

I'm sad that Compass could simply upgrade the Atom (helical gear, CF pushrod, better fixtures for the canopy, new tail case and rotor) instead of trying to release a brand-new 500 that's taking forever to show up and is not stretchable AFAIK.

Cheers!

EDIT: Hey Atom fans, we could start a petition to Compass: Please make the Atom 500 Ultimate, based on the current model, just with the so needed upgrades!

[quinn]

I can't say I ever had a problem with the main gear and I was running the 4025 up to 3000 headspeed with 515mm blades at 14 pitch. I did crack the main frame from all the torque, but no stripped gears. Not sure if I had these white ones though.

[PowerDyne]

Originally Posted by ARM_Coder

I rebuilt my 5.5 yesterday, but all 5 gears (now 4) I have in stock are the "Snow White Edition". So no abuse is allowed.

I don't think temperature plays a role here, because it's summertime here in Brazil. Although an untimely cold front arrived and cooled the weather a bit, it's still balmy here.

I'm using the 9T pinion and Rotortech 515 blades. The pinion may play a role here, since the 5.5 upgrade kit brings a 8T. Perhaps the guys at Compass realized that the stretch kit was too hard on the gear, and opted to alleviate this reducing the pinion. But the HS yielded with the 8T is too low for my taste, and I suppose that's true for most.

The 5.5 is a kit that definitely demands a black helical gear IMO. Just to compare, the Trex 500L has such a gear, in a diameter bigger than the Atom's, and a higher KV motor to make up for the larger diameter. In this sense, the Atom is really dated.

I'm sad that Compass could simply upgrade the Atom (helical gear, CF pushrod, better fixtures for the canopy, new tail case and rotor) instead of trying to release a brand-new 500 that's taking forever to show up and is not stretchable AFAIK.

Cheers!

EDIT: Hey Atom fans, we could start a petition to Compass: Please make the Atom 500 Ultimate, based on the current model, just with the so needed upgrades!

I do think a helical gear set would be a very good solution. More contact area between the pinion and main, and better meshing always helps in gear train stability.

[Mon_t]

let's hope they keep producing the straight cut gears, I for one don't fancy paying $75 for a pinion and main gear.....

[ARM_Coder]

Helical gears have not to be that expensive. Think about Align. The problem is that Compass uses Delrin instead of nylon, hence the high price tag.

[aburkhardt]

I keep breaking them. :/ This one appears to have bubbles in the plastic.

[aburkhardt]

What do you guys think about pinions?! I love the 10T but I'm wondering if I should drop to the 9T. Tony ran this with 473mm blades at 3000+ rpm. I'm running cyclone 505mm closer to 2600 rpm.

[cyclo]

I am running the stock 9T with 515mm blades on my Atom 5.5 with the stock 1100kv motor... I am running at 100% throttle ungoverned. With this setup it is fast and responsive enough (though not as fast as my 550U at 2400 rpm governed).

I never had a problem with the Atom main gear but I do lube it with White Lightning bicycle chain wax lube after I initially detected white plastic flakes in and around the pinion area.

[aburkhardt]

Originally Posted by cyclo

I never had a problem with the Atom main gear but I do lube it with White Lightning bicycle chain wax lube after I initially detected white plastic flakes in and around the pinion area.

When I replaced it this time I did use a dry lube. Maybe it will last longer. Going to the field today, threw a 9t in my toolbox. Mesh seems good.