RC Today Show Podcast and KDS

[JustPlaneChris]

Nick, we knocked a few teeth off the main gear on the maiden flight. We're working with Allen and KDS to try and figure out if this was something we did wrong, or something else.

Right now it's looking like you have to mesh the pinion to the main gear much tighter than normal, but unfortunately that isn't made clear in the manual so I meshed it like I would any other helicopter. Why that would cause it to strip isn't exactly clear yet.

Other than that, I enjoyed the build and it certainly flies well. We will likely have more information about this possible gear issue (and the resolution) over the next few weeks.

[Eury]

I wonder if the similarities to the Logo (from what I have seen) would allow you to use a Logo pinion and main gear. I have both in my spares, I'll probably end up with a KDS, I'll have to try that.

[JustPlaneChris]

Nick, I had the same thought, but didn't have a chance to try it before we gave it away.

[Znybar]

Seeing as there's just the one holding point for the engine mount (no bearing below the pinion gear), it's a design that's more prone to torsion forces. If you don't have the teeth meshing well enough they'd be prone to stripping. I've had mine all the way in and haven't had any issues in flight. One of the few design issues with the heli in my opinion, but in fairness it was designed before pinion bearings became widespread and works fine as is.

I'd avoid using helical gears (if the Logo gears are that is) because they just add to the problem. Notice that KDS have addressed this issue in the Agile.

[Eury]

Logos have flown for years without a pinion support without issue, although they do have herringbone gears.

[JustPlaneChris]

Well, I wouldn't say "without issue", as the Logos have been known to have gear stripping issues with the high power setups. In fact, now the updated "SX" series comes with a counterbearing that supports the bottom of the motor shaft / pinion assembly.

I don't think it's a show stopper, but it is something to be aware of.

[Ghostflyer1]

I hear Allen handed you his personal 550 to beat up on.... How's that coming along??

[JustPlaneChris]

We have beaten the crap out of it without failure.

Finalizing the review this weekend, it'll go up on the RC Today Show site soon.

[Ghostflyer1]

So did you figure out what was going on with the demo unit ?

[JustPlaneChris]

Yep. We stripped the gear because the tooth profile on the stock pinion is rather blunt, so you gotta mesh the pinion tight to the main gear to get enough tooth contact.

Or you can use a Rhino pinion, which has a better tooth profile and meshes much better. Either seems to work. I prefer the Rhino solution myself (2 for $5!) but the stock pinion will clearly work if meshed tight enough.

[bwoollia]

Nice review on the 550 by the way! Weird problems with the gear mesh. I haven't experienced any of that with my 600.

[JustPlaneChris]

Thanks!

The 600 has a different main gear and pinion than the 550, so that's probably why you didn't notice the same things we did with the 550.