Flight log and double-idler performance

[BHChieftain]

Well, I'm just about to cross the 300 flight mark (297), with 166 flights on my stretch config, and 30 flights on a new 13T pinion + the double idler mod. So far the pinion and belt look fine, I will pull the belt off at 50 flights to see if there is any indication of sawtooth wearing.

I'm using SAB 465mm blades, 13T, ~2250headspeed, getting 6min flight time on a 2600mah 6S pack.

Other notes, I only have 5 crashes out of nearly 300 flights-- waaaaayyy better ratio vs. when I was flying my little gaui 200... that was like 1 in 25...

Really happy with this heli. Only fairly high maint parts are the tail bearings for me, I was going thru them fairly quickly. With the double idler I'm running the belt with a little more slack, maybe that will reduce stress on those bearings.

Chief

[DoubleCH]

Originally Posted by BHChieftain

Only fairly high maint parts are the tail bearings for me, I was going thru them fairly quickly. With the double idler I'm running the belt with a little more slack, maybe that will reduce stress on those bearings.

Make sure tail rotor is balanced as best as possible.Vibes kill tail bearings much more than belt tension does. I shim my tail fin with layers of duct tape to not let it amplify any vibes. Also make sure tail gear doesn't wobble on the tail shaft. It can happen because tail gear drives the tail shaft by just a pin and the area around the pin on the tail gear can wear out leading to a wobbling tail gear. I CA'ed the tail gear onto the tail shaft making sure the gear runs as true as possible on the tail shaft more than 600 flights ago and they are still good along with the tail shaft bearings to this day [touch wood] requiring no maintenance on the tail except for oiling the bearings and tail slider once in a while.

[BHChieftain]

Sage advice. I am a stickler for vibe-freeness-- I dynamically balance the tail with tape. Also use the alum. tail gear to avoid that pin problem.

[DoubleCH]

I AM talking about aluminum tail gear which is all I've been running. You may be surprised how much wear on the tail gear the pin can make especially if you fly hard.

[BHChieftain]

Yikes! I'll pull the tail at my next maint interval and see what the situation is. Actually lately the last set of tail bearings have been holding up well.

Chief

[DoubleCH]

You will know when the pin wears out the CNC gear. When mine happened I could hold the tail hub and wiggle the CNC tail gear left and right, rotate it back and forth.

[BHChieftain]

Great tip,thanks!
Chief

[BHChieftain]

I overhauled my tail, and while I was at it decided to check out the pinion wear...

After 34 flights on a new 13T pinion WITH the double idler mod, I have some news... not so good...

Might be hard to see from the pic, but the pinion is still showing signs of significant wear. At least the wear is more even, not showing the sawtooth pattern. But I doubt I'll get more than 20-30 more flights out of it.

If I can't score a 13T steel pinion from someone (hint hint, you know who you are), I'll go back to the 14T. I may need to remove the 2nd idler as that was only needed to take up the slack on the 13T.

Also, after 140 total flights on the stretch with the alum tail pully (the one that comes with the stretch kit), the pully looks fine-- I am not seeing much wear by the pin so far.

Chief

PS, I have only been flying easy circuits and flips/loops/rolls. No smack (I wish...)

[DoubleCH]

I thought you started out this thread with 30 flights on the pinion already and you only get 4 more flights since? Or do you mean another pinion already? Sounds like you may be running belt too tight if the wear on the pinion is not saw-toothed but even, especially when you fly relatively mild at only 2250rpm HS. The idea of double-idler mod is to have more teeth contact so that you can get away running run loose belt tension without slipping. Loose belt tension as long as it doesn't slip is easier on belt wear.

[BHChieftain]

Hi, I started with zero flights on a new 13T pinion with the double-idler mod, so 34 flights total when I took that picture. I am running my belt pretty loose-- which I really like. I'll take another snapshot at 50 flights to see how we are doing. That pinion metal is just too soft...

Chief