A-109 Scale Protos 500 build

[kavic5150]

Looks good so far. Of course we are going to want to see video of some rolling take offs and landings.

Will you be able to get to the pulley bearings? I'm always suspicious of mine and lube them almost as often as the motor bearings.

[BHChieftain]

Originally Posted by kavic5150

Looks good so far. Of course we are going to want to see video of some rolling take offs and landings.

Will you be able to get to the pulley bearings? I'm always suspicious of mine and lube them almost as often as the motor bearings.

You know, I never have oiled those bearings and I've never had a problem.

I plan on taking the bird out of the fuse every 50 flights for a full lube-- just did not want to hassle with the motor every 10...

I think the rolling liftoffs are cool too.

I'll also eventually install lights along with the 4-blade head-- probably do that next season.

Chief

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[BHChieftain]

Ok, the project got delayed a bit-- wanted to make some progress over Thanksgiving break, but I crashed my son's Miss Geico catamaran and needed to build up a new one and blueprint the sponsons...

Anyway, got the new ceramic bearings in the motor. After pulling the motor apart I heated the stator side with the bearings in the oven at 225degrees for 10 minutes (got that tip from a recent Boca Bearing newsletter), and they came out with a light tap. New ones installed no problem.

3rd picture shows the 2nd idler pulley installed.

Chief

[Dr. M]

Why did you install that second idler pulley near the motor? I have a feeling that might subject the belt to too much strain around the pinion and lead to premature wear and failure...

[BHChieftain]

I suspect I will need to shorten the tail boom a tad to fit the fuse, so this is to take up the slack-- figured I'd install it now and if I don't need it I can pull it out.

Chief

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[BHChieftain]

Almost done building the stretch kit and tried a test fit in the fuse. I shimmed up the bird about 1". Looks like I won't need to trim the boom-- it is about 1" too long, but the fuse has a cone on the tail that I can trim to accommodate the tail rotor.

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[crickr1]

With that fuse is it possible to use stock boom with 1 idler?
I'm running stretch w/2 pullies in an EC135 fuse. I forget stock length since I only have stretch

[BHChieftain]

On the stretch boom I did remove the 2nd idler-- when I did the test fit I had the boom in the almost fully extended position. I'll put the stock boom on and see how short it is. I can modify the fuse tail cone if the boom is too long, but not sure what I can do if it is too short.

Chief

[BHChieftain]

Ok, just did a test fit with the stock boom--- way to short...
Chief

[crickr1]

Guess you need to open tail little more.You can Also find lower kv motor and use larger pinion to shorten boom little more. Not sure of any pelts that would work

[BHChieftain]

Got the stretch bird together and did a test power-up. All looks well. Next stop is to modify the landing gear-- I am replacing the servo driven retracts that came with the fuse with electric retracts-- they are stronger, action is slower, and they don't need servos to drive them (just plug into Gear channel). But they are larger than the stock units and the fuse will need some mods to accept them.

Chief

[BHChieftain]

Progress is slow but steady. Did 2 test hovers on the stretch bird. Decided to remove the 2nd idler pulley and extend the tail cone on the fuse. Now on to the landing gear mod...

Chief

[kavic5150]

[crickr1]

Originally Posted by BHChieftain

Progress is slow but steady. Did 2 test hovers on the stretch bird. Decided to remove the 2nd idler pulley and extend the tail cone on the fuse. Now on to the landing gear mod...

Chief

Why did you choose to remove? Were you having any problems?

[BHChieftain]

No problem -- the tail cone on the fuse can easily be extended to accommodate the length and I think less wrapping around the pinion will extend the belt life a bit.
Jq



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[solex227]

BHChieftain

Great job so far cant wait to hear how the maiden goes and see the 4 blade head installed.

Solex227

[BHChieftain]

Did 4 test flights at the field on the frame (no fuse).

First 2 flights all went well, tail was smooth, but all I was doing was hovering.

3rd flight I did some collective pumps and BAM, lost the tail, and she spun for a bit-- man, it is hard to keep orientation when the bird spins AND you don't have the canopy on! It was close, but I was able to keep her level when she spun, the tail regained hold, I found the orientation, and brought her down safely. Glad I have been practicing piro hovering lately!

I had the tail gain on my bird set for the stock protos, and this one is running way lower headspeed (14T pinion). On my futaba radio, my starting gain was 60%. I cranked the gain all the way to 95%, and still did not get any tail jitters. But even at that gain level, as soon as I started turning the bird to the left, the tail would slide out. For some reason it holds well during right hand turns...

Any clues? I've got to get the tail reliable before doing anything else.

Prior to the flights, the tail was buttery smooth, I have not done a thorough check post flight, I'll do that later. But the tail holds perfectly when just hovering. Main blades and rotor head were fully balanced, I don't see any vibe issues.

Config is flybar, futaba BLS251, Quark HH gyro. This combo has been perfect on my stock protos.

Note, I am running 430mm blades on this stretch kit, headspeed was very low. My throttle was set to 85%. I suspect the headspeed is simply too low-- I am planning to try again at 100% throttle.

Any other things to look at?

Chief

[dr dremel]

I´m running 14T on 65% TC for aerobatic flight, sometimes 55 when I want to it to be whisperqiet. Fut 9254 on tail and quark gyro. tail holds very well for my style of flying @65, have to be careful @55. I doubt it´s too low HS. I know you have the stretch kit on, but if anything that should improve your tail hold over stock.

Cannot help any further unfortunately as this is my first FB setup and the quark was literally set it and forget it

[flint723]

Originally Posted by BHChieftain

Did 4 test flights at the field on the frame (no fuse).

First 2 flights all went well, tail was smooth, but all I was doing was hovering.

3rd flight I did some collective pumps and BAM, lost the tail, and she spun for a bit-- man, it is hard to keep orientation when the bird spins AND you don't have the canopy on! It was close, but I was able to keep her level when she spun, the tail regained hold, I found the orientation, and brought her down safely. Glad I have been practicing piro hovering lately!

I had the tail gain on my bird set for the stock protos, and this one is running way lower headspeed (14T pinion). On my futaba radio, my starting gain was 60%. I cranked the gain all the way to 95%, and still did not get any tail jitters. But even at that gain level, as soon as I started turning the bird to the left, the tail would slide out. For some reason it holds well during right hand turns...

Any clues? I've got to get the tail reliable before doing anything else.

Prior to the flights, the tail was buttery smooth, I have not done a thorough check post flight, I'll do that later. But the tail holds perfectly when just hovering. Main blades and rotor head were fully balanced, I don't see any vibe issues.

Config is flybar, futaba BLS251, Quark HH gyro. This combo has been perfect on my stock protos.

Note, I am running 430mm blades on this stretch kit, headspeed was very low. My throttle was set to 85%. I suspect the headspeed is simply too low-- I am planning to try again at 100% throttle.

Any other things to look at?

Chief

I assume you installed the 18t tail pulley? My stretched protos with 470's held the tail fine down around and under 1600 rpm (4s 100% throttle 13t pinion).

If you can't get wag with 95% gain in tx then it would seem like your gyro channel isn't working. Idk what Tx you have but make sure it is enabled and on the right channel.

Also I have forgotten to plug the gyro signal wire into the Rx before.... luckily figured it out before I tried to actually fly.

You could also double check the tail endpoints.

[BHChieftain]

Originally Posted by flint723

I assume you installed the 18t tail pulley? My stretched protos with 470's held the tail fine down around and under 1600 rpm (4s 100% throttle 13t pinion).

If you can't get wag with 95% gain in tx then it would seem like your gyro channel isn't working. Idk what Tx you have but make sure it is enabled and on the right channel.

Also I have forgotten to plug the gyro signal wire into the Rx before.... luckily figured it out before I tried to actually fly.

You could also double check the tail endpoints.

Yes I used the alum. tail pulley that came in the kit. I used the exact same components and servos/gyro as my stock kit which has been flawless for about 200 flights. I am a bit flummoxed...

I even doublechecked that the belt was not twisted in the boom.

I'll reset the Quark and try again next weekend...

I was wondering if there is any chance that using the shorter main blades (430mm) could have anything to do with the low headspeed... I understand I can run low HS with the longer blades, but with the shorter ones??

Chief