Bergen Gasser EB

[lperagallo]

misteru2, If you are talking about the tail driven gear, you should be locking the driven tail gear to the main shaft in the indent with the set screw in the main shaft. There will be some clearance between the main gear and the driven tail gear, but not much. There should be very little backlash between the driven tail gear on the main shaft to the bevel gear on the tail rotor transmission.
Remember to loosen the rear main bearing block bolt and the four rear tail transmission bolts to release the tail transmission before setting the main gear split collars. Then push the tail transmission gear down on to the driven tail gear to get very little backlash, then tighten the rear main bearing block to hold everything in place. Then tighten the rear tail transmission bolts. Remember to lock tight all the bolts and set screws with the exception of the split collars.

Lou

[cbergen]

Lou,

He does NOT have a driven tail....... :arggg:

[lperagallo]

Mister2u, OH sorry, I don't know where I got the idea it was a driven tail.

Lou

[mister2u]

I'm a bit confused. What's the difference between a driven and a non-driven tail. I thought that since the tail was driven by the main gear it was considered a driven tail. :dontknow

[MarkWebber]

The undriven tailrotor does not spin in an auto. The driven tailrotor gear set drives the tailrotor in an auto. Hence the "driven". :wink:

[rkeith2]

And it makes for some spectacular with the wind autos :mrgreen:

Ask me how I know this :WOW

[mister2u]

I see. So, how does the beginner (while still learning to hover) know that he does or does not have a driven or non-driven tail rotor?

[rkeith2]

When you are spooling the heli down the tail blades will stop while the mains are still turning.

[mister2u]

If my memory serves me correctly, I've noticed that my tail blades are still spinning when I'm spooling down the main blades. I'll have to check again once the new gear is installed.

[MarkWebber]

Real easy...if you can rotate the tail blades in one direction without the mains moving, you have an undriven tail.

Or the even easier way...listen to Chris, he's already said "undriven".

[mister2u]

Ok. That's simple enough. Either way. Thanks Mark. :glasses2:

[rkeith2]

I think Chris said :arggg:

[mister2u]

Ok, I got the new gear on this time with no backlash whatsoever and adjusted the tail transmission gear accordingly (so I thought). The main gear spun freely, also. To make a long story short, I ordered two (just in case) replacement gears this weekend.

[mister2u]

Ok, I have the new gear on. I've included pics. Does anyone see an issue? I loosened up the transmission assembly as well as the boom. Next, I positioned the pinion and the gear to get as tight of a mesh as possible while still allowing the main gear to spin freely. Finally, I retightened the boom and assembly while still maintaining the mesh shown in the pics.

[lperagallo]

What is all that stuff in next to the tail gear on the second picture? That looks a bit excessive if it's gear dust.

Lou

[mister2u]

Yea, that is gear dust, but from the previous gear that was replaced (I blew the gear dust off after having seen it on these pics). I haven't used this gear yet.

[v22chap]

It looks like you may have the steel tail drive gear to far forward on its shaft as the gear doesn't set even with the rear of the crown gear. There are two different spaced divots on that shaft one forward of the other and if you get it in the wrong one it will be to far forward and will allow the gear and shaft to slop back and forth.

Check to see if you have slop in the steel drive gear and shaft ,,back and forth in the cage ,,,if it moves it is on wrong and will allow the gear to slide back thus making to much gear slop and will tear the crown gear up eventually .

I think the pix I drew on will show you the problem . The arrowed parts of both gears should be flush with each other ( or closer than they are )... this tells me that there must be slop on the shaft and since the gear is ahead when you set the proper mesh and it feels good ... then it slides back and it will be to much distance to be meshed good .... if it is in fact not sliding back ... it is still out of mesh because it is to far forward making only the front of the teeth on both gears make good contact ..... I think :roll: :idea: :hug:
Hope this helps

[mister2u]

Thanks, v22chap! I'm going to have to check that out. I thought that I positioned the steel gear drive as far back as possible. Gonna have to give it another once over.

[mister2u]

I have corrected my gear mesh issues for the main gear and pinion on my EB. While trying to hover, the tail end kept going to the left (clockwise). I tried adjusting the rudder trims to no avail. It seems like I came across a post regarding such, but I can't seem to locate it. Would anyone happen to have any suggestions.

[mister2u]

Ok, I spoke with Larry this afternoon and he gave me a few issues to look at. He said that this was a common issue if the gyro is reversed or the rudder assembly is incorrectly installed. That's good news to hear and an easy fix. Gonna check on it this evening.

[mister2u]

Ok Bergen brethren, I finally got it done. I got my first hover in today! It was awesom beyond words! I was able to get 2 1/2 tanks in before tragedy happened. Actually, it wasn't that bad. My set screws that secure the tail rotor gearbox vibrated loose. Luckily I was landing so I only damaged my rotor blades. I still had some tail drift to the left, even after substantial trim was applied. I think that may have been do to them not being tracked correctly. I need to watch Gary's video again. I'm not sure what my headspead was because I was alone and didn't want to try that task alone. I can honestly say that my time spent on the simulator helped out more than I would know. I've had G3.5 since October of last year and I know for a fact that i've spent over 100 hours on it. I'll be on it later this evening as well. Ok, that should do it. I just wanted to share my joy with my fellow Bergenites! One more thing, however. Would anyone happen to know the size of those two set screws for the tail rotor gearbox?

[cbergen]

Glad to hear you got her in the air!!

Have you read through this post? It helps with setting up a 401 gyro system and is a good idea even if using a different gyro at least as far as neutral mechanical setup. It should help with the drift problem.

http://www.helifreak.com/attachment.php?attachmentid=9027&d=1157677350

Couple of quick questions, what is your gain, HH and NON HH? What is your rudder ATV set at?

The 2 screws securing the gearbox to the boom are 3X4 SHCS. Be sure to use good fresh blue loctite, and a washer under the head may help distribute the load to the boom as well.

[mister2u]

Thanks for the info Chris. The HH and non HH are set at 80% and 70%, respectively. The ATV for the rudder is set at 80% and 80%.

[mister2u]

It's me again. I eventually had to order a new tail gear as I discovered a broken screw lodged in the existing one from the other weekend. Well, it came in yesterday, I installed it and took to the skys. The EB in flight was amazing (though I am still hovering)! Everything is dialed in and the tail holds marvelously! Just wanted to keep everyone posted on my progress. Thanks for everyones help in assisting me while trying to get into and understand this hobby. I will keep you posted as I progress.

[mister2u]

Hello HF's! Just and update and a question or two. I've been doing pretty good with my hovering so far. She fell from grace yesterday, however, but she wasn't too far up. Forgot to friggin threadlock the tail pinion set screw. Anyway, I got up this morning and was able to straighten the bent pieces out with no problem (i thought i was going to have to order additional parts). The main blades got nicked right by the blade grips, but not enough to cause flying problems. I'm just getting back in from testing her out this evening and she's hovering just fine. Something unusual happened, though. I was only hovering about 3 feet (thank goodness) and the engine started to whine and loose power; like it was out of fuel, but it wasn't. I landed safely and tried to give it some throttle, but had not luck. The engine tried to engage, but it just couldn't find the power to. Like I said, it seemed to be sucking fuel, but there was plenty in it. Also I noticed while hovering that fuel was coming out of the overflow line, but the tank had less than half a tank of fuel in it. After I noticed that, I added more fuel and began to hover again. It was then that the engine seemed to be loosing power after about 4 minutes or so into hovering. I know that is a lot, but does anyone have any suggestions? Also, I have already installed the Z-RC insulator. Thanks.