Vibration issue with my logo 500se

[thefrog]

I finally fixed my tail vibe issue on the 500SE after replacing pretty much all the tail parts several times over and trying every option I could think of over the course of the year.

Last week I dumb thumbed it inverted backwards into the deck - broke most of the airframe so not much to salvage. I won't be buying another Logo to replace it - was far too frustrating.

[Laughingstill]

Originally Posted by BigIreland

Glad I found this thread. I've been fighting tail issues since I got my 500SE. Love the heli but I can't really do much as far as tuning until I get this knocked out. I've been through two complete tail hub assemblies, 2 sets of blades and I just replaced the shaft itself. Hopefully this will fix it and I can get that famous Logo smoothness.

Originally Posted by thefrog

I finally fixed my tail vibe issue on the 500SE after replacing pretty much all the tail parts several times over and trying every option I could think of over the course of the year.

Last week I dumb thumbed it inverted backwards into the deck - broke most of the airframe so not much to salvage. I won't be buying another Logo to replace it - was far too frustrating.

Guys the issue is a simple one. Mikado is not know for having mis-machined parts regularly. Once in a while, sure, everyone will. I still say the issues is something you have missed mechanically. If the tail is fine in a hover at 2000 but goes nuts at 2200, the stresses are bringing out a problem that already exists. I ran my Logo 600 to 2600 in the head and the tail stayed rock solid the whole time. I have owned no less than 12 Logos in almost every size and they have bee awesome, every one. I described a small tail issue I had in a previous post but after that was solved, the 600 was perfect.
Take it apart, inspect every individual piece, reassemble it correctly.....go fly

[el guapo]

Originally Posted by BigIreland

Glad I found this thread. I've been fighting tail issues since I got my 500SE. Love the heli but I can't really do much as far as tuning until I get this knocked out. I've been through two complete tail hub assemblies, 2 sets of blades and I just replaced the shaft itself. Hopefully this will fix it and I can get that famous Logo smoothness.

you have to shim the tail, the two carbon plates have to be parallel, you can not have pre load on the bearings... hawk RC and RC tek make aluminum clamps for the tail on the 500se. Lynx makes one for the 600. the plastic mikado ones squish when new, so you'll set it up, it will be parallel for a few days, then it settles and it will need to be shimmed again. once they get old, they are more stable. also the the shim washer used under the bell crank is junk. our it least it has been in the last three I bought. some of the old dudes seem to be resistant to admitting there is a problem with the washers in newer kits.

look at your washers. if they look cheep. buy these.

http://grandrc.com/QuickUK-General/c...duct_info.html

[thefrog]

Originally Posted by Laughingstill

Guys the issue is a simple one. Mikado is not know for having mis-machined parts regularly. Once in a while, sure, everyone will. I still say the issues is something you have missed mechanically. If the tail is fine in a hover at 2000 but goes nuts at 2200, the stresses are bringing out a problem that already exists. I ran my Logo 600 to 2600 in the head and the tail stayed rock solid the whole time. I have owned no less than 12 Logos in almost every size and they have bee awesome, every one. I described a small tail issue I had in a previous post but after that was solved, the 600 was perfect.
Take it apart, inspect every individual piece, reassemble it correctly.....go fly

I hear you, but unfortunately for me it was not as simple as take apart, check and reassemble. That was done several times over 10 months and most components were replaced as I went through all the threads I found on the web. I even had the local Mikado dealer take a look at it over a 3 week period and they only made it worse. I really enjoyed it's flight performance but the issue left a sour taste - I wasted a lot of time and money chasing the fix without success.

[BigIreland]

Originally Posted by el guapo

you have to shim the tail, the two carbon plates have to be parallel, you can not have pre load on the bearings... hawk RC and RC tek make aluminum clamps for the tail on the 500se. Lynx makes one for the 600. the plastic mikado ones squish when new, so you'll set it up, it will be parallel for a few days, then it settles and it will need to be shimmed again. once they get old, they are more stable. also the the shim washer used under the bell crank is junk. our it least it has been in the last three I bought. some of the old dudes seem to be resistant to admitting there is a problem with the washers in newer kits.

look at your washers. if they look cheep. buy these.

http://grandrc.com/QuickUK-General/c...duct_info.html

Thanks, I'll check the clamps and the shim out. Also, when I was changing the tail shaft, the two shims that go between the hex piece and the pulley according to the instructions need to be 5x10x0.2. I have those in but I am only supposed to use 2 of those right? I was thinking that maybe not having enough shim might be my issue. The only spares I could find were 5x10x0.1 online.

[el guapo]

Originally Posted by BigIreland

Thanks, I'll check the clamps and the shim out. Also, when I was changing the tail shaft, the two shims that go between the hex piece and the pulley according to the instructions need to be 5x10x0.2. I have those in but I am only supposed to use 2 of those right? I was thinking that maybe not having enough shim might be my issue. The only spares I could find were 5x10x0.1 online.

you are supposed to use the number of hub shims that give you the least amount of side to side slop. if you don't have any side to side slop, you might be binding the bearings.

what I do, is I completely assemble the tail onto the boom without the belt. tighten every thing up. then i spin the tail hub, you get a better spin with tail blades on. it should spin for a while. if it doesn't. then start loosening the bolt until you figure out what is binding it.

on some of my logos I couldn't use any shims in the hub.. and had to make the pulley thinner with a file..... but that came back to bite me with my 500. when I put an carbon SE tail on my 500 two shims where not enough. I needed like 8 of them. I used hobbyking 450 pro main shaft shims.

[BigIreland]

Originally Posted by el guapo

you are supposed to use the number of hub shims that give you the least amount of side to side slop. if you don't have any side to side slop, you might be binding the bearings.

what I do, is I completely assemble the tail onto the boom without the belt. tighten every thing up. then i spin the tail hub, you get a better spin with tail blades on. it should spin for a while. if it doesn't. then start loosening the bolt until you figure out what is binding it.

on some of my logos I couldn't use any shims in the hub.. and had to make the pulley thinner with a file..... but that came back to bite me with my 500. when I put an carbon SE tail on my 500 two shims where not enough. I needed like 8 of them. I used hobbyking 450 pro main shaft shims.

I have absolutely zero side slop. In fact, I noticed that the carbon fiber sides look a little warped. Something is definitely up. I'll be taking those shims out one at a time and rechecking it then. Also, I could not find any of the metal tail clamps for the 20mm 500 boom. Do you have a link? Everything I found was for the 600 boom. I took a test flight today with the new tail shaft and it was worse.

[lamk]

I struggled with the 500se vibration for a month. Wasted a lot of good flying time. These are the things that I find that contribute to the vibration.
I think the length of the SE boom make it more prone to vibration c/w a 500 because it's longer and therefore less stiff.
A shorter or a larger diameter boom will be less prone to vibration.
Tail blade balance and quality is critical. Edge main blade are great but there is a batch of really bad tail blade and I did not realize it until I switch to plastic KBDD tail blade after trying two brand new set of edge tail blade to fix the vibration.
The rudder control rod guide position can affect the vibration because the rod will vibrate like a string in a musical instrument and amplify the tail vibration. I move it away from the midpoint and the vibration is significantly less and one can add an extra guide if needed.
Switch to the plastic tail case. I hate the way the plastic clamp for the CF tail work. Once you tighten the clamp the boom is deformed and there is no adjustability after that. Than there is the problem of getting everything square up and to make sure the bearings are not binding etc. etc. "Downgraded" to a plastic tail and no more headache.
So after a month of disassemble reassemble, new parts after new parts(tail shaft, bearing, shims, new boom, new tail assembly) for the CF tail with no success, the fix for my 500se was plastic tail case with new tail shaft and bearing, kbdd blade and move the control rod guide position.
Hope this will help someone.

[BigIreland]

Got mine fixed!!

I think it was the bolt that holds the 2 spacers and the bearing that goes over the belt and pulley. I noticed that I had that one too tight. The spacers were compressed to the point where the carbon sides were looking a bit warped. This is just guess because I tore the damn thing apart at least 12 times. I'm just glad it works!! Now I can fly it!

[lamk]

Nice!!!