Help! My Mini Titan is bucking like a Bronco!

[Cloud Cruiser]

I bought this MT used and abused. I have changed the main shaft and feathering shaft. It has a full metal head and swash by Kasama. It has a Futaba 401/s9650 on the tail, and i have experimented with the gain control. I have changed the Dampers, and adjusted belt tension, and changed tail blades. But I still have an intermittent problem that shows up as a tail wag and then the tail starts to buck up and down like a bucking bronco! Can someone make some suggestions as to what I should do next, short of putting it out of "my Misery!" "LOL"

Thanks

Robert

[RMG2]

I bought this MT used and abused. I have changed the main shaft and feathering shaft. It has a full metal head and swash by Kasama. It has a Futaba 401/s9650 on the tail, and i have experimented with the gain control. I have changed the Dampers, and adjusted belt tension, and changed tail blades. But I still have an intermittent problem that shows up as a tail wag and then the tail starts to buck up and down like a bucking bronco! Can someone make some suggestions as to what I should do next, short of putting it out of "my Misery!" "LOL"

Thanks

Robert

Belt skipping on the sprockets??? That was the first thing that crossed my mind???

Whatever it is, it will likely be something simple, but sometimes hard to find:confused:

When ya find the issue please share it to expand our MT knowledge base.

[rotorhead58d]

check the tail shaft bearings. they may be starting to go. sounds like it's binding up.

[Cloud Cruiser]

Ok, I'm in the process of tearing it down now. So strange the way it acts. One minute its fine, the next it's doing a basketball impression. I'll check all the bearings while its apart. Any suggestions as to how to get the bearings out of the kasama blade grips?

Robert

[paintballkidz]

bobing can be a sign of low head speed?

[rotorhead58d]

Ok, I'm in the process of tearing it down now. So strange the way it acts. One minute its fine, the next it's doing a basketball impression. I'll check all the bearings while its apart. Any suggestions as to how to get the bearings out of the kasama blade grips?

Robert

put them in the oven for about 20 minutes on 200 degrees. they should slip out easily.

[Cloud Cruiser]

bobing can be a sign of low head speed?


Hi Paintballkidz, My head speed in normal is 2860 rpm, 3150 idle up 1, and 3450 in idle up 2. I remember reading about your MT have some similar problems. Did you ever get that figured out?

Robert

[Cloud Cruiser]

put them in the oven for about 20 minutes on 200 degrees. they should slip out easily.


Thanks Rotorhead58d, Will there be any o-rings or spacers between the bearings in the grips?

Robert

[paintballkidz]

Wierd, it was because my head speed was low

[rotorhead58d]

Thanks Rotorhead58d, Will there be any o-rings or spacers between the bearings in the grips?

Robert

you should watch some of finless bob's build videos for this head. they are on his page.

there will be a 3 piece thrust bearing that will be loose inside, and there may be a spacer. i'm not sure. it's all loose in between the bearings.

[chopchopchop]

I bought this MT used and abused. I have changed the main shaft and feathering shaft. It has a full metal head and swash by Kasama. It has a Futaba 401/s9650 on the tail, and i have experimented with the gain control. I have changed the Dampers, and adjusted belt tension, and changed tail blades. But I still have an intermittent problem that shows up as a tail wag and then the tail starts to buck up and down like a bucking bronco! Can someone make some suggestions as to what I should do next, short of putting it out of "my Misery!" "LOL"

Thanks

Robert
Dude - have previously had a similar problem - ended with a bang but the problem was with the tail rotor shaft. If you have the plastic one check that the holding pin is seated in the grove properly, mine (brand new) had a faulty groove. She held in normal but when flicked to flight mode - the higher rpm then makes the tail rotor slip.

good luck - PS replaced with metal tail rotor shaft = no problembo !!!

[Cloud Cruiser]

Thanks Rotorhead and ChopChop. I'm looking for the video now and will also check the gear on the tail shaft.

Robert

[rotorhead58d]

http://www.helifreak.com/showthread.php?t=37732&page=7

i know these are for the bigger rappy's, but it will show you the basics

[Cloud Cruiser]

Thanks Rotorhead.

Update, I just tried another esc. I thought maybe mine was suspect! Wrong, Still does the same thing. I have some parts ordered, and should get them wednesday or thursday!

The quest continues!

Robert

[rotorhead58d]

have you checked your mainshaft for straightness?

[Cloud Cruiser]

Here's the latest. I received some new parts today. New gyro, stock blade grips and bearings. I'll post back saturday to update the effects these new parts have on the problem.

Robert

[Cloud Cruiser]

Well I just got back from flying the Mini Titan. Things went much better this time around. I changed so many things last night,so I'm not sure which one thing or combination of things solved the problem. I'm going to list everything I've done to resolve the problem.

Flybar
Main Shaft
Feathering Shaft
Tail Shaft and gear
Main Gear
One-way clutch
ESC
Gyro
Tail Blades
Main Blades
Bearings thru-out
Then I took the Kasama Head off and replaced it with a stock head. My intentions were to just change the Grips, but the Kasama head is about 2mm shorter, and the stock grips would not tighten due to the Feathering shaft being to long.
After all this and basically buying two Mini Titans, She's not a Bucking bronco anymore. :thumbup:

Robert