rebuild = vibe on throttle up

[skered53]

impact totaled the frames and the Tarot bottom plate, this time the MX motor actually rubbed off some of the aluminum plate onto the top of the can. rebuild, into a hover just fine, idle up translate into a shimmy on the landing gear. is it possible the motor shaft is tweaked ?
the following were replaced or i installed new
frames, plastic bottom plate , main shaft bearings, boom, TT, front TT gears and bearings, tr hub, tr blades, tr smaller brgs, TT brgs, the TT and the 4 small tr bearings are ceramics, the unbrella gears were Align.
did the shorted the Compass head links thing ( bought the compass 500 links and drilled the mast 7.5 mm shorter) I did use a used main shaft that was straigthened to within .001" ............ MMM, maybe I jsut answered my own question.
Guess I'll bring a new 3G mast to work and drill that 2nd hole tomorrow ( good thing I kept the mast gripping jig )

summary, Which is more likely to cause a langing gear induce shimmy as I bump from 70% to 96% throttle ? a tweaked motor can or a main shaft ??

[Deet]

what didn't you replace?

[Feeback]

You never know what resonance can do sometimes, but to make an effort to answer your question, seems more like the main shaft than the motor to me.

[torpedoarmed]

Back the motor away from the pinion. Spoolup look at the pinion and shaft, see if it is true or maybe bent.
Also if while backed away form teh pinion you can feel maybe a vibe through the frame and stuff, you may have lost a balance weight in the motor housing.
If this is the case, it is time for a new motor.
You may also have ping'd the bearings inside the motor which also could cause a vibe.

[skered53]

installed a new mast tis morning, the issue is still there but maye reduced a little bit.
Will see if the LHS has that hacker motor still, if not then this evening I will install my rebuilt 500M motor.
I'll try backing the motor away from the pinion and look see if i can determine a wobble at the pinion.

Deet, the rotor hed was swapped for a different brand, mast was a used, and the motor had that sudden stoppage, just about every rotating part was changes ( except for the rear unbrella gears and it's 2 brgs)

She sure seems quite after this rebuild, can the ceramic bearings make that difference ? ( 2 on the TT, plus the 4 small ones , 2 at front bevel gear and 2 on the tr drive shaft )

I finally put some 500 sized lg on it

Thanks Guys

[skered53]

two different motors, three different rotor heads on different masts.
LHS suggested diffrent bx tape, i said it was he same, LHS said try a tie wrap, that did it. I also secured all the wires coming out of the BX into their own bundle( mounted on starboard frame) .
Thanks

[Deet]

it won't be the tape

pull the entire tail off the heli, boom block and all and spin it up with no blades

[skered53]

Deet, I did the no blades run up as I was re-building, ran it with tail and tr hub only, no vibes, added main rotor hub, no vibes, added tail blades, no vibe.

I 'll give it a few more flights and keep increasing the idle up %, I think I went up to 91% this morning without issue
If anything comes back, I'll pull the tail as you suggest.

Thanks guys, this beast have been down since I planted it on the 4th ( my Kasama tail hub slung a grip n blade )

[dj80550]

I'm going through the same thing right now, 24 days to be exact. It's becoming a real frustration now. Here is my post on the other site, something might jump at you:

http://rc.runryder.com/helicopter/t700741p1/

[toonttm]

opps

[toonttm]

Originally Posted by dj80550

I'm going through the same thing right now, 24 days to be exact. It's becoming a real frustration now. Here is my post on the other site, something might jump at you:

http://rc.runryder.com/helicopter/t700741p1/

Wow, your problems sound so similar to mine except I have a belt drive. My vibes kick in as soon as I add the tail blades. I'm now investigating around the boom block as like you, everything else is new. If I have any success I'll certainly be posting here.

Since I have had this problem I have noticed a few comments in other threads about people owning 500s and getting an unsolveable vibe problem, as you mention a lot of people just seem to give up.

[torpedoarmed]

Originally Posted by skered53

installed a new mast tis morning, the issue is still there but maye reduced a little bit.
Will see if the LHS has that hacker motor still, if not then this evening I will install my rebuilt 500M motor.
I'll try backing the motor away from the pinion and look see if i can determine a wobble at the pinion.

Deet, the rotor hed was swapped for a different brand, mast was a used, and the motor had that sudden stoppage, just about every rotating part was changes ( except for the rear unbrella gears and it's 2 brgs)

She sure seems quite after this rebuild, can the ceramic bearings make that difference ? ( 2 on the TT, plus the 4 small ones , 2 at front bevel gear and 2 on the tr drive shaft )

I finally put some 500 sized lg on it

Thanks Guys

I didn't determine my motor took a hit till I did as I suggested and backed it from the pinion, when I did an spooled up no blades, the thing vibrated across the floor.

Pulled it apart, the lower bearing (Scorpion 3026/2600) was shot, when I removed the pinion there was drag (bend)

I replaced the shaft, the new one, the pinion slid on no drag and replaced teh bearings. However this did not fix it, it turned out I probably slung a balance weight in the motor because it still vibed across the room, bought a new one and it was cool.