Swash Tilting Backwards

[smsodhi]

I recently had a large crash in my 600pro. I have rebuilt it and changed the whole tail assembly, boom, torque tube, front torque tube gear box, mainshaft and bearings, put a new dfc head on it. new torque tube gears, autorotn gears, L mainframe.
I test flew it and on switching from normal to idle 1 and 2 the heli tilted backwards.
I bench tested it today and the vibes were around 1400 at normal and the swash tilted backwards, on switching to idle 1 and 2 vibes reduced to around 400 swash leveled off, I know this is the opposite of what happened inflight, maybe i got confused at the field.

Any way, is the tilting due to the raised vibrations, and as I have virtualy rebuilt the heli with all new bearings , could it be the motor causing the vibes and then the vibes causing the swah to tilt backwards?
Thanks for any help

[smsodhi]

Checked the motor bearings, they are OK.
I guess all I want to know is will a vibration level of around 1400 cause the swash to tilt backwards?
Something is causing a vibration at lower RPM which reduces at the higher RPM

[TdB]

Main blades balanced? Tail blades balanced? Tail hub bent? (had a bent tail hub on a 450, replaced a lot before I found that one).

Tim

[smsodhi]

I have bench tested without the blades on and am getting these readings. The tail rotor hub is OK, but I will spool her up without the tail rotor on and see if it makes a difference . Thanks

[smsodhi]

Removed the tail, still vibrates, removed the main gear and still vibrates. So must be the motor I checked the bearings and they seem fine. The motor is now running hotter than before.
Time to get a new motor

[TdB]

Can you post your log and some pictures of the sensor mounting?

Tim

[markleyland]

If you are positive all your bearings are good in the tail case, rotor hub, TT, head, main shaft, and that none of the shafts are even slightly bent and both main and tail blades are balanced, try using different mounting tape! The motor is probably hotter on the bench because it's not under load. You already said the motor bearings are fine so you can count them out and you would probably be able to hear it if they were shot away.

Good luck mate, don't rush into buying a new motor just yet, unless it's an Align then just sling it (joke).

[smsodhi]

I have replaced all that has been mentioned. Was a bad crash. All shafts changed, new torque tube , new tail rotor housing new tail rotor shaft, changed main shaft bearings, new DFC head. new feathering spindle. I spooled her up with main gear removed isolating the motor and was getting the same vibrations, at normal 1400, swash tilts backwards, idle 1 and 2 vibrations drop to 600 and 400 respectivly and swash levels off.
I have just assumed the motor must be vibrating as this is the only thing on the heli moving now.
I have ordered another 600mx from fast lad, got their last one.Will try it tomorrow and let you know. Was so tempted to get the KDE motor, but resisted.
Thanks.

[markleyland]

Thinking about it I've read the Align M - MX motors produce a high level of vibration but nothing that you should be able to solve with the right mounting tape. Use a Spartan plate if you have to.

[smsodhi]

I just got my new 600MX motor and the max vibes I get now are 300
No more tilting of the swash now. Also the vibes go up from normal to idle1 then idle 2 as would be expected, Not the other way round as before.

So Tim and Markleyland a big thank you for your support.

I think next time I have a big crash like this I will get the kit. It will be cheaper!!

[markleyland]

Glad you got it sorted