Protos 500 - Really bad vibrations!!

[craigjell]

So my protos was working fine a week ago when I decided to change the ESC out. I only removed the side frame to get access then put it back again and now when I spool up, I get such bad vibrations that it makes a loud grinding sound. When I hold it I can feel the vibrations and grinding but can't see anything wrong!

The belt is tight but not overly so, the main shaft feels smooth when rotating by hand, all pulleys are in place and the motor when run on its own sounds fine. The main gear appears a bit wobbly but its flown fine before with the same gear.

What can I check next? Does anyone recognise the sound? Its such a blatant noise I'm convinced its something obvious but no luck so far.

[JoeBailey]

Check the belt on all 4 sides craig, then check how its running through the pulleys at the rear. It should run accross the centre of the pulley. If you havnt done so watch the finless bob vid on setting the belt tensions and spacings both front and rear. Its defo a belt issue.

Check the pulleys are rotating too.

sent from my Samsung tab 3

[craigjell]

Thanks Joe, its running through all pulleys but I'll have another look to ensure its dead centre. The noise and grinding appear to be coming from either the 3rd bearing block or the boom. I've order some of the CNC upgrade pulleys , a new main gear and some bearings for the servo mount blocks so when I fit those, I'll be very careful with the belt placement.

I've not checked out finless bob's video on the protos - I'll make sure I watch it before fitting the new parts.

cheers Craig

[craigjell]

Problem solved, thanks for the help Joe - it was as you said, the belt tension or lack thereof. I honestly didn't think it needed to be THAT tight!! I was in fear of it snapping but, I've just had three absolutely awesome flights on it (VBar Pro) and I'm as happy as a pig in s**t!
Cyclics are fast and sharp, tail locked in, plenty of power - 'oh - its on!!'

cheers Craig

[pgkevet]

was that my imagination or was the bearing crying there?

[Mike Sanders]

I love it when a problem is solved.

[craigjell]

was that my imagination or was the bearing crying there?

I'm not too sure TBH ... The main racket was from the belt/ pinion slipping a tooth but, one of the bearings was a bit notchy so it wasn't helping matters..

[debrooker]

Problem solved, thanks for the help Joe - it was as you said, the belt tension or lack thereof. I honestly didn't think it needed to be THAT tight!! I was in fear of it snapping but, I've just had three absolutely awesome flights on it (VBar Pro) and I'm as happy as a pig in s**t!
Cyclics are fast and sharp, tail locked in, plenty of power - 'oh - its on!!'

the belt does need to be tight and keep an eye on the tail box, mine kept slipping forward and loosening the tension.

Now get it stretched - awesome upgrade for ~£100

[Mikej]

Good news - enjoy it, they're a real hoot

[craigjell]

the belt does need to be tight and keep an eye on the tail box, mine kept slipping forward and loosening the tension.

Now get it stretched - awesome upgrade for ~£100

I've got the tail box bolts nice and tight but yeah, I'll keep a check on the tension. I've been considering the stretch from day one but:
470mm blades are expensive for their size (although I've seen some cheap Chinese carbons for £12.50 a pair on EBay that may be okay)!
Apparently, 3000mAh is about right for CG and extra load but I've recently bought 4x 2650mAh so don't want to fork out for more packs just yet.
I think I'm going to enjoy it for a while then once I've battered my packs I'll go for the stretch and low-rider hub..

[debrooker]

I use 2600 and 2200 packs with my stretch, never noticed any issues due to CG. Also the stretch kit comes with SAB blades in the price.

Anyhow enjoy the model its alot of fun

[MishuPtm]

I had pretty bad vibrations as well, so i gave up on my protos and ordered an align. I'll try to tension the belt as in bob's videos, maybe it's not lost after all...

[craigjell]

I had pretty bad vibrations as well, so i gave up on my protos and ordered an align. I'll try to tension the belt as in bob's videos, maybe it's not lost after all...

Yeah, I know the feeling well! I crashed mine and when I put it back together, the belt skipping was back! I was about ready to bin it but I watched the finless vid again, had one last try and got it
working nicely again. The secret is to have even belt tension at the back and front - tight but not guitar string tight. You can visually see if the belt will skip by turning the head by hand and watching the main
gear - the belt will ride up where theres uneven tension.

Craig