TDR strange sound...

[bullet3030]

I have a strange sound problem with my new TDR. I have like 3 flights on the bird and im now seaching what this sound could be..

In normal mode it's not there only when I give up or down.. but in idle(hs arround 1700) it's there all the time.


What did I allready do to find this problem;

I did a bench test today without the main head to see if i can track this sound, but it wasn't there.

Allready checked the main and intermediate shaft but nothing strange there.
I did try some different spacers to see if this would help with like 0.1mm play or no play at all but no effect.

Repositioned the TT bearings.... no effect.

I removed the motor/crocomount (pyro 700-52 woh edition) with pinion and changed the spacer for a thicker one so the pinion would come down a bit just to see if somethings would change but it did not

I also spooled up the motor appart from the heli but cound't really here strange things there also..

I'm suspecting the motor or related with the crocomount ore some bearing.

I got no vibes or what so ever and everything's really smooth.It flighs like a dream but this sound is keeping me from al the fun.

Here is a test video i did yesterday switching between hs you can here this higher sound comming up.

[ame]http://www.youtube.com/watch?v=646j0IuyzCg[/ame]

[Egroeg]

Your TDR sounds more than healthy.
If you are referring to that characteristic sound...I know what you mean...mine does that too.
It's just the resonating frequencies of the mechanical parts working in harmony....especially the power system trying to keep the head speed steady.
It's a very characteristic sound on the TDR SOUND MACHINE

[DT75]

Sounds like motor noise to me. Reminds me of electrical interference noise.

[bullet3030]

Originally Posted by Egroeg

Your TDR sounds more than healthy.
If you are referring to that characteristic sound...I know what you mean...mine does that too.
It's just the resonating frequencies of the mechanical parts working in harmony....especially the power system trying to keep the head speed steady.
It's a very characteristic sound on the TDR SOUND MACHINE

You really think this Hi scratsching sound is normall?? I never heard a TDR make a sound like this..and it really worry's me.

If you ever have a video of your TDR making this sound please let me know!

[Egroeg]

Forgive my ignorance....but mine sounds very much the same as yours while hovering and moving the collective up and down.
The sound changes on higher rpm.
2 years now pyro/ jive 120 ... No problems!
Unless of course you have a bad bearing or something.

[Groucho_]

I can't make out any scratching noise from the video...

Sounds more or less like every other TDR video on youtube.

Still, you know what sound it used to make before, and what sound it's making now.

Also that canopy seems to have been designed to amplify any sounds coming from within...

[bullet3030]

I'm just back from another test flight.I mounted the CB this time to see if this helps and it sheems like this sound get's more stable now.. Not really know how to explaine.I did not really know what a TDR sounded like but I sheen allot of movies on yt and a fellow owner pointing me on my video about this sound I had.It's not that this sounds like a normall mechanical sound maybe some would notice it or some won't, but to my ears it's not normal.I also think that if it is a mechanical sound that it migh be amplified bij the crocofence ??

I did not installed the CB before because with this type of pyro it's not a must according to the seller.

I did also see a little shake on low HS but maybe this is because of the white dampers.

Maybe ill give it a couple of flights to see what happens.I hope the CB dousn't apply to mutch heat.

guess ill be checking thing more frequently.

[CyprusFlyer]

Agree, sounds normal just watched a video of mine and no different, I found that the Pyro does emit some very high frequency sounds at certain speeds even when spooled up out of mesh. I thought it might be the centrifugal cooling fan on the motor.

[jhunter]

What is so special about that pyro? You want to use the cb on all pyro's because of their smaller bearing.

[bullet3030]

it's got an extra bearing inside..and is rewounded by hand.

[ChrisH]

Mine got a lot quieter when I greased all of the gears, did you do this? Also, what happens if you go above the screechy rpm ... Does the noise go away or get louder?

Of note, my buddy's TDR with Pyro was louder than mine with 4525...

[bullet3030]

I only greased the main and itermediate gears but that got all messy although i did just a little... don't know if i will do that again.I will try a higher RPM to see what happens.

[Egroeg]

You need the counter bearing in all TDR s in my opinion...because it stops the axial play since gears are slanted.

[kimmik]

But the pinion is mounted right at the base of the motor shaft, so shaft flex should be negligible. With the oversized bearings on scorpion I think it's reasonable to follow Jan's recommendation not to use counterbearing

[Mercuriell]

I think I know what you mean - a high pitched sound like a dentil drill - I have had this on the Kasama Faifa while the pinion gear on the TT beds into the crown gear. I think it is the pinion mating with the 1st stage gear - try putting some grease on see if it changes the sound. I don't think it is of concern. Be careful shimming up the pinion - quickest way to destroy the bearings on the Pyro is to preload them - I don't use any shims at all and make sure there is a gap between the motor and pinion ~0.3mm

[AcidDrink]

I am no expert but it does sound all right to me. high pitch sound comes from the motor most likely.

[bullet3030]

Yes it's definitely that sound!!..

Thanks guys that eases my mind.. I really really did a carefull job on installing all this. Now I installed the CB also with a minor play between pinion and CB like Jan said in the manual with selecting the exact shims.Also the pinion is at the perfect hight when looking at the gears

I just don't think there is anny play between the motor bearing and pinion but I dont think there is anny preload also. If I would move the pinion down a bit the shim wil vib between the motorbearing and the pinion I think so removing that shim would be the only option then ?

It does all get some extra heat so making a hole in the canopy will be my next job.

[ZuvieleTeile]

@Bullet3030
I don't want to be picky here, but please refer to the German version of Jan's manual.
Being Hollandian, there is a good chance, that you might be able to read it.

Jan refers to the minor play between the Pinion and the CB only BEFORE tightening the mounting screws. ( This does not come to light in the english version)
This prevents preloading the CB.
Since the pinion gets pulled out by the helical gear, it is desirable to have the CB carrying the axial load and not the small bottom bearing of the Pyro (bottom = opposite of pinion)

In case the bearing has to be exchanged lateron it is much easier to do that on the CB.

[donskills]

Originally Posted by bullet3030

I only greased the main and itermediate gears but that got all messy although i did just a little... don't know if i will do that again.I will try a higher RPM to see what happens.

Just my two cents but, IMHO Jan is if not the finest, definitely top 5 heli designers in the world today. The simplicity and function of his design to prove advice's to grease the gears regularly. I think that is one good idea to follow. I have and will on all my future helis do just that. I am not aware of too many high performance mechanical devices that don't rely on proper lubrication.
Again, just my two!!

[bullet3030]

Oke I will check it aigain and just move the pinion down a bit so there is some minor room between the motorbearing and pinion.

So do I remove that shim then on just leave it in?

I will alway's go for a specialists opinion like I did in the first place to grease the gears.
The only thing I hate is dirt everywhere and that's what happend allthoug I just used a tiny bid.
So this wil have like a opposite affect you should say.