RunRyder - Oscillation in My Tail Rotor

rrTV-PHOTO

New HD TV

HOME rrTV-PHOTO GALLERIES MY GALLERY HELP-FAQ

myHOME PM pmRR MEMBERS 680 ONLINE 29 EVENTS SEARCH REGISTER START HERE

1 page

454 views

POST REPLY

GrandRC	.	CanoMod	.	Futaba-RC
	.		.

e-Century Hummingbird - Swift > Oscillation in My Tail Rotor

LJS
Veteran
Location: Minnesota, USA

Hi All,

I was just dialing my Swift in this weekend after making some modifications to it over the winter (aluminum head block, BEC, new bearings). As part of my maintenance, I picked up some new tail rotor grips. However, when I put them on, I found that they bound. So I had to reuse the old ones.

Anyway, the bottom line is that I now have an up and down oscillation in the tail rotor. What are some possible causes of a vertical oscillation? I really ought to try another set of tail grips. There is also the possibility that I had just one of the tail blades too tight.

Your help is appreciated.

LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-03-2008 03:34 AM

coolice
Key Veteran
Location: Northamptonshire, England

Hey LJS,

Normally an up & down oscilation of the tail rotor points to something being out of balance that is rotating, in this case the main rotor or tail rotor.
As you have had both apart this stands to reason that there could be an issue with one or the other.

Up front a classic mistake could be a mis-aligned flybar, I know when I re-assembled mine wrong it produced a shimmy on the model in flight from side to side ratehr than up & down on the tail rotor.

You mention your tail blades and one being tight, this could also effect the balance if it cannot fully straighten out though the centrefugal(spelling?) force of it rotating.

I'd check the main & tail rotors first to eliminate them before looking elsewhere.
.

Ian Contessa
Team Robbe SchluterUK

03-03-2008 11:33 AM

HOMEPAGE

LJS
Veteran
Location: Minnesota, USA

Hi All,

I can't figure out what it is. It was silky smooth before I put the new aluminum headblock in. That's the only thing that I changed. Well, that and increasing the headspeed by about 80 rpm (it's now 2100).

Coolice, I checked the flybar with a dial caliper. It is dead on in terms of alignment.

Could the aluminum headblock be the cause of my problem? I haven't been too impressed with the quality of Century parts lately.

Thanks,

LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-08-2008 08:41 PM

coolice
Key Veteran
Location: Northamptonshire, England

Hey,

It's not out of the question that you could have a wrongly machined head block, hence then have a symmetry issue somewhere in either the mainshaft mounting or feathering spindle/blade grip area.
But I dont think that will be your problem.

I seem to recall reading some had problems with the clamping facility of the head block, more precisely if it wasn't nipped up just right then the block is held offline. However I cant recall a topic or thread to revert back to so we can clarify this.
My head block has been fine, I literally just fitted it and have not had any issues so perhaps I was lucky in the way I fitted it.

I would suggest perhaps removing the whole head assembly and re-fitting it to the model 180 degree's to the orientation it is now and trying again. Remove the jesus(Head) bolt and loosen the clamping and rotate the head 180 degree's on the mainshaft and re-fit/tighten the clamping and try flying the model again.

Just as a matter of interest where are your boom steadies mounted, to the under carriage or main frames?
This is another idea as the head speed has now risen then the U/C could be resonating and in turn transfering any vibes to the tail boom.

Also your belt tension, is it slack, tight or inbetween? Another option is to alter the tension and try again.

Tail blade balance is another area to check as well before looking more indepth at the mechanics, to rule this out first.
.

Ian Contessa
Team Robbe SchluterUK

03-08-2008 11:17 PM

HOMEPAGE

LJS
Veteran
Location: Minnesota, USA

Thanks Ian. I'll check those things out.

LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-09-2008 06:54 AM

LJS
Veteran
Location: Minnesota, USA

Hi All,

I flew the Swift again today trying to isolate the cause of the shake. The skids were shaking a bit as well as the tail, so I was beginning to think that it might be the new metal head that I put in. However, by the end of the flight it had smoothened out quite a bit. I'm beginning to think that it might have been the new dampers that I put in.

I'm going to fly it some more and see if the shake goes away. It was silky smooth before the head work.

Keep 'em flying.

LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-16-2008 04:23 AM

coolice
Key Veteran
Location: Northamptonshire, England

Hey,

Ah brillaint, you may have figured out the problem and it's certainly possible the cause is the new tight dampers.

Keep us informed of how you get on as more flight time is put on them.
.

Ian Contessa
Team Robbe SchluterUK

03-16-2008 12:08 PM

HOMEPAGE

LJS
Veteran
Location: Minnesota, USA

Hi Coolice,

It must have been the dampeners, because she was silky smooth today. And what a rocket it is too. I upped the headspeed to 2100 and she is really flying fast. Seemed crisp in the maneuvers too.

I'm liking her quite a bit right now. She's going to be a good workhorse that helps me learn inverted, backwards, and inverted backwards.

Oh, another pleasant surprise is that I'm still getting 6 minute flights with the 2100 headspeed.

Keep 'em flying.

LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-17-2008 03:10 AM

coolice
Key Veteran
Location: Northamptonshire, England

Hey LJS,

I'm glad your now sorted mate, whenever a model developes an issue after adding upgrades it's sometimes difficult to find the cause of the problem but it can just be until things have bedded in as in your case.

I have always found the Swift goes much better above 2000rpm, my own is running between 2100~2200 using a 6s LiPo, 600+ motor & 550 mains.
At higher RPM's while the model is more responsive it's not twitchy at all, but is so much more stable as well and copes with strong winds very well.

It's good you can now tear up the sky and enjoy the model while learning new manouvers. Let us know how you progress.

Chat soon dude.
.

Ian Contessa
Team Robbe SchluterUK

03-17-2008 12:05 PM

HOMEPAGE

LJS
Veteran
Location: Minnesota, USA

Hi All,

Turns out it wasn't the dampeners. But I did finally find the problem. I got to measuring the new head block I put on and it was .005" out. The hole for the main shaft wasn't machined in the center of the part. It makes sense that it was the head block because aside from tail grips, it was the only new part on the machine. Last year it was fine.

I called and told Joe at Century about it. He wouldn't send me a new one unless I paid for it -- so I did. Put the new one on and it's smooth as silk.

That's three things I put on this winter and none of the parts fit:
- tail grips: bound when tightened
- another set of tail grips: bound when tightened
- head block: grips bound when tightened. Had to file down both brass spacers to .084". Then the heli vibrated when I flew it.

- new head block: Oh yeah, this one fit! So the spacers I filed down had to be replaced. Joe didn't send me those so I had to make a trip to my LHS. Luckily they had it in stock. But finally that headblock worked and is smooth as silk.

I won't buy another Century heli. Their poor parts quality and customer service are too much for me. When Align has problems, they get them fixed. When Century has problems they leave it up to the customer to fend for themselves. It's too bad. I really liked my Swift.

Keep 'em flying.

LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-27-2008 02:08 PM

laughingstill
Key Veteran
Location: Gainesville, Fl, USA

You call Century back and talk to the manager not Joe. If that does not suffice, then talk to his manger and so on until you are completely satisfied. That is a horrible example of customer service and you should not have to stand for it.....Ron

3DMP-E, Logo 6003D, Logo103D Carbon and Trex 450se Flyin Firefighter

03-27-2008 02:26 PM

coolice
Key Veteran
Location: Northamptonshire, England

Hey LJS,

I'm so sorry mate you got treated a little badly in this case.
Ok I can see the whole "pay for the new block and then be re-embursed when your old one is returned" but that could be said in the phone call.

Topic will be highlighted on the Private forum and I will ask that you get an appology as we'd obviosuly like to keep your custom.
.

Ian Contessa
Team Robbe SchluterUK

03-27-2008 03:23 PM

HOMEPAGE

Century Heli
Senior Heliman
Location: CA. USA

Hello LJS:

I would like to first apologize for any issues you've had with your Swift. The Swift was designed to be an easy to maintain helicopter with very competitively priced replacement parts. In regards to your headblock, the standard policy for a defective item claim is as follows:

1) Ship the item back for inspection. If the item is deemed defective, a replacement will be sent. This is the slower process.

2) If the item is urgently needed, a cross shipment can be initiated. This means we send you the item and it is charged for. The customer then sends the defective item at the same time back to us. Upon receipt, the item is inspected. If deemed defective, a refund will be applied for the replacement. This is the faster process.

These are the standard procedures. Of course if there are any special circumstances, the rules can be bent but that is dependent upon a manager's approval.

In the case of the tail blade grips, we have found that if the steps of assembly are not followed exactly and a washer or spacer is missing, the tail blade grips can bind. I don't know how you assembled your tail blade grips but without inspecting them, we don't have an answer for the binding issues. If you like we can inspect these for you to determine what could possibly be the issue. If you require anything else, please call in and talk to me personally. I'm sure I'll be able to help you.

Thanks,
-Paul
Manager
Century Helicopter Products

03-27-2008 06:34 PM

LJS
Veteran
Location: Minnesota, USA

Hi Paul,

I'm glad you brought the tail grips up. I paid for those in good faith thinking they would fit. They did not. I didn't ask you to send them to me and then I'd pay if they'd work like you did to me. I bought two sets and ate the cost of both.

I know about the spacers. I also know that in my Swift manual it says those spacers are included with the tail grips. They should be. But they are not.

The bottom line is that I don't have the time or patience to screw around with your system where parts don't fit, and I'm supposed to send them in and maybe get credit and maybe not. You had me pay for shipping out twice, want me to pay for shipping back on a $25 dollar part. That's $15 in shipping. And then when your guy sends me the part at my expense, he doesn't bother telling me that the spacers I had to file down to make the first one fit will no longer work.

I put three sets of parts on my Swift this winter. None of them fit. You're batting 1000.

Someone in your organization knows what they're doing because I've gotten 380 flights out of my Swift. But your aftermarket support is horrendous and I'm done with you.

Thanks anyway.
LJS

600E, 1910 1Y, 8S FP4270, GY611
600N, OS50 Hyper, GY611
Logo 5003D, 600+, 6S TP 5000, DS760

03-27-2008 06:50 PM

Century Heli
Senior Heliman
Location: CA. USA

Hello LJS,

If you had sent back your headblock with a valid Return Authorization number, there should be no problem in getting funds back for the part. This isn't a questionable issue. We haven't had any claims for off center headblocks that I know of so we would really like to compare our it to our current stock and to prevent the issue on future production runs. I don't know what your conversation with Joe consisted of but if you had told him you may need new blade grip spacers, I'm sure he would have included them in your package at no extra charge. As for the tail blade grips, if you could get those back to us, we would like to inspect them. We haven't had an issue with the tail blade grips until you've brought this up. That is why we would like those back for inspection, not only for your sake but also for the sake of the rest of the replacement parts that are on the shelves of various hobby shops and for future production runs. There would be no out of pocket expense from you for this as I can get a call tag out and have UPS pick these up from you. We're trying to work with you and provide the help that you need.

03-27-2008 07:51 PM

1 page

454 views

POST REPLY

A Main Hobbies	.	Boca Bearings	.	Modefo's RC Helicopters
	.		.

e-Century Hummingbird - Swift > Oscillation in My Tail Rotor

UPDATE SCREEN PRINT TOPIC

Advertisers

Subscribe to This Topic