OK, I looked in my parts bin and found a complete HK450V2 tail assembly, so I just used that. It is much better and much smoother. The tail is not binding anymore and the gyro seems to be holding. I only tested it very shortly, I have much tweaking to do and want to mount main blades and test it with that, but the original V1 plastic tail blade grips had brass bushings in it while the HK450 tail unit had full ball bearings. Those $9 kits are not worth it. The cheapest anyone should go is an HK450GT. Now, I have a tail wobble, some of it I cured with a little bit of delay for my slow analog servo. the rest is vibration. Should my tail blades be loose or snug?

Originally Posted by shahram72

OK, I looked in my parts bin and found a complete HK450V2 tail assembly, so I just used that. It is much better and much smoother. The tail is not binding anymore and the gyro seems to be holding. I only tested it very shortly, I have much tweaking to do and want to mount main blades and test it with that, but the original V1 plastic tail blade grips had brass bushings in it while the HK450 tail unit had full ball bearings. Those $9 kits are not worth it. The cheapest anyone should go is an HK450GT. Now, I have a tail wobble, some of it I cured with a little bit of delay for my slow analog servo. the rest is vibration. Should my tail blades be loose or snug?

Well, that tail spins at about 15000rpm, maybe more - that's 250 rotations per second! Holy crap... (Did I do that math right? Jeez...)

SO, a minor thing can really be a problem on the tail - that's why it's often the hardest part to get right, and the variability it causes is the reason for gyros in the first place. The gyro is there to correct for minor issues due to that high speed and extreme sensitivity - a human just can't control a thing like that, at least not very well.

I mention that because the rest of the answer is basically yes to everything. Balance of the blades, tension on the blades, play in the linkage and servo, play in the servo mount (you mentioned), slow servos, belt irregularities or bad tension, wobbly gears, vibrations, friction in the mechanics/linkage... all of that and a lot more contributes to tail performance. Do your best to get all of it right. I tension my tail blades so they don't flop around but only a tiny bit tighter than that - at 250 hertz, they can be kinda tight and will pull out straight just fine. Don't get them too tight though because they need to be able to lead and lag a bit - that's a whole 'nother post really

Thanks jasmine, you've been a great help. I learned something today. Hopefully I will be able to tweak it good enough to fly. Eventually the head will be changed out to a nice V2 purple one I have and maybe this platform can go in my scale MD500 body. Let's get it airborne first. Tomorrow I will work on repairing my crashed Hausler 450 V2 which needs a new main gear and feathering shaft maybe (those V2 shafts are thicker) The blades look OK, can I reuse them?

mmmm.... it's a judgement call really. I don't re-use blades that have been crashed, but sometimes it's probably ok. CF blades can develop micro-cracks you can't see and that can cause unexpected failures - uh... the blade explodes. So, I don't use them again but I know people who do.

Just wanted to pop back in to say thanks for the advice given. I moved the balljoint in a little on the servo horn and adjusted my hover pitch to give higher head speed and after about 5 flights today I can confirm I'm no longer suffering the wag or lack of authority.

It's also helped reduce the amount of drift in hovering. It's not completely gone but its very manageable

Now I just need the wind to stop gusting (0-25kph!) and I might get a chance to try a real lift inverted hover!

Thanks!

No problem - you keep sending me Dr. Who and I'll keep sending helicopter advice

The internet is awesome

Well, it's been going a long time now, I doubt it will get canned anytime soon. On the same note, keep family guy coming our way

Incidentally, after I posted this I took it back out as the wind had died down and binned it on the second battery tail span 270 degrees, then I corrected it wrong and in she went from about 8feet.

Ordered a full 450GT v2 kit as they have it in the Uk warehouse. It seems mine was a bit of a v1/v2 hybrid.

The tail lost control by itself? What all are you running on it now? Don't feel too bad, I crash almost every time when my helicopter does something I didn't command, unless I have lots of room to recover. I have the HK450 Pro GT... it's all "pro" frame and everything, did you order that or the old style with four frames? Reason I ask is because I think the Pro is way better quality - but it's not compatible with the old ones for the most part.

Yeah, I know it sounds odd but the tail span its self. I'd be inclined to think its the gyro.

Still using the Esky kit while I wait for the orangeRx receivers to turn up. Acer-lab D12-MG servos on everything. Looking to get a spartan quark gyro when funds allow.

I ordere the regular 4 piece version as it shares parts with my current one. I might opt for the Pro next time if its much better? Main reason I didn't is its not all CF and alloy like the other one....

Ryan

EDIT: this is the one I went for.. http://www.hobbyking.com/hobbyking/s...x_Compat_.html

This one is metal and CF where it counts...
http://www.hobbyking.com/hobbyking/s...x_Compat_.html

Seems to be decent quality also, but I had to change a few things on it.

Torque tubes put me off a bit, how do you find them?

Also, what did you replace on it? If I go for one next time ill order the additional parts at the same time.

Noticed these are also out of stock which would meant more time not flying

Originally Posted by bulldog5046

Torque tubes put me off a bit, how do you find them?

Also, what did you replace on it? If I go for one next time ill order the additional parts at the same time.

Noticed these are also out of stock which would meant more time not flying

It flew good with the stock stuff but it was very loud with a lot of vibrations. So, I replaced the boom and torque tube with Align parts, and I replaced the main gear also. It still shakes a lot though, so I may replace all the bearings too. The torque tube is a good design, it's just not as durable as the belt.

This is before any of the replacement parts, and you can hear how loud it is, but it flies ok.

HK-450 Pro GT Demo (4 min 22 sec)