HK 450 MT build Thread.

vinay · February 22, 2010, 03:28:11 PM

No we directly put it in HH mode and took off.

anwar · February 22, 2010, 03:31:01 PM

That should have worked, at least it has in the past whenever I have helped others quickly setup their helis.

vinay · February 22, 2010, 03:32:35 PM

There seems to be a problem with the gyro, Not sure though. I will replace it and update here when I am free.

Quote from: anwar on February 22, 2010, 03:31:01 PM
That should have worked, at least it has in the past whenever I have helped others quickly setup their helis.

This is a cheap HK Gyro not the futaba, so problems may be there.

RotorZone · February 22, 2010, 03:58:01 PM

Quote from: anwar on February 22, 2010, 03:31:01 PM
That should have worked, at least it has in the past whenever I have helped others quickly setup their helis.

Yes, it should have worked. But the symptoms are like the center was not learned correctly. So my thinking to make it learn again and see if that fixes it.

vinay · February 22, 2010, 05:21:10 PM

Voila! Eureka! Found the problem!!!

The radio was acutually mixing Throttle to rudder by 20% ie, revolution mixing was on. I think this might be the issue. I need to disable this right?

gauravag · February 22, 2010, 05:24:49 PM

That is it.
You certainly need to disable that mix !! Great to hear you found out

anwar · February 22, 2010, 05:37:54 PM

Quote from: vinay on February 22, 2010, 05:21:10 PM
The radio was acutually mixing Throttle to rudder by 20% ie, revolution mixing was on. I think this might be the issue. I need to disable this right?

http://www.rcindia.org/helis/thunder-tiger-mini-titan-arf-pro-build/msg13161/#msg13161

I thought you were watching this thread

vinay · February 22, 2010, 05:58:10 PM

I was actually busy with my own thread

Also the revo combined with low head speed was the final issue. Now do I still need to do the Rate mode adjustment or straight away jump to HH?

anwar · February 22, 2010, 06:11:45 PM

The answer to that question is "How lazy are you"

Seriously, it is recommended that you do it rate mode first, but if you want to just test fly it, go with HH. When you get over the excitement

you can always go back and do "The Right Thing (tm)" !

vinay · February 22, 2010, 07:03:47 PM

Its not about laziness, its all about patience

after all, after all that reading, understanding, building, crashing, repairing, Heck lots of sim practice, Headaches of y this is like this, I atleast want to hover my own Heli

My first RC device, that I had been waitiing from since I was in 5th standard. Hope you understand my feelings

anwar · February 22, 2010, 07:21:22 PM

I totally understand

And unless you start doing "tail-out inverted" flights (like "hurricane" maneuvers), you may not even feel the need for doing the rate mode setup first (or course, depending on the gyro capabilities).

vinay · February 22, 2010, 07:27:45 PM

That is probably later

. But first thing is that if the heli flies well, I will ask Rajesh to test fly it in 3D mode. I want to know what the hype is all about the TREX clones and the HK401B Gyro. Also before flying this weekend I will be changing the ESC from TowerPro 40H to the far SUPERIOR Switched BEC Turnigy Plush 40A.

. I still need to solder the XT60 Power Connectors and the 3.5mm bullet connectors to it.

vinay · February 23, 2010, 09:16:55 PM

Oh CRAP!

All this time I was thinking that the HK450 MT was a V1 head. I just removed the head to check for the feathering shaft, and OFFF fell the thrust bearing on the table, I looked up and saw a huge 4mm feathering shaft sitting there.

I Now have 4 3mm feathering shaft with me ordered from Hobby City thinking my Heli had a v1 Head.

Luckily the feathering shaft is not bent at all! I put it back using blue locktite. Time to order from EBAY

anwar · February 23, 2010, 09:21:45 PM

Those rubber dampers on the feathering shaft are critical to blade tracking. Since you had problems with tracking, that is one thing you should pay attention to while you are re-assembling that area.

vinay · February 23, 2010, 09:37:58 PM

Just checked the TREX V2 head diagram. They go inside the head. I think there will be 4 of them, 2 on each side Correct? How to check if they are bad? Will they be loose?

http://www.completeheli.com/T-Rex-450SE-V2-Rotorhead-Assembly-Parts

I believe number 5 is the damper O rings?

Apart from warped Blades, Does bad tracking means different pitch on each blades?

vinay · February 23, 2010, 10:28:56 PM

Even if they were loose, I dont have spare dampers, I have v1 dampers only. Have to order.

anwar · February 23, 2010, 10:30:58 PM

Right, two on each side (Align part # HH2018). This is the one where I was saying that you can temporarily get away with cutting small pieces of glow fuel tubing.

If they are not worn out or missing, then you will not be able to "tilt" the blades inside the head, and they will be a "snug" fit. They tend to loosen after many flights.

The common solution to blade tracking is to adjust the small linkage that connects the main blade holder to the see-saw arm below. Obviously, this can result in slightly different main blade pitch between the two blades. In such cases, better tracking has more value than exact same pitch on both blades. It is rare that you run into this though, as it is really an indication of either some bent parts or warped blades or linkage rods not being symmetrical (in length).

vinay · February 23, 2010, 10:33:02 PM

F shaft not bent. dampers are snug fit.

So blades are bad.

vinay · February 23, 2010, 10:36:04 PM

Anwar, when tightening the screws of the feathering shaft, I tightened them FULLY with loctite(blue). Now when I rotate the blade holder, w/o connecting the ball links, they are not as smooth as before. its very slightly clicky. I mean its very slight, i can only feel it. did I over tightened it?

EDIT: Also are these the right part?

http://www.helipross.com/align-t-rex-450-drive-belt-xl-ht1003-1.html
http://www.helipross.com/align-t-rex-450-feathering-shaft-hs1251.html
http://www.helipross.com/align-t-rex-450-f3-8m-thrust-bearing-hs1268.html
http://www.helipross.com/align-t-rex-450-damper-rubber-set-hs1266.html

anwar · February 23, 2010, 11:11:33 PM

We all tighten the feather shafts pretty well with blue loctite, as we don't want the main blades to shoot off like arrows in flight

If you are feeling "clicky" movements, that would *typically* point to bad/worn bearings in the main blade holder (those would be parts numbered 10 and 11 in the picture you posted above). I would say continue flying it until you have some more/real reason to investigate further.

Yes, these are the right parts.

vinay · February 23, 2010, 11:13:20 PM

ok, I will order tomorrow then, Helipross is cheaper compared to other, including the expensive ems shipping.

vinay · February 24, 2010, 08:17:01 AM

Is there any alternative for this you guys use at the club? They are pretty expensive stuff.

http://www.helipross.com/align-t-rex-450-anti-rotation-bracket-spacer-hs1232-1.html

anwar · February 24, 2010, 09:10:03 AM

You will have to find cheaper sources, does HC not have them ?

BTW, why are you getting spare ones ? Typically you do not have to remove them when you want to remove the head ! Just pull the swash all the way to the top manually (like you are at maximum pitch), slightly bend the top of the anti-rotation bracket backwards (away from the main shaft), and the long ball link on the swash can be pulled out of the anti-rotation bracket. I never had to remove this part unless I was changing the frame itself !

vinay · February 24, 2010, 11:24:38 AM

I think the ones on the right side of the pics are used to hold the servos in place. Its like the nuts for the servo screws. not sure what anti rotation brackets are.

vinay · February 26, 2010, 09:03:03 AM

Anwar, How long before helipross ships?

I booked on 24th night.

Current Status: Processed.

Looks like HeliDirect had faster processing time of just 6 hrs

but way too expensive.