HK 450 MT build Thread.

[vinay]

Ok, My HK450 MT was always drifting. I was very confused. I always suspected the heat and vibrations So I went ahead with the Anti-Vibration mod to the HK401B to avoid the slight drift.

The link explaining the mod is given below.

http://sergio.salvi.ca/2009/10/18/mystery-gyro-g401b-modifications/?src=hk


There is a slight modifications though. I applied hot glue on the boards that are perpendicular so that they wont break. But did not apply hot glue on all four side to stick the board to the plastic as explained in the above link.

I just Inserted the circuit back and stuffed in a lot of sponge.

There was a hard foam at the base of the Gyro cap that was holding the circuit in place. I removed that.

Then I finally used the Hobbico latex foam receiver wrapper to hold the circuit in place. It was a nice tight soft fit.

TO avoid the burning 40 degree C sun. I covered the Gyro with a white card board.

And I used 2 layers of tape to mount the Gyro.

Results? I flew the heli in tail in - nose right - nose left and did a couple of 8s at slow speed and high speed.   ROCK SOLID.

The heli some times when I change battery still drifts. In such case I have to switch the rate-HH switch thrice and it again works.

OK Photos explain everything.

Finished 7 packs and I wanted to fly more 

[vinay]

Guys,

Since I get only sundays for me to fly. Did 6 battery packs yesterday. I was still hesitent to remove the training gear, so went ahead with it and did some hovering, bascically nose left/right/in. I was able to bring the heli almost close to me on the nose in hovering and land it(with training gear of course.)

After some good practice and fast and slow 8s and some stall turns, decided to remove the the training gear for the last battery pack. I was a bit nervous but went on with it. Successfully did three 8s and back to the helipad.

What I noted was that my heli never used to wag even at full gyro gain with the landing gear and there was a slight drift occasinally. But after removing the landing gear, the tail started to wag and the drift was gone. A simple gain change and the wag was gone.

With Adarsh standing beside me, and with his encourangement and guidance I was able to do 5 Loops!!!   That was great for a fresher like me. The only problem I see is the size of the Heli, as soon as it goes a few meter away, I cant even see it Time for an upgrade ?  

Some Photos:

1)My HK450 MT beside Adarsh's Raptor 90 with a CCPM head conversion. 

2)Adarh's FBL Trex 600.  

3)Ujjwal fixing his Bluebaby! 

[anwar]

Saw someone's mail blades fly off in different directions  last week, on an HK 450 GT Pro.  Apparently, the way HK ships these heli heads is tempting enough for people not to take it apart and rebuilt it themselves.  They seem to tighten it well enough to confuse people that they did a good job of putting it properly (with grease and threadlock).

Always take the head apart, and put it back together yourself on these HK ones.

[vinay]

Very TRUE!

[vinay]

As usual since I get only Sundays to fly and with 8 battery packs in mint conditions here are the updates:

1)The Pyro issue has vanished. I ramped up the EPA from 100 % to 150% and I get Crazy pyro rates. Something like 3 X 360* per second. It worked, and I could fly like a pro.(Did I?    )

2)Did 3 packs with training skid and removed them off for the rest 5 packs.

3)Jonied the Landing club. Did Tail - in, Nose left/right/IN landing w/o the training gear.   couple of times.

4)Was able to do 900+* stall turns. (I dunno what its called, where you take the heli almost vertical, do a 1/2 pyro and come down.) Well I was able to do 3 pyros there . This has become my new favorite.

5)Did lots of loops and Well on the last battery I did a mistake of doing a loop against head wind and the heli touched the ground and bounced off at the bottom of the loop.
DAMAGE = the frame was bent the it got pressed towards the motors cooling fan and ate all its teeth! :p Luckily nothing more. I just corrected the bend with a nose plier and I was off to do more tricks.

LESSON LEARNT - Not to do loop against head wind, unless you have High HS and good altitude.

BTW - enjoyed a lot!!!

Problems faced: Iam not able to do aileron flip. The Heli totally loses orientation and almost comes down crashing - Is this the limitation of the HK401? the tail is DS480.

Elevator flips seems fine, but didn't try much as I am not comfortable Nose-In Inverted hovering on sim. Next time I will take camera.

[ujjwaana]

Great going Vinay.. sigh!! missed the action y'day at Jakkur

[anwar]

Nice progress !

You wouldn't have to type this much if you had posted videos

[vinay]

Next time for sure Anwar bhai. 

[RotorZone]

Yes, loads of progress in a day!! From shaky thumbs to fearless flying is another change I noticed in your flying.

[ujjwaana]

2)Adarh's FBL Trex 600. 

Change the spelling of Aadarsh dude... dont you want the member ship card ?

[vinay]

Change the spelling of Aadarsh dude... dont you want the member ship card ?

I am for sure he wont mind! 

[vinay]

Yes, loads of progress in a day!! From shaky thumbs to fearless flying is another change I noticed in your flying.

Yes Rajesh, I could fly like that on the sim, but it just took time to study and feel my heli! then it was easy. Even the wind did not bother me much

The good thing is that, I dont use the spacebar too often on the sim, I usually fly till the fuel get over. Even if the heli is far, I try to get it back and land rather than pressing space bar. that gives real confidence and feel on how to handle a heli when its far - by giving slight input and reading its response. 

[vinay]

With myself busy from a long time, and both my helis in crashed condition, I thought I will atleast post some pics to keep my building spirit up. All my helis will be revamped with new spare parts.

1)Red Romeo. - Spartan Quark Gold case- Futaba S9257 or MKS 8910 - henge 933 digital, 700 W motor, ICE 75 lite, TIG 325mm CF (based on suggestions from Rajesh).

2)Blue Angel. - Hk401B - ds480 - mg14 - 700 W motor, plush 40, HK 325mm CF.

3)Black Beauty - Futaba GY401 - ds480 - mg14 - 700 W motor, plush 40, HK 325mm CF.

[vinay]

OK, Built the 2 Helis - Blue Angel and Black beauty. The Fly beautifully! 

1)My 2/4 helis

2)Black Beauty - Gy401 and ds480

3)Blue angel - Hk401 and henge 922

[vinay]

4) 450 with the PRO tail with built in chinese weight mod

5) I have mounted the Gyro and the RX on the bottom plate where the vibrations are LEAST!

Hope you enjoyed!  

[vinay]

Forgot to add, I have tuned the head to such a level that Iam able to squeeze in +12.5 to -12.5 pitch  on both the helis. Dont ask how much time I spend on building these. But they fly perfectly.

[anwar]

5) I have mounted the Gyro and the RX on the bottom plate where the vibrations are LEAST!

Trying to think this through... Wouldn't being so far away from the main blades (ie head) cause that location to have more vibrations than just mounting it under the tail boom block ? 

I have also  seen many times that that depending on the stiffness of the landing skids, they can vibrate quite a bit too, and being close to them may not be a good idea.  Plus, all bigger electric helis have them around the boom line (fuel engine ones have other considerations, making this decision obvious).

[vinay]

I touched the boom block and the the boom plate when heli was spinning at 3k rpm at 0 degrees. what I noted is that the boom block receives vibrations from head and tail both. Believe me its an HK heli(not as smooth as align) and I noted that the HK401 gyro performs better when placed below. The boom block was a vibrating nightmare. Though these 2 new helis that I have built vibrate very less, I thought its better they stay there in a safe place.

Also I have seen many people placing directly under the main shaft (sujju for example). But since the motor comes right besides it in the align model, I had to place it near the rear end of the bottom plate.

[anwar]

Which is the 700W motor you are using, this one ?

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8137

[sujju]

vinay.. most of my gyros are placed top or preferbly at the bottom of the boom block... i have placed the Mikado v bar unit of my fbl rave on the base plate only because the rave does not have boom block like the aligns ones... there is no harm in placing a gyro right below the main shaft or the bottom plate but only be careful when you crash inverted (the main shaft will hit the gyro directly)

[vinay]

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8137

Ya the same ones.

@sujju - ya I agree that it may pierce the gyro if crashed inverted.

[vinay]

Just crashed! I know a picture is worth a 1000 words.

[vinay]

1)Crashed canopy.

2)A link came off after crash.

3)I heard a flutter as the heli went out of control and crashed. Was this the culprit?

[vinay]

Watch the video. The flybad is inverted by 180 deg. I am now able to rotate the Flybar with lil effort. did the flybar turn and cause the flutter?

This was built with new head and tail. Was expecting atleast 70+ flights out of it. But failed after 10+

[ujjwaana]

So sad... the heli looks like Katrina struck her! (the cyclone - not the 'Shiela' one    )

It broke my heart! Hope your much precious electronics are safe! I mean Quark and Castle combo.