HK500 - FBL conversion with all stock parts - Poor mans conversion..

[jogeiremil]

Hi,
I have a HK500 which has given me a lot of headaches. Actually this heli is a certified frankencopter - it is composed of 3 HK500's, all of which has given me trouble with Gears that are stripping, tails vibrating like crazy due to too large tolerances between bearings and axle, 5 degrees slack in the rotor head after maybe 20 flights - and a lot of other crap..

I have changed some parts for stock align in hopes of getting it to work, but to no avail.

Now a days, the damn thing is just taking up space in my workshop.. I have tried to give it away, nobody is interested in this piece of junk.

What to do? I can't just throw it away, and I don't have the conscience to try to sell this helicopter.

Answer is pretty clear, convert to Flybarless, mount my spare Align 3G system and fly it to pieces. Try maneuvers that I normally don't have the courage to try - who knows, maybe I learn something.

When something hits the fan.. Good riddance! Then its ready for the trash bin.

I have started the conversion, using only stock parts, a hacksaw and a hammer.
The setup is giving me +-12 degrees pitch, and 8-9 degrees cyclic pitch.
After adjusting the swash plate using my hammer, almost all slack is gone :-)

What do you guys think, should I wear my motorcycle dress and helmet when flying this heap of junk?


0 Degrees


12 Degrees


-12 Degrees

[jogeiremil]

3G installed - Do anyone have the 3.0 update firmware. Align give me a 404 - page not found...

[Abenn]

Can't help you with the 3Gx -- I ditched mine in favour of a Microbeast after being unsuccessful in getting it to fly my 550.

As for the HK500, with my TT flybarred version I first replaced the tail gear with Align parts because I knew the stock slider was notchy. Then, after a 10-second or so test flight, which I abandoned because of vibration, I replaced the whole head, swash, main shaft, and main gears with a spare set I had from when I converted my Align 500 to fbl. The HK500 has been reliable ever since.

[Sndflea]

I have the 3G software. PM me your email address and I'll send a link to it on my Box account.

[jogeiremil]

Originally Posted by Sndflea

I have the 3G software. PM me your email address and I'll send a link to it on my Box account.

:-) Thank you very much, but I found a link in a forum that still works. So no need anymore.

I upgraded the unit to v3.0

Now i am just waiting for good weather to go and try this heli..

Will post the link later.

[jogeiremil]

Hovered today, slight bobble in the elevator axis, probably have to lower the gain - and / or do something else.. I am running blades for flybarred helis.. much lighter - more responsive.

Dampers are also for flybar setup..

My 600 rjx fbl head dont have dampers.. - Should I machine some steel "Dampers" for this fbl setup?

[jogeiremil]

Dialed the elevator gain back to 10 o'clock. Bobbling gone. I flew a whole battery - did some flips and some inverted hovering.

I must admit that I now want to throw more money at this heli.. maybe a rjx fbl head.. some new blades.. a shiny new canopy..

But then I remeber all the stripped hex heads, stripped gears and so on.. maybe I should just enjoy while it lasts.

The heli is upgraded from junk. Right now it is actually fun to fly!

😀

[jogeiremil]

Increased the headspeed today. Not good, sudden pitching down in fff and oscillations at hover.

Measured current hs to approx 2300 rpm. At this hs, the heli flies good.

Do anyone know what parameters need adjusting for using fb-blades in a fbl system?

[Solmanbandit]

2300 is a bit low for a 500. What KV motor and pinion are you using?

[SumOFparts]

Speed limit for that high ratio tail is 2650 rpm according to align manuals.....

[jogeiremil]

Originally Posted by Solmanbandit

2300 is a bit low for a 500. What KV motor and pinion are you using?

Hi :-)
Im running a 1700 kv motor, 6s 3000 battery. pinion is 12 tooth.

The motor is a hobbymate 3650, ESC is a mystery(!) 85A.
Motor and ESC was bought from DX.com... - yes.. el cheapo...


At 2300 rpm the motor and esc is barely warm to the touch.
I think maybe my problem is that the FBL unit is expecting a fbl head, with fbl dampers and fbl blades.. my heli has none of the above..

I am sure that there are some sliders I can tweak to make the mathematical model of the helicopter inside the 3G-units controller software match the real helicopter - I just not sure which sliders to change :-)

[jogeiremil]

Originally Posted by SumOFparts

Speed limit for that high ratio tail is 2650 rpm according to align manuals.....

Hehe.. I have had a lot of trouble with the tail going into 26-2700 rpm with this heli.. there was a resonance at around that point due to too large tolerances between the shaft and the bearings. (I think it was..) That issue was resolved by gluing the shaft to the bearings using retainer R48 - Green Align glue bottle.

Guess you get what you pay for..

[Solmanbandit]

I think maybe my problem is that the FBL unit is expecting a fbl head, with fbl dampers and fbl blades.. my heli has none of the above..

If you are running a flybarred head, that could be problem. The paddles and the FBL unit can end up fighting each other.

At 100% throttle, you are running approx 2500 head speed. I would bump it up one tooth to a 13T pinion.

[jogeiremil]

Originally Posted by Solmanbandit

If you are running a flybarred head, that could be problem. The paddles and the FBL unit can end up fighting each other.

At 100% throttle, you are running approx 2500 head speed. I would bump it up one tooth to a 13T pinion.

Hi, :-)
Regarding the head - Well, not exactly.. I have removed the paddles from the head. see the images in the first post.

I have converted the flybarred head to a flybarless head - but the dampers for instance, are intended for use with a flybar.

Correct me if im wrong, but:

1700 kv * 6s * 3.7v / (162/12) = 2795 rpm at 100% using 3.7 volts pr. Cell as the nominal voltage?

[jogeiremil]

I guess I was misleading in the post stating that I dont have a fbl head. I meant a proper one.. :-)

[Solmanbandit]

Correct me if im wrong,

You didn't add the efficiency factor. No motor runs 100% efficiency. Use this website, it is much easier and does the math for you. BTW, I can guarantee that your motor is in the mid 80% percentile for efficiency. So 90% is being nice.

http://dhrc.rchomepage.com/calc.htm

Considering that you are using a FB head, using FB blade grips is asking for a lot of issues. The FBL blade grips are much different than the FB blade grips. As far as the dampeners go, that isn't an issue. The only time that becomes a real issue is if you use the DFC head.

[jogeiremil]

Originally Posted by Solmanbandit

You didn't add the efficiency factor. No motor runs 100% efficiency. Use this website, it is much easier and does the math for you. BTW, I can guarantee that your motor is in the mid 80% percentile for efficiency. So 90% is being nice.

http://dhrc.rchomepage.com/calc.htm

Considering that you are using a FB head, using FB blade grips is asking for a lot of issues. The FBL blade grips are much different than the FB blade grips. As far as the dampeners go, that isn't an issue. The only time that becomes a real issue is if you use the DFC head.

I was wrong - of course I have to factor in the efficiency factor.

The head is converted using mixing levers to get proper resolution / mechanical advantage. See the images in the first post.

[Solmanbandit]

If it works, then go for it. I still don't see how it can have the proper leverage though. I tried FB blade grips once and it was ugly.

[jogeiremil]

Originally Posted by Solmanbandit

If it works, then go for it. I still don't see how it can have the proper leverage though. I tried FB blade grips once and it was ugly.

Hehe, im not sure it works.. :-) thats why i post in this forum.
This project is just for amusement. I dont treat my other helis like this ;-)

Did you connect the blade grips directly to the swash?

Actually I have too much leverage using the mixer arms. I can only get +- 11 degrees collective pitch.

[Solmanbandit]

I would buy a fbl head. They are not that expensive and you will have a better experience.