600N DFC conversion pitch problem

[Kiwi Flyer]

Ok what am I missing here? I'm just going through the set-up on a stock 600N Limited Edition (version 1) to DFC flybarless conversion. The issue is relevant to the following parts:

Align H6NH002XX DFC 600N mast
Align H60248 DFC swashplate
Align H60242 DFC main rotor grip arm set

The problem I am having is that I cannot get the pitch range correct. With ball links on the grip arms screwed in as short as they will go I'm still getting around +4/5 degrees at mid stick. Obvious solutions to get pitch down to zero are lowering the swashplate (for which I would need a shorter elevator arm - not even sure if one exists), shortening the grip arms or using a longer mast - although I'm pretty sure all the parts are correct for this conversion. Has anyone else run into this problem?

[Bladefx]

the only thing I could suggest is trying the normal main shaft
>you cant change the length of 3 swash links because of the elevator < that's true
I went with the swash driver set up and titanium links because I run lower head speeds, sorry not be of more help.

[Kiwi Flyer]

That is an option of course but I can't believe I'm the only one who has come across this, unless I have made a blunder somewhere.

[Bladefx]

the other thing I can see be different is the center yoke the dfc yoke is shorter than stock
this wouldn't help you because you need to raise the spindle to get 0*
I agree with you it is pretty hard to screw up , try the stock main shaft since it's a conversion

[Kiwi Flyer]

Stock main shaft is too long. As you say it's pretty hard too screw up but I seem to have managed it somehow. I'm thinking of doing away with the turnbuckles on the arms and going with a set screw and thin locknut (a bit like the KDE arms that I see are available) in the hope I can shorten them a bit. So nobody else has this issue??

[DanMcN]

I have one 600n DFC and one stock head, gave up on the buying DFC shafts. I just buy the long 600n H60159 202mm and cut them to 184-185mm, then drill a 3mm head block hole. Actually works out, I can use the 202mm main shaft on either heli, cut a shaft down if I need a DFC. At zero pitch if the main shaft is too short, the A frame and blade grip to swashplate arm H60202 ball links are bottomed so you don't have any blade angle adjustment. If the main shaft is too long, the H60202 link rod ends are not threaded deep enough. I have a friend that converted to DFC and had the same main shaft length issue. He was getting upset buying shafts that didn’t work. If you find a shaft that works I’d like to know.
I have a AR7200 and use the swashplate upper inner ball link holes for the 6deg check.

Good Luck!

[Sirolf]

Long story short the DFC nitro main shafts don't work! Mod one of your previous ones and get a hole-to-hole distance of 155.5 mm.

[Skinny_j]

Mine is a conversion and it works fine with the dfc mainshaft.

[Bladefx]

Skinny could you give us a bit more detail. pics, maybe the part #s you used?

[Skinny_j]

Yes, here is the mainshaft I'm using

http://www.helidirect.com/align-600n...et-p-29945.hdx

Are you using the dfc main rotor head too? If you have the dfc grips/arms on a non dfc head this might be your issue. You need all the dfc stuff for it to work.

Here's everything you need

http://www.helidirect.com/align-t-re...39-p-26156.hdx

Here's everything you need,

[Skinny_j]

This is the only pic I have now I can take a closeup later.

[ticedoff8]

Check your TX.
If you are using the 3GX and a Spektrum radio, the radio has a "Swash Mix" screen. I think the default is 65% for "no mix"

Also, you may have to re-center all your servos (0 out all the sub-trim settings on the radio) and check that you have 90 degrees between the servo arms, links and swashplate before you go too far.

Then, shorten / lengthen the "servo to swash" links as needed to get 0 degrees on the blades at center stick.
Do the fine center adjustments and swash leveling with the radio's sub-trim (if you are using the 3GX).
Then adjust the high and low collective pitch with the servo end point or travel volume on the radio.

My guess is that your original head wasn't mechanically set correctly and you compensated for it with radio adjustments.

[Kiwi Flyer]

Originally Posted by ticedoff8

Check your TX.
If you are using the 3GX and a Spektrum radio, the radio has a "Swash Mix" screen. I think the default is 65% for "no mix"

Also, you may have to re-center all your servos (0 out all the sub-trim settings on the radio) and check that you have 90 degrees between the servo arms, links and swashplate before you go too far.

Then, shorten / lengthen the "servo to swash" links as needed to get 0 degrees on the blades at center stick.
Do the fine center adjustments and swash leveling with the radio's sub-trim (if you are using the 3GX).
Then adjust the high and low collective pitch with the servo end point or travel volume on the radio.

My guess is that your original head wasn't mechanically set correctly and you compensated for it with radio adjustments.

Unfortunately this isn't the problem. I started this setup with a new model in my 14MZ and CGY750, and with all subtrims/servo neutral positions etc. at zero and taking the time to find the most suitable holes on the servo horns I have good geometry on the servo linkages. The "servo to swash" links are essentially not adjustable due to the fixed length of the elevator arm - meaning at mid stick the swash cannot be moved up and down without sacrificing a nice 90 degree setup on the servo horns and linkages. The best solution has to be (as has been suggested) modifying an old mast - which I'll get round to doing very soon.

[MikeKimC]

Originally Posted by Kiwi Flyer

Ok what am I missing here? I'm just going through the set-up on a stock 600N Limited Edition (version 1) to DFC flybarless conversion. The issue is relevant to the following parts:

Align H6NH002XX DFC 600N mast
Align H60248 DFC swashplate
Align H60242 DFC main rotor grip arm set

The problem I am having is that I cannot get the pitch range correct. With ball links on the grip arms screwed in as short as they will go I'm still getting around +4/5 degrees at mid stick. Obvious solutions to get pitch down to zero are lowering the swashplate (for which I would need a shorter elevator arm - not even sure if one exists), shortening the grip arms or using a longer mast - although I'm pretty sure all the parts are correct for this conversion. Has anyone else run into this problem?

I ran into the same issues as you ... this is what I did to achieve zero pitch on two trex 600 nitro's. I cut 2 to 3mm off the elevator link ... this allowed me to screw it further into the elevator arm ... by doing so I was able to drop the aileron ball links to a level swash and a zero pitch on the head. I've been flying both these helis all summer with no issues! You can also adjust small indifference's to top and bottom pitch settings in your pitch travel adjustments of your radio. See the attach pic for a better explanation and I hope this helps

BTW I'm using the exact same parts as you listed

[magiko]

I have the same problem getting zero pitch at half stick, yet right at 90 degrees and threads stuck inside the bumper, get 3 degrees in the middle of the stick, not that I can do.

[MikeKimC]

Originally Posted by magiko

I have the same problem getting zero pitch at half stick, yet right at 90 degrees and threads stuck inside the bumper, get 3 degrees in the middle of the stick, not that I can do.

Do as I did ... cut 2 or 3 mm off of the plastic elevator link and screw it in deeper ... it will allow you to level your swash lower and then you'll be able to unscrew your DFC arm links.

[magiko]

proves ok to cut it, but I understand if I cut the excess plastic to lose more or shorten the patella patella 2 mm, since my patella rests on the aluminum.

[MikeKimC]

Originally Posted by magiko

proves ok to cut it, but I understand if I cut the excess plastic to lose more or shorten the patella patella 2 mm, since my patella rests on the aluminum.

By lowering your swash you will have to lengthen your DFC links ... you plastic ball links on your arms will no longer be resting on the aluminum trim rings

[magiko]

yes yes, I understand, what happens is that the google translator did not explain well.

I mean I support my patella in the elevator the elevator has a molded plastic, should reduce that area?? see if I can make a picture to explain it.

but if and caught your idea and I'll do it, just had this doubt.

[MikeKimC]

Originally Posted by magiko

yes yes, I understand, what happens is that the google translator did not explain well.

I mean I support my patella in the elevator the elevator has a molded plastic, should reduce that area?? see if I can make a picture to explain it.

but if and caught your idea and I'll do it, just had this doubt.

lol no need to get angry or frustrated ... we have a language barrier here! Just cut 2 or 3 mm off the elevator link and try it ... if your talking about the ridge on the ball link, just file it off or use a trex 700 ball link that has no ridge ... you'll see that it works!