ARK X400 Coning angle

[avalon]

Just got an X400, I have been flying a GWS Dragonfly for a few months and haveing a ball with it. Chose the X400 because the LHS is the importer so it makes it easy to get parts. I have found it quite a handful after the Dragonfly, forgot to mention I fly indoors in my warehouse. Taking a look at the rotor head I noticed there was no coning angle, wondered if I could intoduce some if that would make it more stable. I am only interested in Scale fo I would be happy if I could get it a docile as I can before I try and put the body on. Any help would not go astray on this one.

[swatson144]

The stock x400 is pretty tame as it is. I'd just add a little expo and maybe some dual rates, in the TX setup. I just use one of my switches set off my normal line up. When I want to tone it down flick the switch up. that gives me -30% expo, for hovering etc.

Steve

[avalon]

Tame!!! mine is like a wasp on a piece of elastic. Tried the expo route I tried different amounts but the heli was so slow to respond that all I ended up with was over control. I guess that I am flying in a small space 10x8 meters. I know hat nearly everyone rubbishes the Dragonfly but I can get that in to a hands free hover without too much effort so I guess that is my yardstick at the moment.

[swatson144]

When the head speed gets up they can get pretty responsive. What are you running?

My stocker is setup at 2400 RPM and my bling one at 2700 RPM both are pretty tame but the extra 300 RPM makes a difference in responsiveness.

I don't much like flying with expo as it seems things happen too quick when you hit the steep points. Hovering it's fine.

It may be the room. The x400 will move a lot more air than the MDF so if it gets the air in the room "dirty" it'll be a hand full. I suspect this is what is happening from the "too slow comment". When you first take off does it seem ok and then get worse?

Maybe give it a try outside?

Steve

[avalon]

Thanks for your responce. I am not too sure what head speed as final setup was done by the LHS. Having flown gasers in the past I would think by the sound of it that 2400 would be about right. You may be right about ait turbulance, I had not taken that into account, although the hover patten is the same from start to finish. As I reach the end of the battery life and you start to hear the motor sag the heli becomes far more stable? Outside is a bit of a problem being in the centre of Sydney the closest licenced field (i.e. one I can leagaly fly in) is an hour away bit too far to go for just 11 minutes flying! Might sneak down to the local park early one morning and give it a quick go there, If you dont hear from me again you know I got caught :wink:

[swatson144]

What pinion and KV motor? we can calc from that and be very close.

How high are you hovering? In GE they tend to be a little twitchy Over waste high you'll be out of GE.

Wow I never knew it was against the law to park fly there! A churchyard or parking lot may be a better place for that kind of illegal activity, as parks are probably well patrolled. Not that I'd ever recommend an unlawfull act :wink: .

Steve

[avalon]

It is a standard X400 kit the instruction book says Motor gear 14T and Main gear 138T. There are no markings on the motor, instruction book gives 2 as recommended 2800~3000KV for 14T or 3500~4000KV 13T logic would say that it is the first one. Ground effect does change things a lot. I know if I stay too long too close to the floor I fall into a vortex ring.

[swatson144]

Yep I have that book too :) What motor? Mega 16-15-3, align 420LF, etc? We'll go from there.

Steve

[avalon]

LOL...Just left YOU a reply to our other thread in the LED. I do not know what motor it was as it came with the heli and there are no markings on it at all, Guess not a lot of use but has gold end caps and a black can. I would think that it would be the smaller of the 2 motors as it came with the 14T motor gear, also the importer here is tight as so I would think it would be the cheaper on as he would want to maximise his profit!

[swatson144]

Well I won't get all preachy on this :) .

It works thus.

assuming 2550 KV on the motor

2550kv*11.1v*14t=2677 rpm * .8 =2150 ish

More likely since it is new and the trend seems to be 3500-3200 kv

3300kv would get you around 2700 rpm.

It'd probably be worth the time to measure the motor shaft diameter and pick up the Align set for that diameter. 11,13,15t are available for 3.2mm for about 5$. If I'm guessing right for indoor scale type flying the 11t would make you happy and give a little more flight time. That'd give a tamer 2200 ish RPM HS. Room to spare as the minis seem to get sluggy at about 1800. If I'm wrong you'll have a 13t to prove it :D .

Steve

[avalon]

Thanks for that, I will pop down to the LHS and pick up some different size motor gears. Might take a couple of days but will let you know what happens.

Bruce