BeastX plus expo

[chris427]

Just got a 450 dominator with beastx plus. Been learning how to set it up as checking the previous owners settings, good job I did as pitch was all over the place. Anyways I've noticed that it has no expo in the tx settings, on a dx6i, so when I asked someone about adding expo they told me not to and it's likely to crash if I add it, always used 20%+ expo on the flybar raptor with JR tx. So before I add expo should I, do you, will it crash?

[Grumpy]

You can add expo in the Tx, no problem at all. I typically use 20-30% on my FBL helis, some like the feel of expo, some dont. Whoever told you that it would make the heli crash was basically 'full of cr@p'.

[chris427]

Thanks, just reading different forums and posts. It recommends not running expo in set modes on BX like sport, extreme and to go to the menu and set it to transmitter behaviour and that stops the default settings clashing with the tx expo. Might have to have a look in to that tomorrow but I agree, sounds strange it'll crash by adding expo. First FBL heli so all strange at the moment and a big learning curve but found the set up easier than a fly bar heli.

[waveydavey]

I don't think it will crash but you shouldn't use Tx expo as well as a preset, the BeastX team themselves say that behaviour could be unpredictable. The presets are really poor in any case, Tx mode and set your rates to suit, including expo if you want.

[kenny d]

You set it up with parameters menu B , there is 4 preset choices from normal to extreme, these are pre set flying behaviours from lazy to twitchy you can also choose
to set it up your self in transmitter, I would start with normal fly it and see how you like it , if it's too lazy pick the next on up etc

[Grumpy]

The FBL has no way to 'know' if expo is set in the Tx... All that expo does is cause the channel output signal and the stock movement to not be linear to each other, the actual signal that the transmitter emits doesnt change, just the distance you have to move the stick changes. As far as the Microbeast is concerned it simply receives the signal, it doesnt 'care' how far the actual stick had to move to generate that signal... So it's impossible that it would cause the FBL to malfunction in any way due to use of expo.

[waveydavey]

Nobody is saying it will crash. It's not quite the post I remember from the BeastX team but it's along the same lines. The original was a little more alarmist

How can I increase rotation rate for aileron, elevator and rudder?

The rotation speed on all 3 axis is mostly limited by the capability of the sensors. This is appr. 600deg/s. Practically even less as due to calibration you loose some deg.
The roation speed is only determined by the length of the stick signal (and especially has nothing to do with your cyclic pitch adjustment at setup points J or L and also has nothing to do with the cyclic pitch when steering cyclic on the ground!). So increasing/decreasing the stick throw, mostly done by increasing/decreasing servo throw or using Dualrate in the TX for the specified function, will increase/decrease roation rate.
The presets in parameter B are nothing else than different preset dualrate/expo curves inside the MB. When using these it is recommended not to change the output signal in the TX as especially when using expo this will bend, compress or stretch the curves leading to very strange flight behavior (it just is not like adding 5% of expo as the curves between TX and Microbeast will multiply and not sum together!) If you like the feeling of course you can do this. For example a slight increase in stick throw for increasing the roll rate will not significantly deform the Microbeast's internal curve and can be done with no problem. But easiest thing would be to switch flight behaviour to "blue=TX" and adjust the curves in your transmitter as you like (therefor I'd suggest to start with 70% D/R and 25% expo on cylic and 85% D/R and 40% expo on tail). When setting parameter B to "blue = TX" these internal curves in MB will be disabled. So 100% stick should give 100% rotation rate. This may vary depending on TX brand as any manufacturer use another signal output as maximum. So this can be at 107 or 110% or also at 95%. Manufacturers calculate expo curves different, so we can't tell you what our preset curves correspond to which TXs expo values as we use our own expo and there is no data available for comparing. We did outfly these values and programmed them in the source code so we can't tell what these are in Futaba or JR percentages.
If parameter B is set to blue and the tail gain is switched to heading lock mode you can see by the status LED at which tail stick position the maximum possible rotation rate on rudder will be reached: At that specific tail stick position it will start to flash. At this point the maximum gyro controlled rotation rate is reached. By increasing the stick throw any more the LED will go off. At this point the rate control is switched off and the tail will spin freely. Here the only limit is the maximum possible tail pitch throw and normaly the tail will spin ultra fast. This can be used for example for performaning tail slides or turns with very fast spinning tail. For normal flying around this is not recommended as you may accidentaly steer into the uncontrolled area and the tail may spin too fast or very uneven.

[chris427]

Thanks for the replies guys. It think the best thing I can do is check it's in normal mode so should be docile enough, try it and if it's too docile then change to the next one up, or change to transmitter setting and add expo. I've watched the videos on the set up and got the manual and seems straight forward enough.

[chris427]

Ok first hover done in the garden this morning. First time using FBL so couple of things I noticed were, 1 It likes to be airbourne before you correct the initial take off position unlike flybarred. 2 The tail kicked on spool up, not sure if it should do that but gyro held well once corrected. 3. I'm in normal mode on the BX and it felt twitchy but slow if that makes sense? Seemed as though I was moving the stick to correct the cyclic and nothing happened so moved a bit more then it went too far so ending up over correcting the other way so think I'll change it to sport mode for a bit more response and 4 I am still playing with the head speed, bear in mind I'm just starting to re learn hover so head speed was at 65% at hover and it was a a bit up and down and a fair bit of pitch correction needed so that seems like head speed too low so upped it to 75% at hover with 85% at top stick. I'll get a better place to fly it as only in a small 20x20 garden with fences and a garage wall close and rain! Does any of this make any sense?

[kenny d]

All sounds pretty normal to me , I find they need a reasonable head speed to make them feel locked in , I think when the tail is jammed on the ground & the FBC is trying to correct but can't , you can get a bit of tail kick when it lifts off , I usually lift off in Idle 1 getting it in the air asap

[chris427]

I've upped the head speed now and re checked pitch and swash level and all seems ok to me. The tx has 61% gain in it for HH mode so just upped it to 65% (DX6i), if it wags I'll knock it down again but agree once in the air it settles down quickly and a slight rudder input soon straightens it out and it stays there. It does wander though and no chance of fingers off hover so some tweaking to do,

[waveydavey]

Hey Chris 65% in my experience seems high for tail gain on teh BeastX with Spektrum Tx what ball distance on your tail servo. Do yourself a long voyage of discovery and go straight to Tx mode and set your rates and expo on the Tx. Balance your piro speed left to right by changing your end points and reduce your rates if needed for roll and pitch

[chris427]

The 61% was already dialled in from the previous owner as bought it as a flying package but didn't see it fly before buying, what sort of gain do you think would be a ball park figure to dial in? Ball is in the middle of the 3 holes. I think I'll do just that with the expo tomorrow, usually run 20-25% but not tried sport yet so I'll give it a go first as only still learning.

[waveydavey]

Chris I wouldn't add expo whilst in one of the presets. Change the control behaviour to Tx and set your expo and rates around that. If it was there and working then leave it for now mate, all Beastx's I've had on various models with Spektrum have been around the 40-45 mark with around an 11-12mm ball centre, that's on 6 and 700 size

[chris427]

Yes not going to add expo while in a pre set flight mode but going to see what sport is like before going tx setting. The gyro gain seems high but doesn't wag so I might increase it until it does so I know the max then back it off until it stops wagging but doesn't let go and see where it's at, can't see it needing 61% but realistically only flying, adjusting and flying will show me whats better or worse. I'll measure the ball centre tomorrow and see where it's at.