Microbeast USB interface with AR7200BX?

[Offset]

After ordering the Microbeast USB interface I have found out that there is a Spektrum USB interface for the AR7200BX, which is what I have.

I'm trying to find up to date information, a lot of what I'm finding is over a year old. I believe the MB dongle will work with the AR7200BX if what I read is accurate, but does the software have full functionality yet?

Will I be able to adjust everything from the PC. More specifically will I be able to adjust servo throws for keeping the swash centered through the full pitch range, like coll>elev mixing works in the flybarred helicopters?

I always assumed there was no differences between the 2 BX units aside from one also being a receiver. When will I learn...

[2400rdr]

The Microbeast interface works fine. You'll need to update your AR7200bx to v3.1 firmware to use the interface, but the Beast software detects the lower version firmware and takes you to a website for the update.

The interesting thing about the microsettings software is that it addresses so few of the possible settings- I was surprised when I looked at it. It does basic setup for servo frequencies, pulsewidth, virtual swash type and so on. It also does a small number of parameter changes, but I can't tell you much about these because I've just started with an AR7200, and haven't gotten to the fine tuning yet.

All in all, it's nice software, works well, and is good to have. It just doesn't give access to all of the programming facets.

[sutty]

I've never used the software, so I can't tell you what it does, other than to say that top and bottom swash levelling won't be one of the options as it is not supported in the MB.

Levelling at mid stick is sufficient, and would likely be sufficient for any FBL unit, even in those that offer it as an option. Bear in mind that the FBL unit is always actively moving the servos, so if as a result of uneven throws you were rolling gently left, in a punch out, then the MB will apply corrections to the right as you went.

It has so much to do in a climb out to keep you straight, fighting the wind etc, then knowing what is true level for the swash becomes practically an irrelevance. It simply puts the servos into the position required to give you a straight climb, and that is that.

One of the latest FBL units from Spartan, the VX1 doesn't have this option either, and when the manufacturer was questioned about why it was not available, he answered, Well if you all want it I can add it, but why would I bother when it would bring nothing to the party. The control loops are actively positioning the servos at all times, how would knowing what the ideal level position at top and bottom help this, and where would I bring that into the flight code? It would still have to let the sensor feedback information have priority. That's not word for word, but it was what his answer amounted to.

I remember that one of the technical guys from BeastX has also stated this, at least once, somewhere in this forum.

Important in FB systems, otherwise you would have issues if you had an unlevel swash at full pitch, +ve or -ve, as there is nothing to correct it, but it doesn't apply quite the same in FBL.

Cheers

Sutty

[2400rdr]

I agree. The only thing that the USB interface really seems to be excellent for is the firmware updating. The rest is very easy to do using the built in interface.

[Offset]

The reason I'm wanting to adjust the the throws is because I can't seem to work out the the way the elevator behaves when increasing collective.

I understand that the FBL system will keep the helicopter stable on hovering through all pitch ranges but when performing a rapid punch out the helicopter leans back noticeably as the elevator throws farther than the two aileron servos.

It's a B450X and the elevator uses a push/pull servo horn that connects to another horn lever that connects to the front on the swashplate. Not sure if this is a design flaw or if there's something I'm missing in how this should work.

My step G is solid, horns are as close as possible to 90 degrees at neutral pulse and so is the secondary horn lever for the elevator. The horns are positioned exactly to 90 degrees with step G trim and also the bell cranks are at 90 degrees.

If I just did casual flight this wouldn't be noticeable but as my skills are progressing I'm noticing flaws in the helicopter as I start performing more smack 3D.

I guess this USB connector will only be good for updating firmware, the reason I bought one is because on the BeastX forum one of the reps made mention in a year old post that they would be adding throw adjustment later on.

http://www.beastx.com/showthread.php...-and-pos-pitch

aiya...

[sutty]

Interesting that they talk about including it, over a year ago, and yet around that time I also read from their lead developer that it was pointless. Either way, it hasn't eventuated, so I guess they must have turned their attention elsewhere.

That having been said, in its absence most still do not have an issue, so if you do then there must be something different going on with your helicopter. Are you able to do a video of the difference in the swash angle between your stick positions, and your servo horn positions/angles etc?

Cheers

Sutty

[DoubleCH]

Yes, feedback control system in the FBL controller will theoretically correct any mechanical asymmetry/imperfection, the problem is that feedback control system needs to see "deviation" before it can correct. For leisure maneuvers you won't notice this relatively short period of time of deviation compare to the lengthy period of leisure maneuvers. But for quick maneuvers like hard-stop tic-tocs, full-pitch pumps, the deviation is much more noticeable because the time period dominates most of the time period of the hard-start and hard-stop parts of the maneuver. You do want to have the mechanical side of things set up as good as possible and not rely on feedback control system of FBL controller for precise quick maneuvers.

To OP, what happens if you check swash-leveling in step K where you work collective full range? Do you see swash getting out of level when you reach full collective? For the 450X push-pull elevator servo system, it's much more important to get the final elevator arm to be perfectly horizontal than the push-pull bell cranks although the bell-cranks and the pushrod pairs still need to be in perfect parallelogram (or rectangular to be best but not absolutely necessary).

If you have to choose between putting on servo horn a notch too high or a notch too low, consider not just which one is closer to result in horizontal final arm but also consider direction in relation to the other 2 servos. For example, if both rear cyclic servo centers are .3 of a notch too low such that you would install both servo arms on the higher notch (better to be .2 notch too higher than .8 notch too low). And then if your front servo center is .2 of a notch too high, even though installing servo arm .3 notch too low sounds better than .7 notch too high I would still try install the servo arm 0.7 notch too high because it'll be off the same way as the 2 rear servos. This may result in less out-of-sync with the 3 cyclic servos on full collective, even after perfectly align servo arms in step G.

Another thing to check is slops on the push-pull elevator servo mechanism. Because of extra linkages, elevator servo may not end up providing the full throw the rear cyclic servos do.

About PC settings, it's more than just updating firmware. Many of the flight parameters allow 4-5 coarse settings where the 5th or 6th allow a PC preset value which can be much more fine-tuned with PC. I love to pre-set all the PC settings to my liking and I can still easily swap between the PC pre-sets or BX presets back-and-forth at the field simply thru' the TX and Setup button (without the need of PC). I also like that tail pre-compensation setting has a few more parameters available to tweak and fine-tune (only accessible by PC).

[sutty]

Originally Posted by DoubleCH

Yes, feedback control system in the FBL controller will theoretically correct any mechanical asymmetry/imperfection, the problem is that feedback control system needs to see "deviation" before it can correct. For leisure maneuvers you won't notice this relatively short period of time of deviation compare to the lengthy period of leisure maneuvers. But for quick maneuvers like hard-stop tic-tocs, full-pitch pumps, the deviation is much more noticeable because the time period dominates most of the time period of the hard-start and hard-stop parts of the maneuver. You do want to have the mechanical side of things set up as good as possible and not rely on feedback control system of FBL controller for precise quick maneuvers.

I'm presuming this was to me, as it was followed with, "To the OP", but I should clarify that I wasn't trying to suggest that it is not important to have a good precise mechanical set-up with good quality servos that travel at the same speed, proportionally with slopless links, etc. Of course it will all help.

The point I was trying to make was that having levelling at top and bottom won't improve this, if it has been done electronically, thus explaining why it is missing from a number of FBL controllers. For example they won't be able to apply a proportionate amount of speed to one servo, when moving it at full speed, in a full pitch manoeuvre, just because it knows it doesn't have quite so far to go. What it can do, just as it would for anything else that moves it offline, is to back off one or two of the servos a little to keep it straight. Yes it has to do this reactively, but it has to do that for all sort sof things, and knowing where the electronic full +ve and full -ve level pitch locations are for each servo can't really help. If they move at disproportionate speeds, because of motor speed, assymetry of the servo horns or links etc, fixing this up electronically at top and bottom won't change this at all and the FBL controller will still be left to correct reactively.

So what if it is reactive, it can still do a very good job. The tail is also reactive, but if, when well set-up, it can correct after seeing only say 0.1 degrees of uncommanded rotation then so what. I've had gyros that I couldn't even see any tail kick at all in even the most aggressive of pitch pumps, or heavy pitch manoeuvres, without any form of pre-comp, so they must be extremely sensitive. I don't know what the sensitivity range is, but it must be small. Additionally, in horrendous gusty winds, I have watched in awe at various FBL controllers, mine and those belonging to others too, make it appear as though it were an almost completely windless day, at least in terms of cyclic, holding the heli in a perfectly flat, apparently twitchless hover. Collective, well that's a different matter, bobbing up and down like a cork sometimes, but I'm sure you see the point I'm making. Hands off, totally reactive control, yet you see virtually nothing in terms of uncommanded rotation.

If it really helped, or could help, why wouldn't one of the latest state of the art controllers incorporate this? Moreover, why would the MB developers describe it as simply a sop to those who believe it to be important and why would the developer of the Vortex describe it as a waste of time, that could easily be incorporated if people wanted it, but it won't help?

Again not trying to suggest that accurate physical set-up isn't important, clearly it is, I'm just interested in knowing how electronically making it level top and bottom could make a difference? Indeed it is probably worse because you are more likely to satisfy yourself that your heli is perfect after you have 'electronically' covered up a whole bunch of mechanical imperfections.

I think your suggestion to have offsets in the same direction sounds extremely logical, even if it means they are slightly further away from centre than they might be if they were at the other side. I know for a fact that I haven't done this on at least one of my set-ups, as I remember looking at it when in the reference position with one of them pointing off in the other direction.


Cheers

Sutty

[DoubleCH]

I'm not suggesting the need for electronic means to balance swash on full collective. I'm saying it's important to get mechanical side of things as good as possible in order to not rely on feedback control loop system to correct because that involves delay and will be noticeable on quick maneuvers.

My suggestion of considering position servo arm offset in the same direction may or may not fix OP's problem especially depend on how far off each servo arm is, but I think it's worth a try.

[Offset]

Thanks for the input guys!

With the tripod on in step K there is a difference in min/max collective with the elevator.

I'm going to focus on the elevator mechanics some more and see if I can close the gap by manipulating the elevator mechanics some more.

I did fail to mention though that I upgraded the servos to the Hitec 5065, and the servo horns from the stock servos did not fit, so I did have to adapt the Hitec horns to fit the the tight spaces for the ailerons with a dremel.

To me they seem to be the same length as the original, but perhaps the elevator servo's Hitec horn plus the stock secondary horn lever/final arm are not the right fit for each other and it's affecting the overall throw.

Having everything at a 90 degree angle in step G perhaps this is still just a horn length issue.

[DoubleCH]

Originally Posted by Offset

To me they seem to be the same length as the original, but perhaps the elevator servo's Hitec horn plus the stock secondary horn lever/final arm are not the right fit for each other and it's affecting the overall throw.

This may very well be your issue. If the 2 elevator pushrods aren't parallel, that means the hitec servo horn is not the right length as the original and will definitely throw off the travel and result in swash not maintaining level from full positive collective to full negative collective.

[Supertuna]

Anyone help me with getting the usb to work on my pc have tried both my windows 7 and mac book but both can't see usb?

update: read the instructions!

[ukiah74]

Originally Posted by Supertuna

Anyone help me with getting the usb to work on my pc have tried both my windows 7 and mac book but both can't see usb?

update: read the instructions!

i am having the same issue but im still using XP..