Acro mode on quads

billyd

New member
I have successfully modified a quad to access acro mode in the editor. Why don't the stock quads have acro mode available? Only stabilize, alt hold and loiter, a very boring way to fly and a very odd design decision for RFX.

However, I don't see where I can change the gains for acro mode, only the stock stabilize, loiter and altitude holds gains appear to be available. As a result I am getting alot of hunting after increasing the roll rate to 720 degrees per second, about the roll rate in today's racing quads. Where do I find those PID values for Acro mode in the editor?
 

csgill75

Well-known member
I assume you are editing the H4 Quad 520.

The values your looking for are highlighted here in the picture.

I originally edited the model in 7.5 to get the rates of 720. The navguide in 7.5 has the ability to show the actual pitch and roll rate of the model in real time when you perform the maneuver. The roll and pitch rate does control how fast the quad can perform the manuver, but this particular model left stock maxes out at about 540-550 degrees per second. It won't go any faster without further editing of the model (size, weight, power, etc). In RF-X the performance is the same so you're only getting a rotation rate of 540 even though its set to 720 because of the limitation of the model setup.

There are a couple edits from 7.5 that might work though, check out the Swap pages for edits of the H4 that may have already been shrunk down to a 250 size which is the size it should be for a racer. The stock model is to big for the performance you want. You can import AV's created in 7.5 and older into RF-X.

This one was one I found, edited by some people on RC Groups. It might be something you can start with. I have not tried it yet.

http://www.knifeedge.com/forums/downloads.php?do=file&id=21953
 

Attachments

Last edited:

billyd

New member
Thanks but I am talking about the proportional gain for Acro mode. I already have the roll rate where I want it. But the gains are too high and it causes the model to hunt.

As far as I can tell the only editable gains are for the stock three modes, stabilize, alt hold and loiter. I don't see a listing for acro gains anywhere, unless they are shared for acro mode? I tried reducing the stabilize proportional gain but it had no effect on the acro mode hunting after a flip.
 

csgill75

Well-known member
The Rate Gains are not separated for each mode. It is all shared.

In playing with this model I have also found that it is impossible to shrink down a model in RF-X. It is possible to do in previous versions. I have reported this issue and hopefully it is resolved in a future update as being unable to reduce the size of the model limits what we can do with the editor.
 

billyd

New member
Ok but I thought I saw separate pids for each mode, maybe I was mistaken. Anyway it didn't seem to have any effect. I will continue to reduce the gains and see if I can remove the hunting. Perhaps that's why they released the quad models with Acro disabled, their flight model can't handle it....
 

billyd

New member
I was able to get things better but it's still a mess. The quads in RFX float really bad. I mean they just defy gravity. I can point the quad vertical and it just stays in the air forever.

Also the yaw authority is really bad. I have maxxed out yaw gain to 100 and it still floats all over the place. Also at full throttle the fc goes bonkers.

I am sure I am doing some things wrong. But the floating issue is in the stock copters as well. I've attached my feeble attempt at making an acro capable quad. It's not good so don't get your hopes up.

Please help me make this fly better. Much appreciated!


Edit removed file and uploaded new version in next post.
 
Last edited:

billyd

New member
Ok I've made some progress. Increased Yaw D term and throttle gain and that helped alot. Model is flyable now. At least I have a quad to practice acro on it's still far from perfect but good enough to practice with.
 

Attachments

csgill75

Well-known member
Knife Edge simply brought over the Multirotor controller from 7.5 to RF-X. It is designed after the arducopter system if I remember correctly. It is possible to use multiple Old fashioned Gyro's instead, and in 7.5 there are a couple still setup that way. A lot of mixing going on, but every aspect of flight is controllable, with just one flight mode, the one you create, available.
 

Attachments

Last edited:
Top