Version 2.4 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area. Although not as big a change as the 2.3 release, it still includes a respectable number of enhancements and bug fixes.
The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P in 25% steps.
Thanks go to the numerous contributors including users and their detailed bug reports, developers and testers. Hopefully all together this will add up to a nice smooth release!
As per usual, please post your comments, issues in this discussion. For enhancement requests for future versions, feel free to add them to the issues list. Note: you can "star" an issue to receive emails when someone comments on the item. On the dev side it helps us because we can get an idea as to which feature requests are the most popular by sorting by the number of people how have starred each issue.
It is a bug fix for an issue that one of the other users encountered. The bug was that a print command to the serial port was causing a delay which in turn caused an issue with the APMs ability to measure the current roll/pitch information. It would have happened when switching modes (loiter to stabilize) under certain conditions.
I saw the posts on floating motor mounts, nice, but that's more engineering than I want to get into at the moment.
I will try some things tomorrow - I want to try add more weight to the board (in small increments), change the foam again, re-balance props, lower RATE_D and change motor/ESC around (to make sure it's not that).
Was hoping that this had some software solution because basically as more people get their APM2's online this is going to become an issue. The variation of vibration insulation used around the world will be so extreme that to get the "right" type and amount will be a real hit or miss affair.
Also, forgot to mention, that the motors test should work for hexas now too.
I've ordered 3 of the rangevideo antivibe mounts Chris mentioned. They basically suspend the tray in between rubber bands. Until they arrive I'm gonna make my own similar affair, but tonight I am currently cutting up silicon cake cases to go under each motor, I'll report any improvements.
Also I've found that lightly rubbing sandpaper down the leading edge of the props can help alot, Occasionally they have sharp edges which cause the prop to buzz even when its balanced.
This is true. While it makes sense to make the unit mechanically smooth, there are many variables that can induce vibration and maybe some degree of software filtering of obvious vibration could help.I think I might try to get some auto hose and build some dampers ($9 x 16 for premade is a little pricey)
For this reason i've only APM1 on my quads.
APM2 uses sensors much more accurate but also very sensitive, and I think that still needs to be improved the filter that discriminates wrong vibrations.
I do not think is a good idea to hook the APM2 with the o-ring, in time you know that gum glazes and easily broken, an o-ring falls off in flight I think is a bad experience.
I have to ask Chris to send me a APM2 to make comparative tests.
Did you stay throttled up between the first and second landing?
I don't think it necessarily has anything to do with which motor has the vibes. Could be the right/rear, but not necessarily.
ArduCopter 2.4.1 on MP and GIT:
For all users who are already using version 2.4 I strongly recommend upgrading to 2.4.1.
That fixes a small problem, however, is not indifferent.
Is not necessary to reset the eeprom or APM after the upgrade.
The motors test that I created for the hexa is not included in the version inside the planner upgrade, but only in the GIT (at the moment)... thanks to Max Levine for the first structure of this code.
Yes, you need to avoid decoupling the board from the airframe in the frequency which the airframe can respond at, or else you get control oscillation. I think APM controls come out at 50hz, and the DCM is running at 200hz. So, the sweet spot is to have a mount which is coupled above 50hz, but decoupled between below 50hz.
I had my APM mounted on mounts with a natural frequency around 20hz, and it wasn't working. I couldn't even take off because the control oscillation was so great.
I think there's an easier way to make anti-vibe motor mounts. Use the style similar to what I've made, ring mounts. They are designed to be used in tension, so you don't need an elaborate system. Just got get some automotive oil hose, maybe 3/8" ID. Cut it into rings. Drill two holes and push M3 buttonhead screws through. Then stick one mount between each leg of your motor mount and the motor. So you'll need 16 for a quad. Done.
I would suggest sticking some lead plates to the bottom of your APM2, then putting it back on the foam. That will change the natural frequency. You should be able to get lead at the hobby shop, as airplane guys use it for balancing.
So you insulating the motors from the mounts? Won't the vibration be transferred through the screws anyway?
Edit: Sorry didn't understand initially, so two connection points per motor, one between motor and rubber ring, the other between mount and ring, motor totally insulated?
should the motor test works with quads? i was geting crazy here.
Thanks for your job,