Replies to This Discussion

Permalink Reply by malcolm churn on February 1, 2012 at 6:07pm

You dont need the 3gx if your using an ardupilot (APM) with the traditional heli software. The APM acts as a flybarless controller. 

Have a look at the main discussion here

There is also a lot of info on the wiki

I would try and get some flights on a sim before you fly yours, the APM will always level the heli in stabilise mode but you need to be able to at least hover to tune it.

Randy has some designs for a plate for the 450 to mount the APM 

Permalink Reply by Chris Pitts on February 1, 2012 at 8:54pm

I've got a few hours in the lab's copy of RealFlight, and I can hover from all angles there. I've also played a lot with Ardupilot's hardware in the loop. For the most part, we'll have a dedicated pilot with years at the sticks doing the flying when we can, so thete are options there.
Good to hear that I can be shot of that 3GX module. That'll free up the space I need for the avionics. I'll bet the XBee fits nicely in that bottom slot.

on getting that base installed, I think the base might not fit on the pro V2. It looks like it might not mate up with the one piece landing skids. I'll have to take a closer look.

Permalink Reply by Chris Pitts on February 15, 2012 at 4:04pm

Looking closely, I can't see how the plate would mate up. The 450 Pro V2 looks like it's got a pretty radically different configuration than the previous versions.

 

The landing gear is one-piece, and it's got little tabs that protrude upwards from the where they meet the bottom CF plate. They are secured with a single screw in the center of the base on each end.

 

Any plans to make a second base for this setup (perhaps also set up for the APM 2.0 hardware)? If not, my plan is to mount it aft of the main rotor on the top, where the gyro would be mounted on most of the helis I've seen.

 

I've already test flown the setup without the APM hardware. My APM 2.0 is still on backorder, so I can't wait to get some real hardware. I'm using a barebones Arduino Mega just doing HiL simulations right now.

Permalink Reply by Ravi on March 6, 2012 at 7:17am

Hi malcom, i had been following your forum for sometime. i got my purple APM2. i loaded the heli code using Mission Planner. everythings seems to be OK. i have configured it and installed it on Trex450. the setup graphs respond to the radio sticks. but after connecting the power supply to ESC the servoes do not respond. they should when you tilt the heli in roll and pitch. telemetry is also fine. i am using a flybarless head of make 'tarot'. do io have to arm APM2. and how do i do that.

Permalink Reply by Chris Pitts on March 18, 2012 at 2:18pm

If it's faulting after you hook it up to the ESC, it might be that the ESC isn't putting out 5V. The APM is really picky about voltages, and the stock ESC that came with my T-Rex 450 Pro V2 is a 6V output, which won't work.

 

Along that same thread, I have a question for the house: Is there a performance difference running the servos on 5V instead of the stock 6V?

 

I assume that they'll work, because that's what the directions say to do, but if there is very little difference at all, then I'd like to keep everything on 5V for the purpose of doing acrobatics. I think the ultimate expression of unmanned performance would be to perform autonomous acrobatics, but to do that, I have to make sure the heli would be up for heavy maneuvering running 5V on the servos.

DeveloperPermalink Reply by Randy on March 18, 2012 at 5:50pm

I think Ravi got his problem sorted eventually.  I believe he was looking at the output on the AP Mission Planner's status screen and seeing no pwm output for the servos.  In fact, the issue is just that we're not sending that info for the heli, the servos do actually move.

 

I think there is a performance difference between 5V and 6V.  I don't know if it's big enough to affect acrobatics but even at 5V, my trex450 seems pretty responsive.  I suspect it could still do flips if I was that good a pilot.