I have just bought the ArduPilot Mega 2560 Full Kit... plus the Triple Axis Magnetometer HMC5883L. I should have it built over the weekend.. then i'm off to a my mates machine shop, and i'll make the splitter plate for the lower frame onto which i am going to fit the Ardupilot. the magnetometer i'll put on the tail as suggested. I am going to use my X-cell Razor 600E. For those that dont know its around the 50 size nitro heli.
Do i need to buy any other sensors i.e. the Sonar... i can fly a helicopter all day long but this is my first time flying one with stabilisation so any tips would be gratefully appreciated.
If this works well then i am going to try and use it on my x-cell gasser. i can get up to 20 minute flights with this. But i think for the time being a battery 600 is the way to go.
i'll post some pictures when i have it all together.
Replies
Still struggling with my APM mount. I've got the case, and I've got a really nice platform under the tail. Now I just need to put the 2 together. And no, it's not that heavy. The plate is all hogged out on the bottom, it's only about 1.5mm thick with a pair of longitudinal beams left.
Currently I have the APM attached to a damper plate with foam tape. Then those two are sitting on some gel pads, all held down with a loose strap. I can see that the system works from the standpoint it's nice and loose. Should absorb vibes well. Especially with all that mass. Though the damper plate seems useless. It's mass is little compared to the APM casing, and the foam tape is much too rigid compared to the gel. They might as well be one mass. (the plate, theoretically absorbs vibes, not passing them on to the second mass)
But the darn thing is just not restrained at all. I could see it easily moving out of alignment on a hard landing, or especially in transport. And that's critical to making the thing work properly. If it moves just a few degrees, it won't fly right.
My basement is starting to look like it's been snowing aluminum!
Right now for a problem i'm having, no matter where i put the mag on my heli, it always seems to be seeing a slight field from somewhere. the only power is coming from the usb, so i'm a bit lost, the frame is carbon and maybe its picking up static from somewhere. Where are you guys attaching your mags?
The HK Dual Redundant power setup should be bullet proof!
A little to heavy for 450 size helis.
I'm a little lost as to why we need revo mix, on most heading hold gyros, ure always told to turn off revo mixing as it can confuse the system. I thought the apm worked like a HH gyro. say your pointing north, you apply collective, the tail tries to kick because of the torque reaction, the gyro just puts enough control in to keep it pointing north. The way the tail seems to look on the bench is the same as my HH Futaba.
I'm probably wrong.
Finally finished my APM case. It took longer that I thought, but also came out better than I thought, despite making a number of mistakes.... It's not perfect, but it's a good prototype for a CNC design.
Total weight with the APM installed is 125g, or 4.4oz. It's a bit heavy, but not too bad. Hopefully it proves it's worth with nice quiet gyro signals!
I've never had the 12c thing, but one thing i do have to be careful of, if i plug in the xbee it causes a restart, which is really scary, the heli was doing flips and rolls. had to shut the throttle and run like mad. i dont know if its voltage or maybe something else.
Well, I finally managed to get home before it got dark and managed to get the TR500 airborne, despite the failing light and 2 degrees of frost!
I had loaded the current MP update last night and I updated the TR500 with the latest code delivered from the current version of MP
I was very pleasantly surprised by just how smoothly the first flight went - I got rock solid stability, with no overcorrection or other shakes, using the P values Malcom uses on his 600 (P=1) for pitch 'n roll, and using the values from his screen dump of t'other day for the Yaw
Had to fly with a handful of right rudder 'cos I'd used the Tx endpoints to limit the rudder travel so as not to hit the tail pitch slider limits - but once I'd used the manual setup button for the tail travel in APM I ended up with about 3mm less than full right travel on the tail pitch slider, so no wonder I had to hold the tail with so much right pedal
I'll sort this tonight,. Also, I felt it could do with a bit more positive tail authority so I will have to alter the rate values (I think thats the right parameter to change?): if it's too vicious I can always expo it out on the ruddder D/R switch - I'm in the habit of calibrating the radio and setting the travel in MP with the expo switched out and the Hold switched in so I get the full 0 to 100% range on the collective pitch servo throws
Just about the only issue that arose was that, before frostbite set in to my fingers, the heli dumped itself hard down from about 10 feet up - the motor stayed at the same revs, so I suspect a mighty glitch in the APM - most probably it was a brownout, as the cyclic and rudder stayed in the same position and she descended under power on what looked and felt like negative pitch
Thanks to the 80's vintage Morley "spacehoppers'" there was no harm done, and not much bounce as I run them slightly underinflated (I've always found them ideal as training gear - they dont snag in grass, they slide beuatiffully when practicing flare-outs that get left a tad late, and they absorb a lot of ham-fistedness on my part
What I reckon happened was the power demands of the APM and the servos dropped the power from my Align 1900mah 7.4v rx pack, which connects to the Spektrum TX (an Orange clone since Speccy's UK prices are somewhat taking the P). It connects through an Align B6 voltage regulator.
I read with interest your posts on the various power hacks and capacitor power cacheing, butam reluctant to go thisroute unless I really have to - so I'll try again with a decent quality 8 to 10A BEC and a 3S 11.1V 3000MaH 30C pack - I just cannot see how the 4 digital servos and the APM,mag,sonar and GPS couldpossibly draw more than 8A unless a servo were shorted rather than stalled
So I'll retune the PID's and see what can be done tonight with a decent BEC and 3S pack - am not too worried about the weight as I'll need ballast to bring the CG just forward of the main mast, when the Sea King fuselage goes on, so it might just as well serve a useful purpose, and the 3S pack's ideal for this
Since the stab mode seems fine, next up is to test the Alt Hold then Loiter - one fianl questionet on this topic - I've installed my mag well aft, clear of any steel (incl screws!) with cable (pins) forward and components down. So how come the compass reafing on MP when connected is 90 degress West of where it should show - my dec value is correctly set for the locality.Does the mag rely on the GPS to reference North - I cant think that it does but cant think of a reason for the skewed compass reading
Thanks to you all for making this very satisfying maiden flight possible - your research and development work has proved invaluable!
DA
Has anybody tested the final implementation of the improved head setup code? I haven't yet. Hopefully I get lots of time to spend on this this weekend as my wife took the kids visiting family for the weekend.
I'm almost done my APM1 case. I still haven't decided the final mounting location. I started thinking about mounting it on the flanks of the heli, sort of beside the tail boom support. Anybody have an opinion on that?
I don't want it underneath. It won't fit inside the frame behind and below the main shaft, or anywhere else inside the frame. Behind and below the tail is my first option. I could also put it above and behind the tail boom mount.
I had a look at the 2.2B6 code to be get some sense of what they've done to us heli guys, in regards to the new PID tuning.
From what I can tell, they've pretty much left it alone, and I think functional. For Stabilize pitch and roll, it appears we are left with the simple P+I controller which IIRC, is how it was before. So, only Stabilize P+I terms need to be worried about. They have not routed our Stabilize PI loop to the Rate loop. That's what I was afraid of.
However, I have determined that if you don't have an external gyro, the Stabilize Yaw P+I loop is in fact routed through the new PID rate controller. I don't know how that will work out but I think it should be OK from what I've heard about Igor's PIDT1 system. It does mean I will have to retune my yaw system. Have to proceed with caution since helis have WAY more yaw authority than a quad.
If you try Acro mode, I believe you will get the new PID system. Proceed with caution! Randy and I have found the previous incarnation of Acro mode don't work at all for us. No telling what happens now. I suspect the same problems that caused it not to work with P+I will make it even worse with PID!
I have an idea on how to change Acro mode so that it works for us, and will probably look at that in near future. In a nutshell, acro mode acts like a rate mode gyro on the pitch and roll axes. I believe the problem is that the system gets confused by the vibrations from the rotor blades. I intend to make the system work more like a heading hold gyro in the pitch and roll axes. Basically, it will work exactly like Stabilize, except instead of returning to level when you release the stick, it will hold the angle you left it at.
Here's the latest thing I've been working on. I wanted to make an aluminum case for the APM, both to protect it, give me a good way to mount it and the receiver, and also to create a faraday cage. I got the bottom half done. The machining isn't great as my mill really sucks, and I'm an amateur.
I might consider making something like this for sale if there was any demand. I priced out some CNC machining and it could maybe be done for $50/each or something on that order. It's not too heavy... the bottom half is about the same weight as the APM. I don't thing it's something a 450 would want to carry around, but not a big deal for a 600.
And my camera mount I was working on, it might end up that I need to do something different. The large platform, I'm just not sure it's going to work out. The batteries may need to be back on the frame for balance. I'll see.
-
9
-
10
-
11
-
12
-
13
of 26 Next