Little update, After flying with the double "Star" plate setup it does seem to help a bit. This was flying with a haevy camera (Canon C500). I have an all day shoot tomorrow so I'll really know how it's working... BTW, I am at about 21lbs auw with the C500 and I am still getting 14min of flying time with the 5s 8000's (in parallel). Everything is nice and cool to the touch after as well. Josh
Good to hear... Looking forward to seeing the footage. what does your setup weight with everything except batteries and camera?
So the weather finally got good enough to get outside for a snowshoe and a I2C test while at it. Similar to Josh... I am running a Cinestar 8 450mm frame with APC 14x4.7 SF, Tiger 3515's 400kv, Castle ICE 50 esc, MK FC 2.1 and 6s with a Bec pro converting to 12V for the FC and of coarse the I2C converter. My MK tool settings I started with were exactly the same as my stock MK Cinestar 8 runs. Gyro D= 14 acc/comp= 90 Stability= 8 P= 100 I= 120 I was pretty impressed by how well it flew... basically just as well as the MK Bl's as far as I could feel with my setup which is pretty much setup for AP and pretty slow to transition. Maybe if you are looking for tight sport flying it might be a tad more sluggish but maybe not. I started with the above settings minus the gyro D which was originally at 30 with my other setup. There was bad vibration/grumbling and I reduced it to 14 which just about solved it... my battery in my laptop died at that moment so I was stuck with those settings for the rest of the flights. I think going to 12 or 10 there would be perfect. Some more tweaks in the gyro I and comp. A lot more power for sure and I am using 14 4.7 SF APC's which worked nicely. I still have some roll Radian hunting/jitter going on and my settings were Pan ( off mostly ) 80, Roll 140 and Tilt 120. The whole thing could be balanced a little better as well so a few factors contributing to the vibrations etc. Definitely more vibes from these motors to be considered into the equation and they caused the Radian to stutter a little. I was pretty happy with how it went and considering that I could only make one change before my laptop battery died, it went very well. So well I did a few runs with the 5D3 ( in the link below ) and also a couple with my FS-700 which looked similar if not slightly better jitter wise. I will post some of that in the next few days. I am going to Whistler for the next week and am going to do a fair amount of shooting with multiple setups and was going to put another WKM, that's sitting here, in this frame if the I2C didn't work. I think its close enough to real good that I will hold off and fly it as is with some adjustments and some Graupner 14X8's wth our Epic. Maybe even with the APC's. You might wanna download the clip to check it... vimeo really sucks these days for smooth playback.
Brad, just to confirm, you did not perform the MK flt ctr mod using higher capacity caps and upgraded 5v regulator. Instead, you're simply running an inline 12v BEC in between the 6s lipo and flt ctr board and using the original on board 25v capacitor and 5v Recom/Traco regulator? Good 1st results.
It looks nice Brad. I also started the conversion process (Still waiting for the motors though). I will try different ESC setups (Turnigy Plush with BLHeli firmware, HK Red Brick wit SimonK firmware and Castle Creations ICE) and will note the differences. I'm more confident now after seeing some several setups with this tiny I2C converter.
Brad those are great results! I will be trying a higher acc/comp setting to see if that helps my setup out. Mine is still a little jittery... but I haven't been able to get it to smooth out enough. Ill report back with how it does today. Josh
Howard, correct I didn't want to change out my FC until I knew it was going to be worth it. The problem currently with this config and the MX-20 is that I can't really monitor battery voltage so I think I will replace the recom and caps for 6s. Josh, Ya higher gyro D's for me made the thing shake big time when giving more gas so a combo of the acc/comp and less D should get you some results. I did run a bit without the Radians and the my issue is coming from them for sure as far as the roll hunting/twitching that I have going on. I am beginning to think that the center roll axis of the weight mass needs to be lower than roll axis pivot itself. There is just too much play with hobby grade servos and belts for it to sit perfectly balanced as it kind of tips back and forth. The multi flies so solid and locked that there shouldn't be an issue. Ozkan, Yes it will be interesting to see how they differ.
Ozka Ozkan is nothing wrong with the converter. It does what is meant to do. Some people are having problems cause their setup is not right. Make sure that the frequency and timing of the ESC's are correct. Also make sure the calibration with the I2c is correct. If you are hearing ckicking on the motors then the timing is out. Bill
I've been pondering how you guys might get correct battery telemetry. If you could fake out the FC board into "seeing" a flight battery voltage as though you had a 4S, would that be good enough? It wouldn't give you the actual voltage of the flight battery, but you could use it to give you a "Minimum Input Voltage" warning on the MX-20 when the "virtual 4S" battery hits 14.4v say. I haven't quite figured the best way of accomplishing this, but it might be just a simple voltage divider between the LIPO and the FC board that scales down the 6S to 4S ranges. On the FC board, the schematic shows the LIPO voltage ("SPANNUNG") being connected directly to a an analog-to-digital converter pin on the CPU, hence the idea of "hmmm, I wonder what would happen if the FC saw LIPO voltages in the 4S range?" Let me know if you think this is viable and I'll see if I can get the problem solved.... Andy.
Until recently i have used the spectrum telemetry module from the dx8 gimbal/remote to get voltage and temp> operator then gave the values. Cannot look on the display anyway! Thijm
That is indeed one of the advantages of the MX-20 -- it speaks the voltage level to you so you don't have to look at the display.... Andy.
YAYAYAYA BRAD YOUR A GENIUS! I now have the smoothest looking footage I have ever had with this setup. It's a night and day day difference between what I was getting and what I have now. It was flying almost exactly like it did with the MK BLs. I was flying in a 5-8mph wind with gusts around 10mph so there is a little bit of bounce in the footage but not even remotely close to what it was before. Current settings are P:100 I:120 D:8 Acc/Comp: 95 Stability: 6 I was also able to increase the gains on the roll and tilt Radians a LOT and it smoothed things out. After reviewing the footage on a larger screen I do have a VERY slight amount of jitter so I need to lower the tilt (thats what it looks like anyway) just a bit. Ill post up some raw footage for you in a bit. I need to tear the copter apart really quick to pack for a trip tomorrow. San Diego here we come. Josh
Very nice indeed. You must be a very happy camper Josh. So, it wasn't the coverter after all. Good to know, Now on with my project. Bill