MX400 Pro default motor and ESC in-flight volt/amp chart

[xStatiCa]

My fist attempt at getting a graph of the volts and amps during a flight with my MX400 Pro. I do not have the RPM sensor so that important info is left out. My throttle curve is 100/80/100 with -10/0/+11 pitch.

I started out just hovering and some slow forward flight. I then did 3 max climbouts about 10 seconds apart in the middle. The battery had about 2 - 3 minutes of use on it before starting this session.

Looks like the default ESC is hardly taxed with AMPs. This explains why it is hard to tell it is even warm after flights. I was always curious how much current was being drawn because it was always so cool to the touch after flights.

Just got an eagle tree micropower e-logger and I am excited so I had to post something :).

[broncomech]

Your graph looks very simular to the ones I am getting on my new EagleTree logger. I was sent the optical RPM sensor vice the halleffect I ordered I figured I would give it a try but have had poor luck getting clear RPM data, many spikes to 25k+ and drop off to zero. I think there is too little flat surface on the main drive gear for the sensor to work properly.
Do you have the temp probe for your logger?

[xStatiCa]

I don't have any extra sensors. I plan to get the optical RPM sensor when my local hobby shop gets them in. They got the loggers but none of the sensors were shipped to them.

I assume you painted half of the gear black correct? Are you sure it is aimed properly? I can't wait to get the RPM sensor so I hope I can get it to work. Can you post some pictures of your RPM sensor installation?

[broncomech]

http://www.helifreak.com/album_mod/upload/32a78e5d7922dfc20c92a0cb80b10406.jpg

Yes 1/2 the drive gear is painted flat black, I attempted black magic marker but it was too shiny to work properly. I am not 100% sure the sensor is properly aimed as the instructions do not mention orientation of the sensor windows. mine are mounted paralell to the black/wiite line on the gear face, the mount is twisted for alignment. I originaly had it paralell to the frame but signal loss was excessive
The mount is .025 brass and the sensor is held on with heat shrink to allow for vertical adjustment for the gap. The foam tape behind the mount is to dampen vibraton, without it I could not get more than a few seconds of logged rpm before loss of signal.
I have ordered the magnetic pickup and hopefully can get more reliable results with it. I plan to mount two magnets inbeded the underside of the autorotation gear and mount the sensor to the lower frame useing the screw just below the optical sensor and some more brass shim.

[xStatiCa]

My RPM sensor and temperature sensor was delivered yesterday.

I have my rpm sensor installed with double stick tape. I don't have any copper stuff to use. I now just need to remove the gear and paint it half black now. Did you use any special kind of paint or did you just use standard flat black paint at walmwart?

I installed the temp sensor too but I have a feeling it will not work very well without finding a way to keep the sensor against the motor. I have it just looped around it currently.

My first flight will hopefully be tonight after I stop by walmart for flat black paint. Hopefully the paint can dry in an hour :).

[xStatiCa]

I have installed an Align 430L motor and Jazz ESC since the last graph but here is a test spoolup I did which shows that the RPM sensor is working. I used Krylon Ultra Flat Black. I will take a picture of my installation later tonight and post it.

The flat spots in spoolup was me doing that on purpose and not normally how I spoolup.

My headspeed is still way to high. I plan to reduce my throttle from 65% to 55%. I think I am way outside the best RPM range for the default wood blades. I really want it down to about 2400. I really like this Jazz ESC. It will be interesting to see how it holds the RPM later tonight when I get a chance to fly it.

[xStatiCa]

Looks like I need to tweak something because outside the optical sensor did not work hardly at all. I will try moving the sensor closer but it is already about 2 mm away I think.

I added a zoomed in view of a section that did work with the RPM during a max climb. Looks like the Jazz keeps the RPM within 51 RPM during a max climb. Very good results it seems.

[xStatiCa]

I moved the sensor from 2 - 3 mm to 1 - 1.5mm. I will try it again tomorrow to see if that helps the optical sensor work properly during the day. I just did another test at night and it worked just fine.

It turned out that my crash did not do any damage. 15 - 20 foot fall with zero damage. 1.5 feet of grass seems to be a nice cushion as long as the blades aren't spinning :).

I aslo attached a pic of my mounting setup.

[broncomech]

I think you may be on to something with the daylight causing problems with the rpm sensor's ability to generate a solid signal. Your graph above looks like most of mine generated durin full sun light flights. My evening tests in the driveway have produced much better rpm graphs but still have spikes or loss of signal errors.
Check EagleTrees site for the latest update for the logger software and firmware as that addresses the rpm spike issue.
http://www.eagletreesystems.com/LatestApps/Plane/beta/setup.exe
I was also using ultra flat black for 50% of the drive gear and bare plastic for the other half. You might try painting the other half with flat white and see if that reduces the error to an acceptable rate.
I am switching to the magnetic pickup when I rebuild my heli. After my last crash it needs a new lower frame and a seesaw that the screws will stay in along with a new main drive gear. My EagleTree logger took a hard hit and is still working fine but it is going to get moved to a more protected location before its next flight. I will keep you posted on my progress with the magnetic pickup once I get back in the air.

[xStatiCa]

I am already using the latest beta software and firmware that goes with it(as of 4 days ago anyway 3.77 ).

Since the sun beats down on the gear I have a feeling that moving the sensor closer will not help things enough to make the flooding of the sensor go away entirely but hopefully it helps a little. I still havent had a chance to test it yet in daylight. The sensor needs to use a frequency of light that the sun doesn't emit ;).

It would be interesting to know if the magnetic RPM sensor would work on the outside of the 430L motor. I have heard that using that method works as long as the magnets of the motor can be detected from right outside the casing.

I use the plastic seesaw with the machine screws that come with the aluminum hub and bearings from towerhobbies. They are much longer than the normal self tapping screws. They are a bit too long when going into the plastic seesaw but placing the washers on the outside helped that. I am pretty sure the washers are supposed to go between the seesaw and the aluminum hub but it would be a pain getting them in there anyway :). I don't think there is any chance they are coming out becaise they seem pretty tight and are almost touching the arms on the head side.

[broncomech]

I have heard that the mag sensor can be used on outrunners but I don't know if it will work with inrunners as there is a lot of separation between the rotor and the case plus the field generated by the windings between the magnets and sensor may cause inaccurate readings. I will try and see if I can get any readings off of my stock Helimax motor first then one of my home built CDRom based motors and let you know the results.

[broncomech]

Results are in-runner no rpm sensed, out-runner works great just need to ensure the number of magnets per rev is set properly.
Mag sensor is on the heli after some work on the mount I have the first powered run with good results. set up is 2 magnets embedded in the auto gear lower side, sensor mount is attached to the aft motor mount screw
and the sensor is shrink wrapped to the mount.
Attached graph is first 2 runs with no rotor head/ blades installed. parts on order so no real in flight testing will be conducted until next week :(

[xStatiCa]

How did you embed them in the gear? Any pics would be appreciated. I might buy the magnetic sensor if I cant get the optical one to work properly. I am not giving up on the optical just yet though.

[broncomech]

I will post some pics in the morning of the sensor install.
Basically all you have to do is find a drill bit that is the same diameter as the magnets then select two points 180 degrees apart and inboard of the teeth to prevent damaging them then drill just deep enough to get that magnets flush with the gear surface. Make sure you install the magnets in the proper orientation and seal with thin CA, I clamped mine with wax paper over the gear & mag to ensure a good bond to the gear but not to the clamp

I might buy the magnetic sensor if I cant get the optical one to work properly. I am not giving up on the optical just yet though.

Give the shield a try that could be what I was missing to get mine to work consistantly. doesn't have to be fancy you could use a styrofoam plate and scotch tape to construct something light and easy to attach

[xStatiCa]

Installed the longer boom and align 325 wood blades. Going from the 280 helimax (290 align equivilent) wood blades to the align 325(helimax 315 equivilent) I had to shave some off the end that goes into the blade holder because it was binding with the feathering shaft lock nuts. I had to swap the align blade spacers with the helimax spacers from some broken blades I had. This required drilling the spacer screw hole (not the main blade bolt hole) a little further out because the align's spacer screw is further in than the helimax spacer.

I lost about 200rpm doing this which brings my RPM down closer to what I was wanting :). I used to get 2640rpm with a 280/290 blade at 60% throttle but now I get 2440. I might be able to stay with the 11 tooth pinion now and go up to 65% throttle at 2510rpm or 70% at 2600rpm.

The graph below is a log of the headspead per governed throttle position. I only did 55%, 60%, 65%, 70%, 75%, and 80% throttle in that order. You will see the flat spot at each position on the graph.

I haven't flown it yet. Almost afraid to :)

[broncomech]

Sorry I didn't get this posted yesterday

[xStatiCa]

Thanks. Any particular reason for choosing the underside of the auto gear instead of the top side of the main gear?

Btw... I finally got a chance to test the optical sensor outside with it moved closer. It was a little better but still not very good at all. I might just keep it as is and only do rpm testing at night under some parking lights at and empty parking lot.

This was the first actual flight of the extended boom and 325 blades with the 430L motor and Jazz ESC. Oh my!! This thing is a rocket now. I used to be able to go to full throttle and watch it slowly climb for a few seconds and end up at 30 feet or so. Now if I were to hold it for that long the thing would be 150feet in the air. I need to tame it down by reducing main blade pitch or I am going to crash this thing quickly.

I was trying to run it at 2500 RPM but there is some bad vibrations even with things locktited and tightened good at that RPM which was causing things to loosen like the belt because of the carbon boom slipping and the horizontal fin loosened up all the way(plastic mount). This caused more vibs which really screwed with the gyro causing the ESC's governing mode to go crazy trying to adapt to the constantly changing tail rotor pitch. I bumped the RPM up to 2600 and the bad vibes seem to be gone now for the most part and everything is purrrring now with insane power. I do still have a slight yaw drift to the left that I need to figure out. I am at 75 gain on the gy240 already and it is not gone yet so I will try going to 80 next flight and see if that fixes it.

After all this though I probably would have been fine staying with the default motor for awhile longer as I am just at the forward flight stage even though I am starting to get comfortable with hovering and moving around inverted on the sim. I will probably end up reducing my main blade pitch to tame this beast until I need the power.

[broncomech]

Thanks. Any particular reason for choosing the underside of the auto gear instead of the top side of the main gear?

Yes there were a several of reasons;
1. auto rotation gear runs truer on my MX
2. I am on my 3rd main gear now if the mags were mounted there it would require more work to relocate the magnets........ (lazy) :roll:
3. Eliminate the need to use any twisting in the mount, hopefully this will reduce vibration induced errors
4. Existing screw locations and space were better under the auto gear for the mount style I used.
Almost forgot to add one of the main reasons for using auto gear.
5. Head rpm for spool down can not be recorded if using the main drive throttle off = zero rpm long before the rotor stops.

[broncomech]

That is the most stable readings using the optical rpm sensor I have seen so far with this system on a small heli, what sample rate are you using?
I have been using 4X per second to allow for more record time between downloads for normal flying and 10X for setup testing.
I was forced to fly indoors today due to high wind so my first flight with the magnetic sensor was an average of 18 inches off the floor with a couple of shut downs to adjust tracking.

[xStatiCa]

The RPM recordings were done at night at a parking lot (with lights of course). 10 readings per second is what I use. The Jazz 40 ESC helps govern the RPMs pretty well :). The readings in the sun are pretty useless for me. I might switch to the magnetic sensor but for now I just make sure to fly at night when I need the RPM data.

[broncomech]

Here are my latest numbers, nice easy 5 min flight in the front yard/street with a set of Align carbon 315 mains donated by my friend. These blades refused to track on his MX400pro with all Arc/Helimax aluminum upgrades from the swash plate up, best we ever got was 3/8 in split. I'm running Align plastic 450Xl grips, pitch rods, and feathering spindle in the MX400 aluminum center mast. Tracking is much better but seems to change every flight from dead on to one blade thickness out the next then back, I can't figure it out unless there is some minor slop causing the tracking change.

[broncomech]

.delete duplicate post

[xStatiCa]

Were you just hovering? The amp draw seems pretty flat/calm.

[broncomech]

Not really hovering but close to it, mainly just doing lazy eights at about ten mph forward speed. I have limited room to fly , two lane street with sidewalk on each side by eighty feet long lined with lots of trees to avoid so I keep it slow and easy at home.

[broncomech]

Here is my latest log still on the stock motor and starting to find its limits,
its about time to upgrade to a 430L motor.
I got 3 good flights in today working on flips and some inverted flight with a few loops and rolls thrown in just to mix things up.