IRCHA here I come

2012 is my 5th year flying helicopters and I really want to go to IRCHA 2012.  I think every heli pilot owes it to himself to OD on helicopters for 5 days at IRCHA – from morning to night.  So at least one of my friends is going with me and we shall have a jolly ‘ol time.  I’ll be saving money and working some side jobs to pay for the trip, but going just as a spectator.

IRCHA Jamboree dates for 2012:   Aug. 15th-16th-17th-18th-19th

Nice Helicopters

If you haven’t already, take a look at the design of the German made TDR. I love the 2-stage drive train.

http://www.henseleit-helicopters.de

It’s competitor, the Diablo, is similar but different in several ways too. And then there is the belt 2-stage drive train from the Goblin. I have to say, though, the most readily available model in the USA and versatile heli that is THE QUIETEST machine is the Synergy E6/7. For that alone it is super impressive, but it is made in China and I’m not a huge fan of supporting that market.  Curtis Youngblood’s Balistic even has helical tail gears (metal), but its gears are almost as loud as Align’s crappy gears. The Trex700′s clone (I forget the name) has even worse sounding gears – terrible high pitch wine.

Vbar v5.2 gov setup

I’ve detailed 9 things to be aware of while programming your v5.2 gov (on the workbench, with no blades installed).  I hope this information will spare you allot of wasted time and give you success in setting up the gov the first time taking out the guess work.

1) The Bailout Arm light will not light up green until about 10 long seconds has passed after full RPM has been reached!!!! (this killed me so all of my initial tests were false negatives. That is why I previously stated my Bailout was not working.) Until I exercised patience only then did I have results as expected.

2) I recommend initially setting up the Motor Off slider with the idle checkbox disabled. Follow MrMel’s video #18 on his Vbar 101 series.  If you don’t disable it just be sure the Bailout Arm light is off during setting the Motor Off slider such that there is no delay when flipping out of throttle hold. Otherwise if Bailout is armed the idle feature may make the motor run and confuse you.

3) I set my Motor Off endpoint and Motor On endpoint all the way down and up until the status bar was completely empty and completely full. This resulted in having -106% and 106%. My final tweaking ended up being -114% for the Motor Off slider. That is the only way I could get combination of both the lowest idle rpm and desired bailout speed via the throttle hold transmitter value. I now do not have any delay when flipping out of throttle hold while the bailout is armed and the motor is idling.

4) To my disappointment I have found while adjusting the throttle hold value it also changes the idle RPM of the motor. This should be accounted for in the software somehow.
Repro steps:
a) enable bailout and idle modes; no blades; on the workbench.
b) spool up to full RPM.
c) wait 10+ seconds until the Bailout Arm green light appears.
d) hit throttle hold.
e) the motor should now be idling.
e) increase/decrease the throttle hold value on the transmitter and notice the idle rpm changing too.

5) Related to point #4 above, I must lower/raise the Motor Off slider until just after the motor rpm starts (lowest possible idle rpm). Otherwise if I leave the Motor Off slider to the point where there is no delay while flipping out of throttle hold then the idle RPM is too high (~1100RPM)! This should be accounted for in the software somehow.

6) Edit: The idle is much lower when the motor is engaged and blades on, etc.  Headspeed RPM was more like 10RPM, so that is totally fine.  At least on my particular setup the idle rpm is 37% headspeed (700/1900)! That still seems like allot to me. I would think maybe 5-10% would be an appropriate idle RPM. I wonder if this high idle percentage is intentional.

7 ) In MrMel’s Episode#18 video the software does not have the Idle check box present? I’m waiting on an answer on this.

8.) I’ve asked MrMel for an appendix video demonstrating the motor idle feature on the workbench to give an example of what to expect. For example, initially I didn’t truly know what to expect and was unsure during my v5.2 tweaking and testing on the workbench.

9) ** If you make any settings changes, return to normal mode with throtle stick down and throttle hold off, then test your changes. Otherwise you may experience this: During my testing and tweaking I was moving back and forth between the setup wizard and the main screen while simultaneously switching in/out of throttle hold. I was also adjusting throttle hold values on the transmitter, and adjusting the Motor Off slider. Any one or more of these adjustments caused the phenomenon where the motor would spool up to max headspeed RPM (~2200) and then very slowly lower to my specified RPM over the course of 60 seconds time.

Then follow MrMel’s setup videos:
http://heli.dacsa.net/MrMelSite/VBar101.htm

New E-Calculator Formula

How to decide on headspeed: KV of the motor, and pinion tooth count.

I have additional information for calculating headspeed RPM, but it goes deeper than before and considers motor RPM first.  There are few who delicately calculate the both motor RPM and headspeed RPM for optimal flight time and power combination.  Those two factors are my goal and [so far] have been successful not by accident.  Bottom line is electric pilots cannot look for the plug-n-play enjoyment of a nitro heli.  A nitro power setup is forgiving merely requiring motor tuning – that’s it.  An electric power setup simply requires pilots to approach setup in a calculated manor, else the consequence will either be equipment failure and/or poor flight time & power.

Motor RPM is a factor since it drives the gears.  The motor has a sweet spot – not the main rotor.  So we look at the motor speed first, and at the end we target ~85% of max motor RPM relative to 3.7v per lipo cell, and with this motor RPM should the gear ratio allow ~18% headroom.  The calculation logic is as follows:

1. End of flight should be 3.7v per cell (Lipo’s).
2. Your ESC should always exceed your max amp draw
3. Average Amps = Nominal Voltage * Motor Max Watts (conservative manufacturer specification, so perhaps increase by 10-15%)
4. Milliamps (mAh) only means more/less flight time.
5. Preferably have the highest C rating in your battery pack(s).
6. Calculate the numbers in parenthesis ( ) first.
7. Battery voltage numbers are from nominal voltage.  For lipo’s that number is 3.7v per cell (Example: 12s = 44.4v).  The reason for 3.7v is to account for voltage dropping, and allow RPM to be the same from start to finish in your flight, else you are more likely to experience RPM sag at the end.
8. Max motor RPM = (KV * Nominal Voltage)
9. Max headspeed = (Max motor RPM \ Gear Ratio)
10. Choose a desired headspeed for initial calculation only.
11. Motor RPM  = Desired Headspeed * Gear Ratio
12. Motor RPM percentage = (Motor RPM \ Max Motor RPM) * 100      And should be ~85%
13. Headroom RPM = Max Headspeed RPM – Desired Headspeed.
14. Headroom percentage = 1-(Motor RPM \ Max Motor RPM) * 100     Should be ~15%
15. Repeat steps 10-14 until Headroom Percentage is ~15% AND Motor RPM Percentage is ~85%.
16. Now, relative to a typical headspeed for this size helicopter, this is the optimal headspeed you should run for this motor for the governor to work most efficient.
1. Too little headroom will result in shorter flight time and RPM sag (bog) at the end of your flight.
2. Too much headroom will result in warmer motor temperatures, warmer batteries, and shorter flight time.

These rules and calculations should aid you in shopping for a motor and pinion, and start you on the road to success.  Naturally a higher KV motor to weight-of-heli ratio will always result in shorter flight time while it may be more powerful.  Now that is your preference.

Personally my goal is to equal a nitro helicopter’s performance since that is what I originally came from, so I opt for lower KV motors and lower headspeeds.  This doesn’t mean less power – it means more realistic helicopter performance compared to a nitro, and the electronics in your power setup will be happier.

I’m exited Vbar 5.2 just came out! So that means if you upgrade to Pro on the mini Vbar you have a gov. Check out MrMel’s videos – he is such a wealth of information and was instrumental in helping me with my gov setup. But now the setup is more simple and concise so there is less to be concerned with. What else is interesting to me is the gov programming is supposed to be more ESC friendly for weaker/slower gov’s (maybe), however still not compatible with Kontronic.  Lastly pirouette compensation has been optimized for travelling maneuvers while pirouetting, but you may not see a difference while merely pirouetting in a hover – only in an actual maneuver.   I have yet to try 5.2 but I’m anticipating nothing but good things.

What’s new in 5.2
http://www.youtube.com/watch?v=MqAc4tWZNA8

How to connect the RPM sensor to the mini vbar (Hyperion Phase sensor)
http://www.youtube.com/watch?v=c1NVKcgJN24

Pictures & Setup of my heli – Trex700e

In case anyone wants to see pictures of my Trex700e and setup information you can visit my RunRyder profile here:

http://rc.runryder.com/helicopter/gallery/56481/

IRCHA 2011 and my heli flying again

Well, IRCHA 2011 came and went pretty quick too.  Viewing the videos and pictures on RunRyder is PD-awesome.  My absolute favorites are Kyle Dahl’s Logo Xxtreme heli including several tandem Logo Xxtreme flights with Kyle and other Mikado pilots.  Then there was TSA’s pilot Luigi Rungi who totally gave a show with the new TSA Infusion 700N flying between two banners stuck in the ground, and all I gotta say is WOW.  The guy is awesome, and the heli is awesome.

As for me, a friend of mine is willing to trade heli assistance with parts so I can get my 700E back into the air again.  The last crash cost was about $250 or more, unfortunately.  I really hope my luck returns with many crash-free flights with zero dumb thumbs.  So, I may be flying by September.  I also need to get the rest of my stuff up for sale.

See you in the air,
Sam

Snohomish Fun Fly Chronicles

Well, the Snohomish fun fly 2011 came and went.  What a super fun time Friday-Sunday.  Matt Botos was absolutely nuts with the new Synergy E6 and E7.  They are very quiet and very fast.  The Futaba flybarless unit really looked solid with all the intense fast and sudden maneuvers they were doing.  I was looking forward to witnessing the Futaba units in action by some good pilots.  So far I like the Vbar, BeastX, and Futaba.

Tim S. from Oregon put on amazing shows during the day and especially at night.  Holy cow he improved big time!  Super fun to watch at night for sure.  I was having so much fun Saturday that I crashed about 8:30pm.  I was kinda tired but I was confident I could fly a fun flight with my yellow glasses on.  I could see the heli perfectly fine, but 10 seconds into the fight while doing some low maneuvers the brain signal did not send to my thumb and I crashed.  It was like I was in simulator mode or something.  It was a sure sign my brain was fried and was time to call it a day.  Here’s a little picture:

Tail shaft bearing replacemtent

Hello, Frank.
I recently made a short 1 minute video on replacing my tail shaft bearings by pressing out/in with an Arbor press.  It was easy as pie.

Tail shaft bearing worn out

During inspection I discovered the inner race of one of my tail shaft bearings was badly worn out.  Here in the video you can see wobble.  The bearing is secured, and the shaft is not wobbling within the bearing – it is the inner race wobbling  between the outer race.  Thanks to a friend I have a new set I will install Saturday.

I also took time to balance my tail assembly (hub & grips).  I used a magnetic prop balancer and simply filed away the tip of the heavy grip.  Now it is balanced, so before it might have been vibrating and maybe the reason for this bearing wear, and/or it could just be normal wear over time.  Lord knows I pirouette like mad too, so maybe that’s why.  :-D