Projects Playing with a Spektrum AR636

[LooseNut]

Totally agree with the more parts and complications getting them set up, that's why I started playing with it as an FBL, shooting for simplicity for a beginner.
The problem I ran into with the B400 is the Swash is a smaller diameter so a little throw goes a long way.
With the stock setup I was getting +16.03 and -16.04, so I reduced the Swash percentages, Ail +42/Ele +42/Pitch -42.
That backed the Pitch off to +12.24/-12.25.
I can reduce the Pitch further by reducing the percentages, but I have a feeling that it is just making it worse. Reducing the percentage reduces the resolution as well as the travel and it was pretty noticeable rocking the heli on the bench and watching the stability reaction. For that reason I started with the gains at 60% and then slowly reduced them to get rid of the shakes. 45% gains for Roll and Ele had it pretty stable, however it seemed to lag behind and let you get into a PIO trying to hold it level. Big no-no for a beginner and I was barely keeping up with corrections with the wind gusts. For the record, Heading gain is at 100%, not shake or wobble, but will drift slowly with the cross wind gusts. Head winds held pretty tight.
For a gut check I took my little B 230s out just to see how much difference there was. Not quite Apples to Apples, just something to get a reading on.

 

[D.O.G.]

Reduce the pitch on the blade and increase your head speed. You mention, " I'm persistent if nothing else " and with that can-do attitude, it will be a matter of time and you'll get it. A lot of trial and error comes with getting your Heli the way you want. +16/-16 is a crazy pitch to start off with. Start off with 10 degrees then move up in pitch. I like flying my birds at 13 degrees and awesome flyers like Geena like a higher pitch on their blades for 3-D flying. As for drifting, I would check your servo linkage size to make sure they're the same size. Make sure the surface that you put your Heli on is level and basically check everything out again just to see if you overlooked something. I'm just throwing stuff out there.

 

[LooseNut]

I'm just throwing stuff out there.

Every little bit helps.
At the end of the day, I can certainly make things work when I've dug in my heels. What I need for an outcome though is something that others can re-create and get good results. For cheap. So I have to keep reminding myself of that.
I have a tendency on my own projects to just throw money where it's needed. Or machine time for custom parts. Not an option for most folks.
I'll set it down to 10 degrees and see where the percentages end up. Second to that, I do have some shanked balls that I could use on the grips as well, That will reduce the Pitch throw and keep some resolution. I'll just have to change the link ends since the E-Flite are the smaller 4mm. But there I go swapping further to non-stock and can make it harder for a newbie to do.
Tradeoffs.
Just a note, I've been setting my own Helis up to 12.5 so it's just what I'm used to.

 

[LooseNut]

Reduce the pitch on the blade and increase your head speed

Ok D.O.G., went through everything again. Too bad I don't have some floods around the test pad. Ha!
So here's where it went. at 10.5 degrees +/- I'm at 35%. Going back into the SPS I reset the the gains. Yep, testing starts over. I played with them a bit rolling and pitching here on the desk before I made the changes and the movement was barely perceptible. Setting gains up it gets in the 70 - 75% range to be notably active, meaning what you would see in Idle 1 on the Brain.
I did reset the center pitch on the Yaw, think maybe now that it has flown the servo clamp on the Boom has found it's home. If you're familiar with the B400 you know that the front mount screw is on the frame and the back mount screw is on the Boom hanger. it finds it sweet spot after a couple flights and stays there then you tweak the pushrod.
I set up "Idle 1" so all the gains match "Normal". Up to this point all the testing has been done on "Normal" modes with the Pitch 40,40,50,75,100 and the Throttle Linear. "Idle 1" is set up with Pitch linear 0 to 100 and the Throttle 80.
So we'll try for some head speed and see how it goes.
Haha! All this farting around is probably making me a better pilot, stunts aside.

 

[D.O.G.]

Just for shits & giggles and your set your normal mode to 46/48/50/75/100. and give that a try

 

[LooseNut]

normal mode to 46/48/50/75/100

Can do that. Less negative on spool up?

 

[D.O.G.]

Can do that. Less negative on spool up?

I'm sorry but I don't understand less negative.

 

[D.O.G.]

Are you talking less negative pitch on the blade?

 

[LooseNut]

Yeah, that gives less negative pitch on spool in "Normal". Just curious, I guess I've always used the 40, 40. Keeps it planted on the spot with a little negative and never was told any different.

 

[LooseNut]

I was off reading up on the new spark fun pressure sensors, sorry to take so long to notice the reply.

 

[D.O.G.]

Keeps it planted on the spot with a little negative and never was told any different.

You want to spend the least amount of time on the ground. Tony gave me those numbers when I first started to fly and I've used those numbers for normal ever since. I'm lost then. I found a video that Tony made. You probably know most of it but there could be something in this video that might shed some light. Take a look

 

[LooseNut]

Ok, so just for the record.
I am neither a Newbie nor an Expert, I have been playing with Helis for a couple years and can competently get up and down and fly around the yard. I've watched lots of vids on Youtube and used the MFG manuals for setting the particular Helis I've flown, asked many questions of the few Heli pilots I know, and made some adaptions based or recommendations for them and Youtube stuff, sometimes with mixed results since as we all know, just because someone makes a Vid, doesn't mean they know what they are doing. Crap shoot Vids.
My muscle memory has been adapted from flying fixed wing planes for practically 50 years. I started with a rudder only Galloping Ghost in a .049 powered Lil Esquire. If you've never flown and trimmed a plane for Rudder only flight, you don't know what you've missed.
I've spent much of my career working with development of prototype equipment and the last 11 years designing and developing training systems.
There is a method to my madness. I also know that a successful project takes far longer without group input good or bad. Sometimes we find the answers we seek when things go haywire.
So about 8 am this morning the wind was calm, I'd had a cup of Coffee, and the sky was blue. Perfect time to put the latest changes to the test.
Setting aside caution, I spooled it up, flipped to Idle up one, hopped into the air about 2 feet. The the proverbial poop hit the fan.
The tail started a fast right drift and a left roll ensued. The speed of destruction far exceeded counter corrections as the left rudder and right roll overcorrections just meant hitting the ground in the opposite orientation with the tail dropping. (Elevator? or attitude change causing pitch change?)
So the results? No Boom strike this time. I hit the throttle hold fast enough not to wipe out the gear, no breakage to the frame/skids/tails that I have found. What it did tear up was the Main blades, the Tail blades, as well as a slight tweak to the Main Shaft. I've examine it more when I do repairs.

 

[D.O.G.]

Ok, so just for the record.
I am neither a Newbie nor an Expert,

But you have more knowledge and yrs in this hobby way more than I do so I'm sorry for underestimating your talent. Good luck!

 

[James M. Lewis]

Holy Cow LooseNut!!!!!!!!!!!! That was also my very first bird "Galloping Ghost" while station in West Germany 1972-1975 Man did I have fun and you're so right about "Rudder only". Was so into it my wife said I had "ants in the pants" doing more moving than the aircraft was. Talking about muscle/mind memory, think I brought back the "twist" the way was moving about. Glad people saw me flying, otherwise someone would call the nutty wagon with the straight jacket. Real bummer about your mishap. I never did get over losing either an airplane or helicopter thru the years. Guess that's my greatest fear in the hobby. I can relate to where you're coming from in your profession, my was the maintenance of army helicopters. Just waiting for my new FBL's to arrive, order (2) for my Augusta A109 already built (over a year's worth) and my 450 size CH54 that am presently scratch building. It's fuselage is made of 1/16" plywood and nearly 3' long and has 13 parts. Included a picture of one in my earlier trends. When finish this fall will have close to 100 hours in it's built. Very new to FBL systems and fortunate to live near fran11784 (a member of our forum), who knows his stuff about aircraft. I know you'll figure out what went wrong and have her fixed up like new. Your input is excellent reading and a great source of information. I've learn from so many people in this forum and yours is also in my archives.

 

[LooseNut]

I'm sorry for underestimating your talent.

D.O.G. no sweat, I just wanted the basis in for later readers, I really appreciate the inputs from any source, all data points to consider. There is something going on that I haven't caught yet. Pretty sure it has to be vibration related and after reading the reasoning for the later model SPMAR636 having an aluminum bottom I think those thoughts are starting to gel.
Everything has a frequency, harmonics is a common term, that can be amplified by additional vibrations and become self cancelling. Similar to tossing rocks in the lake and watching the ripples cancel as they cross.
Since the AR636's I have are the earlier models with 3 gyros and probably without the accelerometer (not verified yet), I'm guessing that the Aluminum bottom changes the frequency of the vibrations enough to overcome the interference with the gyros.
The Canada RC forum had a fellow that made his own plate at 7.7 grams after comparison weighing two of the AR636 Rx's and claims is solved some issues in the 230s. He also updated to the newer version of software for the 230s as well. I did my own 230s to the Version upgrade and it cured the problem with the right roll/tuck it always did, but I think that the weight/mass of the B230s was different enough from the B270 that it wasn't a problem. The B270 is closer to the weight/mass of the B400 and it's quite possible that the same resonance is appearing and fouling the gyros. Later posts to the same thread mention others success.
I'm going to make a plate this evening and get the Rx re-mounted as part of the rebuild I do. So we'll see what happens. It was certainly perplexing to wag the Heli around on the bench and see all the stability working and then have it sit mute when needed in actual flight mode.
BTW, I'm going to change my B230 pitch curve and see/feel the difference so I know what to expect. I have the most flight time on it, so I should get a good read.

 

[LooseNut]

I brought back the "twist"

Hahaha! Now that's funny!! I don't think I was dancing around so much, but doing loops to keep it from climbing out of site was always a gas. I think the toughest part was gaging the altitude/distance to have a greaser landing somewhere close enough to retrieve the plane without looking like you were pretending to fly Free Flight.
Crashing was just a part of flying back in those days, the GG was on 27 mhz with a regen receiver, same as the CB's, Dad flew on Ham Band 53 mostly until the later 60's early 70's, when he was building sets for the guys in the club. I still fly with a fellow that has one of Dad's rigs and fly's it.

 

[James M. Lewis]

I got some oldie by goodie color photos in 1974 & 1975 with a German & American club that I was a member. I was station at an old Luftwaffe air base we took over after the war. During it's hey day they flew Messerschmitt Bf 109s and latter in the war the first Messerschmitt ME 262 jet planes called it home. A lot of history there and we had a German who as a youth was station there. He ran the Army Recreation Services and had tons of old Black & White photos to share. Will try to download them for everyone to enjoy. It was in 1975 that I saw my first RC helicopters built by two German friends. Nicest bunch of guys you could ever met. We all were family

 

[LooseNut]

Roger that, would be nice pics to see. Just so we don't get too far off topic, probably best to post them in the Lounge section though, good place to reminisce.

 

[James M. Lewis]

The photos I have are of the RC club not of WW2.

 

[LooseNut]

Right, but this thread is for the AR636 under the Tech section for Helis, and we wouldn't want to have an interested person having to dig through off topic stuff to find information they are seeking.
I'll start a Reminiscing thread over there, I'll show you some old pics too. If I stick it in the wrong place I'll have Tony move it.