Projects Playing with a Spektrum AR636

[LooseNut]

So like most pilots, I have a couple of the Spektrum AR636 receivers sitting around collecting dust. I also happen to have some parts Heli's sitting around as well.

I ran across some chats where people were trying to figure out how to use them in Heli's, mostly receivers scrounged from busted planes that were already programed, not just Stock units.

My stock units have the ver. 1.43 program installed which adds a lot of features you don't have on a preset unit.

Since all the naysayers jump on anyone that brings it up, there isn't much in the way of success stories out there.

Well, after playing around today, I got one rigged up on a beat up Blade 400.

Everything seems to work, and shortly after I got it working and was playing with it, the tail servo went out. All the servos are the stock E-Flite units, so no big expectation for them anyway.

Very Cool thing since I've recently set up a 7210 Beast unit, an Ikon 2, and I have two Brain 2 units to finish up, I was already thinking of how they are doing it and going about it from a "don't make changes in the TX" point of view, I was able to set up a "Flaperon Type" aircraft which uses the 2 Aileron servos for Flaps and added a mix for the Pitch (Elevator).
Everything was done in the receiver program. Sub trims, reversing, travel, mix, ect.

I can play with the Heading Gain, Priority, and Rates to dial things in as I go, but for now I'll have to dig up a few more pieces to make it fly.

Here's a quick clip on the desk:

 

[Tony]

I know you are just playing around with it, but wanted to point out you would not want to fly the helicopter this way. When you hit the elevator, only the elevator servo moved. For a cyclic, you need all 3 to move. So if you go forward elevator on this setup, you will have to increase collective as the helicopter will want to drop. If you pull back on the elevator, you will have to decrease collective as the helicopter will want to go up. Just something I noticed. But yes, it would be nice to repurpose these Rx's, however planes may be a safer bet. But keep tinkering!

 

[LooseNut]

I figure it's worth a shot. I've already been playing with a 320S and bumped the update to 4.40 to get rid of the tumble they seemed to have. I was looking over the scant programming they let you see and just got curious.
If nothing else, at least someone looking for info can find the bread crumbs I leave behind instead of a ghosted thread. That's a really annoying thing.
It can be used as a standard Rx, so if nothing else, there is that.
I'll keep fooling around with it though and see what I can come up with. I was happy to get that far. The big holdup is being a 6 ch Rx and they are using one for the F-Mode.
That leaves 5 and some creativity with the mixer.

 

[Tony]

Yep, always fun to play around with these things. And yes, keep posting results as I'm sure someone is looking for updates!

 

[LooseNut]

Started playing with Elevons and Tx needed charged. always something.
I have the Swash set at "Normal" for all this playing around. It's a Reverse Swash on the Blade, so thinking about that at the moment.

 

[LooseNut]

So the short answer is YES! It will work.
Turns out I was over thinking the whole thing. The Tx is set for 120 degree swash instead of normal, and I had to change the Pit from +60 to -60 for the Leading Link Grips.
On the Rx side, the Airplane type is "Normal" and the port assignment for the Ailerons are both #2. The Post assignment for Gear is 5 and the assignment for Aux 1 is 6. (ELE).
As far as the F-Mode, it is completed as normal, assign the switch to the Gear. If you are using a 2 position switch, then you will set up #1 and #3 for rates and gain. If you use a 3 position switch, then you can set up all three for rates and gain.
There are a lot of Vids on Youtube discussing Rates and Gains as well as setting up the Telemetry for adjusting gains at the Tx.
What holds true is setting ALL the end points, sub trims, Servo reversing, Expo. and rates from the SPS program in the Rx, otherwise, things can go afoul just like setting up a fixed wing aircraft. The Rx will see those changes from the transmitter as inputs from gusts or the pilot and either ignore your expected stability or over compensate for a perceived correction and crash.

The Rx plugs are
AIL - gets the Rear left Servo
ELE - gets the Front Servo
RUDD - gets the Rudder Servo
GEAR - left open
AUX1 - gets the Rear right Servo

Remember, this is a Blade 400, so the swash is reversed from what you normally see.

So at this point, I have it set up and working with a Poor Mans FBL head. I need to tuck in some wires and balance some blades I have kicking around, setup the blade pitch and throttle curves, and it will be ready to commit possible flight. Should be interesting to see how it actually reacts. Scary concept right?

Now, as far as setting up Safe, I ran across some interesting blogs that talked about Txt editor changing and even more interesting was a thread in RC-Groups that has an additional program you can download for making changes that you can't perform on the Spektrum SPS program. Just google a search on "Modify settings on a AR636 SAFE select receiver". it will pop up the link. Read through it, pretty interesting stuff, at least to me.

I'll fiddle with that safe of it later when I have time to run down the Rabbit Hole, my current work project is sucking all my creativity and spare time at the moment, so getting in the air with this first attempt is going to be it for now.

 

[LooseNut]

Since your Stability modes are "Priority", "Rate" and "Heading", I'm only going to play with Heading on the Yaw first, not sure I want Pitch and Roll holding a heading.

Please feel free to give some input. I'm certainly not an expert, but I don't have anything invested at this point, everything was in the boxes I had as "Spare Parts" or "Swap Shop", so if I ball it up, not a big deal other than some head scratching time.

 

[LooseNut]

BTW, this is what I mean by "Poor Mans" FBL. Yes, it's a gutted FB head. Yes, they do work, I've done it before while I was waiting on "Real Parts". Yes, the grips are flipped to make leading links.

Pretty cool huh?

 

[D.O.G.]

It's not a poor man FBL but a smart man's ingenuity

 

[LooseNut]

They don't call me Loosenut for no reason.

 

[LooseNut]

Ok, so first flight.
Checked and rechecked everything. The main shaft has some light run out (not surprising) so I get some vibration from that. The Plastic head unit is also a little wallowed out, that lends to the vibration too.
I ran it up without blades and made sure the ESC signal loss killed the motor.
I had the heading gain for Yaw at 99, Priority 125, and Rate at 99. So I figured it should stick the Yaw position and most likely wobble with overkill.
Roll and Pitch were set with Heading 0, Priority 125, Rate 80. Figured this would keep it stable in Hover and allow for light maneuvering.
No D/R, No Expo. I was going to be right on it or hit the Kill.
Throttle Curve 0 - 100, Pitch Curve 40, 40, 50, 75, 100 on FM 0.
Go Time!
Started to run it up, broke ground around 60% and had a stable hover about 2 feet off the ground. I rocked it in roll to test the stick, first left, then right. Was sitting stable and ready to try pitch and I lost it before moving the stick. It rolled right and caught the Blade tip. Hit the Kill. Bummer.
Checking it over, the Collective servo is wiped out, Gear shot and the servo sits at one end. The Aileron servo lost some teeth on the gear. Everything else seems ok.
I think that servo bit the dust just like the Tail servo did when I was setting up the system. Aside from the addition of the stripped gears, it acts just like the other one.
So conclusion of the first attempt?
I think it's going to work. I need to order a EMax ES08MD to complete the set I have and replace All the servos. Should have did it in the beginning, I've never had great life out of the E-Flite servos.
But hey! It looks like it is actually going to work on some level!!!!!
Cost at this point? $0.00
Going to order a servo, make a Main Shaft and Swap the Head to a Tarot 450 FBL Conversion unit (TL45110-02) that I have sitting in my stash. Think I picked it up for $50 plus shipping. So the whole project will still be below $100.

 

[LooseNut]

My thoughts at this juncture.

The AR636 has 3 gyros and with the Heading option on all three Axis, the Yaw should respond much like the old Gyro units on the Fly Bar heads. What it gives you is stabilization in the Roll (ailerons) and Pitch (elevator). Once I have it reliable, I'll experiment with heading on those 2 Axis, but the stabilization with rate and priority is a definite plus for learning to fly.
It's by no means a replacement for a Ikon/Brain/Beast unit, it is what it is. It's for planes and used for Heli flight. It's cheap since you can find them at swaps for $10-$30 now that all the "SAFE" receivers are out on the market. If you are helping a beginner, you probably have an old one kicking around like the 2 I have.
A cheap Flybar Heli can be found again, collecting dust or for sale on Market Place for under $100. I've acquired 5 for next to nothing. 2 Clone 450's, 2 B400's, and the ARK 500 ($80) with all the electronics in each one.
The problem is getting replacement parts for the Fly Bars, thus the "Poor Mans FBL", or spend more money to get a FBL head.
If you can put a young Guy/Gal in a easy to get started Heli for under $200, chances are they will get to the point of buying up and sticking with it rather than taking their $400 - $1000 wad of parts home and tossing it in a corner.
I'll keep working on it and post what I do, how I did it, and the failures I achieve. The challenge is fun for me. and hopefully beneficial to other folks.
Ha! I have patents on things everyone told me was impossible, "work the problem, see if it can be done", that my motto.

 

[LooseNut]

The third EMax ES08MD showed up today, so I installed servos tonight. When the tail servo went out, I installed a EMax ES09MD in it's place. So now we have all Emax servos on the B400. The openings get a little file massage since they are just a tad longer, but not enough to cause a problem, just tight if not accomplished.
The second thing about the ES08MD is that the output shaft is the same diameter, but the teeth are slightly different than the E-Flite servos I'm replacing. The Servo arms are soft enough that you can push them on and "broach" the new splines. Looking at them under a magnifying glass, they look pretty good. Up to you if you try that or not, I'm going with it. The stock arms for the EMax servos seem a bit flimsy for the job.
One thing I did do was set the servo centers prior to installing the arms with a servo tester.
With the servos in and the arms on, I set up the minor adjusts to sub trim in the Rx program.

Here's a point to keep in mind. All trims, sub trims, Expo, and D/R need to be done in the Rx. The Spektrum Rx for "Safe" mode, and in this case "Stability" mode DO NOT like it when you adjust trims in the Tx. It looks at the incoming change as if it was a Stick movement and trys to follow and compensate. That leads to some funky interpretations and "Glitches" which people complain about. You must keep that in mind. Same with the fancy Gyos systems like the Brain/Ikon and the Beast. Setup in the Gyro/Rx settings only.
I turned off the trims in my Tx just so I don't do a Brain Fart moment.

I set the Tx up like you would for a 230S with the exception of the Panic button and the Swash is set to 120 degrees instead of 90 one servo.
The Rx set up is Aircraft type: Wing type "Normal" and Rudder type "Normal". Note that "Normal" shows one servo for both Ailerons. The programing takes care of the Mixing for you.
Rx Pin out is : Ch 1 - Throttle (ESC), Ch 2 - Aileron (Left rear Swash), Ch 3 - Elevator (Front center Swash), Ch 4 - Rudder, Ch 5 - Empty (Gear), Ch 6 - Pitch (Right rear Swash).
The Mix is set by the Tx Swash 120 setup. In the "Function List", I set the Swash at Ail = 60%, Ele = 60%, and with the reverse Swash, Pitch= -60%. This reverses the direction that is needed on the B400 and is allowed by the Spektrum programing.
You will also set the Throttle and Pitch Curves in the Tx, just like on the 230S. Switch assignments for Idle Up and Flight Mode are also done in the Tx, as well as the Auto detect Telemetry.
I am running the Version 1.xx shelf stock AR636, so no "safe" mode is available.

I've got another Blade upgrade Aluminum FB Head piece to upgrade the worn out plastic one on my "Poor Mans FBL", the Align FBL will work if I adjusted the Main Shaft length and used a set of Align Blades. The Grips between the 2 Mfg's are different thickness. I'm going for cheap parts from the Scrap box, so aside from a Servo ($11.49 + Tax and Shipping), we are still on track. I'll swap it in tomorrow evening and I'll make the new main shaft this weekend.
So that's where I'm at currently.

 

[LooseNut]

I finished setting up the head last night with the new shaft and Aluminum head piece.
When I was setting pitch, I was getting +16.03 and -16.04, so I reduced the percentages, Ail +42/Ele +42/Pitch -42.
That backed the Pitch off to +12.24/-12.25.
I opted for the Change in the Tx on this because like the Pitch reversing, there isn't a way to reduce the throw for Pitch in the Rx.
Doing that reduces the resolution so now I noticed that the stabilization movement is reduced as well.
The better way is to go in on the Servo Arm. Not as easy on the B400 since the Elevator Servo runs through a series of links and bellcranks.
I'm sticking with the original Rate and Priorities that I set, so we'll see what it does. The Yaw wasn't effected since there was no change to it.
It's a little gusty outside, so I'll just wait it out, no since adding things that can go wrong in the mix.
Pics of the setup

 

[Tony]

Nice progress!

 

[LooseNut]

Thanks!
Well, I tempted the wind, got tired of waiting.
Good news is, looks like it's going to work.
Bad news is I failed the inspection of the tail boom, so here I was chasing the tail and wondering why? Powered back and thought I'd dial a little offset and there is was, plain as day looking at the boom was a whack mark from last time and it was crooked. LOL, Silly me!
So time to swap it out. Easy enough, I keep stock on hand to make them. Think I even have one I cut down from an Align 450L out in the garage.
But even in the uneven winds and bent tail chasing I had it sitting 6 inches in hover.

 

[Tony]

Ah yea, chasing tail issues. I think we have all been there multiple times for one reason or another. Awesome that it's working out though!

 

[LooseNut]

Ding is circled, can plainly see the bend from this view. Tail chaser at it's finest. Haha!

 

[Tony]

Yep, can definitely cause some belt dragging, that's for sure.

 

[LooseNut]

Not sure what folks prefer, Carbon Fiber or Alum, but in my escapades I've found Alum dents and causes less damage, if any to blades.
Any opinions?