Wanting return to base on plane
« on: January 31, 2019, 12:34:29 pm »
Hello librepilot family,
 I have a revo nano that I want to put in my ZOHD Nano Talon.  The main reason I want to put the flight controller in the plane is I'm new to flying far away from myself, so I want the insurance if I lose control link that the rtb will engage and fly the plane toward me untill I can regain control and take the plane over or I wouldn't mind if I had to flip a switch to engage the rtb.

Questions
The nano talon is a vtail, can I set up a mix for it to work with LP

 Is that RTB possibility? Can I set librepilot up to do what I just described?

I pretty sure I need a gps, is there anything else librepilot will need to engage return to base?

I have been looking at this gps. Will it work?
https://www.racedayquads.com/products/rdq-bn-880-flight-control-gps-module-dual-module-compass-with-cable
 
I have been thinking of putting one of my quadcopter motors on it and that got me thinking about esc and what esc protocols are supported?one shot? BLheli_s? BLheli32?

So if I put the revo nano in the plane and change the esc, I'm thinking I will need a bec, ubec, anything to provide power. So I think to keep things simple i think I should just run the flight controller at 5v so I can power servos off of it.

I will be running 4 and 5 cell battery so I will need a Step down converter does anyone recommend one? Buck? Switching?

What voltage does Servos run at?
 And how many amps do they pull?
I know they are all the different but would 1amp be enough to run 3 Servos? Or do I need 1 all per se

I have also been thinking a osd would be nice,  does anyone recommend one or know where to get one?
« Last Edit: January 31, 2019, 01:19:21 pm by AerialPerPlexity »

Re: Wanting return to base on plane
« Reply #1 on: January 31, 2019, 04:22:50 pm »
To answer a few of your Questions
The nano talon is a vtail, can I set up a mix for it to work with LP- Yes LP has a very powerful mixer but I have never used it

 Is that RTB possibility? Can I set librepilot up to do what I just described?- Yes many use Revo to do this. I have one on flyingwing working well

I pretty sure I need a gps, is there anything else librepilot will need to engage return to base? Yes you will need gps, a DJI clone one works well there is a fourm page on gps for revo
 
I have been thinking of putting one of my quadcopter motors on it and that got me thinking about esc and what esc protocols are supported?one shot? BLheli_s? BLheli32?  On wiki page it tells you what esc are supported at the moment

So if I put the revo nano in the plane and change the esc, I'm thinking I will need a bec, ubec, anything to provide power. So I think to keep things simple i think I should just run the flight controller at 5v so I can power servos off of it.
I run a BEC for the FC it's better than using a BEC off esc more overhead.

What voltage does Servos run at?
Normally 5v to 6v for the servos you would use for a mini talon
 And how many amps do they pull?
Depends on type
I know they are all the different but would 1amp be enough to run 3 Servos? Not enough remember you are powering other items as well eg FC, gps, osd

I have also been thinking a osd would be nice,  does anyone recommend one or know where to get one?
Yes VirtualPilot AEROMAX OSD works well.
Or any mwosd or miniosd.

Re: Wanting return to base on plane
« Reply #2 on: January 31, 2019, 06:34:05 pm »
Oops looks like @hawkview beat me to it.  I will leave it though.  You can see several ideas.

I'm new to flying far away from myself, so I want the insurance if I lose control link that the rtb will engage and fly the plane toward me until I can regain control and take the plane over or I wouldn't mind if I had to flip a switch to engage the rtb.
This is very important and smart thinking.  Two ranges to worry about.  To fly close to max RC range, you must have RTB setup and all the pieces that means.  To fly close to max FPV video range, you must use self leveling "Attitude" mode, else video goes out, you try to turn around and you don't know if you are upside down.  :(  Important to realize that flying behind trees or really anything (hill, building, etc.) can make it loose connection.

The nano talon is a vtail, can I set up a mix for it to work with LP
Yes.  Simple part of setup.

Is that RTB possibility? Can I set librepilot up to do what I just described?
Yes, but for fixed wing, it is a less documented, and more difficult procedure.

Is there anything else librepilot will need to engage return to base?
Mag/compass is required.  This is built into the Revo class FC, but we usually recommend to use an aux mag built into the GPS you buy.  DJI GPS is the easiest one to use as it puts both GPS and mag data on a single connection.  Aux mag (vs. onboard mag) is a little less important on large aircraft or fixed wing than on quadcopter because fixed wing has only one motor and you can often install the FC farther away from mag field sources (ALL high current wiring with motor power on it).  With aux mag, you can move it away from mag field sources (magnets and high current wires).

I have been looking at this gps. Will it work?
https://www.racedayquads.com/products/rdq-bn-880-flight-control-gps-module-dual-module-compass-with-cable
I believe that is a uBlox GPS and as such it will work.  I don't think it has a mag/compass if you want that though.  It has a mag/compass that looks like it is compatible to work as an I2C (FlexiPort) (APM) aux mag.  Ebay also has some cheap APM GPS/mag; about $16 shipped.  Whatever you get, you will probably have to solder the correct connector on it.

I have been thinking of putting one of my quadcopter motors on it and that got me thinking about esc and what esc protocols are supported?one shot? BLheli_s? BLheli32?
Same ESC protocols are supported for fixed wing and for quads.  Fixed wing does not need fast ESC response, so even 50Hz PWM ESC protocol is fine.  Make sure your ESC protocol works with the version you want to use.  You may consider using "next" instead of 16.09.

So if I put the revo nano in the plane and change the esc, I'm thinking I will need a bec, ubec, anything to provide power. So I think to keep things simple i think I should just run the flight controller at 5v so I can power servos off of it.
I fly 3 cell fixed wing with just the linear BEC built into the ESC and four 9g servos.  I would NOT do that with more battery cells because of increased heat from linear BEC.  Also, I always mount the ESC on the outside of the plane for good cooling.  You need good cooling airflow for it to survive a whole flight.

I will be running 4 and 5 cell battery so I will need a Step down converter does anyone recommend one? Buck? Switching?
I have used the HobbyWIng 3A for some small purposes like that; functional and inexpensive, but I don't have a lot of aircraft that use them.
https://www.ebay.com/itm/HOBBYWING-RC-UBEC-5V-6V-3A-Max-5A-Lowest-RF-Noise-BEC-for-RC-Quadcopter-Drone/161905000720

What voltage does Servos run at?
And how many amps do they pull?
I know they are all the different but would 1amp be enough to run 3 Servos? Or do I need 1 all per se
5V or 6V.  5V is fairly universal.  6V is for more strength and speed but really not needed for small to normal sized planes.  Expect a couple hundred milliamps max per small servo when they are moving at full speed and not binding and much less when quiet.  You can expect probably 500ma for all servos combined for a small plane and good servo linkages and hinges.

I have also been thinking a osd would be nice,  does anyone recommend one or know where to get one?
MicroMinim OSD with MSP protocol is probably the standard here and elsewhere.


Failsafe is the key to RTB.  There is RC based failsafe (RC sees signal loss and sends different servo pulses to FC) and FC based failsafe (RC stops sending servo pulses on signal loss and FC does all the failsafe stuff so modes and trims are set in FC).  Understand and pick one and make sure it is set up and works (test it for a second with say full up elevator set up).

Onboard RF sources:  Be aware that onboard transmitters such as FPV, telemetry and switching BECs can reduce your RC range and can also affect your GPS satellite count.  I actually use OpLink as an LRS for several of my fixed wing GPS planes.  Ground range test with these transmitters off and on to compare if they affect anything.

Twisting all high current wiring from battery to motor, and routing these away from mag sensor is important to help avoid these mag fields affecting mag sensor.

There are some extra things about fixed wing GPS flight.  You need to enable GPS speed based PID reduction or your roll/pitch PIDs will oscillate (looks like flutter).  I always leave rudder set to unstabilized manual.  I always fly manual mode first.  You need to adjust Rate, then Atti PIDs, finally Airspeed PIDs and several airspeed limits.  Pick some flight modes to use with GPS.  Test RTB "hover" LAST then longer RTBs.  This is a long process to get it all working, but it is fun to make a waypoint flight and have it fly itself.  You may need to set all waypoint error destinations to -1 to disable that if you don't have all your airspeed PIDs and limit settings done correctly.  There are hacks to skip these setups...

Does your canopy have magnetic hold downs?  That is a no-no.  My testing show that the mag sensor needs to be over 1 foot / 300 mm from my mag hatch.  I often mount my GPS/mag on top of the rudder to get it away from motor wires and hatch magnets.

One last thing.  There is a PID windup in manual mode so that when you switch to Atti (Rate less so) it (aileron/elevator) goes crazy for a few seconds and you have to hold full control to make it more level.  There are several work arounds.  Reducing throttle to zero when you switch modes zeros the PID windup (unless you disable that, don't disable).  After setup, using Rate mode instead of manual stops the windup and feels very much like Manual.  Also, I hear (from @jdl) that using a Stabilized#N switch setting, but setting all stabilizations for that switch position to Manual works around this (if I recall our conversation).

Personally, I think everyone should use a Bixler 1 for their first GPS plane.  :)

You will definitely have a lot of questions.  :)
« Last Edit: January 31, 2019, 09:50:19 pm by TheOtherCliff »

Re: Wanting return to base on plane
« Reply #3 on: January 31, 2019, 11:59:09 pm »
Wooow!!!! That is alot of great information! Thank you very much for that. So yes my plane has magnetic hatches, but i think I can take all the magnets out and be okay with the help of some tape on one to hold it in place . I will have to come up with something to hold it in place.  In LP can I set up an idle up switch.  What i want to do is when I arm the plane the motor is completely not moving with zero throttle and then when I flip a switch the motor will spin almost like the prop freewheeling so when I'm at zero throttle in the air the propeller Will still be spinning and then when i am landing I would like flip the switch So then I could stop the prop to land. Im just curious if its possible?  What port does an aux mag usually plug into? Flexi? Main port?  If its not built into the gps. Wha do you think about this osd?

https://toyzdepot.com/products/youngrc-micro-minimosd-minim-osd-mini-osd-module-w-kv-team-mod-for-f3-naze-flight-controller?gclid=Cj0KCQiA1sriBRD-ARIsABYdwwHsBPUrtdG8TNsjS64tHqZ6_yBPflyHd1A45S6Uqghg4XuCYGwmAtoaAiU2EALw_wcB

And that bed you suggested looks good. Exept it would take until I mid March early April to ship to me it says. So I'm going to order one from Amazon. Thank you so much guys. I'm sure i Will have more questions next time

Re: Wanting return to base on plane
« Reply #4 on: February 01, 2019, 05:33:17 am »
Some things to be aware of:
- it won't arm unless the throttle is completely off
- a stopped prop generates less drag than a slowly spinning prop (strange but true)
- you can do what you ask with the transmitter throttle trim
- you can probably do what you ask with some fancy transmitter configuration

That OSD looks like the standard MicroMinim OSD.  I believe that is the one that most people use.  Small, light, cheap, sold everywhere.  I like to solder wires to it rather than buy it with pins installed, but to each his own preference.  $5 shipped from eBay.  As with the BEC, if you don't like waiting, you can find a different eBay seller that has faster delivery and still has better prices.
https://www.ebay.com/itm/MICRO-MINIMOSD-Minim-OSD-Mini-OSD-W-KV-TEAM-MOD-For-Naze32-US/123598979967

BEC from USA shipper
https://www.ebay.com/itm/HOBBYWING-RC-UBEC-5V-6V-3A-Max-5A-Lowest-RF-Noise-BEC/162781351806?epid=1039554737

Stuff is so cheap now days I confess that I buy several at a time.  I have 3x stock of both the OSD and the BEC.  :)
« Last Edit: February 02, 2019, 01:07:29 am by TheOtherCliff »

Re: Wanting return to base on plane
« Reply #5 on: February 03, 2019, 03:36:14 pm »
Thank you for finding me links to supplies and all the valuable information you have volunteered. So my questions has to do with location of the placement of the fc, gps, and everything else. So I can completely change anything if anyone has any better ideas of where things would be better placed. So full disclosed all the odd Metal stuff in the pics of the fuse is for CG and it will all be removed prior to the rebuild. So currently I have the frsky R9M lite for my tarranis x lite and the slim + receiver running pwm. I am going to keep that Controll link for now, in the future I would like to set up oplink for control and data. I would like to see the distance difference between 100mw on 433mhz or 100mw on 915mhz.

   What do you think would be the best place for the revo nano to avoid interference on the internal mag?  For the first try i didn't get an aux mag. I am going to try my best without one first and if I have to I will go the aux mag or something with it in it route.

 So what interferes with the mag?  Is it any type of metal? Or is the power wires and magnets and metals of that type? Does batteries like the lipo affect the mag? How far should the fc be from the servos? Does the vtx interfere with the mag? I have seen this stuff that looks tin foil but its copper, would wrapping the wires in that help or make things worse.

I am hopping I can take out all the magnets and run all the power wires along the bottom of the plane. I think in the front of the back compartment where the current gyro stabalizer is. There is also a flat wing mod that helps the flight performance that I am going to do to my nano talon this rebuild. So in that back top bay. There is that cross bar that hooks the wings together and its currently broken and I need to take it out and replace it with some straight tube. I have seen a guy use Some aluminum that looked and worked great. there are 3d Printed files, or what i was hoping I could find some square carbon or glass fiber Tube that the wing spars fit inside. So then all I need to do is secure it. Question what is the best Non 3rd interference meterial (wood?)that would do the best close to the fc. On YouTube channel  painless360 he started to test 5.8ghz video antennas and he found out that 3d printed antenna holders attenuate the signal and was even changing the frequency the antenna was broadcasting and all those fancy values you test antennas for, were all changing because the 3d printed materials. With those new finds I want nothing to do with 3d printed parts on my craft.

I feel antenna placement is pretty ok I usually get good reception.  But like I mentioned earlier in the thread, There is one angle my plane doesn't like when I start to get away from myself and get all turned around. I think it happened when the plane is pointed back at myself because of the battery that blocks the main antenna. So the slim + rx has diversity antenna would placing them on the wings be good? I have seen them like go threw the wing in a vertical fashion. I like the idea of one threw wing but does it add more drag?  And if I don't put something the other side to balances it out on the plane, will it pull to what ever side the antenna is going through? Or since the antenna is so small it will slice through the air no issues. I better wrap this up before I get to side tracked.

Respectively

Ps. I have been thinking of changing out the stock esc and motor.  To put a sunnysky 2306 2300kv i have laying around and the esc's should have working becs, would it be better to use the bec off the esc or have a stand alone bec handling the power duties?
« Last Edit: February 03, 2019, 03:55:55 pm by AerialPerPlexity »

Re: Wanting return to base on plane
« Reply #6 on: February 03, 2019, 06:03:52 pm »
This is a small airplane, so mounting stuff farther away will be difficult.

It's important that you twist all high current cables, battery to connector, connector to ESC, ESC to motor connectors, motor connectors to motor.

Try to keep the GPS away from other antennas (RC Rx, FPV, telemetry, ...)

Find some non-magnetized screwdrivers to work with so you don't magnetize your screws, but that isn't too big an issue.

FC can be anywhere.  Just keep it away from high current cables, servos, and motor.  It doesn't have to be on CG.  Metal is only bad if it is magnetizable / large.  Wire landing gear and pushrods come to mind.  Theoretically you should avoid these even if they are not magnetized, but I would only worry if they are magnetized.

On this small an airplane, you pretty much must remove hatch magnets.  Testing is best.  With FC on bench (not moving at all) and connected to GCS and looking at scopes page, 3D mag sensor, move magnetic airplane parts (hatch, servos and motor) in all orientations around FC to see how close they can be.  The scope traces basically can't move at all.

To test wiring for mag fields, build airplane first and then you must strap the airplane down very solidly so that it doesn't move at all at full throttle, and watch the mag scopes as you move throttle to full.  MUST leave prop on to get full flight current load.  Wiggle servos.  I generally haven't had problems with either servos or the motor, but I don't fly planes that small either.  Reroute, reinstall to get around problems.  Generally, just being careful when you route servo wires is good enough for servos.

If you plan to run power wires on the bottom of the airplane, then try to mount the FC at the top of the airplane.  Wrapping wires doesn't help cure mag fields.  Twisting + and - (and others doesn't hurt) together is the key.

VTx can interfere with many things.  Testing (e.g. VTx on/off) to make sure it doesn't is best.

Carbon fibre and metal are RF shields, but not in a good way.  They can block RC and telemetry.  But sometimes they are still the best for a particular part.  Try to avoid big sheets between you and the RC Rx.

RF is funny stuff.  Everything affects it, most things you can live with.  I like wood, but even wood can have moisture in it.  Getting a big battery or big sheet of carbon between you and the RC Rx is probably the most common issue.

By the way, RC Rx diversity is good.  Mount the antennas at 90 degree angle to each other and far apart as practical.

Switch on board transmitters (FPV, telemetry, RC Rx) on to see if you loose any GPS satellites or RC range test range when they are on.

Beware that 433mhz hits 1280mhz because it is close to a small odd number factor in frequency.  433 x 3 = 1299

There is a guy here, jdl, he flies a Talon, fast and long range.  He uses a bungee to launch it.  I fly Bixler shaped planes because they have a lighter wing loading and seem to me to be the smallest that can handle the weight and still be easily hand launched.

I worry that a small plane will be a handful to get into the air.  Is the stock configuration hard to launch?

Re: Wanting return to base on plane
« Reply #7 on: February 05, 2019, 04:35:44 am »
The stock nano talon is a dream to get into the air. I get 100% ready to fly, put my goggles down and Chuck the plane up all while I'm in the act of giving my plane full throttle, I have yet to come up short.

I have been think of maybe moving my vtx to the back of the plane by the vtail,  where this store put telemity there.
Check this link out. I put it up so I could get your opion.

https://store.mrobotics.io/product-p/mro-talon0318-mr.htm

How far can video signal travel? If I moved the vtx to the back I would need at least 14 inches of wire between the camera and the vtx?

If everything checks out and I'm going to test it all tomorrow.  I would like to put the revo nano in the front of the top back compartment as well as the slim+ receiver I am going to mount in the middle of the compartment so that way the antenna can get to each wing. On one wing I want to mount one antenna vertical polarized going through the wing and the other antenna Horizontally running parralle down the other wing. Then move the vtx to the back. Right in front the rear vtail wings in the middle, the gps all the way to the front top of the plane. The bec, esc and all the power wire down through the bottom of plane.

Re: Wanting return to base on plane
« Reply #8 on: February 05, 2019, 06:16:31 am »
14 inches or even more will work, but it also depends on how much electrical interference you have in the area.

The worst that will happen is that you will get some video noise.  If you do, and you want to get rid of it, then you should use some thin video coax (75 ohm) for signal/ground.

Re: Wanting return to base on plane
« Reply #9 on: February 12, 2019, 10:30:16 pm »

I just got the revo nano flashed with the 16.09 firmware And I got the Sensors calibrated, outside of the plane and I know, i will recalibrate the Sensors that require so, when the hardware is installed, before I fly her.

I have the bird completely stripped down, and I am going to build it back up the way I think will work best and I will hope for the best.

Does anyone have any experience with a pepperbox or a helical for Video, if so how was your experiences?
« Last Edit: February 12, 2019, 11:09:31 pm by AerialPerPlexity »