safe receivers

[ericrw]

Is there a Safe receiver that enables models to take off and land itself ??

[Denis Watkins]

There is Eric, take a look over this recent thread

**LINK**

[Dave Hess]

Posted by ericrw on 07/09/2018 17:41:38:

Is there a Safe receiver that enables models to take off and land itself ??

To land by itself, you need a GPS module as well as the receiver with stabilisation.

Taking off without GPS is no problem. All you need is a stabilisation receiver or you can use a separate stabilisation module withe a normal receiver. Stabilisation modules start at about £12. These ones look quite good and get good reviews, though i haven't tried one myself:

**LINK**

all these things require a bit of setting up. That Cub in the link to my thread is a ready-made solution for £200 quid, and it flies really well too.

[Biggles' Elder Brother - Moderator]

I'm sorry guys but you have this completely wrong!

I did a lot auto-flying when flying commercially, there is (as far as I am aware) no Rx that do this.

The devices you link to are just gyros. They will stabilise the aircraft in the air - assisting it to fly straight and level or to follow your commands. Any movement of the aircraft which is detected by the gyros (roll, pitch or yaw) that isn't matched by a stick input is corrected and removed - that's all.

To auto land or take off you need a flight controller and a GPS. Although the device David linked too says it a "Flight Controller - it isn't, its just a gyro. Flight controllers come with comprehensive and complex support software to programme their way-points and navigation etc.

Examples include devices such as the EagleTree Vector system etc. That particular one includes OSD failities for FPV - but can be used without. Typical prices ange from £70-200 for a decent system. They are very powerful, but be aware they are also very complex and you'll need be very computer savy.

Flight Controllers are extensively used in MR's. Most MR versions don't cross over to Fixed Wing well. Their use in fixed wing is growing but still a minority activity even within the Flight Controller world.

BEB

[Biggles' Elder Brother - Moderator]

As a follow up on this and to try to answer the OP's original question - which it occured to me over night I hadn't actually done - sorry Eric:

From what understand, standard SAFE receivers cannot do take-off and land - they are just slightly more advanced versions of gyros that have some local programming for self righting and stuff like that.

But,...Spektrum talk of "SAFE PLUS receivers". These are supposed to be able to do more, for example a form of Return to Home auto land and loitering (flying circles about one point). It still can't auto fly or take-off.

But there are two problems as far as I can see with SAFE PLUS receivers:

1. They are not adjustable and cannot (say Spektrum) be fitted to another aeroplane than the one they are supplied in. So if you want this you must buy the whole thing, model and all!

2. To bear that out I can't find any SAFE PLUS receiver for sale separately. Plenty of SAFE receivers yes, but they don't do these things, but no SAFE PLUS receivers. I may have missed it - but well I can't find them if they are available separately.

There are threads discussing removing SAFE PLUS receivers from donor models and relocating them. But if you have no way of ajusting the control pararmeters this is unlikely to be very sucessful in my view unless the two aircraft are very similar in response - so same size/weight, similar roll and pitch rates etc.

So Eric I think the answer at the moment is "no you can't buy a SAFE PLUS receiver to do this, but you can buy a model that will do some of it"

Or you could splash out on a full blown fixed wing flight controller like the Eagletree Vector - but, as I know from experience with it, be prepared for a demending and steep learning curve if you do that!

BEB

[ericrw]

Hi, my interest in such Safe receivers is because I have, because of age 87yrs and recent heart surgery, I found it necessary to fly models with the EFLR310013 Safe Rx, for eg, Apprentice. However, I have been able to install this safe Rx into other models; which takes a lot of the anxiety away. There are 3 modes, beginner, intermediate and experienced. I fly mostly in the intermediate mode and if you aim the craft in line with the Runway, and slowly reduce the throttle, it will land by itself. I expect it would also Take-Off in the same manner but I`ve not tried that yet. Anyway thanks to all who contributed.

[Biggles' Elder Brother - Moderator]

Yes Eric, the standard SAFE Rx's can be moved - but apparently not SAFE PLUS?

Here's to you keeping on flying mate, long may you enjoy it!

BEB

PS Incidently, I don't think it will be very long before we do see fully integrated receivers with GPS and full auto-pilot, mission planning and way-point capablity. All the elements are there and in use but I suspect the manufacturers have decided that at present bringing them togetehr is just a bit expensive for the mass market (as far we constitute a mass market!) But it won't be long before costs come down and expectations go up!

Edited By Biggles' Elder Brother - Moderator on 08/09/2018 17:17:04

[BackinBlack]

iNav software is capable of fixed wing control when used on suitable flight controllers with GPS add on receivers.

Return to Home, circling home and auto launch/land can be configured.

[Dave Hess]

Posted by Biggles' Elder Brother - Moderator on 07/09/2018 22:58:06:

I'm sorry guys but you have this completely wrong!

I did a lot auto-flying when flying commercially, there is (as far as I am aware) no Rx that do this.

The devices you link to are just gyros. They will stabilise the aircraft in the air - assisting it to fly straight and level or to follow your commands. Any movement of the aircraft which is detected by the gyros (roll, pitch or yaw) that isn't matched by a stick input is corrected and removed - that's all.

I don't think it is wrong . The Carbon Cub+ has a receiver with GPS and gyro. It can take off, fly around in it's own restricted zone (3 options) and land by itself exactly where it took off. All you need to do is open the throttle to take off and push a single button for three seconds to land. That's what we tested in this thread:

**LINK**

[PatMc]

Posted by Dave Hess on 08/09/2018 19:14:38:

I don't think it is wrong . The Carbon Cub+ has a receiver with GPS and gyro. It can take off, fly around in it's own restricted zone (3 options) and land by itself exactly where it took off. All you need to do is open the throttle to take off and push a single button for three seconds to land. That's what we tested in this thread:

**LINK**

Isn't that a model using the SAFE+ Rx that BEB described in his second post ?

Do you know of a retailer selling the SAFE+ Rx that doesn't come in a package with the model ?

[Biggles' Elder Brother - Moderator]

Sorry Dave you are wrong!

1. The Carbon Cub S+ is an example of the SAFE PLUS specific models available I referred to earlier. As explained Spektrum themselves say you can't transfer the Rx. I believe them. The OP ask for an Rx, this does not fit the bill.

2. SAFE PLUS does not "fly itself". It can auto land and loiter - again a point I made earlier. Any so-called "flying itself" is just a random trip within the GPS fence - an uncontrolled "wander" in straight lines until it bumps into the fence! A random walk inside GPS boundaries is not "flying itself" in my or most people's books!

3. The Rx you actually linked to doesn't even do that! It is just a Gyro, that you think you can link to GPS and some miracle it will enable a plane to fly itself. It won't.

You are I'm afraid wrong. As I say I have used these technologies I know what they are capable of.

BEB

Edited By Biggles' Elder Brother - Moderator on 08/09/2018 21:03:21

[Dave Hess]

You can buy the receiver and GPS as spare parts, like you can see here from Wheelspin. The carbon Cub comes in BNF version, so presumably these will work with any compatible Spektrum 6+ channels transmitter (not DX6i).

**LINK**

Failing that, I've seen them sold on USA RC forums for around $50. I bet they'll turn up on our Ebay sooner or later from crashed planes.

If that's not enough, you can always buy a BNF cub or Sportsman and take the stuff out of it, then sell the rest as spares to repair all the crashed ones.

I guess you can make any definition what you think flying itself means, but I would say that a plane that can fly around the sky without flying away, without going out of control and with no input from a transmitter is flying itself.

Edited By Dave Hess on 09/09/2018 00:34:28

[Biggles' Elder Brother - Moderator]

You just don't get it do you Dave? Following your link ultimately takes you here. Look at the "Compatibility" conditions, it lists the part numbers:

HBZ3200, HBZ3250

 

And only those. They are the part numbers for the Carbon Cub +. Its a spare for thsat plane and that plane only. In other words, its as I said told you now three times, this only works in one model! Spektrum themselves say this in their blurb on SAFE PLUS quoting from them

"A SAFE Plus receiver is not intended to be taken from one model and placed into another and it's AS3X gain settings are not adjustable"

 

You will find that here near the bottom of the page.

 

On that page, nearer the top, you will find a table of SAFE and SAFE PLUS capabilities. They do not list auto flight! They list auto landing and loitering together with the standard gyro facilities of pitch and roll stabilisation.

 

Please read the literature as I'm getting a bit bored repeating the same things over and over!

 

BEB

[Dave Hess]

Let's take a step back and think about this for a bit: The receiver and gps modules have no idea what plane they're in. If Hobbyzone were really clever, they could at most lock the receiver to the ESC, but I'd be surprised if they have done that. That means that all the functions will still work if you install them in a different plane. Whether they work well, we can't say at the moment unless anybody has already tried it and reported on it.

We know that similar stabilisation receivers have gain adjustment on the main controls for the stabilisation, but most reviews I've seen mentioned that the stabilisation worked OK on default settings. The gain was only needed to fine-tune the 3D mode. I would place any bet that if you took the Carbon Cub+ stuff and put it in a medium sized normal plane, it would work. Obviously, the nearer it is to the size, weight, speed and style of the Cub, the better.

I would guess that there are two main reasons that Hobbyzone say that these modules are only for the Carbon Cub+. Firstly, they don't want to accept any liability when someone fits it in a gas turbine jet expecting it to land automatically when they press the land button. Secondly, there must have been some collaboration with Spektrum to get the software right, and they want to get the best commercial advantage for their work/ideas. Personally, I wouldn't take much notice of what they say in that respect. They can't change physics.

Note that they say "can" produce unexpected results, not "will".

"Q- Can I take the receiver out of my SAFE equipped model and put it in something different?

A- It is not recommended. SAFE equipped receivers are specially tuned for the aircraft it came with. Putting it in a different aircraft can produce unexpected results, resulting in incorrect or over correction of the control surfaces and potential aircraft damage."

Whether it works or not, we can't say either way at the moment, but I have enough confidence to try it in another plane. I've ordered a couple of Flitetest planes, which should come soon, so I'll take the receiver and GPS out of my Cub and try it. I will then report back my findings.

As an aside, you'll notice that many suppliers list these parts, but often out of stock. Is that because I'm not the only one to try it?

[Biggles' Elder Brother - Moderator]

Dave - I give up on trying to explain to you - so here it is straight from the shoulder!

Your "advice" (which was always speculative and based on very limited experience, despite your authoritive tone) is now starting to boarder on the irresponsible. On a purely speculative basis you are now advocating going against the express instructions of the manufacturer on a safety issue.

We cannot allow that on this forum. This site has a reputation for high quality informed and responsible advice. Many modellers rely on the quality of advice offered here. We cannot allow you to come along, as a relatively new member, and put that at risk. We also of course have a responsibility for the technical accuracy and quality of any advice offered as publishers. We cannot allow you to compromise that either.

As a moderator I have explained to you at some length why your advice offered here originally was seen by us as inappropriate. I will not spend more time on that nor will take such efforts again. We expect no further posts, on this or any other thread, advising people to take courses of action which are technically ill-informed, potentially dangerous or contradict the explicit instructions of the manufacturer on safe use - especially from someone with little experience of such systems. Please take note of this.

BEB

[ericrw]

One of the other models that I put an eflr130031 safe receiver into, was a "Flying Super Model" Fokker Dv11. I had to follow advice from "Rcgroups"; which entailed making alterations, within my Spectrum D6 Tx. They have a designated Blog for " Installing Safe RX into another `plane". Members have added their modified models to a list, which is quite numerous.

With regard to my model, It does not take-off or land purely by it self; you have to control only the throttle and ensure the model is flying inline with the runway ! The safe Rx automatically, adjusts the other controls .

[Biggles' Elder Brother - Moderator]

Yes Eric, you can indeed transfer SAFE receivers, and many people have done it sucessfully. Spektrum have no issue with that particularly. As I say above such devices are really just receivers with an integrated gyro.

But not SAFE PLUS receivers - that's quite another matter. As the manufacturer Spektrum explicitly advise against it.

BEB

[Former Member]

[This posting has been removed]

[Dave Hess]

Posted by Ikura on 09/09/2018 16:02:54:

As BEB says, you are then operating a model in an unsafe, untested and irresponsible manner, which is just playing into the hands of all those tryng to restrict our flying activities.

Edited By Ikura on 09/09/2018 16:08:27

At the risk of being permanently banned, I'd say that I can understand what you mean, but testing this possibility is no more dangerous than allowing a beginner to fly a plane on a buddy box. The Auto land and stability modes can be switched off in an instance if anything goes wrong. Don't forget that I am a very experienced flyer. I can't see that there's anything reckless in what I propose.

When you look at the Youtube videos of various guys sending these planes spiralling in the moment they hit the auto-land button, you could ask the question about whether these sort of planes should be allowed at all.

This reminds me of when the safety officer came down the line of planes at my previous club picking each one up in turn and then told me that I mustn't fly mine because "the C of G was too far back" in his opinion! The same plane as I had flown 100 times before when he wasn't there. I asked him to let me demonstrate it, but he said no. He didn't even have an A certificate. I'm not exaggerating.  I guess different people have a different frame of reference. Everybody is entitled to their opinion.

Every time we build a plane or try anything new in it, there's a calculated risk, but we use our skill, knowledge and experience to weigh up these risks and act accordingly.

Just to make it clear, I might be new to the forum and a little out of date on the newest technology, but I was designing and flying rubber duration planes when I was 10 years old, I flew RC planes extensively for more than 14 years, in fact my wife divorced me because of it. It's actually written on her divorce application. I must have built at least 100 RC planes, many of them self designed. I have a degree in mechanical engineering and I taught electronics for 10 years. I don't believe that I'm doing anything reckless.

The Carbon Cub+ as a ready-made plane is perfect for OP. That's what I advised him in post #3. I have stabilisatin receivers in my Wat4 Foam-e and in my Hobbyzone Sukhoi, so I why can't I mention them?

I never advised anybody to put the Cub+ stuff in their plane, I only said that I thought that it would be possible and I'm going to try it. What's more dangerous: Puta gas turbine in a jet and take it to a show where there's thousands of people or put a Cub+ receiver with an instant override button in a foam plane and fly it at the local flying field? I think you need to get things in proportion. 

Edited By Dave Hess on 09/09/2018 18:19:54

Edited By Dave Hess on 09/09/2018 18:22:49

Edited By Dave Hess on 09/09/2018 18:27:16

Edited By Dave Hess on 09/09/2018 18:31:34

[Former Member]

[This posting has been removed]

[Chris Bott - Moderator]

If you wish to experiment with another system that has these functions, why not research iNav and use a ?20 F4 flight control board with a ?15 M8N GPS receiver?

That way you're not stuck with fixed PIDs or stuck with corrections that work in the wrong directions for some of your servos.

I intend to check this out as soon as I've got through some other projects on my ever growing list.

Edited By Chris Bott - Moderator on 09/09/2018 19:43:14

[The Wright Stuff]

double post

Edited By The Wright Stuff on 10/09/2018 08:46:58

[The Wright Stuff]

Posted by The Wright Stuff on 10/09/2018 08:29:46:

Posted by Ikura on 09/09/2018 18:33:20:

Whenever you post a description of what you are proposing, you don't avoid the responsibility of what you say or do.

I'm sorry Ikura, BEB, but while I agree with a degree of caution in this particular thread, I can't agree with the subsequent generalisation. Most of what we talk about on this forum is to some extent proposing, doing, or testing aspects of model building and flying that were beyond or to the side of what the manufacturer intended. That's what makes the hobby so diverse.

Firstly, if you've ever used a different glue to the manufacturer's recommendation, or you've fitted an electric motor when the instructions called for I.C., or programmed an open platform Tx, or used after market receivers not authorised by the Tx manufacturer, then surely this is from the same hymn sheet... who decided where the line was drawn?

Secondly, I think there is a huge difference between describing an approach one intends to experiment with, and recommending it to others as an accepted practice. Of course there is some responsibility to a degree, and this is an area for common sense to be applied, but ultimately, the sole responsibility is with the pilot/operator. The ANO is very clear on this point.

[Biggles' Elder Brother - Moderator]

As someone who spent his entire career in research I would totally agree with you TWS. I certainly wasn't, and I don't think Ikura was either, suggesting some sort of blanket ban on experimenting, testing and research. But this is not experimentation or research, this is just "let's unplug it in and see what happens"!

Recently I have been assisting a clubmate with some experiments, the question he wanted to answer was "could a stabiliser make an aircraft with a very rearward CoG (and hence unstable) flyable?" He was interested because he was nearing completion of a warbird, its already heavy (wing loading circa 45 oz/sqft) and now he needs 1.5Kg of lead to balance it! That would make it way, way too heavy! So is there another solution?

The approach we took was the following:

1. Take a well sorted model the pilot is very familiar with (in our case an Sbach) and install a gyro.

2. Undertake a series of test flights: starting with the gyro, but the CoG in the "right place", then slowly and progressively add small increments of lead to te tail and shift the CoG progressively backwards. Each flight moved the C0G about 1/8th of inch back and the aircraft was evaluated for stability and flyability with and without the gyro enabled.

If the aircraft had started to show any undesirable behaviour we could have stopped the series of flights whilst the symptoms were still relatively benign and so avoided the risk of a dangerous situation developing. The crucial points were: progressing cautiously, under control at all times, having a high degree of confidence in the next step justified by previous tests and careful assessment of each flight.

So how does this differ from what is proposed here? Well first of all no manufacturer has explicitly advised us not to do it, there is no progression here - it's just plug in and try it, there is no basis here on which to feel the confident in the next step. This is not experimentation - this is just "suck it and see" and in a safety critical environment you can't have that! Aviation gave up on "kick the tyres and light the fires" so time ago!

Another example, you mention trying new glues - yes we all do it, but would you make the first use of a new, radically different, glue on the main spar of time intensive build? No of course not, you'll probably try it out on a bit of scrap, or none crucial part of the model. That is experimenting, again you have progression and control.

The fear here is not that Dave will cause damage with his "test" - although we can't even rule that out - he is a competent pilot I'm sure. If there problems he can switch the device out and just fly the model manually. No, what I worry about is a far less experienced and able pilot reading of Dave's adventures and thinking "Oh I really struggle to fly that sounds just the ticket to me" - but who is going to bail them out when it all goes to hell in a handcart? They can't just turn it off and fly the model. They are going to panic, lose control and heavens knows what might happen next?

No, as I say, no problem with carefully and sensibly designed experiment - but we really can't have folks advocating this sort of cavalier approach of "ignore what the manufacturer says, let's just try it anyway"!

BEB

[Bob Cotsford]

Not being familiar with Spektrum Safe Plus I've just abused Google for articles such as this. It actually sounds as though it could easily catch out unwary/hasty purchasers as it sounds to need a precise setup process at the field so that it knows where the flying area and ground zero are.

Now, I'm of the opinion that Horizon's message not to repurpose these units is in line with the standards of the day - avoid any chance of litigation. This is the way of the world, 2/3 of any instruction book or manual now consists of warnings that CA glue is not edible and knives have sharp edges.

While these warnings may be needed in these days of instant no-win no-fee litigation ( note I never said 'nanny state'!) I do feel that we need to hear of experimenters like Dave. At least if it's tried in a cautious manner by an experienced flyer then we can say yes, it can be done subject to considerations a, b and c, or no, it really won't work. If someone responsible doesn't try it and let us know the result then there's nothing to warn the less experienced against lobbing it into their Spitfire and letting loose on the basis that it sounded like a good idea.

Every time we launch a new design there is the potential for an unexpected problem to appear, isn't the standard warning 'if you're not prepared to lose it don't launch it'?

If one treats this like any other stabiliser system, ie make sure all controls operate within limits and in the correct sense and one follows the correct on-site initialisation then it's worth a punt . Of course the appropriate style of airframe and power source progression would help, don't start with a 30cc Edge 540!