phil_g

My 1958 Orbit 10 Reeds set, converted to 2.4ghz :

singlechannel

A belated thanks for the Half Tone Plans. Just finished a model so this looks like the next.

phil_g

Just to add to the Digimac 1+1 post with the video, here are a couple of internal pics.
I've converted it from Corona to Frsky using a 2-way module, set to V8 mode to match all my older receivers.
I tried a slightly different idea this time - its a Futaba-style module mounted edgewise in the case,
with an RP-SMA extension lead (male-female) connecting the aerial. Its quite a rigid extension, hence the loop.
Makes the layout a lot easier than trying to align the module with the extisting aerial hole.
The encoder is mounted on the side next to the stick unit, and theres a 2S 500mah lipo almost lost in the base.
Cheers
Phil
PS the case isnt bowed, its a bit of parallax from getting the camera too close!

gnaton

These pictures are of my O.S. Minitron TX-II Single Channel 2.4 GHz conversion, and 23 year old Hearn's Hobbies (Australia) 'Sportster'.

The Sportster is a 1951 design for free flight and single channel R/C, 50 inch span. The model was originally powered by a Taipan .09 diesel, and recently converted to an 85 watt 2830 880kv brushless motor, 9x4.7 slow fly prop and 3S 1000 mAh LiPo. Weight 2 lb 2 oz. A real floater.

Over the years I have built 4 Sportsters, the first in 1964 guided by an O.S. valve transmitter and valve receiver.

It is a lot of fun flying single channel again, on a calm evening. Thanks Phil for making this possible with your transmitter conversion board.

phil_g

I flew the converted Digimac 1+1 yesterday!
I skived off for an hour or two to test the Vic Smeed Poppet out which I'd recently fitted out with a 10gm motor and Single Channel radio on rudder only. This is the one that had its wing snapped in two when one of the cats jumped on it ages ago. AUW after the repairs is 8oz. Its only running 20 watts from a 2S 500, but that seems just about right. Rather than a 'button' s/c tx I decided at the last minute to use the converted Macgregor Digimac 1+1 in the post above as that needed a trial run too.
That Vic Smeed knew his onions:
Cheers
Phil



[youtube]http://www.youtube.com/watch?v=DNVU6vWp64Q[/youtube]

gnaton

My O.S. Minitron 10 channel reed transmitter converted to 2.4 GHz. Thanks again Phil, for the conversion details and PIC IC.
Thanks to Ian_C for giving me the Tx to convert.

The switches were soldered to the PCB, so for rigidity I just cut the tracks and left the original components for interest. The lower half of the PCB (which I cut off) had the 10 pots for tuning the transmitter to the receiver reeds. The small PCB had the original RF components and 40 MHz crystal (still legal for R/C in Australia). I desoldered the components and used this for mounting the FrSky RF module. The original PCB's were hand-soldered and the constructor didn't scrimp on the quantity of solder.

In 1965 I had the 12 channel (later and smaller) superhet version of this Tx on 27 MHz.

So far I am using this Tx to fly my Hearn's Hobbies 'Sportster' (Post 54 this forum) as I am getting my mind and thumbs revalidated on Mode 1. I fly mode 2 along with a small percentage of Australian's, however most Ozzies fly Mode 1.

Mark_B

gnaton

phil_g

Thats an excellent conversion Mark, really neatly done. I particularly like the internal crib-sheet, I might pinch that idea!
What a lovely looking set the OS is, I can imagine the pleasure it gives you showing it off down at the flying field.
I too fly propo mode 2, but I now make the switch between reeds, S/C and propo without drama, if anything it was the progressive throttle that I fumbled with until I got used to it again, in my "first-time-around" reeds days we flew only gliders. My track bike has race shift, my road bike has road shift. The human brain is a smart cookie - it just makes the switch without fuss.

There are some who will say its sacriledge to modify a lovely piece of equipment like the OS but I for one would much rather see it flying regularly and reliably than stuck in some collectors cupboard in the vain hope that one day it might be worth something. By flying the updated set you're not only keeping the memory of reeds and of quality OS gear alive, you're introducing the concept to newer flyers who may have never seen or heard of reeds.

So very well done Mark!

Cheers
Phil

gnaton

Thanks for your comments Phil. However the conversion would not have been possible without you spending the time to develop the project.

I agree about converting old radios to 2.4 GHz. You can't fly old radios on 27 MHz at club fields here in Australia, and I am not sure of the safety implications of flying 50 year old wide bandwidth electronics either.

There are many R/C flyers who have never seen single channel or reed equipment flying. They can now see just how far R/C equipment has developed. Apart from that it is great fun!

Thanks again,

Mark_B

phil_g

Andrew Boddington, son of the late great DB, donated one of his Dads old rudder-only Pulse-Propo models to my pal Shaun. It is fitted with an Adams Baby magnetic actuator (the type that flaps wildly in flight!).
Wanting to keep the actuator element of this antiquated control system, I made a pulser which sits between the rudder channel of a modern rx and the Adams magnetic actuator. Its really simple, just 2 components, an 8-pin PIC and an 8-pin H-bridge , both mounted in a common 16-pin socket.

Unforch the video frame-rate doesnt show the movement too clearly but heres the lowdown (Shaun did this video):
[youtube]http://www.youtube.com/watch?v=HLVk97zI2lg[/youtube]

And heres a brief flight clip which I accidentally cut short when I fumbled the camera controls.
This is taken at the MAA in Flamborough - it made my day to see Boddo's model fly again on 2.4g Pulse Propo:
[youtube]http://www.youtube.com/watch?v=aIBVNHphkE8[/youtube]

Cheers
Phil

phil_g

A couple of new sets I made up this week, both using Frsky DIY. The first one is quite conventional, its a Macgregor MR200 bang-bang set. This particular one is quite nice & clean, & all the case patterning is intact. It uses the S/C escapement emulation encoder as before.

And the second, I wanted something small, single channel, but proportional, with the intention of finding an Adams magnetic actuator to make a 2.4g pulse-propo outfit. It uses the Macgregor Digimac 1+1 emulation encoder [link]. I would have liked it smaller but the only readily-available stick unit pretty much defined the final size. The Futaba 7C and OS Pixie are there just to give some scale. The single-axis stick came from half of an old 2ch car radio, and the set runs off a 2S 450mah lipo. Originally it was to be a strictly rudder-only set for S/C gliders, but in the end I added the 'plus one' button on the stick unit which I suppose makes it more versatile, with propo rudder and sequential 3-position throttle. The label is a bit naff. I'd love to find a way of making a proper anodised logo plate, like the ones sported by old Skyleaders and Krafts etc.

Cheers
Phil
www.singlechannel.co.uk

Rubber flier

Ifly freeflightrubber contest models and have beentrying to makea simple single channel 2.4Ghz radio controlled dethermaliser. I do not have much electronic experince or knowledge so I have not got very far! What you have produced seems to be perfecr for what I need. What is the range and which receiver do you use? Would you be kind enought to send me details so that I can make one?

Best wishes from over the pond!

Merry Christmas to you and yours

John

Rubber flier

Very keen to see the details of your single channnel system . I want to use it a a radio dethermaliser.

Rubber flier over the pind

phil_g

Just a quick update, I've done a couple of remote dethermalizer options for John (Rubberflyer) and my local clubmate Gordon Warburton. Johns uses one channel as a simple DT trip, which is all his rubber powered models need, and Gordons has two channels, one for DT and one for an electric motor - to comply with the FF rules the motor is a one-shot operation, once the user stops the motor it cant be started again. Although Gordons has two functions, it uses a single button on the tx, first press is motor run, then after the glide the same button trips the DT. Both Johns & Gordons sets use an OrangeRx RF module and a tiny Orange receiver. I think they both deserve a medal for building-radio equipped models yet resisting the urge to add a rudder!
Cheers
Phil

zl3vml

Hi guys,
Do you have any circuits for encoders you could share? or where to obtain encoder boards?
I would like to build a simple 3 or 4 ch set (2.4GHz) that I can use in free flight models, mainly for DT but with the option for using the other channels if needed.
Thoughts are around proportional rudder, as in controlling the rudder trim tab to assist getting back to the field again and maybe also throttle/esc for test/trim flights etc.
I have converted a few radios to 2.4GHz but am unsure of just exactly what is required in the way of encoders to drive a 2.4GHz module on it's own.
Thanks for any info you can share.
Mark

phil_g

Mine are supplied built & tested Mark but I'm not a business, just a bloke in a shed doing it for interests sake.
Have a look at the Macgregor Digimac 1+1 emulation encoder, it does propo rudder and sequential throttle which you could use for D/T or whatever. Would that be ok?
Heres the demo: https://www.youtube.com/watch?v=fHaUvmsJdU4
Theres also a 2+1 version but the 1+1 is more popular over here. Maybe have a read of the documents for each, they're on the Archive page of http://www.singlechannel.co.uk
Alternatively if you're up for a challenge there are lots of controller boards now to have a go yourself - arduino, STM etc - all the 2.4g modules need is a conventional PPM stream.
Cheers
Phil

zl3vml

Thanks Phil, lots of info there and a great website too.

The 1+1 & 2+1 boards look to be exactly what I would need I probably did not express myself too clearly, 1 ch for DT and a 2nd for the rudder tab but not fully proportional, just left & right buttons to move the tab over enough to induce some kind of a turn in the model. They 'are' free flight after all :-)
A 3rd ch would be for things like motor control or turning on the locator alarm etc.

Yes - I would like to knock something up myself using PicAxes, since I am using them for various other airborne modules but have no idea of how to work out the encoder side for the 2.4 modules to operate properly.

I started reading through the info on your website late last night before heading to bed so will read more today and contact you directly.

Cheers - Mark

grotto2

My Feedback: (2)

If you look down near the bottom of my page
http://www.mindspring.com/~rellis2/rcpattrn/retro.htm

You'll see a simple program for an atmega controller that will do the job for an escapement model.
I also have another program source that you can use with a servo to get 1=right, 2=left, if you prefer.
You should be able to modify it to add non-proportional channels as needed.
-Ron

zl3vml

Thanks Ron - that is great info.
I did think about cannibalizing the board from my old RCM&E transmitter that I converted to 2,4, but I want to make up more than just the one transmitter for the rest of the free flight guys in our club.
Suppose I could copy just the encoder portion of it but using a pic based encoder board would be so much simpler (and smaller).
(I am hoping to make these up real small so that they can basically just fit in the hand and be easily carried while setting off after the model.)

Mark

phil_g

Mark if you're that familiar with the PicAxe then you'd have no difficulty making your own - and make an interesting project of it. PPM is just setting and resetting an output after specific delays - thats all it is. I dont use picaxe (I'm an assembler programmer) but I did a search and came up with these two links:
http://www.picaxeforum.co.uk/showthr...ol-of-RC-plane
and
http://www.trainelectronics.com/Radi..._PPM/index.htm
Theres plenty of help on forums and you'd have the satisfaction of doing it yourself.
I can help with pic hardware, RF, timing and interfacing questions.
Go on, have a go!
If all else fails, (which it wont!) then my board is one of many 'plan-B' options... so you've nothing to lose!

I would suggest tackling it in stages. Write an encoder that just generates a frame of (say) 4 channels at neutral, no inputs or controls.
Then get the first channel to vary by checking an input - if its high, delay 500uS longer. If its low, delay 500uS less.

To get started, write a subroutine called 'pulse'. This will set an output bit, wait 300uS, then reset it and return. Thats all it does,
Write another subroutine called 'sync' that first calls pulse then waits 8ms and returns.
So your 'all neutrals' 4-channel frame would be something like this. Note that the channel width includes the 'pulse' width, so a 1500uS neutral channel comprises the 'pulse' (300uS) plus the 'delay' (1200uS) values. For standard 1ms to 2ms servos, one extreme is therefore 700uS delay and the other 1700uS.

:frame (this is a label)
call pulse
delay 1200uS
call pulse
delay 1200uS
call pulse
delay 1200uS
call pulse
delay 1200uS
call sync
goto frame

Then for your second stage you could change channel 1 depending how a button or switch was set on one of the inputs:

:frame (this is a label)
call pulse
if button=1 then delay 1700uS else delay 700uS
call pulse
delay 1200uS
call pulse
delay 1200uS
call pulse
delay 1200uS
call sync
goto frame

Coupled to a typical 2.4ghz module this will operate a receiver and servo exactly as you'd expect, with the servo sitting at one end of its travel and moving the servo to the other end when the button is pressed - then you can gradually build from this simple start.

A simple two-way rudder channel might look like this:

:frame (this is a label)
call pulse
rudder=1200
if rightbutton=1 then rudder=1700
if leftbutton=1 then rudder=700
delay(rudder)
call pulse
delay 1200uS
call pulse
delay 1200uS
call pulse
delay 1200uS
call sync
goto frame

In practise you'd use the built-in pull-up resistors on the inputs with the button to ground, and you'd test for zeros.
Sorry if this is too basic, I suspect so if you've done some picaxe R/C projects. I've never used one at all but this is pretty much all you need to get a basic encoder working regardless of the processor used. I did notice that one of those links insisted that the frame must be 22.5ms long. Thats not true for 2.4g modules, most just need a minimum sync of about 4ms, the overall rate isnt critical and doesnt even have to be a fixed value - a lot of PPM sets have a variable frame rate.

Cheers
Phil

zl3vml

Phil thank you very much indeed,
That is exactly the info I was after and it all appears pretty simple really now that I have got my head round the general idea of what the encoder does, so thanks, you have helped me enormously..
Time to dig out my proto boards and have a play again.

Which of the (el cheapo) 2.4GHz modules that you have used would you say were the better options - or less critical of the pulse trains?
I have been using the FlyDream modules and they are absolutely fantastic but not the cheapest out there.
Sort of thinking about the "Orange" line of TX modules since their receivers are pretty small and have (so far) worked great for me in all my models.
(But that is with a Spektrum transmitter)

I am really trying to induce some our older club members to come back to the free flight fold again and hopefully if I can knock up some cheap & small (and for them "low tech") units I could convince them. They certainly seemed interested in the concept of 1] a radio DT link and 2] being able to turn on the alarm unit. 3] The rudder option would just be a bonus if they wanted to use but at this stage it would mainly be for my own benefit.

Cheers - Mark

phil_g

In building & testing the single-channel emulation encoders I've used OrangeRx for Futaba, OrangeRx for JR, Frsky DFT, DHT, V8HT, V8FT, V8JT, Fly-Sky, Corona DSSS, Corona FHSS 2way, Hitec HPF-MI, Spektrum DM8... all work just fine, My personal preference by a long way is Frsky, I like the now-obsolete V8 series, but the D series are perfectly ok. Avoid the Spektrum DM9 as it has a weird ppm timing problem, and also anything FASST as they have a minimum channel count and some FASST modules use the PPM pulse width to control things like output power and failsafe mode. I have had a DM9 and a 6EX FASST module working but its a faff, actually my Gem S/C is a DM9. Personally I'd go for Frsky every time.
If you are definitely going ahead, and if you PM me your postal address I will send you FOC a bare PCB which will mount directly to any Futaba-style module via 5 long pins. It suits an 8-pin pic chip, just needs an 8way dip socket, a 78L05 5v regulator, couple of caps & diodes, will save you some wiring and make a neat job of it.
Heres a really old video, actually the PCB is much smaller now but mounts just the same https://www.youtube.com/watch?v=XM3SQ1briWY
Or you can do it on stripboard, whatever you prefer. There are lots of examples on http://www.singlechannel.co.uk
All I wanted to do was to encourage you to have a go Mark, do please let us know how you progress.
Cheers
Phil

zl3vml

Phil, thanks again for the info and your offer, I will PM you soon as I have looked at some tx modules and decided which to buy.
No rush at this stage as ordering anything from HK these days seems to take a few weeks at best to arrive anyway.

Actually, now that I think of it, I do have an (Orange) tx module in an old Futaba tx that I converted that uses the 5 pins, DSM2 I think, so would be great for some immediate results in the meantime while I track down some small boxes to use.
I like the "old style" design and look of aluminum boxes like some of the ones on your website but for now will go with whatever I can find just for demo purposes.

Cheers - Mark

zl3vml

I might be putting the horse before the cart here but went hunting around for some cases for the transmitter(s) and then remembered a bunch of old laptop power supplies I have .... I knew I would fine a use for them someday.
Should be a perfect size for the diy Orange module plus encoder and a 9v battery.

The bigger ones would even accommodate the Orange modules like the one in the Futaba set and they have a convenient hole to fit the antenna as well.

Mark

049flyer

My Feedback: (18)

Here is my Owen Kampen designed Skamp. I re-drew it in CAD and cut out with a laser cutter. Flies great with a Cox Pee Wee .020 for power.