World Engines UK Expert conversion

[Pchristy]

My latest project: an elderly World Engines UK Expert transmitter:

This was originally built as a 35 MHz set, with an Ace Silver Seven encoder. I had intended to keep the encoder when I converted it to 2.4 GHz, but it had developed a really weird fault which I failed to locate. As a result it now has one of Phil's excellent 7 channel Arduino encoders, on a DIYMore "Strong" board.

Power is provided by a couple of LiIon cells salvaged from an old laptop pack. All the "blue bits" used for the aerial, meter and RF board mountings are diy 3D printed.

I've owned it from new. Before I could afford a proper helicopter transmitter, I used this, with a changeover switch changing the throttle function between the left stick and one of the auxiliary sliders. This enabled me to have a crude "idle-up" function for aerobatics, as well as a throttle hold for auto-rotations, though it did require a bit of digital dexterity to switch between the two....!

In fact, my son used it at a Hirobo Cup event for his first contest with a 60-sized helicopter, back in the early 90s! He borrowed my Hirobo Condor, as a more fitting machine than his Shuttle, for the aerobatic event. Unfortunately his competition flight came to a premature end when the 90 degree adapter needed to fit the silencer to the engine fractured in flight, resulting in the engine stopping half way through his roll! He did succeed in righting the helicopter, and carrying out an unexpected auto-rotation, landing it safely, with no damage! He didn't get many points, but he did get the biggest round of applause of the day!

He also won a newly announced OS61 SXH helicopter engine in the raffle, before they'd even appeared in the shops! He always was a jammy little so and so....! The poor old Condor never knew what hit it when that was duly installed!

The transmitter now has a multi-protocol board for the RF module. Unfortunately, its only an ATmega one, with limited storage space, but I've managed to get all the FrSky and Spektrum protocols in, which is all I need.

As an aside, the STM32 MPM boards seem to be pretty much unavailable at present. Neither Banggood nor AliExpress appear to have any. Presumably they are all being snaffled up by the likes of Jumper and RadioMaster.....

And finally, that Condor helicopter survives to this day, sitting on a shelf in my garage. I really ought to see about bringing it back to life again.....

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Pete

[Phil_G]

Nicely done Pete. I think those sticks are the same ones used by Proline in their Competition series?
You should get your lad to do a modern-day 3D display with it
The red button top right, is that for what I think its for?

[Wayne_H]

....The red button top right, is that for what I think its for?

The helicopter self-destruct button, aka s/c helicopter flying

[Pchristy]

I'm not sure if the sticks are shared with ProLine, but I rather doubt it. They are all plastic, and have phenomenally strong springs - even by my standards! I've never handled a ProLine, but I thought they had metal gimbals?

It does have separate electronic slider trims, and it took me a while to get the "mixer" resistance right. I ended up with 33K, which gives around 10% total trim (5% per side). Unlike rotary trims, you are using the full track, rather than just part of it.

The top right red button is the single-channel emulation. The smaller, mid-right button is the timer. The switch above the left stick is the throttle lock. I may yet add rate and expo pots through the holes at the ends of the Talisman plate, where the Silver Seven encoder screws went through.

Now that the latest version of the encoder has all these extra whistles and bells, I'm thinking of adding at least the timer and throttle lock to my Royal Classic Tx. That has an early Arduino Nano / DeekRobot board, so I'll have to tweak a couple of things on the sketch to get it right for that board (PPM out IIRC).

I've made a few changes to that Tx recently, so I ought to go back and update the thread on that, I reckon!

Wayne: You didn't need the single channel button to make helicopter aerobatics "interesting"! I added a switch which transferred the throttle function to one of the auxiliary sliders on the top, keeping the collective on the left-hand stick. Setting the aux slider to around 80-85% kept the throttle open enough for loops and rolls. Then for autos, you had to switch the throttle back to the LH stick, shut the aux slider to zero, then separate the throttle back to the aux function with the switch to initiate the auto. All whilst still trying to control the heli!

As I said, it worked, but required a bit of dexterity to pull it off!

Cheers,

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Pete

[Shaun]

I wish I had time to learn how to 3D print bespoke stuff. Too many other projects to complete and I already have maxed out on hobbies.

Shaun.

[stuart mackay]

In fact, my son used it at a Hirobo Cup event for his first contest with a 60-sized helicopter, back in the early 90s! He borrowed my Hirobo Condor, as a more fitting machine than his Shuttle, for the aerobatic event.

Was that Hirobo Cup the one in Belgium in the early 90s, If it was, I think that was where we first met, as I was flying for Simprop back then , who were the Hirobo importers for Germany and was thrashing a Shuttle around and hitting lots of the obstacles with it!?

[Pchristy]

No, it was at Woburn Abbey IIRC. I think I got the Condor two years after Mark got his Shuttle. I bought a Shuttle as well, so he would have a spare if anything went wrong, and then followed it up with the Condor. The first couple of times we went to Belgium, we only had Shuttles.

I still have the Condor, and it wouldn't take much to get it flying again!

I do recall talking to you in Belgium, though I hadn't put that conversation together with your name here! I remember chatting to an expat Brit, working for Simprop, who was pretty fluent in German. I probably gave you a bit of an ear-bashing over my Simprop Digi 5, which had proven somewhat less than reliable a decade or two earlier! Sorry about that!

BTW, the Lemon Tx module and Rx I got from you are now installed in my Royal Classic Tx and Frog Jackdaw. The radio gear is performing well, as is the model. Shame about the engine, which has turned out to be gutless and temperamental!

With FrSky seeming to pull out of the "hack" module market, I will probably be switching to Lemon for the longer term. The number of X-series receivers available from FrSky seems to be diminishing rapidly too. It looks like they are trying to push everyone up market to more expensive proprietary gear. If that is the case, time to move on. I've still got a couple of FrSky receivers spare, and my Taranis is still going strong after 11 years, but I can't see me buying any more FrSky gear unless they have a sudden change of heart...

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Pete