Equipment for indoor electric scale models

[g_kandylakis]

Thanks Alan...

One other aspect I forgot to mention in the beginning of this profiler discussion, is availability for purchasing.

I am not sure if the Zombie and K&P are indeed available, there was some shortage at some pointwith the Zombie, if anyone can confirm, please do.

The one I know is available, is the Chronos by Jiri Dolezel which was on sale at IIFI 2025 and apparently soon this one by Alan.

Erik Crins is working on something as well, initially for himself, I do not know if it will be made available to others too. Still waiting to see his presentation, hopefully soon.

George

[AllanP]

We expect it to be available in the next couple of weeks or so.

I must hastily observe that this is a collaborative effort and by no means all my own work. The software and App have been written by Dave, who's details I'll share when I've checked with him that its OK to do so. He has also produced the brushless version for an external ESC.
My role has been on the seemingly endless testing and reporting back, and for the schematic & PCB design.

[DaveL]

Hi,
I'm Dave, collaborating with Allan on the Tempo flight profiler, and I hope that it'll be of interest.

Allan has described the version that he is working on, intended for 1s batteries driving a brushed motor.  This turned out to be a bit more complex than the version that I had created, which works with brushless motors on 1s, or 2/3s with a BEC equipped ESC.  It is NOT suitable for brushed motors on 1s - hence Allan's development - but might work ok on 2s, as you'd have to use a BEC equipped ESC - but I can't see anyone using a 2s/brushed motor system.



The Tempo 'Cardinal' (so called because it first flew aboard a Veron Cardinal)  weighs about 2.4g - here's a video of that first flight...

and here is one of Allan, trying out the 1s version indoors...(accursed walls..)

[lincoln]

Those timers are amazing.

For a somewhat simpler, somewhat lower tech approach, this thread about capacitors may be of interest:
Supercaps for free flight models

Note that you can charge to lower voltages for shorter flights with less power, or use a lower farad capacitor for shorter flights but the same power.

Sam in the discussion above has a Guillow Skyraider which flies well with a geared motor and supercap: https://www.rcgroups.com/forums/showthread.php?4508439-Supercap-Guillow-s-Skyraider/page2
He also has a 24? inch Taylorcraft he flies indoors. The sonex413 channel on Youtube has a bunch of supercap flying.

If memory serves, there is a discussion on the web of the Peterborough timer and even a version which allows you to walk away before the motor starts. You have to make it yourself from several components, though you don't necessarily need a circuit board.


I'm impressed with how much power can be obtained from physically small capacitors. Years ago, I had a housemate who made an amazingly good stereo. The capacitors on his homemade amps were the size of beer cans.

One vendor who has a bunch if interesting little motors is Micron Wings in Australia. However, I think there are good suppliers in Europe as well. I think the coreless motors are lighter thn KP for their power, although if you need nose weight anyway, maybe it doesn't matter.

I wonder if anyone is doing supercap Ebenezers?

[9600baud]

Very nice, Dave and Allan!

That looks like a ESP32, right? That does also do the Wifi connection?
I have thought of something similar, maybe with an ATtiny85. That would of course, not have the comfort of using Wifi for configuration, but maybe be a bit lighter?

Very interesting project!

Cheers
Alex

[DaveL]

I've played around with supercap power, and the Peterboro timer, and they're both excellent low tech methods - and it was the sonex youtube channel that got me into supercap power, love the videos there.

The Tempo is based around an ESP32 C3 Supermini.  When I first had the idea, I looked for the smallest bluetooth enabled microcontoller - turned out to be the Supermini.  IT also has onboard wifi - but this uses a lot more power than the BLE (Bluetooth Low Energy).

I'd already written umpteen Android apps using the wonderful online editor at MIT App Inventor, hence going this route, apologies Apple users - but it still took a long time to get it all working reliably, and I think we've cracked it now - thanks to Allan for doing the testing!

I did think about an ATtiny version to save weight ((I'm more familiar with the Arduino mcu's) - but then you need to somehow get your flight profile from the phone to the mcu in the model...I did think about IR, but few phones have the required IR output.

At the mo, I'm playing with the smaller ESP32C3 mini-1 module, which is lighter than the Supermini - but so far proving to be a headache.

Thanks for the interest, I hope to have the website up soon, cheers.

[OZPAF]

fascinating - it's great to see experimentation like this happening. here's to all the small time developers and suppliers.

Good luck with it.

John

[Jmk89]

Hi Dave and Allan

Some thoughts triggered by this thread so far:

• I do like the idea of using an app on a mobile phone to input and control the timer.  The use of pots and pushbuttons in current alternatives seems pretty clunky.
• I can understand wanting to develop one of an Android/iPhone first.  However, when you get a moment to develop the iPhone alternative app, please do so.
• Are you considering just making a DT timer version (i.e. no electric motor control issues)?  This looks like a real advance on the BMK system if you do.
• On the subject of DT, I have been wondering about whether a better actuating system that those currently available (band burner or servo) would be the 2 second powering up of a small electromagnet - my idea is that the DT line would have a small magnet the +pole of which attaches to the end of the core of an electromagnet that is usually off.  When the timer runs down it will charge up the electromagnet so that the relevant end of the electromagnet becomes the + pole - the two = poles repel each other so the DT line is released.  This seems simpler and possibly lighter than the current alternatives.

[DaveL]

I really wish that I knew how to create an iphone app - but, personally, have always avoided Apple products and have no knowledge of how to go about it - from the little reading that I have done, it looks to be fairly complicated.  If there are any amateur developers out there willing to have a go, I'd welcome the contact.

I did look into an alternative route that uses a WiFi connection, with the flight params  entered via a webpage form - which would work on any platform - but using a wifi connection took a lot more power, drawn from the flight battery.  The clue's in the name, BLE....

Regarding auxiliary function such as D/T....  the present Tempo Cardinal (the brushless version) does have an extra pin brought out - the idea is to connect a beeper to this and the app has a field to enter a time value - this many minutes after a flight ends, the pin will go high and activate the beeper - but it just as easily be connected to (say) a hot wire D/T - or I might alter the programming to output a servo signal to activate a D/T?  Lots of possibilities here, and I thought it best to see what others thought for now.

Gaah...should have thought of this earlier...here's a draft copy of the user guide, which describes the widget in great detail.  IT also has the instructions for the kit version - this involves a fairly simple job of soldering some fine wires and should be doable by anyone with a little soldering experience.

[cvasec]

Jeremy, Re your point number4. BMK already does a lightweight solenoid for DT and it has had good reviews.
Ron

[Jmk89]

Jeremy, Re your point number4. BMK already does a lightweight solenoid for DT and it has had good reviews.
Ron

Thanks - I had missed that