Jim.Thompson

And so you should be proud. However, you use of the word "but" here has me fearing I may have been misunderstood.
I don't mean to directly, or indirectly imply anything towards you or other contributors. I gave up on reading the thread long before things began to develop to the point that two of the main parties were banned. Accordingly, I am not in a position to comment any more specifically than I already have.

Retirement?
Sounds good all the best for it.

In the meantime:
Are you able to assist me with linking me to the arduino sketch that compiles and works for the solenoid controller?
It appears that Raleighcopter is unavailable and I would like to keep this project moving forward.
I cannot get the sketch published on GitHub to compile.

Thanks for posting.

Jim.
.

BarracudaHockey

My Feedback: (11)

Prayers for both of you

Glowgeek

Thanks for the thoughts and prayers, fellas. Great bunch here.

1967brutus

the bolded reminds me of the '80's show Battlestar Galactica intro... but it's true.

The underscored holds true for me as well...

But yes... this was an international effort, and we can absolutely be proud of what was achieved, learned and discovered.

1967brutus

No fear, I can only speak for myself, but I took it the way you intended it, no offense taken.

Cat 1

My Feedback: (1)

Sorry Jim,

Like Bert - Its so hard to convey "intent" in text and I took absolutely no offence to your statement.

I will see what I can do in regards to a compiled Sketch... It will take a bit of work as I haven't done this in a while and have to search through my files and "re-engauge" my "computer" skills which are a weakness..

What board are you using and what Version of the "IDE" -

Chris

jorgan

Hello Burtus, apparently you make the Stihl valve assembly? Please can you supply a link? Also, and I've been trying to see what CDI unit everyone uses but there isn't much discussion about it? Have people experiment with different ones, or diy one. Many thanks in advance

1967brutus

Hi Jorgan, there's no link... You can contact me via PM (probably you need to make 6 more posts before you get PM privileges), and we can arrange from there..

The CDI most people use is RcExl, look for the ones with the 1/4"-32 sparkplug size.
Another good supplier is CH Ignitions if you are US based.

jorgan

Thanks very much. I'll have to get onto posting something then I'm in the UK. It certainly very interesting in reading everything that is involved. What was getting me are the CDI units, not cheap, so trying to see if you can do it DIY. Wow I discovered I don't know much about my motors, What timing is involved in the ignition process, compression ratios, 2 and 4 stroke. So have been trying to do some research, so far it's all motor bike stuff that comes up, but I'm sure with a bit more research I'll find things on the hobby IC engines.

Jim.Thompson

Chris,

All good then!

Excellent! I greatly appreciate your offer. No hurry though; I just need to know that the project has not "stalled" so to speak.

I have the Seeed Studio XIAO SAMD21 board.
My arduino IDE is version 2.3.3

Edit:
When I try to verify the file my-mixture-controller.ino I receive this error notice:

"'SPortHub' does not name a type; did you mean 'SPort'?" (at line # 55).

This is below the line that Raleighcopter (the author) warns do no edit below this line.
I don't know what to do about this.

Thanks,
Jim.

Raleighcopter

sorry for my absence. i've been extremely busy with work and life lately. i'll attempt to build the firmware for the controller as soon as i find some time, hopefully within a week or so.

Jim.Thompson

I am not in a hurry, so no great problem. I just want to maintain a sense of momentum moving forward on this project.
Your message has stirred the dream into life again, so to speak.
Good to read you are back on the thread again!

I look forward to your update on the sketch etc in due course.

Jim.

Fxdr

Thanks raleighcopter,
I used xiao.ino script to upload, the screen IS ok and shows servo thrown from 1000 to 2000 and displays temp and pressure, solenoid pulses
I'm not sure of components qualité but checked resistor and various MOSFETs which has some dispersion in values with multimeter despite from the sale batch. I Can hear a little frequency change in the solenoid but not enough Dynamic ti drive it really. I will check the wiring, changé the MOSFET and build a totally New setup to bé 100% sure
Thanks

1967brutus

Hi Jorgan,

You being in the UK, you have at least two good suppliers that I know of for the ignition stuff: JustEngines and MorrisMiniMotors. Of course you can probably get stuff cheaper from AliExpress or similar, but having a salespoint that speaks your language and will actually provide service and warranty, is worth something too, no?

Word of warning: MorrisMiniMotors sells complete conversion kits for a lot of diffrent engines. From what I have seen (and I have had customers send entire engines to me, to PLEASE make them run right, I have even visited folks on their flying clubs to fix things on the spot), these "complete conversion kits" come with a fairly big chance of dissapointment. A few kits were simply handed over to me with th message that I could keep the kit for free if I could get the engine to run right. I fixed the engines but dunked the kits since they are no good to me either.

If you don't believe me: search Youtube for videos of planes actually flying with a Morris-converted engine. I found only two or three over the years. You will find a gazillion videos of their conversions running on the bench, most of them from Morris themselves. The thing is, superficially those engines seem to run right.. However, if you take a CLOSE look to the correlation between throttle arm movement and engine response, you will notice that the engine response does not match the throttle movement, and the guy operating the engine has to use his "throttle-fu" to get those snappy noises...
But you will find only at best a handful of videos of planes actually flying those conversions.

Don't get me wrong, I am not out to slash their business. Their prices are fair, prompt delivery, good workmanship and quality on their in-house made parts (beautifully machined aluminium parts, excellent fit, nice anodized colours and all that). Their ignition conversion parts are top notch. It's the conversion to a different fuel that dissapoints.
If you keep that in mind, it is safe to do business with them.

Ignitions are not cheap when bought through a UK or European supplier. There are ways around that but even so, I'd say 45~60 quid would be the minimum.
Upside is, I still have to have my first ignition fail in normal use (and I have about 11 of them in service), the only way I managed to ruin one (and a beautiful, custom programmed CH-Igintions unit at that) was by immersing a running ignition in water

-Timing is 28 degrees BTDC for gasoline, 34 deg BTDC for methanol fuel, for both 2 and 4strokes.
-Compression ratio usually is suitable for gasoline, with the exception of some older high strung competition engines designed for 0% Nitro FAI fuel (like the Italian Rossi engines for example). Those ususally need an extra headshim.
My first conversions, 10 years ago, I thought lowering CR was necessary, but it turned out most engines run perfectly OK as they are.
-What IS an issue though, is that since spark burns hotter than glow ignition, and gasoline burns hotter than methanol anyway, therefore cooling arrangements need attention in some cases (not all).
The heat will NOT destroy the engine... the resulting pre-ignition does, but only if you keep pushing the engine beyond where it starts giving you its warning signs, and those signs usually come in gentle but clear (engine losing RPM. Using CHT over telemetry allows to entirely avoid that issue.

All in all, I have, despite some pretty hamfisted efforts in the early days (when my knowledge on conversions simply did not yet exist), I have not yet managed to destroy or even wear out any engine yet, and that is telling because for the most I used the cheapest and according to many most low quality engines on the market.

Jim.Thompson

Quote:

I Can hear a little frequency change in the solenoid but not enough Dynamic ti drive it really. I will check the wiring, changé the MOSFET and build a totally New setup to bé 100% sure..........

Good to read you are making progress Fxdr.
Did you do initial power up tests on the bench?

Jim.Thompson

In the meantime, Chris has generously edited a sketch that I have been able to verify in my Arduino IDE.
S.Port lines removed altogether, as I don't use it.
I use FrSky Taranis and RadioMast TX16sMk11 and OpenTx, but no telemetry.

Controller construction question:
Will it be ok if I use a standard tailed 2.2k resistor across the MosFet pins in place of the surface mounted one?
I assume the surface mounted one would be more vibration proof; I might start with a tagged one for bench testing and change it later before flying. I won't be able to fly for many months anyway.

Jim.

1967brutus

That should not be possible, because the frequncy is constant. The sound CAN "change a bit" because what the driver does, is change the duty cycle, so the shape of the blockwave changes, but frequency should be constant. Audibly the functioning of the driver can NOT be confirmed.

The function CAN be confirmed by softly blowing into the tubing connected to the solenoid, while moving the throttle (linear curve from -100 to +100 set), you should notice a linear "resistance".

Alternative, set up a high and low container with liquid (fuel is best for reason of contamination, but in case nothing else availlable, water can do provided you blow the solenoid dry properly) and let the fluid syphon through the solenoid.
Moving the throttle should give THIS visual:


Notice how at "full open" as well as at "full closed" (at the end of the video) the sound very suddenly dissapears, but in the intermediate stage, there is barely any noticable change in the noise.

Also notice that when the solenoid is full open (no noise) the appearance of both the outflow stream, as well as the surface of the liquid in the bucket as by magic turn smooth, while during the intermediate phase there is significant disturbance in the outflow. This is an important phenomenon, that is responsible for a much better carburation, and a much cleaner running engine.

1967brutus

That's a shame, as it can be EXTTREMELY useful for getting a good tune. Necessary it is NOT, but back when I was in the development phase, I could not have done this project without telemetry and the info it provided.

Raleighcopter

the frequency of the pulses is constant but the pulse width changes (pulse width modulation). you won't hear a huge change from closed to fully open. blow thru the solenoid while going from full closed to full open and you'll see if the controller and solenoid is working.

Raleighcopter

it will. use a 1/10 watt or something similar in size to make construction easier.

Cat 1

My Feedback: (1)

I do agree that telemetry is helpful when setting up..but the more helpful telemetry comes external to the controller. (RPM and Temp) - the other can be had from the display but this is not always as "handy" as the radio.

My reasons for pulling S-Port out were of non compatible radio but Jim had other reasons he can explain.. The compiling issue Jim was having seems to be some sort of incompatibility with the S-Port update but eventually I was able to make it all work with the latest update and latest IDE. I have confirmed that David's latest available Sketch will compile if all updates are done on the latest IDE - including the S-Port support.

Good to see others are going to give this a try....

jorgan

Hi Brutus

Thanks very much for the info. I have been shopping and buying all the bits and pieces, the stuff you guys have suggested. So will try to put it together once it arrives, I never get it right first time either, but I'm persistent, unhealthy maybe. I did get the expensive ignition stuff as it doesn't help fiddling with stuff that's not been tested and being a newby is not a good time to experiment. I'm still trying to get my head round how the dwell angle compensation takes place, but I assume that is what's built into the CDI box? I haven't come across the Morris stuff, but have previously bought stuff from Just Engines. I'm going to try an machine the solenoid valve housing myself and see how that goes .

Kind regards
Dion

Glowgeek

Great to see a few more people try this system. It works tremendously well when dialed in.

The Auto advancing CDI units available today can be thought of as "auto retarding" in practice. The CDI knows the RPM of the engine at all times by virtue of the magnet and hall sensor. When you power up the unit it is ready to fire at full advance. When you turn the prop over 200 rpm, or so, the unit instantly retards the firing angle to make starting the engine easier and safer. As engine rpm increases the unit retards the firing angle less and less until it reaches the full advance angle somewhere around 3500 rpm. Whatever you set your static firing angle to will determine the full advance firing angle.

Be diligent in reading the manual, as the static timing on some CDI units is determined on approaching magnet, others on departing magnet. I find that the RCexl timing beeper allows for easier and more accurate timing adjustments than visually watching for spark.

jorgan

Thanks, I got the RCexl unit, well is in the post. So yes an audible or led indication is always the best way. Is there a way to test the CDI units, to see what their dwell characteristics are? I suppose all motors have there own characteristics too? I bet these question have all been asked and answered.

Glowgeek

There are folks who have tested cdi units and have posted characteristics. Try the search engine here and on RCG.

All engines do indeed have different characteristics. You can play with static timing and fuel mixture to squeeze out extra ponies, however it's risky. 28 degrees btdc and the leanest mixture possible, in the air, is the safest i.e. the engine will just quit running, with no harm done, if there is a fueling issue or overheating issue. The engine will not detonate, it will just quit running.

Advancing the timing requires a complimentary richer fuel mixture. If you experience a fueling issue, for example, the engine could run too lean for too long, causing excessive heat and detonation. Not a risk I'm willing to take for a couple hundred rpm gain.

Here I am merely parotting Bert's expertise and evaluations. He's the expert on the finer points of internal combustion engines. If I have posted incorrect info he'll be along to correct me......which I truly enjoy.